Zoom lens

Abstract

In a zoom lens of a fixed total length, at the time of changing the magnification from the wide-angle end toward the telephoto end, the first lens group is anchored while the second lens group is moved, and the third and fourth lens groups are moved so as to be located at the object side of the telephoto end relative to the wide-angle end, such that: the interval between the second and third lens groups is decreased at the telephoto end relative to the wide-angle end; the interval between the third and fourth lens groups is increased at the telephoto end relative to the wide-angle end; and the interval between the fourth and fifth lens groups is increased at the telephoto end relative to the wide-angle end, and at the time of focusing a near object point from a remote object point, the second lens group is moved.

Claims

1. A zoom lens having a macro mode that includes a first mode allowing zooming and focusing including infinity and a second mode allowing obtaining an imaging magnification absolute value greater than 0.25 times, the zoom lens comprising: a lens group A having a positive refractive power; a lens group B having a negative refractive power and arranged at the image side relative to the lens group A so as to be neighbored by the lens group A with an interval of air interposed between them; a focus lens group having a negative refractive power and arranged at the object side relative to the lens group A so as to be movable in the direction of the optical axis in a focusing operation; and a lens group D moving at the time of zooming, arranged at the object side relative to the focus lens group so as to change the distance between itself and the focus lens group at the time of the focusing operation; wherein, in the first mode, at the time of zooming from the wide-angle end to the telephoto end, the lens group A is adapted to move so as to be located at the object side to reduce the distance between itself and the focus lens group at the telephoto end rather than at the wide-angle end; and the lens group B is adapted to move so as to be located at the object side to increase the distance between itself and the lens group A at the telephoto end rather than at the wide-angle end; the zoom lens operating for focusing including infinity focusing by moving the focus lens group having a negative refractive power in the direction of the optical axis; and in the second mode, the lens group A is located within the moving range of the lens group A in the first mode for zooming from the wide-angle end to the telephoto end; and the lens group B is located at the image side relative to a first position and at the object side relative to a second position; the first position being a position at which the lens group B is located in the first mode when the lens group A in the first mode is located at the position same as the position of the lens group A in the second mode or in a zooming state in which the lens group A in the first mode is located at the position same as the position of the lens group A in the second mode, the second position being a position of the lens group B at the wide-angle end in the first mode, the zoom lens operating for focusing by moving the focus lens group having a negative refractive power in the direction of the optical axis.

2. The zoom lens having a macro mode according to claim 1, wherein the lens group D has a positive refractive power.

3. The zoom lens having a macro mode according to claim 1, wherein the object side lens group located between the lens group D and the focus lens group changes the distance between itself and the focus lens group at the time of the focusing operation.

4. The zoom lens having a macro mode according to claim 3, wherein the object side lens group has a negative refractive power.

5. The zoom lens having a macro mode according to claim 3, wherein the zoom lens satisfies the conditional formula (2-1) shown below:
0.2<f obj/f focus<5.0(2-1), where f obj is the focal length of the object side lens group; and f focus is the focal length of the focus lens group.

6. The zoom lens having a macro mode according to claim 3, wherein the object side lens group is anchored at the time of the zooming and focusing.

7. The zoom lens having a macro mode according to claim 3, wherein the object side lens group is the lens group that is arranged nearest to the object side in the zoom lens.

8. The zoom lens having a macro mode according to claim 3, wherein at the time of zooming from the wide-angle end to the telephoto end, the focus lens group moves toward the image side and subsequently toward the object side so as to change the distance between the object side lens group and the focus lens group.

9. The zoom lens having a macro mode according to claim 3, wherein the zoom lens comprises the object side lens group, the focus lens group, the lens group A, the lens group B and the lens group C having a positive refractive power, sequentially arranged in the above-mentioned order from the object side; and the object side lens group and the lens group C are rigidly anchored at the time of the zooming and focusing.

10. The zoom lens having a macro mode according to claim 9, wherein the focus lens group is moved toward the image side and subsequently toward the object side at the time of the zooming.

11. The zoom lens having a macro mode according to claim 9, wherein the focus lens group is rigidly anchored at the time of the zooming.

12. The zoom lens having a macro mode according to claim 3, further comprising: a lens group D having a positive refractive power and arranged at the object side relative to the object side lens group in such a way that the distance between the lens group D and the object side lens group changes at the time of the zooming.

13. The zoom lens having a macro mode according to claim 1, wherein the zoom lens satisfies the conditional formula (2-2) shown below:
1.2<DAwt/DBwt<3.0(2-2), where DAwt is the difference between the position of the lens group A at the telephoto end and the position of the lens group A at the wide-angle end; and DBwt is the difference between the position of the lens group B at the telephoto end and the position of the lens group B at the wide-angle end.

14. The zoom lens having a macro mode according to claim 1, wherein the zoom lens satisfies the conditional formula (2-3) shown below:
0MBm2/DABm2<1.8(2-3), where MBm2 is the difference between the position of the lens group B in the second mode and the position of the lens group B at the wide-angle end; and DABm2 is the distance between the lens group A and the lens group B in the second mode.

15. The zoom lens having a macro mode according to claim 1, wherein the zoom lens satisfies the conditional formula (2-4) shown below:
0.4<MBm2/MBm1<0.96(2-4), where MBm2 is the difference between the position of the lens group B in the second mode and the position of the lens group B at the wide-angle end; and MBm1 is the difference between the position of the lens group B in the first mode when the lens group A is located at the position same as the position of the lens group A in the second mode and the position of the lens group B at the wide-angle end.

16. The zoom lens having a macro mode according to claim 1, wherein the zoom lens satisfies the conditional formula (2-5) shown below:
0.5<Mam2/DAwt<0.98(2-5) where MAm2 is the difference between the position of the lens group A in the second mode and the position of the lens group A at the wide-angle end; and DAwt is the difference between the position of the lens group A at the telephoto end and the position of the lens group A at the wide-angle end.

17. The zoom lens having a macro mode according to claim 1, further comprising: an aperture diaphragm arranged between the air interval immediately in front of the lens group A at the object side and the image side air interval of the lens group A and located at the object side at the telephoto end rather than at the wide-angle end.

18. The zoom lens having a macro mode according to claim 1, wherein the focus lens group consists of a lens component whose inside is filled with a medium.

19. The zoom lens having a macro mode according to claim 1, further comprising: a lens group C arranged at the image side relative to the lens group B and having a positive refractive power, the distance between itself and the lens group B changing at the time of the zooming.

20. The zoom lens having a macro mode according to claim 19, wherein the lens group C is a lens group arranged nearest to the image side in the zoom lens and is rigidly anchored at the time of the zooming and focusing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 1-1 of the present invention;

(2) FIG. 2 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 1-2 of the present invention;

(3) FIG. 3 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 1-3 of the present invention;

(4) FIG. 4 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 1-4 of the present invention;

(5) FIG. 5 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 1-5 of the present invention;

(6) FIGS. 6A-6D show a schematic illustration of aberrations of the zoom lens of Example 1-1 of the present invention (with regard to an object point at infinity) at the wide-angle end;

(7) FIGS. 6E-6H show aberrations of the zoom lens of Example 1-1 (object point at infinity) at the intermediate position;

(8) FIGS. 6I-6L show aberrations of the zoom lens of Example 1-1 (object point at infinity) at the telephoto end;

(9) FIGS. 7A-7D show a schematic illustration of aberrations of the zoom lens of Example 1-1 of the present invention (for imaging distance: 0.35 m) at the wide-angle end;

(10) FIGS. 7E-7H show aberrations of the zoom lens of Example 1-1 (imaging distance: 0.35 m) at the intermediate position;

(11) FIGS. 7I-7L show aberrations of the zoom lens of Example 1-1 (imaging distance: 0.35 m) at the telephoto end;

(12) FIGS. 8A-8D show a schematic illustration of aberrations of the zoom lens of Example 1-2 of the present invention (with regard to an object point at infinity) at the wide-angle end;

(13) FIGS. 8E-8H show aberrations of the zoom lens of Example 1-2 (object point at infinity) at the intermediate position;

(14) FIGS. 8I-8L show aberrations of the zoom lens of Example 1-2 (object point at infinity) at the telephoto end;

(15) FIGS. 9A-9D show a schematic illustration of aberrations of the zoom lens of Example 1-2 of the present invention (for imaging distance: 0.35 m) at the wide-angle end;

(16) FIGS. 9E-9H show aberrations of the zoom lens of Example 1-2 (imaging distance: 0.35 m) at the intermediate position;

(17) FIGS. 9I-9L show aberrations of the zoom lens of Example 1-2 (imaging distance: 0.35 m) at the telephoto end;

(18) FIGS. 10A-10D show a schematic illustration of aberrations of the zoom lens of Example 1-3 of the present invention (with regard to an object point at infinity) at the wide-angle end;

(19) FIGS. 10E-10H show aberrations of the zoom lens of Example 1-3 (object point at infinity) at the intermediate position;

(20) FIGS. 10I-10L show aberrations of the zoom lens of Example 1-3 (object point at infinity) at the telephoto end;

(21) FIGS. 11A-11D show a schematic illustration of aberrations of the zoom lens of Example 1-3 of the present invention (for imaging distance: 0.35 m) at the wide-angle end;

(22) FIGS. 11E-11H show aberrations of the zoom lens of Example 1-3 (imaging distance: 0.35 m) at the intermediate position;

(23) FIGS. 11I-11L show aberrations of the zoom lens of Example 1-3 (imaging distance: 0.35 m) at the telephoto end;

(24) FIGS. 12A-12D show a schematic illustration of aberrations of the zoom lens of Example 1-4 of the present invention (with regard to an object point at infinity) at the wide-angle end;

(25) FIGS. 12E-12H show aberrations of the zoom lens of Example 1-4 (object point at infinity) at the intermediate position;

(26) FIGS. 12I-12L show aberrations of the zoom lens of Example 1-4 (object point at infinity) at the telephoto end;

(27) FIGS. 13A-13D show a schematic illustration of aberrations of the zoom lens of Example 1-4 of the present invention (for imaging distance: 0.35 m) at the wide-angle end;

(28) FIGS. 13E-13H show aberrations of the zoom lens of Example 1-4 (imaging distance: 0.35 m) at the intermediate position;

(29) FIGS. 13I-13L show aberrations of the zoom lens of Example 1-4 (imaging distance: 0.35 m) at the telephoto end;

(30) FIGS. 14A-14D show a schematic illustration of aberrations of the zoom lens of Example 1-5 of the present invention (with regard to an object point at infinity) at the wide-angle end;

(31) FIGS. 14E-14H show aberrations of the zoom lens of Example 1-5 (object point at infinity) at the intermediate position;

(32) FIGS. 14I-14L show aberrations of the zoom lens of Example 1-5 (object point at infinity) at the telephoto end;

(33) FIGS. 15A-15D show a schematic illustration of aberrations of the zoom lens of Example 1-5 of the present invention (for imaging distance: 0.35 m) at the wide-angle end;

(34) FIGS. 15E-15H show aberrations of the zoom lens of Example 1-5 (imaging distance: 0.35 m) at the intermediate position;

(35) FIGS. 15I-15L show aberrations of the zoom lens of Example 1-5 (imaging distance: 0.35 m) at the telephoto end;

(36) FIG. 16 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 2-1 of the present invention;

(37) FIG. 17 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 2-2 of the present invention;

(38) FIG. 18 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 2-3 of the present invention;

(39) FIG. 19 is a schematic cross-sectional view taken along the optical axis of the zoom lens that is exploded of Example 2-4 of the present invention;

(40) FIGS. 20A-20D show a schematic illustration of aberrations of the zoom lens of Example 2-1 of the present invention at the wide-angle end;

(41) FIGS. 20E-20H show aberrations of the zoom lens of Example 2-1 at the intermediate position;

(42) FIGS. 20I-20L show aberrations of the zoom lens of Example 2-1 at the telephoto end;

(43) FIGS. 20M-20P show aberrations of the zoom lens of Example 2-1 in a second mode M2;

(44) FIGS. 21A-21D show a schematic illustration of aberrations of the zoom lens of Example 2-2 of the present invention at the wide-angle end;

(45) FIGS. 21E-21H show aberrations of the zoom lens of Example 2-2 at the intermediate position;

(46) FIGS. 211-21L show aberrations of the zoom lens of Example 2-2 at the telephoto end;

(47) FIGS. 21M-21P show aberrations of the zoom lens of Example 2-2 in a second mode M2;

(48) FIGS. 22A-22D show a schematic illustration of aberrations of the zoom lens of Example 2-3 of the present invention at the wide-angle end;

(49) FIGS. 22E-22H show aberrations of the zoom lens of Example 2-3 at the intermediate position;

(50) FIGS. 22I-22L show aberrations of the zoom lens of Example 2-3 at the telephoto end;

(51) FIGS. 22M-22P show aberrations of the zoom lens of Example 2-3 in a second mode M2;

(52) FIGS. 23A-23D show a schematic illustration of aberrations of the zoom lens of Example 2-4 of the present invention at the wide-angle end;

(53) FIGS. 23E-23H show aberrations of the zoom lens of Example 2-4 at the intermediate position;

(54) FIGS. 23I-23L show aberrations of the zoom lens of Example 2-4 at the telephoto end;

(55) FIGS. 23M-23P show aberrations of the zoom lens of Example 2-4 in a second mode M2;

(56) FIG. 24 is a schematic cross-sectional view of an image pickup apparatus using a zoom lens in the first aspect of the present invention as interchangeable lens;

(57) FIG. 25 is a schematic cross-sectional view of an image pickup apparatus using a zoom lens in the second aspect of the present invention as interchangeable lens;

(58) FIG. 26 is a schematic perspective front view of a digital camera using a zoom lens according to the present invention;

(59) FIG. 27 is a schematic perspective rear view of a digital camera using a zoom lens according to the present invention; and

(60) FIG. 28 is a block diagram of the control mechanism of a digital camera using a zoom lens according to the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

(61) Now, Examples 1-1 through 1-5 of zoom lens in the first aspect of the present invention will be described below by referring to the drawings. FIGS. 1 through 5 are schematic cross-sectional views taken along the optical axis of the zoom lenses that are exploded of Examples 1-1 through 1-5 of the present invention. In each of the figures, (a) shows the zoom lens at the wide-angle end (WE) and (b) shows the zoom lens in an intermediate state (ST) and (c) shows the zoom lens at the telephoto end (TE). In each of the figures, I denotes the image surface and C denotes the cover glass (which is a parallel and flat plate).

(62) Each of the Examples described below is a zoom lens having five lens groups that are a negative lens group, a negative lens group, a positive lens group, a negative lens group and a positive lens group arranged in the above mentioned order from the object side to the image side, of which the first lens group G1 is held immovable and the second lens group G2 is provided with a focusing function and a wobbling function.

(63) In each of FIGS. 1 through 5, the laterally directed arrow shown below the second lens group G2 illustrates that the second lens group G2 finely oscillates back and forth for a wobbling operation.

(64) Each of the arrows directed from (a) to (b) illustrates how the corresponding lens group is driven to move when the state of the zoom lens is shifted from the state shown in (a) to the state shown in (b).

(65) Each of the arrows directed from (b) to (c) illustrates how the corresponding lens group is driven to move when the state of the zoom lens is shifted from the state shown in (b) to the state shown in (c).

(66) Note that each of the arrows indicating how the corresponding lens group is driven to move does not necessarily show the trajectory of the lens group during an operation of changing the magnification.

(67) For example, the second lens group G2 may be so designed as to be driven to make a reciprocating movement of moving toward the image side once and then back to the proper position when the state of the zoom lens is shifted from the state shown in (a) to the state shown in (b).

(68) The second lens group G2 may be so designed as to be driven to make a reciprocating movement of moving toward the image side once and then back to the proper position when the state of the zoom lens is shifted from the state shown in (b) to the state shown in (c).

(69) The fourth lens group G4 may be so designed as to be driven to make a reciprocating movement of moving toward the object side once and then back to the proper position when the state of the zoom lens is shifted from the state shown in (b) to the state shown in (c).

(70) The fifth lens group G5 may be so designed as to be driven to make a reciprocating movement of moving toward the image side once and then back to the proper position when the state of the zoom lens is shifted from the state shown in (b) to the state shown in (c).

(71) In any instance, a zoom lens in the first aspect of the present invention is a compact and high-performance standard zoom lens. Particularly, it will most suitably be used in an application of an interchangeable lens system of a digital camera because it operates as a zoom lens capable of taking a moving image. More specifically, it is a compact and high-performance standard zoom lens having a variable magnification ratio of about 4 and a view angle of not less than 80 at the wide-angle end. In other words, it secures a wide view angle.

Example 1-1

(72) FIG. 1 is a schematic cross-sectional view of the zoom lens of Example 1-1. As shown in FIG. 1, the zoom lens of Example 1-1 includes a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 having a positive power, a fourth lens group G4 having a negative power and a fifth lens group G5 having a positive power arranged in the above mentioned order from the object side to the image side.

(73) The first lens group G1 is formed by a negative meniscus lens L1 with its convex surface facing the object side, a negative meniscus lens L2 having two aspheric surfaces with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side.

(74) The second lens group G2 is formed by a negative meniscus lens L4 with its convex surface facing the image side.

(75) The third lens group G3 is formed by a positive double convex lens L5 having two aspheric surfaces, an aperture S and a cemented lens L6 (lens block) of three lenses including a positive lens, a negative lens and a positive lens.

(76) The fourth lens group G4 is formed by a negative meniscus lens L7 with its concave surface facing the image side.

(77) The fifth lens group G5 is formed by a meniscus lens L8 made of plastic and having two aspheric surfaces and a positive meniscus lens L9 with its convex surface facing the image side.

(78) When zooming, the second lens group G2 through the fourth lens group G4 are driven to move independently but the first lens group G1 and the fifth lens group G5 are anchored relative to the image surface. The second lens group G2 is responsible for focusing operations and wobbling operations. When shifting the focus from infinity to a short distance, the second lens group G2 is driven to move toward the object side.

(79) When zooming from the wide-angle side toward the telephoto side, the second lens group G2 is driven to move so as to increase the interval between itself and the first lens group G1 and subsequently reduce the interval and the third lens group G3 is driven to move so as to reduce the interval between itself and the second lens group G2, while the fourth lens group G4 is driven to move so as to increase the interval between itself and the third lens group G3 and also increase the interval between itself and the fifth lens group G5.

Example 1-2

(80) FIG. 2 is a schematic cross-sectional view of the zoom lens of Example 1-2. The zoom lens of Example 1-2 includes a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 having a positive power, a fourth lens group G4 having a negative power and a fifth lens group G5 having a positive power.

(81) The first lens group G1 is formed by a negative meniscus lens L1 with its convex surface facing the object side, a negative meniscus lens L2 having two aspheric surfaces with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side.

(82) The second lens group G2 is formed by a negative meniscus lens L4 with its convex surface facing the image side.

(83) The third lens group G3 is formed by a positive double convex lens L5 having two aspheric surfaces, an aperture S and a cemented lens L6 (lens block) of two lenses including a negative lens and a positive lens.

(84) The fourth lens group G4 is formed by a negative meniscus lens L7 with its concave surface facing the image side and a meniscus lens L8 made of plastic and having two aspheric surfaces.

(85) The fifth lens group G5 is formed by a positive meniscus lens L9 with its convex surface facing the image side.

(86) When zooming, the second lens group G2 through the fourth lens group G4 are driven to move independently but the first lens group G1 and the fifth lens group G5 are anchored relative to the image surface. The second lens group G2 is responsible for focusing operations and wobbling operations. When shifting the focus from infinity to a short distance, the second lens group G2 is driven to move toward the object side.

(87) When zooming from the wide-angle side toward the telephoto side, the second lens group G2 is driven to move so as to increase the interval between itself and the first lens group G1 and subsequently reduce the interval and the third lens group G3 is driven to move so as to reduce the interval between itself and the second lens group G2, while the fourth lens group G4 is driven to move so as to increase the interval between itself and the third lens group G3 and also increase the interval between itself and the fifth lens group G5.

Example 1-3

(88) FIG. 3 is a schematic cross-sectional view of the zoom lens of Example 1-3. The zoom lens of Example 1-3 includes a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 having a positive power, a fourth lens group G4 having a negative power and a fifth lens group G5 having a positive power.

(89) The first lens group G1 is formed by a negative meniscus lens L1 with its convex surface facing the object side, a negative meniscus lens L2 having two aspheric surfaces with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side.

(90) The second lens group G2 is formed by a negative meniscus lens L4 with its convex surface facing the image side.

(91) The third lens group G3 is formed by a positive double convex lens L5 having two aspheric surfaces, an aperture S and a cemented lens L6 (lens block) of three lenses including a positive lens, a negative lens and a positive lens.

(92) The fourth lens group G4 is formed by a negative lens L7 having two aspheric surfaces with its concave surface facing the image side.

(93) The fifth lens group G5 is formed by a positive meniscus lens L8 with its convex surface facing the image side.

(94) When zooming, the second lens group G2 through the fourth lens group G4 are driven to move independently but the first lens group G1 and the fifth lens group G5 are anchored relative to the image surface. The second lens group G2 is responsible for focusing operations and wobbling operations. When shifting the focus from infinity to a short distance, the second lens group G2 is driven to move toward the object side.

(95) When zooming from the wide-angle side toward the telephoto side, the second lens group G2 is driven to move so as to increase the interval between itself and the first lens group G1 and subsequently reduce the interval and the third lens group G3 is driven to move so as to reduce the interval between itself and the second lens group G2, while the fourth lens group G4 is driven to move so as to increase the interval between itself and the third lens group G3 and also increase the interval between itself and the fifth lens group G5.

Example 1-4

(96) FIG. 4 is a schematic cross-sectional view of the zoom lens of Example 1-4. The zoom lens of Example 1-4 includes a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 having a positive power, a fourth lens group G4 having a negative power and a fifth lens group G5 having a positive power.

(97) The first lens group G1 is formed by a negative meniscus lens L1 with its convex surface facing the object side, a negative meniscus lens L2 having two aspheric surfaces with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side.

(98) The second lens group G2 is formed by a negative meniscus lens L4 with its convex surface facing the image side.

(99) The third lens group G3 is formed by a positive double convex lens L5 having aspheric surface, an aperture S, a cemented lens L6 (lens block) of two lenses including a positive lens and a negative lens and a positive lens L7 having two aspheric surfaces.

(100) The fourth lens group G4 is formed by a negative lens L8 having two aspheric surfaces with its strong concave surface facing the image side.

(101) The fifth lens group G5 is formed by a positive meniscus lens L9 with its convex surface facing the image side.

(102) When zooming, the second lens group G2 through the fourth lens group G4 are driven to move independently but the first lens group G1 and the fifth lens group G5 are anchored relative to the image surface. The second lens group G2 is responsible for focusing operations and wobbling operations. When shifting the focus from infinity to a short distance, the second lens group G2 is driven to move toward the object side.

(103) When zooming from the wide-angle side toward the telephoto side, the second lens group G2 is driven to move so as to increase the interval between itself and the first lens group G1 and subsequently reduce the interval and the third lens group G3 is driven to move so as to reduce the interval between itself and the second lens group G2, while the fourth lens group G4 is driven to move so as to increase the interval between itself and the third lens group G3 and also increase the interval between itself and the fifth lens group G5.

Example 1-5

(104) FIG. 5 is a schematic cross-sectional view of the zoom lens of Example 1-5. The zoom lens of Example 1-5 includes a first lens group G1 having a negative power, a second lens group G2 having a negative power, a third lens group G3 having a positive power, a fourth lens group G4 having a negative power and a fifth lens group G5 having a positive power.

(105) The first lens group G1 is formed by a negative meniscus lens L1 with its convex surface facing the object side, a negative meniscus lens L2 having two aspheric surfaces with its convex surface facing the object side and a positive meniscus lens L3 with its convex surface facing the object side.

(106) The second lens group G2 is formed by a cemented lens L4 (lens block) of two lenses including a negative lens and a positive lens.

(107) The third lens group G3 is formed by a positive double convex lens L5 having two aspheric surfaces, an aperture S and a cemented lens (lens block) L6 of three lenses including a positive lens, a negative lens and a positive lens.

(108) The fourth lens group G4 is formed by a negative lens L7 having two aspheric surfaces with its strong concave surface facing the image side.

(109) The fifth lens group G5 is formed by a positive meniscus lens L8 with its convex surface facing the image side.

(110) When zooming, the second lens group G2 through the fifth lens group G5 are driven to move independently but the first lens group G1 is anchored relative to the image surface. The second lens group G2 is responsible for focusing operations and wobbling operations. When shifting the focus from infinity to a short distance, the second lens group G2 is driven to move toward the object side.

(111) When zooming from the wide-angle side toward the telephoto side, the second lens group G2 is driven to move so as to increase the interval between itself and the first lens group G1 and subsequently reduce the interval and the third lens group G3 is driven to move so as to reduce the interval between itself and the second lens group G2, while the fourth lens group G4 is driven to move so as to increase the interval between itself and the third lens group G3 and the fifth lens group G5 is driven to move so as to increase the interval between itself and the fourth lens group G4. When zoomed from the wide-angle side toward the telephoto side, the fifth lens group G5 is driven to move toward the image side.

(112) [Exemplar Numerical Values]

(113) Various numerical value data (surface data, aspheric data, variable interval data, various data set 1, various data set 2) of Examples 1-1 through 1-5 are listed below.

(114) The surface data includes the radius of curvature r of each of the lens surfaces (optical surfaces) with the corresponding surface number, the interplanar spacing d, the refractive index nd relative to the d line (587.6 nm) of each of the lenses (optical mediums) and the Abbe number vd of the d line of each of the lenses (optical mediums). Unless noted otherwise, the unit of distance for the radius of curvature r, the interplanar spacing d and so on is millimeter (mm). In the surface data, the asterisk * annexed to the surface number at the right side indicates that the corresponding lens surface is an aspheric surface and the mark shown for the radius of curvature indicates that the radius of curvature is infinity.

(115) The aspheric data includes data relating to the lens surfaces that show an aspheric surface profile. An aspheric surface profile is expressed by the formula shown below:
x=(y.sup.2/r)/[1+{1(1+K).Math.(y/r).sup.2}.sup.1/2]+A4y.sup.4+A6y.sup.6+A8y.sup.8+A10y.sup.10+A12y.sup.12 . . . ,
where

(116) x is the optical axis, the direction of advancement of light being the positive direction;

(117) y is the direction orthogonal relative to the optical axis;

(118) r is the paraxial radius of curvature;

(119) K is the conic coefficient; and

(120) A4, A6, A8, A10 and A12 are respectively the aspheric coefficients of the fourth order, the sixth order, the eighth order, the tenth order and the twelfth order.

(121) Note that the symbol E indicates that the following numerical value is an exponent having a base of 10. For example, 1.0E-5 is equal to 1.010.sup.5.

(122) The various data set 1 shows various zoom data at the wide-angle end (WE), at an intermediate position (ST) and at the telephoto end (TE). Zoom data includes the focal length, the F number (Fno), the view angle (2), the variable interplanar spacing d (for an object point at infinity and for imaging distance of 0.35).

(123) The various data set 2 shows the image height, the back focus (BF), the total length and the focal length f1 through f5 for the first through fifth lens groups. These data items are same for the wide-angle end (WE), the intermediate position (ST) and the telephoto end (TE). Note that the back focus (BF) and the total length are those without any filter (the filter part is reduced to the distance in air).

Numerical Example 1-1

(124) TABLE-US-00001 Surface No. r d nd d 1 64.3900 1.950 1.78800 47.37 2 16.6323 6.370 3* 60.0000 1.500 1.58313 59.38 4* 16.6012 2.630 5 25.4912 4.470 1.84666 23.78 6 944.5098 d6(Variable) 7 23.3996 1.200 1.78800 47.37 8 100.0000 d8(Variable) 9* 14.4588 4.150 1.58313 59.38 10* 33.2321 1.070 11(Stop) 1.000 12 27.1904 2.910 1.56732 42.82 13 135.7170 0.940 1.91082 35.25 14 10.3769 3.960 1.49700 81.54 15 19.5832 d15(Variable) 16 108.8658 0.860 1.77250 49.60 17 14.0873 d17(Variable) 18* 80.0000 2.500 1.53110 55.91 19* 66.8694 3.430 20 80.0000 3.400 1.78470 26.29 21 26.1235 12.4700 22 4.080 1.51633 64.14 23 0.745 Image Plane Aspheric Data 3.sup.rd Surface K = 0 A4 = 1.2653E5 A6 = 1.6312E7 A8 = 1.8274E9 A10 = 9.6923E12 A12 = 1.9376E14 4.sup.th Surface K = 0 A4 = 2.7562E5 A6 = 2.9674E7 A8 = 2.1253E9 A10 = 1.3746E11 A12 = 2.6063E14 9.sup.th Surface K = 0 A4 = 2.4478E5 A6 = 7.4257E7 A8 = 3.0322E8 A10 = 5.5238E10 A12 = 4.9598E12 10.sup.th Surface K = 0 A4 = 7.1570E5 A6 = 6.8993E7 A8 = 2.9439E8 A10 = 5.7702E10 A12 = 5.6890E12 18.sup.th Surface K = 0 A4 = 8.8450E5 A6 = 2.6679E6 A8 = 4.2350E8 A10 = 3.7291E10 A12 = 1.4152E12 19.sup.th Surface K = 0 A4 = 9.6408E5 A6 = 2.3884E6 A8 = 3.2859E8 A10 = 2.5318E10 A12 = 8.4509E13 Data Set 1 WE ST TE Focal Length 12.241 24.483 48.974 Fno 3.57 4.79 6.43 2() 89.73 47.87 24.41 Infinity d6 7.9505 8.3129 5.4557 d8 28.0215 12.3494 1.6162 d15 2.0000 5.3427 15.2915 d17 4.3941 16.3611 20.0028 0.35 m d6 6.8433 7.2139 4.2894 d8 29.1287 13.4484 2.7825 d15 2.0000 5.3427 15.2915 d17 4.3941 16.3611 20.0028 Data Set 2 Image Height 10.815 BF 15.90 Total Length 100.61 f1 48.379 f2 39.035 f3 17.040 f4 21.030 f5 44.990

Numerical Example 1-2

(125) TABLE-US-00002 Surface No. r d nd d 1 45.2207 2.140 1.77250 49.60 2 16.3269 5.120 3* 41.8793 1.500 1.58313 59.38 4* 14.4691 3.850 5 23.9939 3.800 1.80810 22.76 6 103.8698 d6(Variable) 7 24.8418 1.200 1.74100 52.64 8 100.0000 d8(Variable) 9* 14.0498 4.300 1.58313 59.38 10* 31.7996 1.300 11(Stop) 1.900 12 179.0098 1.000 1.83400 37.16 13 10.8826 5.000 1.49700 81.54 14 18.9390 d14(Variable) 15 128.8505 1.000 1.83481 42.71 16 15.2795 1.580 17* 37.2148 2.000 1.53071 55.69 18* 57.5081 d18(Variable) 19 75.0639 2.480 1.75211 25.05 20 23.7233 11.1634 21 4.080 1.51633 64.14 22 0.745 Image Plane Aspheric Data 3.sup.rd Surface K = 1.2447 A4 = 2.0075E5 A6 = 2.7611E7 A8 = 2.4894E10 A10 = 3.5331E12 A12 = 9.3037E15 4.sup.th Surface K = 1.0662 A4 = 2.1822E5 A6 = 3.0982E7 A8 = 1.7795E9 A10 = 1.9840E11 A12 = 5.0306E14 9.sup.th Surface K = 0 A4 = 3.8287E5 A6 = 4.3941E8 A8 = 1.5034E10 A10 = 1.3526E11 A12 = 0 10.sup.th Surface K = 0 A4 = 6.6094E5 A6 = 2.9345E8 A8 = 1.6201E9 A10 = 3.6897E11 A12 = 0 17.sup.th Surface K = 82.6051 A4 = 2.9743E4 A6 = 7.3765E6 A8 = 9.2595E8 A10 = 8.7606E10 A12 = 0 18.sup.th Surface K = 271.4873 A4 = 2.8604E4 A6 = 6.8173E6 A8 = 8.5146E8 A10 = 7.3142E10 A12 = 0 Data Set 1 WE ST TE Focal Length 12.243 24.463 48.956 Fno 3.64 5.21 6.48 2() 89.71 47.68 24.46 Infinity d6 6.6446 9.3245 5.9114 d8 30.0675 12.3503 1.5559 d14 3.8142 7.9355 19.7513 d18 6.8162 17.7320 20.1237 0.35 m d6 5.3346 8.0933 4.5785 d8 31.3775 13.5815 2.8888 d14 3.8142 7.9355 19.7513 d18 6.8162 17.7320 20.1237 Data Set 2 Image Height 10.815 BF 14.60 Total Length 100.11 f1 41.219 f2 44.911 f3 18.399 f4 23.276 f5 45.180

Numerical Example 1-3

(126) TABLE-US-00003 Surface No. r d nd d 1 35.2780 1.500 1.77250 49.60 2 15.8293 6.790 3* 57.6000 1.500 1.58313 59.38 4* 14.2261 5.190 5 26.3919 4.360 1.84666 23.78 6 7000.0000 d6(Variable) 7 31.1517 0.800 1.80400 46.57 8 2000.0000 d8(Variable) 9* 15.5216 3.770 1.69350 53.21 10* 50.1195 1.500 11(Stop) 1.000 12 39.2759 2.670 1.48749 70.23 13 270.4115 0.800 1.90366 31.32 14 10.0543 3.860 1.48749 70.23 15 21.2114 d15(Variable) 16* 492.9354 1.000 1.69350 53 .21 17* 20.7531 d17(Variable) 18 86.4143 3.700 1.92286 18.90 19 32.0900 10.7674 20 4.080 1.51633 64.14 21 0.745 Image Plane Aspheric Data 3.sup.rd Surface K = 0 A4 = 3.3370E6 A6 = 2.0165E8 A8 = 1.0212E9 A10 = 5.4041E12 A12 = 8.9913E15 4.sup.th Surface K = 1.4987 A4 = 1.9557E5 A6 = 2.3806E8 A8 = 2.9483E9 A10 = 1.8044E11 A12 = 3.8073E14 9.sup.th Surface K = 0.3907 A4 = 6.9351E6 A6 = 5.4996E8 A8 = 1.7195E9 A10 = 0 A12 = 0 10.sup.th Surface K = 1.7574 A4 = 4.1334E5 A6 = 1.3416E7 A8 = 1.8990E9 A10 = 0 A12 = 0 16.sup.th Surface K = 202.728 A4 = 1.7522E4 A6 = 1.6346E5 A8 = 9.6613E7 A10 = 2.8814E8 A12 = 3.2583E10 17.sup.th Surface K = 3.6836 A4 = 1.5822E4 A6 = 1.7050E5 A8 = 9.1924E7 A10 = 2.5812E8 A12 = 2.7439E10 Data Set 1 WE ST TE Focal Length 12.242 24.488 48.955 Fno 3.57 4.79 6.43 2() 89.78 47.93 24.47 Infinity d6 5.5737 6.8731 5.6229 d8 31.0492 13.9977 1.5000 d15 2.0000 4.8188 17.3305 d17 10.2852 23.2185 24.4548 0.35 m d6 4.2635 5.5889 4.3137 d8 32.3594 15.2819 2.8092 d15 2.0000 4.8188 17.3305 d17 10.2852 23.2185 24.4548 Data Set 2 Image Height 10.815 BF 14.20 Total Length 101.55 f1 68.837 f2 39.366 f3 18.595 f4 28.693 f5 53.562

Numerical Example 1-4

(127) TABLE-US-00004 Surface No. r d nd d 1 37.6738 1.600 1.80400 46.57 2 16.0249 6.690 3* 150.0000 1.500 1.58313 59.38 4* 16.4876 4.200 5 27.0347 3.500 1.84666 23.78 6 d6(Variable) 7 28.3216 0.800 1.77250 49.60 8 200.0000 d8(Variable) 9* 15.7232 3.000 1.74400 44.78 10 490.3068 1.500 11(Stop) 1.000 12 16.3360 3.820 1.49700 81.54 13 23.2523 0.800 1.91082 35.25 14 12.1999 0.490 15* 12.0007 3.150 1.49700 81.54 16* 17.4719 d16(Variable) 17* 444.8035 0.800 1.69350 53.21 18* 17.5046 d18(Variable) 19 145.7109 2.250 1.92286 18.90 20 36.6904 10.5000 21 4.080 1.51633 64.14 22 0.745 Image Plane Aspheric Data 3.sup.rd Surface K = 679.7185 A4 = 6.7199E5 A6 = 3.9402E7 A8 = 5.5522E10 A10 = 4.5495E12 A12 = 1.5151E14 4.sup.th Surface K = 4.9637 A4 = 1.4532E4 A6 = 7.1863E7 A8 = 1.1122E9 A10 = 2.7613E11 A12 = 8.8580E14 9.sup.th Surface K = 0 A4 = 6.9472E6 A6 = 8.8043E8 A8 = 3.7014E9 A10 = 2.8810E11 A12 = 0 15.sup.th Surface K = 1.6031 A4 = 2.4760E4 A6 = 8.2791E7 A8 = 1.4252E7 A10 = 5.7952E9 A12 = 1.0305E10 16.sup.th Surface K = 3.6250 A4 = 5.7091E5 A6 = 5.7708E7 A8 = 9.7804E8 A10 = 4.4932E9 A12 = 7.3015E11 17.sup.th Surface K = 766.4831 A4 = 1.0404E4 A6 = 1.1629E5 A8 = 8.0316E7 A10 = 2.5502E8 A12 = 2.6928E10 18.sup.th Surface K = 4.2550 A4 = 3.8276E5 A6 = 1.4085E5 A8 = 8.4925E7 A10 = 2.6804E8 A12 = 2.7703E10 Data Set 1 WE ST TE Focal Length 12.241 24.485 48.979 Fno 3.57 5.91 6.43 2() 90.00 48.02 24.46 Infinity d6 5.7000 6.5000 5.2883 d8 30.2393 13.6393 1.3000 d16 2.0000 4.5383 14.8313 d18 11.1446 24.4063 27.6642 0.35 m d6 4.4099 5.2297 3.9879 d8 31.5294 14.9096 2.6004 d16 2.0000 4.5383 14.8313 d18 11.1446 24.4063 27.6642 Data Set 2 Image Height 10.815 BF 13.93 Total Length 98.12 f1 51.136 f2 42.797 f3 17.819 f4 24.268 f5 52.616

Numerical Example 1-5

(128) TABLE-US-00005 Surface No. r d nd d 1 28.8842 1.500 1.77250 49.60 2 15.5188 8.000 3* 100.0000 1.500 1.58313 59.38 4* 14.4535 4.340 5 23.7733 4.500 1.84666 23.78 6 188.0989 d6(Variable) 7 30.9233 0.800 1.83481 42.71 8 233.9180 1.500 1.84666 23.78 9 310.2906 d9(Variable) 10* 15.7662 3.570 1.69350 53.21 11* 49.3865 1.500 12(Stop) 1.000 13 42.8599 2.580 1.48749 70.23 14 424.6663 0.800 1.90366 31.32 15 10.4753 3.900 1.48749 70.23 16 20.1406 d16(Variable) 17* 262.4056 0.800 1.69350 53.21 18* 20.4782 d18(Variable) 19 125.3414 3.000 1.92286 18.90 20 34.4440 d20(Variable) 21 4.080 1.51633 64.14 22 0.745 Image Plane Aspheric Data 3.sup.rd Surface K = 32.2556 A4 = 4.0016E5 A6 = 3.4885E7 A8 = 5.8864E10 A10 = 2.4294E12 A12 = 8.0532E15 4.sup.th Surface K = 0.7597 A4 = 3.5415E5 A6 = 2.7107E7 A8 = 2.8882E9 A10 = 2.7390E11 A12 = 6.8676E14 10.sup.th Surface K = 0.4685 A4 = 7.0899E6 A6 = 7.3547E8 A8 = 3.4418E10 A10 = 4.2625E12 A12 = 0 11.sup.th Surface K = 1.1167 A4 = 4.1136E5 A6 = 3.8178E9 A8 = 1.2688E10 A10 = 8.8706E12 A12 = 0 17.sup.th Surface K = 553.4829 A4 = 2.1089E4 A6 = 1.5222E5 A8 = 8.5645E7 A10 = 2.6209E8 A12 = 3.0811E10 18.sup.th Surface K = 4.8168 A4 = 1.6472E4 A6 = 1.6077E5 A8 = 8.1995E7 A10 = 2.3975E8 A12 = 2.6635E10 Data Set 1 WE ST TE Focal Length 12.242 24.478 48.982 Fno 3.57 4.79 6.43 2() 89.73 47.81 24.46 Infinity d6 5.4462 7.2650 5.6269 d9 30.9699 13.5860 1.4422 d16 2.0000 5.5238 17.4737 d18 9.9696 23.3058 25.8429 d20 12.5000 11.2051 10.5000 0.35 m d6 4.0698 5.9338 4.2551 d9 32.3463 14.9172 2.8140 d16 2.0000 5.5238 17.4737 d18 9.9696 23.3058 25.8429 d20 12.5000 11.2051 10.5000 Data Set 2 Image Height 10.815 BF 15.94 Total Length 103.61 f1 56.583 f2 41.452 f3 18.600 f4 27.359 f5 50.664

(129) FIGS. 6, 8, 10, 12 and 14 show various aberrations for an object point at infinity at (A)-(D) wide-angle end (WE), (E)-(H) intermediate position (ST) and (I)-(L) telephoto end (TE) for Examples 1-1 through 1-5. FIGS. 7, 9, 11, 13 and 15 show various aberrations for imaging distance of 0.35 m at (A)-(D) wide-angle end (WE), (E)-(H) intermediate position (ST) and (I)-(L) telephoto end for Examples 1-1 through 1-5.

(130) In the drawings showing various aberrations, SA stands for spherical aberration, AS stands for astigmatism, DT stands for distortion and CC stands for chromatic difference of magnification. The spherical aberration SA is shown for the wavelengths of 587.6 nm (d line: solid line), 435.8 nm (g line: broken line) and 656.3 nm (C line: dotted line). The chromatic difference of magnification CC is shown for the wavelengths of 435.8 nm (g line: broken line) and 656.3 nm (C line: dotted line) as referred to d line. The astigmatism. AS is shown for the sagittal image surface (solid line) and the meridional image surface (broken line). FNO stands for F number and FIY stand for the maximum image height.

(131) For each of the Examples, the distortion of a barrel shape at the wide-angle side may be electrically corrected by way of signal processing. The distortion may be completely corrected so as to make the quantity of distortion equal to 0 for both the reproduced image and the recorded image. Alternatively, the distortion of a barrel shape may be electrically corrected so as to make the quantity of distortion remain by 3% at the periphery of the reproduced image and at the periphery of the recorded image.

(132) The values of the conditional formulas (1-1) through (1-15) are listed below for Examples 1-1 through 1-5.

(133) TABLE-US-00006 EX. 1-1 EX. 1-2 EX. 1-3 EX. 1-4 EX. 1-5 Formula 1.28 1.09 1.16 1.35 1.30 (1-1) Formula 2.36 2.39 2.41 2.40 2.40 (1-2) Formula 1.28 1.09 1.16 1.35 1.13 (1-3) Formula 0.00 0.00 0.00 0.00 0.16 (1-4) Formula 3.19 3.67 3.22 3.5 3.39 (1-5) Formula 0.62 0.60 0.97 0.75 0.82 (1-6) Formula 1.78800 1.74100 1.80400 1.77250 1.83481 (1-7) Formula 1.05 0.94 0.94 1.15 0.95 (1-8) Formula 81.54 81.54 70.23 81.61 70.23 (1-9) Formula 1.91082 1.83400 1.90366 1.91082 1.90366 (1-10) Formula 35.25 37.16 31.32 35.25 31.32 (1-11) Formula 0.77 0.79 1.09 1.08 1.17 (1-12) Formula 1.77250 1.83481 1.69350 1.69350 1.69350 (1-13) Formula 49.60 42.71 53.21 53.21 53.21 (1-14) Formula 26.29 25.05 18.90 18.90 18.90 (1-15)

(134) The zoom lenses in the second aspect of the present invention of Example 2-1 through Example 2-4 will be described below by referring to the related drawings. FIGS. 16 through 19 are schematic cross-sectional views respectively taken along the optical axes of the zoom lenses that are exploded of Examples 2-1 through 2-4 of the present invention. In each of the figures, (a) through (d) show cross-sectional views of the zoom lens in a zoom mode that is the first mode and (e) shows a cross-sectional view of the zoom lens in a macro mode that is the second mode. In each of the figures, (a) shows the wide-angle end when focused at infinity (W inf) and (b) shows an intermediate state when focused at infinity (S inf), while (c) shows a state in the first mode where lens group A is arranged at the position same as the position of the lens group A in the second mode when focused at infinity (M1), (d) shows the telephoto end when focused at infinity (T inf) and (e) shows a predetermined state in the second mode (M2).

(135) Note that a state in the first mode where lens group A is arranged at the position same as the position of the lens group A in the second mode when focused at infinity means a state where the zoom lens is on the way of zooming from an intermediate foal distance (b) to the telephoto end (d).

Example 2-1

(136) FIG. 16 is a cross-sectional view of the zoom lens of Example 2-1. The zoom lens of Example 2-1 includes a first lens group G1 (object side lens group) having a negative refractive power, a second lens group G2 (focus lens group) having a negative refractive power, a third lens group G3 (lens group A) having a positive refractive power, a fourth lens group G4 (lens group B) having a negative refractive power and a fifth lens group G5 (lens group C) having a positive refractive power arranged in the above mentioned order from the object side to the image side.

(137) In the first mode, when changing the magnification from the wide-angle end toward the telephoto end, the first lens group G1 is anchored and the second lens group G2 is moved so as to produce a trajectory of being moved toward the image side and then moved backward, while the third lens group G3 and the fourth lens group G4 are moved only toward the object side and the fifth lens group G5 is anchored.

(138) Focusing operations are realized by driving the second lens group G2 to move in the direction of the optical axis. In a focusing operation from a long distance to a short distance, the second lens group G2 is driven to move toward the object side.

(139) As the mode is switched to the second mode shown in FIG. 16 (e), the second, third and fourth lens groups G2 through G4 are moved to respective predetermined midway positions in the movable range in the first mode.

(140) In this instance, the second lens group G2 is moved to a position where the zoom lens is focused at infinity at the telephoto end in the first mode as shown in FIG. 16(d).

(141) The third lens group G3 is moved to a predetermined position where it is in a state between the intermediate state shown in FIG. 16(b) and the state at the telephoto end shown in FIG. 16(d).

(142) The fourth lens group G4 is moved toward the image side relative to the relative position with regard to the second lens group G2 in the first mode.

(143) FIG. 16 shows the moving directions of the related respective lens groups from the positions of the lens groups at the telephoto end when focused at infinity in the first mode. When the mode is switched to the second mode at the lens positions at the wide-angle end, the second, third and fourth lens groups G2 through G4 are moved toward the object side to respective predetermined positions.

(144) Focusing operations in the second mode are realized by driving the second lens group G2 to move in the direction of the optical axis. Focusing at a short distance is realized by driving the second lens group G2 to move toward the object side, whereas focusing at a long distance is realized by driving the second lens group G2 to move toward the image side.

Example 2-2

(145) FIG. 17 is a cross-sectional view of the zoom lens of Example 2-2. The zoom lens of Example 2-2 includes a first lens group G1 (object side lens group) having a negative refractive power, a second lens group G2 (focus lens group) having a negative refractive power, a third lens group G3 (lens group A) having a positive refractive power, a fourth lens group G4 (lens group B) having a negative refractive power and a fifth lens group G5 (lens group C) having a positive refractive power arranged in the above mentioned order from the object side to the image side.

(146) In the first mode, when changing the magnification from the wide-angle end toward the telephoto end, the first lens group G1 is anchored and the second lens group G2 is moved so as to produce a trajectory of being moved toward the image side and then moved backward, while the third lens group G3 and the fourth lens group G4 are moved only toward the object side and the fifth lens group G5 is anchored.

(147) Focusing operations are realized by driving the second lens group G2 to move in the direction of the optical axis. In a focusing operation from a long distance to a short distance, the second lens group G2 is driven to move toward the object side.

(148) As the mode is switched to the second mode shown in FIG. 17(e), the second, third and fourth lens groups G2 through G4 are moved to respective predetermined midway positions in the movable range in the first mode.

(149) In this instance, the second lens group G2 is moved to a position where the zoom lens is focused at infinity at the telephoto end in the first mode as shown in FIG. 17 (d).

(150) The third lens group G3 is moved to a predetermined position where it is in a state between the intermediate state shown in FIG. 17(b) and the state at the telephoto end shown in FIG. 17(d).

(151) The fourth lens group G4 is moved toward the image side relative to the relative position with regard to the second lens group G2 in the first mode.

(152) FIG. 17 shows the moving directions of the related respective lens groups from the positions of the lens groups at the telephoto end when focused at infinity in the first mode. When the mode is switched to the second mode at the lens positions at the wide-angle end, the second, third and fourth lens groups G2 through G4 are moved toward the object side to respective predetermined positions.

(153) Focusing operations in the second mode are realized by driving the second lens group G2 to move in the direction of the optical axis. Focusing at a short distance is realized by driving the second lens group G2 to move toward the object side, whereas focusing at a long distance is realized by driving the second lens group G2 to move toward the image side.

Example 2-3

(154) FIG. 18 is a cross-sectional view of the zoom lens of Example 2-3. The zoom lens of Example 2-3 includes a first lens group G1 (lens group D) having a positive refractive power, a second lens group G2 (object side lens group) having a negative refractive power, a third lens group G3 (focus lens group) having a negative refractive power, a fourth lens group G4 (lens group A) having a positive refractive power, a fifth lens group G5 (lens group B) having a negative refractive power and a sixth lens group G6 (lens group C) having a positive refractive power arranged in the above mentioned order from the object side to the image side.

(155) In the first mode, when changing the magnification from the wide-angle end toward the telephoto end, the first lens group G1 is moved toward the object side, the second lens group G2 is anchored and the third lens group G3 is moved so as to show a trajectory of being moved toward the image side and then moved backward, while the fourth lens group G4 and the fifth lens group G5 are moved only toward the object side and the sixth lens group G6 is anchored.

(156) Focusing operations are realized by driving the third lens group G3 to move in the direction of the optical axis. In a focusing operation from a long distance to a short distance, the third lens group G3 is driven to move toward the object side.

(157) As the mode is switched to the second mode shown in FIG. 18 (e), the first, third, fourth and fifth lens groups G1, G3, G4 and G5 are moved to respective predetermined midway positions in the movable range in the first mode.

(158) In this instance, the first lens group G1 and the third lens group G3 are moved to respective positions where the zoom lens is focused at infinity at the telephoto end in the first mode.

(159) The fourth lens group G4 is moved to a predetermined position where it is in a state between the intermediate state shown in FIG. 18(b) and the state at the telephoto end shown in FIG. 18(d).

(160) The fifth lens group G5 is moved toward the image side relative to the relative position with regard to the second lens group G2 in the first mode.

(161) FIG. 18 shows the moving directions of the related respective lens groups from the positions of the lens groups at the telephoto end when focused at infinity in the first mode. When the mode is switched to the second mode at the lens positions at the wide-angle end, the first, third, fourth and fifth lens groups G1, G3, G4 and G5 are moved toward the object side to respective predetermined positions.

(162) Focusing operations in the second mode are realized by driving the third lens group G3 to move in the direction of the optical axis. Focusing at a short distance is realized by driving the third lens group G3 to move toward the object side, whereas focusing at a long distance is realized by driving the third lens group G3 to move toward the image side.

(163) In Example 2-3, the effective imaging region is made to show a barrel shape at the wide-angle end and a rectangular shape in a state of showing an intermediate focal length and at the telephoto end in order to correct the distortions produced at and near the wide-angle end by way of image processing. The predefined effective imaging region is subjected to image transformation by image processing so as to transform it into a rectangular image information piece with reduced distortions. Thus, the image height IHw at the wide-angle end is smaller than the image height IHs in a state of showing an intermediate focal length and the image height IHt at the telephoto end.

Example 2-4

(164) FIG. 19 is a cross-sectional view of the zoom lens of Example 2-4. The zoom lens of Example 2-4 includes a first lens group G1 (object side lens group) having a negative refractive power, a second lens group G2 (focus lens group) having a negative refractive power, a third lens group G3 (lens group A) having a positive refractive power, a fourth lens group G4 (lens group B) having a negative refractive power and a fifth lens group G5 (lens group C) having a positive refractive power arranged in the above mentioned order from the object side to the image side.

(165) In the first mode, when changing the magnification from the wide-angle end toward the telephoto end, the first lens group G1 and the second lens group G2 are anchored and the third lens group G3 is moved only toward the object side, while the fourth lens group G4 is moved so as to produce a trajectory of being moved toward the image side and then moved backward and the fifth lens group G5 is anchored.

(166) Focusing operations are realized by driving the second lens group G2 to move in the direction of the optical axis. In a focusing operation from a long distance to a short distance, the second lens group G2 is driven to move toward the object side.

(167) As the mode is switched to the second mode, the third and fourth lens groups G3 and G4 are moved to respective predetermined midway positions in the movable range in the first mode.

(168) In this instance, the third lens group G3 is moved to a predetermined position where it is in a state between the intermediate state shown in FIG. 19 (b) and the state at the telephoto end shown in FIG. 19(d).

(169) The fourth lens group G4 is moved toward the image side relative to the relative position with regard to the second lens group G2 in the first mode.

(170) FIG. 19 shows the moving directions of the related respective lens groups from the positions of the lens groups at the telephoto end when focused at infinity in the first mode. When the mode is switched to the second mode at the lens positions at the wide-angle end, each of the third and fourth lens groups G3 and G4 is moved toward the object side to a predetermined position.

(171) Focusing operations in the second mode are realized by driving the second lens group G2 to move in the direction of the optical axis. Focusing at a short distance is realized by driving the second lens group G2 to move toward the object side, whereas focusing at a long distance is realized by driving the second lens group G2 to move toward the image side.

(172) [Exemplar Numerical Values]

(173) Various numerical value data (surface data, aspheric surface data, various data set 1, various data set 2) of Examples 2-1 through 2-4 are listed below.

(174) The surface data includes the radius of curvature r of each of the lens surfaces (optical surfaces) with the corresponding surface number, the interplanar spacing d, the refractive index nd relative to the d line (587.6 nm) of each of the lenses (optical mediums) and the Abbe number d of the d line of each of the lenses (optical mediums). In the surface data, the asterisk * annexed to the surface number at the right side indicates that the corresponding lens surface is an aspheric surface and the mark shown for the radius of curvature indicates that the radius of curvature is infinity. Unless noted otherwise, the unit of distance for the radius of curvature r, the interplanar spacing d and so on is millimeter (mm) as well as for the data listed in the various data sets 1 and 2.

(175) The aspheric surface data includes data relating to the lens surfaces that show an aspheric surface profile. An aspheric surface profile is expressed by the formula shown below:
x=(y.sup.2/r)/[1+{1(1+K).Math.(y/r).sup.2}.sup.1/2]+A4y.sup.4+A6y.sup.6+A8y.sup.8+A10y.sup.10+A12y.sup.12 . . . ,
where

(176) x is the optical axis, the direction of advancement of light being the positive direction;

(177) y is the direction orthogonal relative to the optical axis;

(178) r is the paraxial radius of curvature;

(179) K is the conic coefficient; and

(180) A4, A6, A8, A10 and A12 are respectively the aspheric coefficients of the fourth order, the sixth order, the eighth order, the tenth order and the twelfth order.

(181) Note that the symbol E indicates that the following numerical value is an exponent having a base of 10. For example, 1.0E-5 is equal to 1.010.sup.5.

(182) The various data set 1 shows various zoom data at the wide-angle end (W) at the time of being focused at infinity, at an intermediate position (S), in a state in the first mode where lens group A is arranged at the position same as the position of the lens group A in the second mode (M1: zoom mode) and at the telephoto end (T) and in a predetermined state in the second mode (M2: macro mode). Zoom data includes the focal length, the F number (Fno), the half view angle, the variable interplanar spacing d and the radius ER of the aperture diaphragm. The data on the second mode (M2) additionally includes imaging magnifications (MG, NA).

(183) The various data set 2 shows the focal length, the back focus length as reduced to air (BF), the optical total length, the image height, the focal length in a macro mode (second mode), the half view angle, the imaging distance and the imaging magnification of each of the lens groups.

Numerical Example 2-1

(184) TABLE-US-00007 Surface No. r d nd d 1 64.3900 1.9500 1.78800 47.37 2 16.6323 6.3700 3* 60.0000 1.5000 1.58313 59.38 4* 16.6012 2.6300 5 25.4912 4.4700 1.84666 23.78 6 944.5098 d6(Variable) 7 23.3996 1.2000 1.78800 47.37 8 100.0000 d8(Variable) 9* 14.4588 4.1500 1.58313 59.38 10* 33.2321 1.0700 11(Stop) 1.0000 12 27.1904 2.9100 1.56732 42.82 13 135.7170 0.9400 1.91082 35.25 14 10.3769 3.9600 1.49700 81.54 15 19.5832 d15(Variable) 16 108.8658 0.8600 1.77250 49.60 17 14.0873 d17(Variable) 18* 80.0000 2.5000 1.53110 55.91 19* 66.8694 3.4300 20 80.0000 3.4000 1.78470 26.29 21 26.1235 15.9057 Image Plane Aspheric Data 3.sup.rd Surface K = 0 A4 = 1.2653E5 A6 = 1.6312E7 A8 = 1.8274E9 A10 = 9.6923E12 A12 = 1.9376E14 4.sup.th Surface K = 0 A4 = 2.7562E5 A6 = 2.9674E7 A8 = 2.1253E9 A10 = 1.3746E11 A12 = 2.6063E14 9.sup.th Surface K = 0 A4 = 2.4478E5 A6 = 7.4257E7 A8 = 3.0322E8 A10 = 5.5238E10 A12 = 4.9598E12 10.sup.th Surface K = 0 A4 = 7.1570E5 A6 = 6.8993E7 A8 = 2.9439E8 A10 = 5.7702E10 A12 = 5.6890E12 18.sup.th Surface K = 0 A4 = 8.8450E5 A6 = 2.6679E6 A8 = 4.2350E8 A10 = 3.7291E10 A12 = 1.4152E12 19.sup.th Surface K = 0 A4 = 9.6408E5 A6 = 2.3884E6 A8 = 3.2859E8 A10 = 2.5318E10 A12 = 8.4509E13 Data Set 1 Focal Length W~S~M1~T = 12.2~24.5~46.1~49.0 Fno W~S~M1~T = 3.6~4.8~6.0~6.4 Half View Angle W~S~M1~T = 44.9~23.9~13.0~12.2 W inf S inf M1 T inf d0(Target) d6 7.95050 8.31290 6.16290 5.45570 d8 28.02150 12.34940 2.23000 1.61620 d15 2.00000 5.34270 14.17200 15.29150 d17 4.39410 16.36110 19.80120 20.00280 ER 5.41920 6.03938 6.9445 6.66945 M2 d0(Target) 89.72640 d6 5.45570 d8 2.96259 d15 17.65955 d17 16.28531 ER 6.66945 MG 0.45000 NA 0.0347 Data Set 2 G1 Focal Length 48.3794 G2 Focal Length 39.0355 G3 Focal Length 17.040 G4 Focal Length 21.0296 G5 Focal Length 44.990 BF 15.906 Total Optical Length(W-T) 100.612 Image Height 10.815 Focal Length (macro mode) = 42.1 Half View Angle (macro mode) = 12.6 Imaging Distance (macro mode) = 89.7 (From object to 1.sup.st Surface) Imaging Magnification (macro mode) = 0.45

Numerical Example 2-2

(185) TABLE-US-00008 Surface No. r d nd d 1 45.2207 2.1400 1.77250 49.60 2 16.3269 5.1200 3* 41.8793 1.5000 1.58313 59.38 4* 14.4691 3.8500 5 23.9939 3.8000 1.80810 22.76 6 103.8698 d6(Variable) 7 24.8418 1.2000 1.74100 52.64 8 100.0000 d8(Variable) 9* 14.0498 4.3000 1.58313 59.38 10* 31.7996 1.3000 11(Stop) 1.9000 12 179.0098 1.0000 1.83400 37.16 13 10.8826 5.0000 1.49700 81.54 14 18.9390 d14(Variable) 15 128.8505 1.0000 1.83481 42.71 16 15.2795 1.5800 17* 37.2148 2.0000 1.53071 55.69 18* 57.5081 d18(Variable) 19 75.0639 2.4800 1.75211 25.05 20 23.7233 20(Variable) Image Plane Aspheric Data 3.sup.rd Surface K = 1.2447 A4 = 2.0075E5 A6 = 2.7611E7 A8 = 2.4894E10 A10 = 3.5331E12 A12 = 9.3037E15 4.sup.th Surface K = 1.0662 A4 = 2.1822E5 A6 = 3.0982E7 A8 = 1.7795E9 A10 = 1.9840E11 A12 = 5.0306E14 9.sup.th Surface K = 0 A4 = 3.8287E5 A6 = 4.3941E8 A8 = 1.5034E10 A10 = 1.3526E11 10.sup.th Surface K = 0 A4 = 6.6094E5 A6 = 2.9345E8 A8 = 1.6201E9 A10 = 3.6897E11 17.sup.th Surface K = 82.6051 A4 = 2.9743E4 A6 = 7.3765E6 A8 = 9.2595E8 A10 = 8.7606E10 18.sup.th Surface K = 271.4873 A4 = 2.8604E4 A6 = 6.8173E6 A8 = 8.5146E8 A10 = 7.3142E10 Data Set 1 Focal Length W~S~M1~T = 12.2~24.5~44.4~49.0 Fno W~S~M1~T = 3.6~5.2~6.1~6.5 Half View Angle W~S~M1~T = 44.9~23.8~13.5~12.2 W inf S inf M1 T inf d0(Target) d6 6.64460 9.32450 7.17320 5.91140 d8 30.06750 12.35030 2.51040 1.55590 d14 3.81420 7.93550 17.62220 19.75130 d18 6.81620 17.73200 20.03650 20.12370 ER 5.17564 5.38054 5.38054 6.41796 M2 d0(Target) 110.72054 d6 5.91140 d8 3.34967 d9 0.40000 d14 20.00066 d18 17.68053 ER 6.41796 MG 0.35000 NA 0.028 Data Set 2 G1 Focal Length 41.219 G2 Focal Length 44.911 G3 Focal Length 18.399 G4 Focal Length 23.276 G5 Focal Length 45.180 BF 14.600 Total Optical Length(W-T) 100.111 Image Height 10.815 Focal Length (macro mode) = 40.5 Half View Angle (macro mode) = 13.4 Imaging Distance (macro mode) = 110.7 (From object to 1.sup.st Surface) Imaging Magnification (macro mode) = 0.35

Numerical Example 2-3

(186) TABLE-US-00009 Surface No. r d nd d 1 102.9772 2.5000 1.51742 52.43 2 175.0279 d2(Variable) 3 61.6287 2.7991 1.78800 47.37 4 19.5239 6.1046 5* 114.4384 1.0728 1.58253 59.32 6* 15.2703 3.4586 7 25.9416 5.2924 1.84666 23.78 8 221.8576 d8(Variable) 9 22.2564 1.2000 1.74100 52.64 10 79.2468 d10(Variable) 11* 14.7769 4.0834 1.58253 59.32 12* 29.7621 1.3338 13 (Stop) 1.8476 14 82.1540 1.0000 1.91082 35.25 15 11.9130 0.0070 1.56384 60.67 16 11.8860 5.4583 1.49700 81.54 17 18.6150 d17(Variable) 18 1.0000 1.77250 49.60 19 16.3256 1.6173 20* 27.2936 1.8481 1.53071 55.69 21* 35.1254 d21(Variable) 22 73.9226 2.7575 1.75520 27.51 23 24.1196 14.7890 Image Plane Aspheric Data 5.sup.th Surface K = 1.3488 A4 = 2.5546E5 A6 = 2.1154E7 A8 = 3.0630E11 A10 = 3.1146E12 A12 = 5.4895E15 6.sup.th Surface K = 1.3329 A4 = 3.1177E5 A6 = 9.5004E8 A8 = 2.9104E9 A10 = 2.0300E11 A12 = 3.5683E14 11.sup.th Surface K = 0.0713 A4 = 3.7502E5 A6 = 1.1749E8 A8 = 9.2227E11 A10 = 5.2627E12 12.sup.th Surface K = 0.2254 A4 = 6.5973E5 A6 = 1.0779E7 A8 = 2.9854E10 A10 = 8.1421E12 20.sup.th Surface K = 1.0292 A4 = 2.9390E4 A6 = 8.0095E6 A8 = 1.8656E7 A10 = 2.1155E9 21.sup.th Surface K = 2.2133 A4 = 3.1227E4 A6 = 7.1415E6 A8 = 1.5676E7 A10 = 1.7602E9 Data Set 1 Focal Length W~S~M1~T = 12.2~24.4~41.5~49.0 Fno W~S~M1~T = 3.6~5.2~6.0~6.5 Half View Angle W~S~M1~T = 42.0~24.2~14.7~12.5 W inf S inf M1 T inf d0 (Target) d2 2.12957 3.37416 5.39500 6.22164 d8 7.42838 8.57158 7.13070 5.29282 d10 28.69251 12.35175 3.37250 1.61926 d17 3.38106 7.01407 14.72100 17.95868 d21 6.82713 18.39167 21.10490 1.45831 ER 5.16833 5.32406 6.1999 6.30225 M2 d0 (Target) 105.09650 d2 6.22164 d8 5.77139 d10 4.73662 d17 16.27760 d21 19.54347 d23 9.99971 ER 6.30225 MG 0.31500 NA 0.02624 Data Set 2 G1 Focal Length 477.817 G2 Focal Length 39.259 G3 Focal Length 42.143 G4 Focal Length 186.280 G5 Focal Length 23.184 G6 Focal Length 46.302 BF 14.789 Total Optical Length 106.628~107.873~109.894~110.721 (W~S~M1~T) Image Height 10.13~11.11~11.11~11.11 (W~S~M1~T) Focal Length (macro mode) = 38.5 Half View Angle (macro mode) = 14.8 Imaging Distance (macro mode) = 105.1 (From object to 1.sup.st Surface) Imaging Magnification (macro mode) = 0.315

Numerical Example 2-4

(187) TABLE-US-00010 Surface No. r d nd d 1 31.1117 2.0691 1.77250 49.60 2 12.6950 8.1256 3 113.4391 2.0914 1.53110 55.91 4* 20.0750 1.5704 5 61.4079 3.3574 1.92286 20.88 6 85.0339 d6(Variable) 7 23.4097 1.4228 1.77250 49.60 8 67.4494 d8(Variable) 9 15.9168 2.5554 1.73400 51.47 10 38.1774 1.1182 11(Stop) 0.8485 12* 13.2801 4.4866 1.49700 81.54 13 70.7511 0.8973 1.90366 31.32 14 12.7475 0.9484 15* 10.3674 3.5053 1.49700 81.61 16* 33.0299 d16(Variable) 17 31.2723 2.5762 1.66680 33.05 18 45.6262 0.8060 1.81600 46.62 19 13.0498 d19(Variable) 20* 375.5090 1.8517 1.53110 55.91 21* 70.4500 1.6314 22 81.1555 3.1185 1.75520 27.51 23 1.028E+04 14.7000 Aspheric Data 4.sup.th Surface K = 9.7034 A4 = 7.5709E5 A6 = 1.1292E6 A8 = 5.9070E9 A10 = 1.9413E11 12.sup.th Surface K = 0.0044 A4 = 1.3700E5 A6 = 5.2212E7 A8 = 1.0043E8 A10 = 8.6168E11 15.sup.th Surface K = 0.0531 A4 = 1.6848E4 A6 = 2.1018E6 A8 = 7.5495E8 A10 = 1.4267E9 16.sup.th Surface K = 4.3734 A4 = 7.4283E5 A6 = 1.6173E6 A8 = 4.7249E8 A10 = 1.3457E9 20.sup.th Surface K = 173.8024 A4 = 1.4194E4 A6 = 8.5213E7 A8 = 3.0672E9 A10 = 8.3193E12 21.sup.th Surface K = 15.2845 A4 = 1.4072E4 A6 = 8.6594E7 A8 = 3.1312E9 A10 = 9.9334E12 Data Set 1 Focal Length Wide~Std~M1~Tele = 12.3~24.0~31.8~46.9 Fno Wide~Std~M1~Tele = 3.6~5.9~6.2~6.4 Half View Angle Wide~Std~M1~Tele = 44.3~24.9~19.1~12.9 W inf S inf M1 T inf d0 (Target) d6 4.38498 4.38498 4.38498 4.38498 d8 27.71988 12.44954 6.85195 0.09416 d16 0.12512 2.54106 5.44925 12.93114 d19 6.94166 19.79605 22.48540 21.76135 ER 5.50770 4.75779 5.25228 6.25359 M2 d0 (Target) 70.98634 d6 4.38498 d8 6.86251 d16 8.41062 d19 19.51351 ER 6.03715 MG 0.38000 NA 0.03358 Data Set 2 G1 Focal Length 16.954 G2 Focal Length 17.560 G3 Focal Length 23.921 G4 Focal Length 65.382 BF 14.7 Total Optical Length(W-T) 96.852 Image Height 11.11 Focal Length (macro mode) = 28.4 Half View Angle (macro mode) = 18.4 Imaging Distance (macro mode) = 71.0 (From object to 1.sup.st Surface) Imaging Magnification (macro mode) = 0.38

(188) FIGS. 20 to 23 show various aberrations for an object point at infinity at (A)-(D) wide-angle end (W inf), (E)-(H) intermediate position (S inf), (I)-(L) telephoto end (T inf) and (M)-(P) second mode (M2) for Embodiments 2-1 through 2-4.

(189) In the drawings showing various aberrations, SA stands for spherical aberration, AS stands for astigmatism, DT stands for distortion and CC stands for chromatic difference of magnification. The spherical aberration SA is shown for the wavelengths of 587.6 nm (d line: solid line), 435.8 nm (g line: broken line), 656.3 nm (C line: dotted line) and 486.1 nm (F line: chain line). The chromatic difference of magnification CC is shown for the wavelengths of 435.8 nm (g line: broken line), 656.3 nm (C line: dotted line) and 386.1 nm (F line: chain line) as referred to d line. The astigmatism DT is shown for the sagittal image surface (solid line) and the meridional image surface (broken line). FNO stands for F number and FIY stand for the maximum image height.

(190) The values of the conditional formulas (2-1) through (2-5) are listed below for Examples 2-1 through 2-4.

(191) TABLE-US-00011 EX. 2-1 EX. 2-2 EX. 2-3 EX. 2-4 Formula 1.239 0.918 0.932 0.823 (2-1) Formula 1.852 2.198 1.996 1.864 (2-2) Formula 0.673 0.543 0.781 1.495 (2-3) Formula 0.772 0.822 0.891 0.809 (2-4) Formula 0.953 0.925 0.877 0.755 (2-5)

(192) FIG. 24 is a schematic cross-sectional view of an image pickup apparatus, or a single lens mirrorless camera, using a zoom lens in the first aspect of the present invention and a compact CCD or CMOS as imaging device. FIG. 25 is a schematic cross-sectional view of an image pickup apparatus, or a single lens mirrorless camera, using a zoom lens in the second aspect of the present invention and a compact CCD or CMOS as imaging device. Each of FIGS. 24 and 25 denotes the single lens mirrorless camera 1, an imaging lens system 2 arranged in the lens barrel, and the mount section 3 of the lens barrel that makes the imaging lens system 2 removably mountable in the single lens mirrorless camera 1. Typically, a screw type or a bayonet type mount is employed for the mount section. A bayonet type mount is employed in this instance. Additionally, each of FIGS. 24 and 25 denotes an imaging device surface 4 and a back monitor 5. Note that, in this Example, the imaging device 4 and the cover glass (parallel and flat plate) C are contained at the side of the single lens mirrorless camera 1.

(193) A zoom lens according to the present invention, which may be one of the above-described Examples 1-1 through 1-5 and 2-1 through 2-4, is employed for the imaging lens system 2 of a single lens mirrorless camera 1 having the above-described configuration.

(194) FIGS. 26 and 27 are schematic conceptual views of an image pickup apparatus incorporating a zoom lens according to the present invention into the imaging optical system 41 thereof. FIG. 26 is a schematic perspective front view of digital camera 40 that is an image pickup apparatus and FIG. 27 is a schematic perspective back view of the camera 40.

(195) This digital camera 40 includes an imaging optical system 41 arranged on the image light path 42 of the camera, a shutter button 45, a liquid crystal display monitor 47, etc. As the shutter button 45 arranged at a top part of the digital camera 40 is depressed, an image is picked up by way of the imaging optical system 41 including, for example, a zoom lens of Example 1 in an interlocked manner. The image of the target object formed by the imaging optical system 41 is made to appear on the imaging device (photoelectric conversion surface) arranged near the image forming surface. The image of the target object optically received by the imaging device is displayed on the liquid crystal display monitor 47 arranged at the back surface of the camera as an electronic image by a processing means.

(196) FIG. 28 is a block diagram of the internal circuit of a principal part of the digital camera 40. Note that, in the following description, the processing means 51 described above includes, for example, a CDS/ADC section 24, a temporary storage memory 17, an image processing section 18, etc., whereas the memory means 52 typically includes a storage medium section.

(197) As shown in FIG. 28, the digital camera 40 includes an operation section 12, a control section 13 connected to this operation section 12, an imaging drive circuit 16, a temporary storage memory 17, the imaging drive circuit 16 and the temporary storage memory 17 being connected to the control signal output port of the control section 13 respectively by way of bus 14 and bus 15, an image processing section 18, a storage medium section 19, a display section 20 and a setting information storage memory section 21.

(198) The temporary storage memory 17, the image processing section 18, the storage medium section 19, the display section 20 and the setting information storage memory section 21 listed above can mutually input and output data by way of bus 22. Additionally, a CCD 49 and a CDS/ADC section 24 are connected to the imaging drive circuit 16.

(199) The operation section 12 includes various input buttons and switches and notifies the event information input to it from the outside (the camera user) by way of any of the input buttons and switches to the control section. The control section 13 is typically a central processing unit, which is also referred to as a CPU, and contains a program memory (not shown). The control section 13 controls the entire digital camera 40 according to the programs stored in the program memory.

(200) The CCD 49 is an imaging device driven and controlled by the imaging drive circuit 16 to convert the quantity of light of each pixel of the image of the target object formed by way of the imaging optical system 41 into an electric signal and output the signal to the CDS/ADC section 24.

(201) The CDS/ADC section 24 is a circuit for amplifying the electric signal input from the CCD 49, operating for analog/digital conversions for the electric signal and outputting the image raw data (Bayer data, to be referred to as RAW data hereinafter) produced as a result of amplifications and analog/digital conversions.

(202) The temporary storage memory 17 is a buffer memory typically including a SDRAM, and is a memory device for temporarily storing the RAW data output from the CDS/ADC section 24. The image processing section 18 is a circuit for reading out RAW data stored in the temporary storage memory 17 or RAW data stored in the storage medium section 19 and electrically executing various image processing operations including operations for correcting distortions according to the image quality parameters specified by the control section 13.

(203) The storage medium section 19 is removably mounted with a card type or stick type storage medium that may typically be a flash memory that records RAW data transferred from the temporary storage memory 17 and the image data produced from the image processing section 18 as a result of image processing and holds them.

(204) The display section 29 includes the liquid crystal display monitor 47 and so on and displays the picked up RAW data, image data, operation menus, etc. The setting information storage memory section 21 includes a ROM section that stores various image quality parameters in advance and a RAM section that stores the image quality parameters read out from the ROM section by way of input operations at the operation section 12.

(205) The digital camera 40 having the above-described configuration can operate as an image pickup apparatus having an imaging optical system 41 where a zoom lens according to the present invention is adopted to operate as an inner zoom system and an inner focus system with a fixed total length and provide advantages in terms of optical performances and securing variable magnification ratio.

(206) While the present invention is described above by way of various embodiments, the present invention is by no means limited to the embodiments and embodiments realized by appropriately combining any of the components of the embodiments are also within the scope of the present invention.

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Abstract

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