IMAGING UNIT, LENS BARREL, AND PORTABLE TERMINAL
20170005125 ยท 2017-01-05
Inventors
- Kazuichiro Itonaga (Tokyo, JP)
- Eigo Sano (Tokyo, JP)
- Nobuyoshi Mori (Tokyo, JP)
- Joji Wada (Tokyo, JP)
- Atsushi Morimura (Tokyo, JP)
- Yuichi Takenaga (Tokyo, JP)
- Takayoshi Hasegawa (Tokyo, JP)
- Makato TSUNODA (Tokyo, JP)
Cpc classification
H04N23/57
ELECTRICITY
H01L2924/00014
ELECTRICITY
H10F39/806
ELECTRICITY
H04N23/55
ELECTRICITY
H01L2924/00014
ELECTRICITY
G02B13/001
PHYSICS
G02B3/0068
PHYSICS
International classification
G02B13/00
PHYSICS
G02B27/00
PHYSICS
Abstract
To obtain an imaging unit, a lens barrel, and a portable terminal which can effectively suppress spring-back of solid-state imaging elements, while facilitating height lowering thereof. An imaging unit includes: a solid-state imaging element; and an imaging lens for forming a subject image on a photoelectric conversion part of the solid-state imaging element. An imaging surface of the solid-state imaging element is curved in a manner that a peripheral side is inclined toward an object side relative to a screen center. The imaging lens constrains the solid-state imaging element to prevent a radius of curvature of the imaging surface from varying. Thus, field curvature, distortion aberration, and comatic aberration are appropriately corrected.
Claims
1. An imaging unit comprising: a solid-state imaging element; and an imaging lens for forming a subject image on a photoelectric conversion part of the solid-state imaging element, wherein an imaging surface of the solid-state imaging element is curved in a manner that a peripheral side is inclined toward an object side relative to a screen center, and the imaging lens constrains the solid-state imaging element to prevent a radius of curvature of the imaging surface from varying.
2. The imaging unit according to claim 1, wherein an optical surface or a flange part of the imaging lens abuts on a peripheral part of the imaging surface of the solid-state imaging element.
3. The imaging unit according to claim 1, wherein a space between the imaging lens and the solid-state imaging element is sealed.
4. The imaging unit according to claim 1, wherein, when seen from an optical axis direction, a portion of the imaging lens extends from the solid-state imaging element in a direction orthogonal to an optical axis, a portion of the solid-state imaging element extends from the imaging lens in a direction orthogonal to the optical axis, and wire connection for transmitting signals to an external circuit is made to the portion of the solid-state imaging element.
5. An imaging unit comprising: a solid-state imaging element; and an imaging lens for forming a subject image on a photoelectric conversion part of the solid-state imaging element, wherein an imaging surface of the solid-state imaging element is curved in a manner that a peripheral side is inclined toward an object side relative to a screen center, and a frame member that suppresses parts other than the imaging surface of the solid-state imaging element is provided between the imaging lens and the solid-state imaging element to prevent a radius of curvature of the imaging surface from varying, and subject light which has passed through the imaging lens passes through the frame member and forms an image on the image forming surface.
6. The imaging unit according to claim 5, wherein a micro lens is provided on an image-side optical surface of the imaging lens.
7. The imaging unit according to claim 6, wherein a diameter of the micro lens becomes gradually larger from the optical axis side toward the peripheral side.
8. The imaging unit according to claim 7, wherein a color filter is provided on an image-side optical surface of the imaging lens.
9. The imaging unit according to claim 1, wherein the imaging unit is included in a lens barrel.
10. The imaging unit according to claim 1, wherein the imaging unit is included in a portable terminal.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENTS
[0046] In the following, modes (referred to as embodiments below) for implementing the present technology will be described.
First Embodiment
[0047]
[0048] As illustrated in
[0049] The intermediate product of the imaging element 11 has a flat-plate shape and is curved into a hemispherical shape with a predetermined radius of curvature by being compressed from the outer peripheral side, and the imaging element 11 includes a central curved part 11a and a flat-plate part 11b around the curved part 11a. The imaging surface 11c is formed in the central part of the surface on the light receiving side of the curved part 11a as a light-receiving part having pixels (photoelectric conversion elements) arranged two-dimensionally, and a signal processing circuit (not illustrated) is formed around the imaging surface 11c. The signal processing circuit includes a drive circuit part which sequentially drives each pixel to obtain signal electric charge, an A/D conversion part which converts each signal electric charge into a digital signal, and a signal processing part which forms an image signal output using the digital signal, and the like. The imaging element is not limited to the aforementioned CMOS image sensor, and other types of elements such as CCD may be applied thereto. In addition, when not explicitly stated, a micro lens and a color filter are formed on the imaging surface 11c, although not illustrated.
[0050] The imaging element 11 has the flat-plate part 11b attached to the substrate 14 having an aperture 14a so as to accommodate a portion of the curved part 11a in the aperture 14a. A pad 11d is formed around the flat-plate part 11b of the imaging element 11, and the substrate 14 and the pad 11d are connected via a bonded wire 15 (wire connection). The wire 15 connects the imaging element 11 and an external circuit (for example, a control circuit included in an upper level device having an imaging unit installed therein) which is not illustrated. Accordingly, it is possible to receive voltage or clock signals for driving the imaging element 11 supplied from an external circuit, or output digital YUV signals to the external circuit.
[0051] The imaging lens 12 is provided at the imaging surface 11c side of the imaging element 11. As illustrated in
[0052] In other words, according to the present embodiment, the radius of curvature of the imaging surface 11c is maintained by constraining the imaging element 11 by adhesively fixing the imaging lens 12 to the imaging element 11, and maintaining its shape by resisting the spring-back occurring in the imaging element 11. Accordingly, field curvature, distortion aberration, and comatic aberration can be appropriately corrected. In addition, spring-back of the imaging element 11 is suppressed using the imaging lens 12 at the object side of the imaging element 11, whereby downsizing and height lowering also become possible.
[0053] Applying an adhesive around the entire periphery of the imaging element 11 allows sealing the space between the imaging lens 12 and the imaging element 11. Accordingly, it is possible to suppress sticking of foreign substance such as dust to the imaging surface 11c. In addition, a medium other than air may be filled in the sealed space.
[0054] The substrate 14 has a housing 13 attached thereto, which shields the light around the imaging lens 12 and holds the imaging lens 12.
[0055] The operation of the aforementioned imaging unit 10 will be described.
[0056] The imaging unit 10 is installed at a position corresponding to the lower part of the liquid crystal display part, with the object side end face of the housing 13 being provided on the back side (see
[0057] The imaging unit 10 is connected to a control part 101 of the smart phone 100 via an external connection terminal (the arrow in
[0058] On the other hand, the smart phone 100 includes, as illustrated in
[0059] The smart phone 100 operates by manipulation of the input key part 60, i.e., and can drive the imaging unit 10 to capture an image by touch of the icon 71, or the like, being displayed on the touch panel 70. Subject light forms an image on the imaging surface 11c of the imaging element 11 via the imaging lens 12. The image signal converted by the imaging unit 10 is stored in the storage part 92 by the control system of the smart phone 100, or displayed on the touch panel 70, and furthermore, transmitted to the outside as video information via the wireless communication part 80.
Second Embodiment
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Third Embodiment
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Fourth Embodiment
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Fifth Embodiment
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Sixth Embodiment
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[0065] The imaging lens 12 can be positioned relative to the imaging surface 11c in the optical axis direction via the frame member 17 by causing the image-side face of the frame member 17 to abut on the flat-plate part 11b formed around the imaging surface 11c of the imaging element 11. On the other hand, the imaging lens 12 can be positioned relative to the imaging surface 11c in a direction orthogonal to the optical axis via the frame member 17 by causing the protrusion 17b of the frame member 17 to abut on the curved part 11a around the imaging surface 11c of the imaging element 11. Subject light having passed through the imaging lens 12 enters the imaging surface 11c via the aperture 17a of the frame member 17. Here, the imaging lens 12 and the frame member 17 may be separated from each other.
Seventh Embodiment
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Eighth Embodiment
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Ninth Embodiment
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Tenth Embodiment
[0069] In the imaging unit 10J according to the present embodiment, the image-side optical surface 12a of the imaging lens 12J is attached to the curved imaging surface 11c of the imaging element 11H, as illustrated in
[0070] In addition, as illustrated in
EXAMPLES
[0071] Next, Examples of the imaging lens suitable for the aforementioned embodiments will be described. However, the present invention is not limited by the Examples described below. The symbols used in each Example are as follows: [0072] f: focal length of entire imaging lens system [0073] fB: back focus [0074] F: F number [0075] 2Y: imaging surface diagonal length of solid-state imaging element [0076] ENTP: entrance pupil position (distance from first surface to entrance pupil position) [0077] EXTP: exit pupil position (distance from imaging surface to exit pupil position) [0078] H1: front side main point position (distance from first surface to front side main point position) [0079] H2: rear side main point position (distance from last surface to rear side main point position) [0080] R: radius of curvature [0081] D: axial surface separation [0082] Nd: refractive index relative to d-line of lens material [0083] vd: Abbe number of lens material
[0084] In each Example, a surface with * after each surface number is an aspheric surface, and the aspheric surface is expressed by the following Math. 1, with the apex of the surface being the origin, the X-axis taken in the optical axis direction, and the height perpendicular to the optical axis denoted by h.
where, [0085] Ai: i-th order aspheric coefficient [0086] R: radius of curvature [0087] K: conic constant.
Example 1
[0088] Lens data are listed in Table 1. In the following (including lens data in the Table), it is assumed that the power of ten (e.g., 2.510.sup.02) is expressed using E (e.g., 2.5E.sup.02).
[0089] The overall specifications of the imaging lens of the Example 1 are listed below: [0090] f=0.84 mm [0091] fB=0.04 mm [0092] F=4 [0093] 2Y=3 mm [0094] ENTP=0.96 mm [0095] EXTP=2.17 mm [0096] H1=1.47 mm [0097] H2=0.87 mm
[0098] Surface data of the imaging lens of the Example 1 are listed below:
TABLE-US-00001 effective surface number R (mm) D (mm) Nd vd radius (mm) 1 0.00 2.30 2* 38.031 0.40 1.58310 59.5 1.78 3* 0.682 0.60 0.98 4* 1.418 0.90 1.63470 23.9 0.87 5* 3.612 0.19 0.38 6 (diaphragm) 0.05 0.18 7* 1.427 0.74 1.53048 56.0 0.31 8* 0.376 0.06 0.51 9* 0.789 0.46 1.63470 23.9 0.54 10* 9.008 0.65 0.88 11 0.41 1.51630 64.1 1.36 12 10.000 0.05 1.51400 42.8 1.48 13 10.000
[0099] Aspheric coefficients of the Example 1 are listed below:
Second Surface
[0100] K=0.50000E+02, A4=0.91594E-01, A6=0.43298E-01, A8=0.90611E-02, A10=0.96295E-03, A12=0.53811E-04
Third Surface
[0101] K=0.10073E+01, A4=0.42866E-01, A6=0.30980E+00, A8=0.33406E+00, A10=0.11637E+01, A12=0.60040E+00
Fourth Surface
[0102] K=0.97639E+01, A4=0.22056E+00, A6=0.39971E-01, A8=0.18526E+00, A10=0.35313E+00, A12=0.19096E+00
Fifth Surface
[0103] K=0.46079E+01, A4=0.57221E+00, A6=0.13272E+01, A8=0.81783E+01, A10=0.25511E+02, A12=0.32938E+02
Seventh Surface
[0104] K=0.26660E+01, A4=0.75905E-01, A6=0.44468E+00, A8=0.26032E+01, A10=0.38162E+02, A12=0.13486E+03
Eighth Surface
[0105] K=0.38839E+01, A4=0.16438E+01, A6=0.39491E+01, A8=0.13444E+02, A10=0.21046E+02, A12=0.23469E+01
Ninth Surface
[0106] K=0.20091E+02, A4=0.16831E+00, A6=0.40405E+01, A8=0.70058E+01, A10=0.61198E+01, A12=0.29349E+02
Tenth Surface
[0107] K=0.50000E+02, A4=0.98947E-01, A6=0.67924E-01, A8=0.19606E+00, A10=0.31160E+00, A12=0.13412E+00
[0108] Single-lens data of the imaging lens of the Example 1 are listed below:
TABLE-US-00002 lens initial surface focal length (mm) 1 2 1.195 2 4 3.175 3 7 0.651 4 9 1.112 5 11 19.296
Example 2
[0109] Lens data are listed in Table 2.
[0110] The overall specifications of the imaging lens of the Example 2 are listed below: [0111] f=1.35 mm [0112] fB=0 mm [0113] F=2.82 [0114] 2Y=3 mm [0115] ENTP=0.96 mm [0116] EXTP=3.36 mm [0117] H1=1.49 mm [0118] H2=0.89 mm
[0119] Surface data of the imaging lens of the Example 2 are listed below:
TABLE-US-00003 effective surface number R (mm) D (mm) Nd vd radius (mm) 1 0.00 2.15 2* 2.811 0.40 1.54470 56.2 1.76 3* 0.428 0.51 0.92 4* 0.878 0.87 1.63470 23.9 0.83 5* 4.690 0.14 0.42 6 (diaphragm) 0.09 0.24 7* 2.920 0.73 1.54470 56.2 0.38 8* 0.778 0.97 0.63 9* 171.080 0.46 1.51630 64.1 1.50 10 10.000 0.03 1.51400 42.8 1.50 11 10.000
[0120] Aspheric coefficients of the Example 2 are listed below:
Second Surface
[0121] K=0.50000E+02, A4=0.80196E-03, A6=0.26087E-02, A8=0.55773E-03, A10=0.43133E-05
Third Surface K=0.82663E+00, A4=0.51712E+00, A6=0.32110E+00, A8=0.86436E+00, A10=0.10197E+00
Fourth Surface
[0122] K=0.25111E+01, A4=0.28043E+00, A6=0.19015E+00, A8=0.16628E+00, A10=0.12696E+00, A12=0.10060E-10
Fifth Surface
[0123] K=0.21799E+02, A4=0.44802E+00, A6=0.21419E+01, A8=0.30040E+02, A10=0.94384E+02, A12=0.27246E-12
Seventh Surface
[0124] K=0.50000E+02, A4=0.43277E+00, A6=0.96506E+00, A8=0.69548E+01, A10=0.13672E+02, A12=0.10000E-11
Eighth Surface
[0125] K=0.10139E+01, A4=0.20724E+00, A6=0.97283E-02, A8=0.71893E+00, A10=0.86320E-01, A12=0.50000E-11
Ninth Surface
[0126] K=0.00000E+00, A4=0.11510E+00, A6=0.10125E+00, A8=0.41053E-02, A10=0.85133E-02, A12=0.40119E-11
[0127] Single-lens data of the imaging lens of the Example 2 are listed below:
TABLE-US-00004 lens initial surface focal length (mm) 1 2 0.987 2 4 1.564 3 7 1.213 4 10 18.246
[0128] It is apparent, from the Examples and ideas described in the specification, to those skilled in the art that the present invention is not limited to the Examples described in the present specification, and includes other Examples or variations.
[0129] The effects described in the present specification are merely illustrative and not limiting, and there may be other effects.
REFERENCE SIGNS LIST
[0130] 10, 10A-10J imaging unit [0131] 11, 11A, 11B, 11C, 11G, and 11H imaging element [0132] 11 a curved part [0133] 11b flat-plate part [0134] 11c imaging surface [0135] 11d pad [0136] 12, 12D, 12F, 12G, 12H, 12J imaging lens [0137] 12a image-side optical surface [0138] 12b flange part [0139] 12c protrusion housing [0140] 14, 14A, 14B substrate [0141] 14a aperture [0142] 14b concave part [0143] 15 wire [0144] 16 combination holder [0145] 17 frame member [0146] 17a aperture [0147] 17b protrusion [0148] 18 micro lens [0149] 20 lens barrel [0150] 21 telephoto lens [0151] 22 annular coupling member [0152] 23 long lens barrel [0153] 24 camera body [0154] 25 wide-angle lens [0155] 26 short lens barrel [0156] 60 input key part [0157] 65 display part [0158] 70 touch panel [0159] 71 icon [0160] 80 wireless communication part [0161] 92 storage part [0162] 100 smart phone [0163] 101 control part