ENDOSCOPE WITH OPTICAL FILTER ARRANGEMENT AND USE

Abstract

An endoscope including: an optical filter arrangement having: a holder; and an optical filter having one of different filter properties in different directions or multiple optical filters with different filter properties, the optical filter being arranged in the holder to rotate about an axis of rotation in at least one beam path of the endoscope in a direction of light incidence in or behind an objective of the endoscope and in front of an image capturing unit or an eyepiece; wherein the optical filter arrangement is configured to change from a first filter property to a second filter property when the optical filter is rotated by 90 about the axis of rotation from a first target rotational position to a second target rotational position.

Claims

1. An endoscope comprising: an optical filter arrangement comprising: a holder; and an optical filter having one of different filter properties in different directions or multiple optical filters with different filter properties, the optical filter being arranged in the holder to rotate about an axis of rotation in at least one beam path of the endoscope in a direction of light incidence in or behind an objective of the endoscope and in front of an image capturing unit or an eyepiece; wherein the optical filter arrangement is configured to change from a first filter property to a second filter property when the optical filter is rotated by 90 about the axis of rotation from a first target rotational position to a second target rotational position.

2. The endoscope according to claim 1, wherein the optical filter, which has different filter properties in different directions, is configured as a basically cuboid filter with two main axes lying perpendicular to each other and to the axis of rotation, which main axes each thrust perpendicularly through two side faces of the basically cuboid filter which lie opposite each other, wherein the optical filter is held rotatably about the axis of rotation in the holder, and the optical filter reaches the two different target rotational positions by rotating the filter arrangement about the axis of rotation by 90, in which in each of the positions one of the two main axes of the optical filter is arranged parallel to the optical axis of the at least one beam path.

3. The endoscope according to claim 2, wherein the basically cuboid filter has a first coating for the first filter property and a second coating on the second filter property respectively on at least two side faces that adjoin each other and are parallel to the axis of rotation.

4. The endoscope according to claim 3, wherein third and fourth side faces of the basically cuboid filter which are parallel to the axis of rotation have third and fourth coatings, respectively, wherein the first filter property comprises two of the first, second third and fourth filters opposite each other on the basically cuboid filter and the second filter property comprises an other two of the first, second, third and fourth filters opposite each other on the basically cuboid filter.

5. The endoscope according to claim 2, wherein the basically cuboid filter has different thicknesses in the direction of the two main axes, which thicknesses are adjusted to a focus of the optical system of the endoscope at different wavelengths of the first filter property and the second filter property.

6. The endoscope according to claim 1, wherein the filter arrangement has two, three or four flat optical filters held by the holder, the two, three or four flat optical filters being arranged rotated by 90 in relation to each other, wherein in the first target rotational position at least one of the two, three or four flat optical filters with the first filter property lies in the beam path and in the second target rotational position at least one other of the two, three or four flat optical filters with the second filter property lies in the beam path.

7. The endoscope according to claim 1, wherein the axis of rotation of the filter arrangement is oriented perpendicular to the at least one beam path of the endoscope.

8. The endoscope according to claim 1, wherein the endoscope is configured as a stereo endoscope with two parallel beam paths and the filter arrangement is configured as a filter wheel with two pairs of filters, wherein one of the two pairs of filters have the first filter property and an other of the two pairs of filters pair have the second filter property, the axis of rotation of the filter arrangement corresponds to one or more of a central axis between the beam paths and lies parallel to the central axis, and the one of the two pairs of the filters align with the beam paths in the first target rotational position and the other of the two pairs of the filters align with the beam paths in the second target rotational position.

9. The endoscope according to claim 1, further comprising an adjusting device configured to rotate the filter arrangement.

10. The endoscope according to claim 9, wherein the adjusting device comprises a magnetic coupling having an outer magnetic ring and an inner magnetic ring operatively connected to an outer magnetic ring, the inner magnetic ring being operatively connected to the holder of the filter arrangement.

11. The endoscope according to claim 10, wherein the inner magnetic ring is coupled to the holder via a gear wheel mechanical unit.

12. The endoscope according to claim 9, wherein the adjusting device comprises an electric motor and a control unit for the motor control as well as an operating unit.

13. The endoscope according to claim 1, further comprising a latching mechanism configured to fix the filter arrangement in the first target rotational position or in the second target rotational position.

14. A method of using the endoscope according to claim 1, the method comprising changing from the first filter property to the second filter property when the filter arrangement is rotated by 90 about the axis of rotation from the first target rotational position to the second target rotational position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The embodiments are described below, without restricting the general idea of the invention, based on exemplary embodiments in reference to the drawings, whereby we expressly refer to the drawings with regard to all details that are not explained in greater detail in the text. In the figures:

[0030] FIG. 1 illustrates a schematic cross-sectional diagram through a part of an endoscope according to the state of the art,

[0031] FIGS. 2a and 2b illustrate a schematic cross-sectional diagram through a part of an endoscope with a rotatable filter arrangement as well as a schematic diagram of the filter arrangement,

[0032] FIG. 3 illustrates a schematic diagram of the rotation of a rotatable filter arrangement,

[0033] FIG. 4 illustrates a schematic cross-sectional diagram through a part of an endoscope with a further filter arrangement,

[0034] FIGS. 5a and 5b illustrate a schematic diagram of the filter arrangement according to FIG. 4,

[0035] FIG. 6 illustrates a beam path of a sideways-facing stereo endoscope according to the state of the art, and

[0036] FIGS. 7a and 7b illustrate schematic diagrams of the filters of FIG. 6 and a filter wheel for replacement in a beam path according to FIG. 6, respectively.

DETAILED DESCRIPTION

[0037] In the drawings, the same or similar elements and/or parts are provided with the same reference numbers in each case; a reintroduction will therefore always be omitted.

[0038] FIG. 2a shows a modified endoscope as compared to the known endoscope shown in FIG. 1, in which the IR filter 20 is replaced by an optical filter arrangement 30 which can be rotated about an axis of rotation 38. The optical filter arrangement 30 comprises a holder 32 which allows the rotation 36 about the axis of rotation 38 and holds a basically cuboid optical filter 34 which is shown principally schematically in FIG. 2b.

[0039] The basically cuboid optical filter 34 has two main axes 40, 42 that lie perpendicular to the axis of rotation 38 and to each other. These run centrally through the side faces of the basically cuboid optical filter 34. By rotating the optical filter 34 about the axis of rotation 38 by 90, the main axis 40 or the main axis 42 are alternately brought parallel to the optical axis of the optical system of the endoscope 10 so that only the coatings on the inlet and/or outlet faces of the optical filter 34 that are active in each case ensure the filter effect with the filter property set in each case. Of the two side faces through which the main axis 40 runs, at least one is coated so that the first filter property is set, while of the two side faces through which the main axis 42 runs, at least one is coated so that the second filter property is set. The first filter property can be, for example, permitting the passage of visible light and blocking IR light, while the second filter property is permitting the passage of infrared light. The embodiments are not limited to a specific selection or combination of filter properties; the filter properties simply have to differ from each other.

[0040] FIG. 3 shows the effect of a 90 rotation 36 about the axis of rotation 38 of the optical filter 34. In a first state, the side faces 1 and 2 and, in a second state, the side faces 3 and 4 are thus located in the beam path, wherein, on the one hand, the side faces 1 and 2 lie opposite each other and, on the other hand, the side faces 3 and 4 lie opposite each other. In the first state or target rotational position, the optical filter 34 has a greater thickness than in the second state or the second target rotational position. The thicknesses in both directions are chosen so that a rotation can occur without refocusing the optical system, hence is adjusted to the filter property.

[0041] FIG. 4 shows another exemplary embodiment of an endoscope 10 with a rotatable filter arrangement 130. In contrast to the filter arrangement 30 according to FIGS. 2 and 3, multiple planar or flat optical filters 134, 136, possibly also 138, 140, are arranged in the holder 132, which generate the first or second filter property respectively. These planar filters 134, 136 are arranged rotated by 90 in relation to each other and correspond to the side faces of a cube.

[0042] An adjusting device 50 with an adjusting mechanism is also shown in FIG. 4 which can also be used for the embodiment in FIGS. 2a, 2b and 3. This is a magnetic coupling which has an outer magnetic ring 52 as an adjusting ring that can be grasped by the hand of an operator and rotated about the longitudinal axis of the endoscope, as well as an inner magnetic ring 54 that interacts magnetically with the former and is entrained by the rotation of the outer magnetic ring 52. The inner magnetic ring has a gear wheel profile on its proximal end which forms a gear wheel mechanism or a gear wheel mechanical unit 56 in conjunction with a gear wheel profile on the holder 132. A rotation of the inner magnetic ring 54 about the optical axis or central axis of the endoscope therefore ensures that the holder 132 with the optical filters arranged on the holder is rotated about the axis of rotation 38 which is perpendicular to the optical axis.

[0043] The holder 132 itself is shown in more detail in FIGS. 5a and 5b. The holder 132 comprises a holder disc 144 which has the gear wheel profile 146 as well as a central holder shaft 148 that comes out from the holder disc 144 and has the 2, 3 or 4 optical filters 134, 136, possibly 138, 140, on its other end. There is no material in the empty space between the optical filters 134, 136, 138, 140. The fact that the second optical filter 138, 140 s in each of the two pairs is optional is made clear in FIG. 5a in that these are only indicated with dashed lines.

[0044] Grooves can also be applied on the circumference of the holder disc 144 at a distance of 90 to each other, which grooves work together with a spring latching mechanism (not shown) to ensure a secure positioning of the filter arrangement in the target rotational positions.

[0045] The filter arrangement 230 shown in FIG. 7b, can be used in FIG. 6 to replace the filter arrangement of FIG. 7a, where FIG. 7b illustrates a filter wheel 232 which can be rotated (reference sign 36) about the axis of rotation (without reference sign) running in the normal of the imaging plane, wherein a 90 rotation rotates the two filters 234, 238 out of the beam paths and the filters 236, 240 into the beam paths. A change in the geometry is not required for this. The filter wheel 232 can be mechanically connected to the inner magnetic ring 54 from the exemplary embodiment in FIG. 4 or comprise it. The filter wheel 232 can have grooves or similar means at a distance of 90 for a latching mechanism.

[0046] In the case that the optical system shown is arranged on the distal end of a long endoscope shaft, a mechanical connection through the endoscope shaft for the rotation of the filter wheel 232 can also be provided, or an electric adjusting motor can be provided or other suitable means can be used.

[0047] While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the

LIST OF REFERENCE SIGNS

[0048] 10 Endoscope

[0049] 12 Shaft

[0050] 13 Objective

[0051] 14 Housing

[0052] 16 Eyepiece

[0053] 18 Illumination unit

[0054] 20 Optical filter

[0055] 22 Optical axis

[0056] 30 Optical filter arrangement

[0057] 32 Holder

[0058] 34 Optical filter

[0059] 36 Rotation

[0060] 38 Axis of rotation

[0061] 40, 42 Main axis

[0062] 50 Adjusting device

[0063] 52 Adjusting ring

[0064] 54 Inner magnetic ring

[0065] 56 Gear wheel mechanical unit

[0066] 130 Optical filter arrangement

[0067] 132 Holder

[0068] 134, 138 Optical filter

[0069] 136, 140 Optical filter

[0070] 142 Empty space

[0071] 144 Holder disc

[0072] 146 Gear wheel profile

[0073] 148 Holder shaft

[0074] 200 Optical system of a stereo endoscope

[0075] 202 Input lens system

[0076] 204 Deflection prisms

[0077] 206 Parallel lens systems

[0078] 210, 212 Optical filter

[0079] 220 First beam path

[0080] 222 Second beam path

[0081] 230 Optical filter arrangement

[0082] 232 Filter wheel

[0083] 234, 238 Optical filter

[0084] 236, 240 Optical filter