Endoscope device

Abstract

The invention relates to the technical field of endoscope light path design, and discloses an endoscope device which comprises an endoscope body, an endoscope tube, an eyepiece and an objective lens window arranged on the endoscope tube. The prism is arranged in the lens tube and is used for changing the propagation direction of light rays; the endoscope light path system is located in the endoscope body and used for changing the transmission direction of light and adjusting the imaging quality of the endoscope; the eyepiece is arranged on the endoscope body and used for changing the transmission direction of light rays, and the light path system has negative focal power, so that the light ray angle of incident light rays is smaller than the light ray angle of emergent light rays, the light path system has a certain divergence effect, the observation range of the lens can be enlarged, and the observation effect of the lens is improved. And then secondary focusing is carried out on the image by moving the position of the focusing group, so that the imaging work of the endoscope is ensured to be smoothly carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of endoscope optical path design, and specifically to an endoscope device. Background Art

[0002] At present, the endoscope technology is constantly innovating, providing diversified options for the treatment of diseases and helping patients recover better.

[0003] For example, the patent application with the publication number CN117017167A discloses an endoscope and an endoscope objective lens, including a first lens with a negative optical power, a part of the image side of the first lens near the optical axis and far from the edge of the first lens is concave; a second lens with a positive optical power; a diaphragm; a third lens with a positive optical power; a fourth lens with a negative optical power, a part of the object side of the fourth lens near the optical axis and far from the edge of the fourth lens is concave; the first lens, the second lens, the diaphragm, the third lens and the fourth lens are arranged in sequence along the optical axis from the image side to the object side.

[0004] However, there are still some problems in the above technical solution. Although the above technical solution can reduce the difficulty of aberration correction and improve the imaging quality, in the endoscope, the lens diameters in the above technical solution are not the same, which makes it difficult to install the lenses in the endoscope, resulting in difficult overall assembly of the objective lens and being not conducive to the miniaturization of the endoscope.

[0005] Therefore, how to ensure that the optical path system can perform imaging work on the premise of ensuring the same objective lens diameter is a problem to be solved currently. Summary of the Invention

[0006] The present invention provides an endoscope device to solve the above problems existing in the prior art.

[0007] An endoscope device includes:

[0008] An endoscope body, including a lens tube and an eyepiece, and an objective window provided on the lens tube;

[0009] A prism, provided in the lens tube, for changing the propagation direction of light;

[0010] An endoscope optical path system, located in the endoscope body, changing the transmission direction of light and adjusting the imaging quality of the endoscope;

[0011] An eyepiece, provided on the endoscope body, for changing the transmission direction of light;

[0012] The endoscope optical path system includes:

[0013] A diaphragm;

[0014] A first fixed group, a focusing group, a second fixed group, and an imaging surface are sequentially provided in the light transmission direction;

[0015] The first fixed group, the focusing group, and the second fixed group are all combined lenses and have the same diameter;

[0016] The first fixed group is sequentially provided with a first lens, a second lens, a third lens, and a fourth lens in the light transmission direction, and adjacent lenses are bonded to each other;

[0017] Wherein the first lens includes a first lens object side and a first lens image side, the second lens includes a second lens object side and a second lens image side, the third lens includes a third lens object side and a third lens image side, the fourth lens includes a fourth lens object side and a fourth lens image side, the first lens object side, the second lens object side, the second lens image side, the third lens object side, the third lens image side, and the fourth lens object side are all flat surfaces, the first lens image side is a concave surface, the fourth lens image side is a convex surface, and the first fixed group has a negative optical power;

[0018] The aperture stop is located in the third lens.

[0019] Further, the focusing group includes a fifth lens and a sixth lens bonded to the fifth lens;

[0020] Wherein the fifth lens is a biconvex lens, the fifth lens includes a fifth lens object side and a fifth lens image side, and the radius of curvature of the fifth lens object side is smaller than the radius of curvature of the fifth lens image side;

[0021] The sixth lens includes a sixth lens object side and a sixth lens image side, the sixth lens object side is bonded to the fifth lens image side, wherein the sixth lens object side is a concave surface, the sixth lens image side is a convex surface, and the focusing group has a positive optical power.

[0022] Further, the second fixed group includes a seventh lens and an eighth lens bonded to the seventh lens;

[0023] The seventh lens includes a seventh lens object side and a seventh lens image side, the eighth lens includes an eighth lens object side and an eighth lens image side, the seventh lens object side and the eighth lens object side are concave surfaces, and the seventh lens image side and the eighth lens image side are convex surfaces;

[0024] The second fixed group has a positive optical power.

[0025] Further, the focal length f1 of the first lens in the first fixed group is -1.85 mm;

[0026] The focal length f4 of the fourth lens is 3.5 mm;

[0027] The focal length of the first fixed group is -3.93 mm.

[0028] Furthermore, the focal length f5 of the fifth lens in the focusing group is 2.44 mm;

[0029] The focal length f6 of the sixth lens is -3.99 mm;

[0030] The focal length of the focusing group is 6.26 mm.

[0031] Furthermore, the focal length f7 of the seventh lens in the second fixed group is 6.89 mm;

[0032] The focal length f8 of the eighth lens is -8.17 mm;

[0033] The focal length of the second fixed group is 44.14 mm.

[0034] Furthermore, the length from the image side of the first lens to the object side of the second lens is 0.09 mm, the length from the image side of the fourth lens to the object side of the fifth lens is 0.32 mm, the distance from the image side of the sixth lens to the object side of the seventh lens is 0.51 mm, and the distance from the image side of the eighth lens to the imaging surface is 1.501 mm.

[0035] Furthermore, the endoscope optical path system further includes a plane where the object is located. The total length between the plane where the object is located and the imaging surface is 21.432 mm, and the field of view FOV of the optical path system is 80°.

[0036] An endoscope device further includes an optical member in the form of a parallel plane plate between the image side of the second fixed group and the imaging surface. The optical member is selected from an optical path conversion prism for bending the optical path, a filter, and a glass cover.

[0037] Beneficial effects: The present invention discloses an endoscope device. In order to ensure that the optical path system can perform imaging work on the premise that the objective lens diameters are the same, the device is provided with a first fixed group, a focusing group, and a second fixed group. The first fixed group includes a first lens, a second lens, a third lens, and a fourth lens. The second fixed group includes a seventh lens and an eighth lens. The focusing group includes a fifth lens and a sixth lens. The length from the image side of the first lens to the object side of the second lens is 0.09 mm. The length from the image side of the fourth lens to the object side of the fifth lens is 0.32 mm. The distance from the image side of the sixth lens to the object side of the seventh lens is 0.51 mm. The distance from the image side of the eighth lens to the imaging surface is 1.501 mm. Furthermore, on the premise that the diameters of each lens are the same, imaging work can still be completed. The optical path system disclosed in this application has a negative optical power, so that the light angle of the incident light is smaller than the light angle of the outgoing light, and thus the optical path system has a certain diverging effect, which can increase the observation range of the lens. Then, by moving the position of the focusing group, the image is refocused to ensure the smooth progress of the endoscope imaging work. Brief Description of the Drawings

[0038] Figure 1 is a cross-sectional view of the lens in an endoscope device of the present invention;

[0039] Figure 2 is a schematic optical path diagram of the endoscope device;

[0040] Figure 3 is the MTF (Modulation Transfer Function) diagram of the endoscope device of the present invention.

[0041] Reference Numerals: 1. Object side of the first lens; 2. Image side of the first lens; 3. Object side of the second lens; 4. Image side of the second lens; 5. Object side of the fourth lens; 6. Image side of the fourth lens; 7. Object side of the fifth lens; 8. Object side of the sixth lens; 9. Image side of the sixth lens; 10. Object side of the seventh lens; 11. Object side of the eighth lens; 12. Image side of the eighth lens. Detailed Embodiments

[0042] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made with reference to the accompanying drawings of the specification.

[0043] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0044] Second, as used herein, "an embodiment" or "embodiments" refer to specific features, structures, or characteristics that may be included in at least one implementation of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is separate from or mutually exclusive of other embodiments selectively.

[0045] The present invention discloses an endoscope device. Referring to Figures 1-3 , an endoscope device includes:

[0046] An endoscope body, including a lens tube and an eyepiece, and an objective window provided on the lens tube;

[0047] A prism, provided in the lens tube, for changing the propagation direction of light;

[0048] An endoscope optical path system, located in the endoscope body, for changing the transmission direction of light and adjusting the imaging quality of the endoscope;

[0049] An eyepiece, provided on the endoscope body, for changing the transmission direction of light;

[0050] The endoscope optical path system includes:

[0051] A diaphragm;

[0052] A first fixed group, a focusing group, a second fixed group, and an imaging surface are sequentially provided in the transmission direction of light;

[0053] The first fixed group, the focusing group, and the second fixed group are all combined lenses and have the same diameter;

[0054] The first fixed group sequentially includes a first lens, a second lens, a third lens, and a fourth lens, and adjacent lenses are adhesively bonded to each other;

[0055] Wherein the first lens includes a first lens object side 1 and a first lens image side 2, the second lens includes a second lens object side 3 and a second lens image side 4, the third lens includes a third lens object side and a third lens image side, the fourth lens includes a fourth lens object side 5 and a fourth lens image side 6, the first lens object side 1, the second lens object side 3, the second lens image side 4, the third lens object side, the third lens image side, and the fourth lens object side 5 are all flat surfaces, the first lens image side 2 is a concave surface, the fourth lens image side 6 is a convex surface, and the first fixed group has a negative optical power;

[0056] The diaphragm is located in the third lens.

[0057] The focusing group includes a fifth lens and a sixth lens adhesively bonded to the fifth lens;

[0058] The fifth lens is a biconvex lens, which includes a fifth lens object side 7 and a fifth lens image side. The radius of curvature of the fifth lens object side 7 is smaller than that of the fifth lens image side;

[0059] The sixth lens includes a sixth lens object side 8 and a sixth lens image side 9. The sixth lens object side 8 is adhered to the fifth lens image side. The sixth lens object side 8 is a concave surface, and the sixth lens image side 9 is a convex surface. The focusing group has a positive optical power.

[0060] The second fixed group includes a seventh lens and an eighth lens adhered to the seventh lens;

[0061] The seventh lens includes a seventh lens object side 10 and a seventh lens image side. The eighth lens includes an eighth lens object side 11 and an eighth lens image side 12. The seventh lens object side 10 and the eighth lens object side 11 are concave surfaces, and the seventh lens image side and the eighth lens image side 12 are convex surfaces;

[0062] The second fixed group has a positive optical power.

[0063] The focal length f1 of the first lens in the first fixed group is -1.85 mm;

[0064] The focal length f4 of the fourth lens is 3.5 mm;

[0065] The focal length of the first fixed group is -3.93 mm.

[0066] The focal length f5 of the fifth lens in the focusing group is 2.44 mm;

[0067] The focal length f6 of the sixth lens is -3.99 mm;

[0068] The focal length of the focusing group is 6.26 mm.

[0069] The focal length f7 of the seventh lens in the second fixed group is 6.89 mm;

[0070] The focal length f8 of the eighth lens is -8.17 mm;

[0071] The focal length of the second fixed group is 44.14 mm.

[0072] The distance between the first lens image side 2 and the second lens object side 3 is 0.09 mm. The distance between the fourth lens image side 6 and the fifth lens object side 7 is 0.32 mm. The distance between the sixth lens image side 9 and the seventh lens object side 10 is 0.51 mm. The distance between the eighth lens image side 12 and the imaging surface is 1.501 mm.

[0073] The optical path system further includes the plane where the object is located. The total length between the plane where the object is located and the imaging plane is 21.432 mm, and the field of view angle FOV of the optical path system is 80°.

[0074] An endoscope device further includes a parallel planar optical member located between the side surface of the second fixed group and the imaging plane.

[0075] In a further embodiment, in order to achieve the effect of expanding the field of view, so that the angle of the outgoing light is greater than the angle of the incident light, the curvature radius and the central thickness of each lens are shown in Table 1;

[0076] Table 1 Curvature Radius and Central Thickness Table of Lenses

[0077]

[0078]

[0079] Among them, the materials and refractive indices of each lens used in this application are shown in Table 2:

[0080] Table 2 Material and Refractive Index Table of Lenses

[0081]

[0082] Among them, the focal lengths of each lens are shown in Table 3:

[0083] Table 3 Focal Length Table of Each Lens

[0084]

[0085] Among them, the aperture stop can be represented by STOP, and the image plane, that is, the imaging plane, can be represented by IM;

[0086] Among them, the calculation formula for the focal length is:

[0087]

[0088] Among them, f is the focal length, n is the refractive index of the material, R1 and R2 are the curvature radii of the object side and the image side, and d is the central thickness of the lens;

[0089] Among them, the first lens is a plano-concave lens, the material is H-ZK1. When calculating the focal length, the refractive index is 1.6131 mm, and the obtained focal length is -1.85 mm;

[0090] The material of the second lens is H-LAF10LA, and the material of the third lens is H-LAF10LA. Among them, the second lens and the third lens are plane mirrors, so their focal lengths can be regarded as infinite;

[0091] The fourth lens is a plano-convex lens, and the material is H-ZLAF4LA. When calculating the focal length, the refractive index is 1.71 mm; the obtained focal length is 3.5 mm;

[0092] Among them, the first lens, the second lens, the third lens and the fourth lens form a combined lens, and the focal length of the combined lens is -3.93 mm. The calculation process is as follows:

[0093] First, calculate the equivalent focal length f of two lenses with focal lengths of -1.85 mm and 3.5 mm eq1 :

[0094]

[0095] Among them, f1 is the focal length of the first lens, and f4 is the focal length of the fourth lens;

[0096] Then, combine it with two lenses with infinite focal lengths. Since a lens with an infinite focal length has no converging or diverging effect on light, which is equivalent to the light passing through it without changing direction, the equivalent focal length after combination with it is equal to the equivalent focal length after combination of the previous two lenses;

[0097] It can be seen from this that the equivalent focal length f eq1 ≈ -3.93. Since f eq1 <0, this combined lens has a diverging effect.

[0098] At the same time, the fifth lens is a biconvex lens, and the material is H-ZPK2. When calculating the focal length, the refractive index is 1.603 mm; the obtained focal length is 2.44 mm;

[0099] The sixth lens is a concave-convex lens, and the material is H-ZF62. When calculating the focal length, the refractive index is 1.755 mm; the obtained focal length is -3.99 mm;

[0100] Then, the combined focal length f of the focusing group eq2 After the above formula, the calculation result is: f eq2 ≈ 6.26. Since f eq2 > 0, the focusing group has a converging effect;

[0101] The seventh lens is a concave-convex lens, and the material is N-SK5. When calculating the focal length, the refractive index is 1.612 mm; the obtained focal length is 6.89 mm;

[0102] The eighth lens is a concave-convex lens, and the material is SF59. When calculating the focal length, the refractive index is 1.805 mm; the obtained focal length is -8.17 mm;

[0103] Then, the combined focal length f of the second fixed group eq3 After the above formula, the calculation result is: f eq3 ≈ 44.14. Since feq2 is greater than 0, so the second fixed group has a converging effect;

[0104] In summary, according to the parameter values of each lens in the above table, the focal lengths of the combined lenses of the first fixed group, the focusing group, and the second fixed group can be obtained.

[0105] The distance between the image side 6 of the fourth lens and the object side 7 of the fifth lens is 0.32 mm, and the distance between the image side 9 of the sixth lens and the object side 10 of the seventh lens is 0.51 mm; combining the focal lengths of the combined lenses, the focal length of the entire optical path system is calculated as follows:

[0106] First, calculate the focal length between the combined lens with a focal length of -3.93 mm and the combined lens with a focal length of 6.26 mm, where:

[0107]

[0108] where f eqab is the equivalent focal length of the combined lens formed by the first fixed group and the focusing group, f eq1 is the equivalent focal length of the first fixed group, f eq2 is the combined focal length of the focusing group, d eq1eq2 is the distance between the first fixed group and the focusing group, and then we get:

[0109] f eqab ≈ -12.19 mm;

[0110] At this time, calculate the focal length feqabc of the second fixed group and the combined lens formed by the first fixed group and the focusing group: It is calculated that feqabc = -17.13 mm, and feqabc < 0, so the entire optical path system is in a divergent state. Then, when using the endoscope including this optical path system, the observation range of the lens can be increased, and then by moving the position of the focusing group, the image can be refocused to ensure the smooth progress of the endoscope imaging work.

[0111] In a further embodiment, the object side is the side close to the object to be observed, and the other side is the image side.

[0112] In a further embodiment, by changing the distances between the image side 6 of the fourth lens and the object side 7 of the fifth lens and between the image side 9 of the sixth lens and the object side 10 of the seventh lens, a new set of data can be obtained, so that the distances between the lenses can be adjusted twice or even multiple times according to the imaging results; the newly obtained data is that the distance between the image side 6 of the fourth lens and the object side 7 of the fifth lens is 0.330 mm, and the distance between the image side 9 of the sixth lens and the object side 10 of the seventh lens is 0.5 mm. At this time, the focal length corresponding to the modified optical path system is -17.13 mm;

[0113] Meanwhile, the distances between the image side 6 of the fourth lens and the object side 7 of the fifth lens, and between the image side 9 of the sixth lens and the object side 10 of the seventh lens are changed again. At this time, the distance between the image side 6 of the fourth lens and the object side 7 of the fifth lens becomes 0.3 mm, and the distance between the image side 9 of the sixth lens and the object side 10 of the seventh lens is 0.530 mm. At this time, the focal length of the modified optical path system is -17.01 mm;

[0114] It can be seen from this that when the focusing group moves towards the first fixed group, that is, when the distance between the image side 6 of the fourth lens and the object side 7 of the fifth lens is shortened, the absolute value of the focal length of the entire optical path system becomes smaller at this time, that is, it has a converging effect, and vice versa, it has a diverging effect. Therefore, the imaging effect of the entire optical path system can be adjusted according to the above results to ensure that the optical path system can perform imaging work smoothly.

[0115] Among them, Figure 3 in it, the ordinate is the modulus of the optical transfer function (modulus of the OTF), and the abscissa is the spatial frequency, with the unit of cycle / mm;

[0116] Among them Figure 3 in 0 (degree) meridian, it means that the angle between a certain ray, the axis of a certain optical element or a certain specific direction and the meridian plane is 0 degree;

[0117] In 20 (degree) meridian, it means that the angle between a certain ray, the axis of a certain optical element or a certain specific direction and the meridian plane is 20 degrees;

[0118] In 40 (degree) meridian, it means that the angle between a certain ray, the axis of a certain optical element or a certain specific direction and the meridian plane is 40 degrees;

[0119] In 20 (degree) sagittal, it means that the angle between a certain ray, the axis of a certain optical element or a certain specific direction and the sagittal plane is 20 degrees;

[0120] In 40 (degree) sagittal, it means that the angle between a certain ray, the axis of a certain optical element or a certain specific direction and the sagittal plane is 40 degrees.

[0121] Principle description: During the optical path transmission process, the position of the focusing group can be adjusted to adjust the final imaging result and ensure the smooth progress of the optical path transmission work.

[0122] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. An endoscope device, characterized in that: include: An endoscope body, comprising a scope tube and an eyepiece, and an objective lens window arranged on the scope tube; A prism, arranged in the mirror tube, for changing the propagation direction of light; An endoscope optical path system, located in the endoscope body, changes the transmission direction of light and adjusts the imaging quality of the endoscope; An eyepiece, arranged on the endoscope body, for changing the transmission direction of light; The endoscope optical path system comprises: Aperture; A first fixed group, a focusing group, a second fixed group and an imaging surface are sequentially arranged according to the transmission direction of the light; The first fixed group, the focusing group and the second fixed group are all combined lenses and have the same diameter; The first fixed group is provided with a first lens, a second lens, a third lens and a fourth lens in sequence according to the transmission direction of the light, and adjacent lenses are bonded to each other; The first lens comprises a first lens object side surface (1) and a first lens image side surface (2), the second lens comprises a second lens object side surface (3) and a second lens image side surface (4), the third lens comprises a third lens object side surface and a third lens image side surface, the fourth lens comprises a fourth lens object side surface (5) and a fourth lens image side surface (6), the first lens object side surface (1), the second lens object side surface (3), the second lens image side surface (4), the third lens object side surface, the third lens image side surface and the fourth lens object side surface (5) are all planes, the first lens image side surface (2) is a concave surface, the fourth lens image side surface (6) is a convex surface, and the first fixed group has a negative optical power; The aperture stop is located in the third lens.

2. An endoscope device according to claim 1, characterized in that: The focusing group includes a fifth lens and a sixth lens bonded to the fifth lens; The fifth lens is a biconvex lens, the fifth lens comprises a fifth lens object side surface (7) and a fifth lens image side surface, and the curvature radius of the fifth lens object side surface (7) is smaller than the curvature radius of the fifth lens image side surface; The sixth lens comprises a sixth lens object side surface (8) and a sixth lens image side surface (9), the sixth lens object side surface (8) is bonded to the fifth lens image side surface, wherein the sixth lens object side surface (8) is a concave surface, the sixth lens image side surface (9) is a convex surface, and the focusing group has positive optical power.

3. An endoscope device according to claim 2, characterized in that: The second fixed group includes a seventh lens and an eighth lens cemented to the seventh lens; The seventh lens comprises a seventh lens object side surface (10) and a seventh lens image side surface, and the eighth lens comprises an eighth lens object side surface (11) and an eighth lens image side surface (12), the seventh lens object side surface (10) and the eighth lens object side surface (11) are concave surfaces, and the seventh lens image side surface and the eighth lens image side surface (12) are convex surfaces; The second fixed group has positive optical power.

4. An endoscope device according to claim 1, characterized in that: The focal length f1 of the first lens in the first fixed group is -1.85 mm; The focal length f4 of the fourth lens is 3.5 mm; The focal length of the first fixed group is -3.93mm.

5. An endoscope device according to claim 3, characterized in that: The focal length f5 of the fifth lens in the focusing group is 2.44 mm; The focal length f6 of the sixth lens is -3.99 mm; The focal length of the focusing group is 6.26mm.

6. An endoscope device according to claim 5, characterized in that: The focal length f7 of the seventh lens in the second fixed group is 6.89 mm; The focal length f8 of the eighth lens is -8.17 mm; The focal length of the second fixed group is 44.14mm.

7. An endoscope device according to claim 5, characterized in that: The distance between the image side surface (2) of the first lens and the object side surface (3) of the second lens is 0.09 mm, the distance between the image side surface (6) of the fourth lens and the object side surface (7) of the fifth lens is 0.32 mm, the distance between the image side surface (9) of the sixth lens and the object side surface (10) of the seventh lens is 0.51 mm, and the distance between the image side surface (12) of the eighth lens and the imaging plane is 1.501 mm.

8. An endoscope device according to claim 5, characterized in that: The endoscope optical path system also includes the plane where the object is located. The total length between the plane where the object is located and the imaging plane is 21.432 mm. The field of view FOV of the optical path system is 80°.

9. An endoscope device according to claim 1, characterized in that: It also includes a parallel plane plate-shaped optical component located between the image side surface of the second fixed group and the imaging surface.

Images