Endoscopic device

Abstract

The present invention relates to the technical field of endoscope optical path design, and discloses an endoscope device, which includes an endoscope body, comprising a mirror tube and an eyepiece, and an objective lens window arranged on the mirror 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, for changing the transmission direction of light and adjusting the imaging quality of the endoscope; an eyepiece, arranged on the endoscope body, for changing the transmission direction of light. This optical path system has negative optical focal length, so that the light angle of the incident light is smaller than the light angle of the outgoing light, thereby giving the optical path system a certain divergence effect, thereby increasing the observation range of the lens, and then by moving the position of the focusing group, the image is secondary focused to ensure smooth endoscopic imaging.

Description

Technical Field

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

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

[0003] For example, the patent application with publication number CN117017167A discloses an endoscope and an endoscope objective lens, comprising a first lens, wherein the first lens has negative optical focal length, and the image side surface of the first lens close to the optical axis and away from the edge of the first lens is a concave surface; a second lens, wherein the second lens has positive optical focal length; an aperture; a third lens, wherein the third lens has positive optical focal length; a fourth lens, wherein the fourth lens has negative optical focal length, and the object side surface of the fourth lens close to the optical axis and away from the edge of the fourth lens is a concave surface; the first lens, the second lens, the aperture, 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 lens in the endoscope, making it difficult to assemble the entire objective lens, which is not conducive to the miniaturization of the endoscope.

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

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

[0007] An endoscopic device, comprising:

[0008] An endoscope body, comprising a mirror tube and an eyepiece, and an objective lens window arranged on the mirror tube;

[0009] A prism is provided in the mirror tube and is used to change the propagation direction of light;

[0010] The endoscope optical path system is located in the endoscope body and changes the transmission direction of light to adjust 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 system comprises:

[0013] Aperture;

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

[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 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;

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

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

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

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

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

[0022] Furthermore, 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 surface and a seventh lens image-side surface, and the eighth lens includes an eighth lens object-side surface and an eighth lens image-side surface, the seventh lens object-side surface and the eighth lens object-side surface are concave surfaces, and the seventh lens image-side surface and the eighth lens image-side surface are convex surfaces;

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

[0025] Furthermore, 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 -3.93mm.

[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 6.26mm.

[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 44.14mm.

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

[0035] Furthermore, the endoscope optical path system also includes a 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 FOV of the optical path system is 80°.

[0036] An endoscope device also includes a parallel plane plate-shaped optical component located between the second fixed group image side surface and the imaging surface. The optical component is selected from an optical path conversion prism, a filter, and a glass cover for bending the optical path.

[0037] Beneficial effect: The present invention discloses an endoscope device. In order to ensure that the optical path system can perform imaging work under the premise of the same objective lens diameter, the device is provided with a first fixed group, a focusing group and a second fixed group; wherein 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, and the focusing group includes a fifth lens and a sixth lens, wherein the image side of the first lens is 0.09 mm away from the object side of the second lens, the image side of the fourth lens is 0.32 mm away from the object side of the fifth lens, the image side of the sixth lens is 0.51 mm away from the object side of the seventh lens, and the image side of the eighth lens is 1.501 mm away from the imaging plane, thereby completing the imaging work under the premise of the same diameter of each lens. The optical path system disclosed in the present application has a negative optical focal length, so that the light angle of the incident light is smaller than the light angle of the outgoing light, thereby making the optical path system have a certain divergence effect, thereby increasing the observation range of the lens, and then by moving the position of the focusing group, the image is focused for the second time to ensure the smooth progress of the endoscopic imaging work. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0041] Figure 1: 1. object side surface of the first lens; 2. image side surface of the first lens; 3. object side surface of the second lens; 4. image side surface of the second lens; 5. object side surface of the fourth lens; 6. image side surface of the fourth lens; 7. object side surface of the fifth lens; 8. object side surface of the sixth lens; 9. image side surface of the sixth lens; 10. object side surface of the seventh lens; 11. object side surface of the eighth lens; 12. image side surface of the eighth lens. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0045] The present invention discloses an endoscope device, referring to Figure 1-Figure 3 , an endoscopic device comprising:

[0046] An endoscope body, comprising a mirror tube and an eyepiece, and an objective lens window arranged on the mirror tube;

[0047] A prism is provided in the mirror tube and is used to change the propagation direction of light;

[0048] The endoscope optical path system is located in the endoscope body and changes the transmission direction of light to adjust 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 system comprises:

[0051] Aperture;

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

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

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

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

[0058] The fifth lens is a biconvex lens, comprising 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;

[0059] The sixth lens includes a sixth lens object side surface 8 and a sixth lens image side surface 9, and the sixth lens object side surface 8 is bonded to the image side surface of the fifth lens, 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.

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

[0061] The seventh lens includes a seventh lens object-side surface 10 and a seventh lens image-side surface, and the eighth lens includes 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.

[0062] The second fixed group has 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 -3.93mm.

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

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

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

[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 44.14mm.

[0072] The length between the image side surface 2 of the first lens and the objective side surface 3 of the second lens is 0.09 mm, the length between the image side surface 6 of the fourth lens and the objective 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 objective 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.

[0073] The 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°.

[0074] An endoscope device further includes a parallel plane plate-shaped optical component located between the second fixed group image side surface and the imaging surface.

[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 center thickness of each lens are as shown in Table 1;

[0076] Table 1 Lens curvature radius and center thickness

[0077]

[0078]

[0079] The materials and refractive indices of the lenses used in this application are shown in Table 2:

[0080] Table 2 Lens materials and refractive index

[0081]

[0082] The focal lengths of the lenses are shown in Table 3:

[0083] Table 3 Focal length of each lens

[0084]

[0085] The aperture can be represented by STOP, and the image plane can be represented by IM;

[0086] The calculation formula for focal length is:

[0087]

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

[0089] The first lens is a plano-concave lens made of H-ZK1. When calculating the focal length, the refractive index is 1.6131mm, and the focal length is -1.85mm.

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

[0091] The fourth lens is a plano-convex lens made of H-ZLAF4LA. When calculating the focal length, the refractive index is 1.71mm, resulting in a focal length of 3.5mm.

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

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

[0094]

[0095] Where f1 is the focal length of the first lens, f4 is the focal length of the fourth lens;

[0096] Then combine it with two lenses with infinite focal length. Because the lens with infinite focal length has no convergence or divergence effect on light, it is equivalent to the direction of light remaining unchanged after passing through it, so the equivalent focal length of the combination with it is equal to the equivalent focal length of the first two lenses combined.

[0097] From this we can know the equivalent focal length f eq1 ≈-3.93, due to f eq1 <0, the combined lens has a diverging effect.

[0098] Meanwhile, the fifth lens is a biconvex lens made of H-ZPK2. When calculating the focal length, the refractive index is 1.603mm, and the focal length is 2.44mm.

[0099] The sixth lens is a meniscus lens made of H-ZF62. When calculating the focal length, the refractive index is 1.755mm, resulting in a focal length of -3.99mm.

[0100] Then adjust the combined focal length f of the focusing group eq2 The calculation result obtained by the above formula is: f eq2 ≈6.26, due to f eq2 Greater than 0, so the focus group has a convergence effect;

[0101] The seventh lens is a meniscus lens made of N-SK5. When calculating the focal length, the refractive index is 1.612mm, resulting in a focal length of 6.89mm.

[0102] The eighth lens is a meniscus lens made of SF59. When calculating the focal length, the refractive index is 1.805mm, resulting in a focal length of -8.17mm.

[0103] Then the combined focal length of the second fixed group is f eq3 The calculation result obtained by the above formula is: f eq3 ≈44.14, due to feq2 is greater than 0, so the second fixed group has a convergence effect;

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

[0105] 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, and 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. Combining the focal lengths of the combined lenses, the focal length of the entire optical system is calculated:

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

[0107]

[0108] where f eqab 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 ≈-12.19mm;

[0110] At this time, the focal length feqabc of the combined lens formed by the second fixed group, the first fixed group and the focusing group is calculated: the calculation shows that feqabc = -17.13 mm, feqabc < 0, so the entire optical path system is in a divergent state. When using an endoscope containing this optical path system, the observation range of the lens can be increased, and then the image can be focused twice by moving the position of the focusing group to ensure the smooth progress of endoscopic imaging.

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

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

[0113] At the same time, the distances between the fourth lens image side surface 6 and the fifth lens object side surface 7, as well as the distances between the sixth lens image side surface 9 and the seventh lens object side surface 10, are changed again. Now, the distance between the fourth lens image side surface 6 and the fifth lens object side surface 7 becomes 0.3 mm, and the distance between the sixth lens image side surface 9 and the seventh lens object side surface 10 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 is displaced toward the first fixed group, that is, when the distance between the image side surface 6 of the fourth lens and the object side surface 7 of the fifth lens is shortened, the absolute value of the focal length of the entire optical path system becomes smaller, 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] in, Figure 3 In the figure, the ordinate is the modulus of the OTF, and the abscissa is the spatial frequency, with the unit being cycles / mm.

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

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

[0118] Meridian of 40 degrees means that the angle between a ray of light, the axis of an optical element or a specific direction and the meridian plane is 40 degrees;

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

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

[0121] Working principle description: During the optical 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 transmission.

[0122] The preferred embodiments of the present invention are 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 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 fall within the scope of protection of the present invention.

Claims

1. An endoscope device, characterized in that: include: An endoscope body, comprising a mirror tube and an eyepiece, and an objective lens window arranged on the mirror tube; A prism, disposed in the mirror tube, for changing the propagation direction of light; The endoscope optical path system is located in the endoscope body and changes the transmission direction of light to adjust the imaging quality of the endoscope; an eyepiece, provided on the endoscope body, for changing the transmission direction of light; The endoscope optical system comprises: Aperture; A first fixed group, a focusing group, a second fixed group and an imaging surface are sequentially provided 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 includes a first lens object side surface (1) and a first lens image side surface (2), the second lens includes a second lens object side surface (3) and a second lens image side surface (4), the third lens includes a third lens object side surface and a third lens image side surface, the fourth lens includes 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 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, comprising 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. The endoscope device according to claim 1, wherein: 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. The 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. The 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. The 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. The 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. The 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