An image-converting optical system and an endoscope adapter

Abstract

This invention provides an image-rotating optical system and an endoscope adapter. It comprises a first lens group, an image-rotating prism, and a second lens group arranged sequentially from the object side to the image side. The angle between the optical axes of the first and second lens groups is equal to the turning angle of the light rays within the image-rotating prism. The image-rotating prism folds the light rays, causing a 90° to 100° deflection, thus achieving a 90° to 100° optical path rotation. Considering docking requirements, the entrance pupil diameter of this optical system is controlled between 3mm and 4mm to better fit the endoscope, and the maximum aperture of the optical system is controlled to not exceed 7.5mm to meet miniaturization and lightweight requirements. These features result in a small overall size for the optical system, achieving a 90° to 100° optical path rotation function within a small volume, thus adapting to the size requirements of the endoscope.

Description

Technical Field

[0001] This utility model relates to the field of optical imaging technology, and in particular to an image-rotating optical system and an endoscope adapter. Background Technology

[0002] Endoscope adapters are also called bayonet lenses. Currently, most traditional bayonet lenses on the market have a horizontal field of view, i.e., a 0° bayonet lens with a 0° field of view. However, in certain scenarios, 0° bayonet lenses present difficulties in operation. To facilitate user handling, a right-angle bayonet is needed that allows for 90° to 100° optical path rotation, i.e., a 90° to 100° field of view. Furthermore, endoscope adapters have strict size requirements because they need to interface with endoscopes. Therefore, there is an urgent need for an optical system that can achieve 90° to 100° optical path rotation and is compact enough to fit endoscopes. Utility Model Content

[0003] The purpose of this utility model embodiment is to provide an image-rotating optical system and an endoscope adapter, so as to achieve a 90° to 100° optical path rotation with a relatively small size. The specific technical solution is as follows:

[0004] A first aspect of this utility model provides an image-spinning optical system, the optical system comprising: a first lens group, an image-spinning prism, and a second lens group arranged sequentially from the object side to the image side;

[0005] The angle between the optical axis of the first lens group and the optical axis of the second lens group is equal to the turning angle of the light rays in the image-rotating prism, and the image-rotating prism is used to cause the light rays to deflect by 90° to 100° by folding the light rays.

[0006] The focal length of the first lens group is negative;

[0007] The second lens group can move along the optical axis of the second lens group;

[0008] The entrance pupil diameter D of the optical system satisfies: 3mm <D<4mm;

[0009] The maximum aperture F of the optical system satisfies: F≤7.5mm.

[0010] In one possible implementation, the first lens group includes a first lens and a second lens arranged sequentially from the object side to the image side;

[0011] The image-side surface of the first lens is bonded to the object-side surface of the second lens.

[0012] In one possible implementation, the first lens is a biconcave lens, the second lens is a biconvex lens, the focal length of the first lens is negative, and the focal length of the second lens is positive.

[0013] In one possible implementation, the second lens group comprises a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged sequentially from the object side to the image side;

[0014] the image side surface of the third lens is cemented with the object side surface of the fourth lens; the focal length of the third lens is negative; the focal length of the fourth lens is positive, and the refractive indices of the third lens and the fourth lens are different; the effective focal length of the lens formed by cementing the third lens and the fourth lens is negative;

[0015] the focal length of the fifth lens is positive;

[0016] the image side surface of the sixth lens is cemented with the object side surface of the seventh lens; the focal length of the sixth lens is positive; the focal length of the seventh lens is negative, and the focal length of the lens formed by cementing the sixth lens and the seventh lens is negative.

[0017] In one possible implementation, the focal length f3 of the third lens satisfies: -13.0mm < f3 < -12.7mm, the focal length f4 of the fourth lens satisfies: 12.2mm < f4 < 14.2mm, the focal length f of the lens formed by cementing the third lens and the fourth lens 34 satisfies: -100.1mm < f 34 < -98.9mm, the focal length f5 of the fifth lens satisfies: 14.3mm < f5 < 15.6mm, the focal length f6 of the sixth lens satisfies: 7.1mm < f6 < 8.2mm, the focal length f7 of the seventh lens satisfies: -4.9mm < f7 < -4.2mm, the focal length f of the lens formed by cementing the sixth lens and the seventh lens 67 satisfies: -30.2mm < f 67 < -28.1mm.

[0018] In one possible implementation, the first lens is a flat glass, the second lens is a plano-concave lens, and the focal length of the second lens is negative.

[0019] In one possible implementation, the second lens group comprises an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens arranged sequentially from the object side to the image side;

[0020] the eighth lens is a plano-concave lens, and the focal length of the eighth lens is positive;

[0021] The image side surface of the ninth lens is cemented with the object side surface of the tenth lens; the ninth lens is a biconvex lens, the tenth lens is a biconvex lens, the focal length of the ninth lens is positive, and the focal length of the tenth lens is negative; the focal length of the cemented lens formed by the ninth lens and the tenth lens is positive;

[0022] The eleventh lens is a biconcave meniscus lens, and the focal length of the eleventh lens is negative;

[0023] The image side surface of the twelfth lens is cemented with the object side surface of the thirteenth lens; the twelfth lens is a biconvex lens, the thirteenth lens is a biconcave lens, the focal length of the twelfth lens is positive, and the focal length of the thirteenth lens is negative; the focal length of the cemented lens formed by the twelfth lens and the thirteenth lens is positive;

[0024] The fourteenth lens is a biconvex lens, and the focal length of the fourteenth lens is negative.

[0025] In one possible implementation, the focal length f8 of the eighth lens satisfies: 35mm < f8 < 40mm, the focal length f9 of the ninth lens satisfies: 6mm < f9 < 6.5mm, the focal length f of the tenth lens 10 satisfies: -7.5mm < f 10 <-7mm, the focal length f of the cemented lens formed by the ninth lens and the tenth lens 910 satisfies: 17mm < f 910 <19mm, the focal length f of the eleventh lens 11 satisfies: -10mm < f 11 <-5mm, the focal length f of the twelfth lens 12 satisfies: 7mm < f 12 <7.2mm, the focal length f of the thirteenth lens 13 satisfies: -7.2mm < f 13 <-7mm, the focal length f of the cemented lens formed by the twelfth lens and the thirteenth lens 123 satisfies: 40mm < f 123 <43mm, the focal length f of the fourteenth lens 14 satisfies: 19mm < f 14 <20mm.

[0026] According to a second aspect of the embodiment of the present utility model, an image-transferring endoscope adapter is provided, the endoscope adapter includes a housing and the optical system according to any one of the first aspect;

[0027] The housing includes a horizontal portion, a vertical portion and a connecting portion, an angle between the horizontal portion and the vertical portion is 90° to 100°, and the connecting portion is configured to connect the horizontal portion and the vertical portion;

[0028] The first lens group in the optical system is disposed inside the horizontal part, the second lens group in the optical system is disposed inside the vertical part, and the image-rotating prism in the optical system is disposed inside the connecting part.

[0029] In one possible implementation, a gripping portion is provided on the outer side of the vertical portion.

[0030] This invention provides an image-rotating optical system and an endoscope adapter. The angle between the optical axes of the first lens group and the second lens group is equal to the turning angle of the light rays within the image-rotating prism. The image-rotating prism is used to fold the light rays, causing them to deflect by 90° to 100°. That is, the turning angle of the light rays within the image-rotating prism is between 90° and 100°, enabling a 90° to 100° optical path rotation. Considering that the endoscope adapter needs to interface with the endoscope and has strict size requirements, the entrance pupil diameter of this optical system is controlled between 3mm and 4mm to better fit the endoscope. The maximum aperture of this optical system is controlled to be no greater than 7.5mm to meet the requirements of miniaturization and lightweight design. These features result in a smaller overall size for the optical system, achieving a 90° to 100° optical path rotation function within a smaller volume, thus adapting to the size requirements of the endoscope.

[0031] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0033] Figure 1 This is a first schematic diagram of the optical system structure provided in an embodiment of the present utility model;

[0034] Figure 2 This is a second schematic diagram of the optical system structure provided in an embodiment of the present invention;

[0035] Figure 3 A third schematic diagram of the optical system structure provided in this embodiment of the present invention;

[0036] Figure 4a This is a first schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention;

[0037] Figure 4bThis is a second schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention;

[0038] Figure 4c This is a third schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention;

[0039] Figure 4d This is a fourth schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention;

[0040] Figure 5a A first schematic diagram of the MTF curve provided for an embodiment of this utility model;

[0041] Figure 5b This is a second schematic diagram of the MTF curve provided in an embodiment of the present invention;

[0042] Figure 5c A first schematic diagram of relative illumination provided for an embodiment of this utility model;

[0043] Figure 5d A second schematic diagram of relative illumination provided for an embodiment of this utility model;

[0044] Figure 6 A fourth schematic diagram of the optical system structure provided in this embodiment of the present invention;

[0045] Figure 7a A fifth schematic diagram of a longitudinal aberration map provided in an embodiment of this utility model;

[0046] Figure 7b A sixth schematic diagram of a longitudinal aberration map provided for an embodiment of this utility model;

[0047] Figure 7c A seventh schematic diagram of a longitudinal aberration map provided for an embodiment of this utility model;

[0048] Figure 7d The eighth schematic diagram of the longitudinal aberration map provided in the embodiment of this utility model;

[0049] Figure 8a A third schematic diagram of the MTF curve provided for an embodiment of this utility model;

[0050] Figure 8b This is a fourth schematic diagram of the MTF curve provided in the embodiments of the present invention;

[0051] Figure 8c A third schematic diagram of relative illumination provided for an embodiment of this utility model;

[0052] Figure 8d A fourth schematic diagram of relative illumination provided for an embodiment of this utility model;

[0053] Figure 9 This is a schematic diagram of the endoscope adapter provided in an embodiment of the present invention. Detailed Implementation

[0054] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art based on this application are within the protection scope of the present utility model.

[0055] This invention provides an image-rotating optical system, see [link to relevant documentation]. Figure 1 , Figure 1 This is a first schematic diagram of the optical system structure provided in an embodiment of the present utility model. The optical system 1 includes: a first lens group 100, an image-rotating prism 200, and a second lens group 300 arranged sequentially from the object side to the image side.

[0056] The angle between the optical axis of the first lens group and the optical axis of the second lens group is equal to the turning angle of the light rays inside the image-rotating prism, and the image-rotating prism is used to cause the light rays to deflect by 90° to 100° by folding the light rays.

[0057] The first lens group has a negative focal length of 100;

[0058] The second lens group 300 can move along the optical axis of the second lens group 300;

[0059] The entrance pupil diameter D of the optical system satisfies: 3mm <D<4mm;

[0060] The maximum aperture F of the optical system must satisfy: F≤7.5mm.

[0061] The object side refers to the side closest to the object, while the image side refers to the side closest to the image plane. Lenses typically have an image-side side and an object-side side. The object-side side is the surface of the lens closest to the object, and the image-side side is the surface of the lens closest to the image.

[0062] The image-spinning prism 200 can deflect light rays within it by 90° to 100° (i.e., achieve optical path reversal) by folding the light rays. The object-side surface of the image-spinning prism 200 is a plane perpendicular to the optical axis, and the image-side surface is also a plane perpendicular to the optical axis. By setting an aperture stop for the optical system 1 on the object-side surface of the image-spinning prism 200, the exit angle of the light rays passing through the first lens group 100 can be compressed, thereby reducing the aperture of the entire optical system and facilitating miniaturization of the entire imaging system.

[0063] The structure of the image-rotating prism 200 in this invention can be any structure that can fold light rays so that the light rays inside the image-rotating prism are deflected by 90° to 100°.

[0064] The focal length of optical system 1 is 18mm to 22mm, the field of view is greater than 10°, the distortion of the entire field of view is less than 0.5%, and the relative illumination of the entire field of view is greater than 90%. The aperture of optical system 1 is less than 7.5mm, which can meet the requirements of lightweight and miniaturization.

[0065] The second lens group is a focusing group. Through a mechanical transmission device, such as a cam structure, the second lens group is controlled to move back and forth along the optical axis, which can achieve focusing on objects at infinity and close distance, satisfying the following relationships (1), (2), (3) and (4):

[0066] 7≤TTL / ImgH≤7.5……Relationship (1)

[0067] 4.5≤f / D≤7……Relation (2)

[0068] 3.2≤f*tan(Semi-FOV)≤3.8……Relationship (3)

[0069] F≤7.5……Relation (4)

[0070] Where TTL is the optical path distance on the optical axis from the object side to the image plane of the first lens group 100 in optical system 1, ImgH is the maximum image height of the imaging plane, f is the effective focal length of optical system 1, D is the entrance pupil diameter of optical system 1, Semi-FOV is half of the maximum field of view of optical system 1, and D is the maximum aperture of optical system 1.

[0071] Applying the above embodiments, by setting up a first lens group, an image-rotating prism, and a second lens group arranged sequentially from the object side to the image side, and with the angle between the optical axes of the first and second lens groups equal to the turning angle of the light rays within the image-rotating prism, the image-rotating prism is used to fold the light rays, causing them to deflect by 90° to 100°. That is, the turning angle of the light rays within the image-rotating prism is between 90° and 100°, enabling a 90° to 100° optical path rotation. Considering that the endoscope adapter needs to interface with the endoscope and has strict size requirements, the entrance pupil diameter of this optical system is controlled between 3mm and 4mm to better fit the endoscope, and the maximum aperture of this optical system is controlled not to exceed 7.5mm to meet the requirements of miniaturization and lightweight design. The above settings result in a small overall size of the optical system, achieving a 90° to 100° optical path rotation function within a small volume, adapting to the size requirements of the endoscope.

[0072] In order to more clearly describe the optical system 1 provided by the present utility model, the following will take Figure 2 the presented structure as an example to describe the optical system 1 provided by the present utility model. In this exemplary structure, the optical axes of the first lens group 100, the image rotating prism 200 and the second lens group 300 are horizontal. In practical applications, the positional relationship of the first lens group 100, the image rotating prism 200 and the second lens group 300 is as described above Figure 1 shown. Figure 2 is a second schematic diagram of the optical system structure provided by the embodiment of the present utility model. The optical system structures provided in the first embodiment and the second embodiment will be respectively described below:

[0073] I. First Embodiment

[0074] In the first embodiment, referring to Figure 3 , Figure 3 is a third schematic diagram of the optical system structure provided by the embodiment of the present utility model, the first lens group 100 comprises a first lens 101 and a second lens 102 which are sequentially arranged from an object side to an image side;

[0075] the image side surface of the first lens 101 is cemented with the object side surface of the second lens 102.

[0076] still referring to Figure 3 , the first lens 101 is a biconcave lens, and both the object side surface and the image side surface of the first lens 101 are concave surfaces. The second lens 102 is a biconvex lens, and both the object side surface and the image side surface of the second lens 102 are convex surfaces. The focal length f1 of the first lens 101 satisfies: -13.8mm<f1<-11.2mm, the focal length f2 of the second lens 102 satisfies: 14.6mm<f2<15.9mm, the focal length f of the first lens group obtained by cementing the first lens 101 and the second lens 102 12 satisfies: -174.2mm<f 12 <-172.5mm.

[0077] With the application of the above embodiment, the first lens group obtained by cementing the first lens and the second lens has a negative focal length, which can increase the field angle of the optical system, enable large-aperture light rays to converge well into the optical system, increase the luminous flux of the optical system, and improve the relative illumination of the optical system.

[0078] In a possible implementation, still referring to Figure 3 , the second lens group 300 comprises a third lens 301, a fourth lens 302, a fifth lens 303, a sixth lens 304 and a seventh lens 305 which are sequentially arranged from an object side to an image side.

[0079] The image side surface of the third lens 301 is cemented with the object side surface of the fourth lens 302. The third lens 301 has a negative focal length, and the fourth lens 302 has a positive focal length. The third lens 301 and the fourth lens 302 have different refractive indices, and the effective focal length of the lens formed by cementing the third lens 301 and the fourth lens 302 is negative.

[0080] By applying the above embodiment, the third lens with negative focal length and the fourth lens with positive focal length are arranged, the third lens and the fourth lens have different refractive indices, and the chromatic aberration generated by the optical system is balanced and the imaging quality is improved by cementing the third lens and the fourth lens.

[0081] The focal length of the third lens 301 is between -13.0mm and -12.7mm, the focal length of the fourth lens 302 is between 12.2mm and 14.2mm, and the focal length of the lens formed by cementing the third lens 301 and the fourth lens 302 is between -100.1mm and -98.9mm.

[0082] By applying the above embodiment, the third lens and the fourth lens are cemented to obtain a doublet lens, which is composed of two lenses with different Abbe numbers and different focal lengths, can better balance the chromatic aberration generated by the entire optical system, thereby improving the imaging quality.

[0083] The fifth lens 303 is a biconvex lens with positive optical power, and the focal length of the fifth lens 303 is between 14.3mm and 15.6mm.

[0084] By applying the above embodiment, the fifth lens with positive optical power can improve the astigmatism of the optical system, thereby improving the imaging quality of the optical system.

[0085] The image side surface of the sixth lens 304 is cemented with the object side surface of the seventh lens 305. The sixth lens 304 has a positive focal length, and the seventh lens 305 has a negative focal length. The effective focal length of the lens formed by cementing the sixth lens 304 and the seventh lens 305 is negative. The focal length f6 of the sixth lens satisfies: 7.1mm < f6 < 8.2mm, the focal length f7 of the seventh lens satisfies: -4.9mm < f7 < -4.2mm, the focal length f of the lens formed by cementing the sixth lens and the seventh lens 67 satisfies: -30.2mm < f 67 < -28.1mm.

[0086] Using the above embodiments, positive and negative lenses with different focal lengths have different refractive abilities for light of different wavelengths. The lens group obtained by cementing the sixth and seventh lenses can use the optical characteristics of the sixth and seventh lenses to compensate for the deviations generated by different wavelengths of light during refraction, thereby correcting the chromatic aberration of the optical system, so that various colors in the image can be restored, avoiding phenomena such as blurred color edges and color stripes, and improving the color authenticity and clarity of the image.

[0087] The parameters of each lens in the optical system provided in Embodiment 1 are shown in Table 1. The surface numbered 1 in Table 1 is... Figure 3 The first object-side surface, that is, the object-side surface of the first lens 101, has surface number 2. Figure 3 The first image-side surface is the image-side surface of the first lens 101, and so on. If the object-side surface and image-side surface of two adjacent lenses are cemented together, the same number is used to represent the cemented object-side surface and image-side surface. For example, if the image-side surface of the first lens 101 is cemented together with the object-side surface of the second lens 102, then the number 2 represents both the image-side surface of the first lens 101 and the object-side surface of the second lens 102. "r" represents the radius of curvature of the lens surface, "d" represents the spacing between the lens surfaces on the optical axis, "nd" represents the refractive index for the d-line (wavelength λ = 587.6 nm), and "vd" represents the Abbe number for the d-line.

[0088] Table 1 Parameters of each lens

[0089]

[0090]

[0091] Table 2 shows the variable interval (D(i)) of the second lens group in both infinity focus and near-object distance focus states in Embodiment 1:

[0092] Table 2 Variable intervals of the second lens group

[0093]

[0094] Figure 4a This is a first schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 4b This is a second schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 4c This is a third schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 4d This is a fourth schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 4a The image shown is an aberration diagram of the field curvature of the second lens group in the infinity focusing state in Embodiment 1. Figure 4bThe image shown is an aberration diagram of the second lens group in the infinity focus state in Embodiment 1. Figure 4c The image shown is an aberration diagram of the field curvature of the second lens group in the close-object-distance focusing state in Embodiment 1. Figure 4d The image shown is an aberration diagram of the second lens group in Example 1 when it is in a close-object-distance focusing state.

[0095] Figure 5a This is a first schematic diagram of an MTF (Modulation Transfer Function) curve provided in an embodiment of the present invention. Figure 5b This is a second schematic diagram of the MTF curve provided in an embodiment of the present invention. Figure 5c This is a first schematic diagram of relative illumination provided for an embodiment of the present invention. Figure 5d This is a second schematic diagram of relative illumination provided for an embodiment of the present invention. Wherein, Figure 5a The MTF curve for the second lens group in Example 1 when it is in infinity focus. Figure 5a The MTF curve for the second lens group in Example 1 when it is in close-object-distance focusing mode is shown. Figure 5c This refers to the relative illumination of the second lens group in the infinity focus state in Example 1. Figure 5d This refers to the relative illumination of the second lens group in the near-object distance focusing state in Example 1.

[0096] II. Example 2

[0097] In Example 2, see Figure 6 , Figure 6 This is a fourth schematic diagram of the optical system structure provided in an embodiment of the present utility model. The first lens group 100 includes a first lens 101 and a second lens 102 arranged sequentially from the object side to the image side.

[0098] The image side of the first lens 101 is cemented to the object side of the second lens 102.

[0099] See also Figure 6 The first lens 101 is made of flat glass, and the second lens 102 is a plano-concave lens with a negative focal length. The focal length of the second lens 102 is between -40mm and -35mm. The side surfaces of the image formed by the first lens 101 are all flat.

[0100] In the above embodiments, the object-image sides of the first lens are all flat, and this is used as the first surface with a relatively large thickness. It is then cemented together with the second lens, reducing the difficulty of tolerance optimization and simplifying the assembly of the front group. The second lens is a plano-concave lens. Placing the plano-concave lens in the front group can converge light into the optical system, increasing the light transmission of the optical system.

[0101] In a possible implementation, still referring to Figure 6 , the second lens group 300 comprises an eighth lens 306, a ninth lens 307, a tenth lens 308, an eleventh lens 309, a twelfth lens 310, a thirteenth lens 311 and a fourteenth lens 312 which are sequentially arranged from an object side to an image side. In this embodiment, focusing of the second lens group 300 is achieved through the twelfth lens 310, the thirteenth lens 311 and the fourteenth lens 312.

[0102] The eighth lens 306 is a plano-concave lens, the focal length of the eighth lens 306 is positive, and the focal length f8 of the eighth lens 306 satisfies: 35mm<f8<40mm.

[0103] With application of the above embodiment, arranging the eighth lens behind an image rotating prism can improve pupil aberration, thereby improving imaging quality.

[0104] An image side surface of the ninth lens 307 is cemented with an object side surface of the tenth lens 308, the ninth lens 307 is a biconvex lens, the tenth lens 308 is a biconvex lens, the focal length of the ninth lens 307 is positive, the focal length of the tenth lens 308 is negative, and the focal length of the cemented lens formed by the ninth lens 307 and the tenth lens 308 is positive. The focal length f9 of the ninth lens 307 satisfies: 6mm<f9<6.5mm, and the focal length f of the tenth lens 308 10 satisfies: -7.5mm<f 10 <-7mm, and the focal length f of the cemented lens formed by the ninth lens 307 and the tenth lens 308 910 satisfies: 17mm<f 910 <19mm.

[0105] With application of the above embodiment, the cemented lens formed by the ninth lens and the tenth lens can enable light to refract more slowly, reduce the light angle, and lower the sensitivity of the lenses.

[0106] The eleventh lens 309 is a double meniscus lens, the focal length of the eleventh lens 309 is negative, and the focal length f of the eleventh lens 309 11 satisfies: -10mm<f 11 <-5mm.

[0107] With application of the above embodiment, the eleventh lens, which is a double meniscus lens with a negative focal length, can converge light and improve field curvature generated by an optical system, thereby improving imaging quality.

[0108] An image side surface of the twelfth lens 310 is cemented with an object side surface of the thirteenth lens 311, the twelfth lens 310 is a biconvex lens, the thirteenth lens 311 is a biconcave lens, the focal length of the twelfth lens 310 is positive, the focal length of the thirteenth lens 311 is negative, and the focal length of the cemented lens formed by the twelfth lens 310 and the thirteenth lens 311 is positive. The focal length f of the twelfth lens 31012 Meets the requirement of 7mm <f 12 <7.2mm, thirteenth lens, 311 focal length f 13 Meets the requirement of -7.2mm <f 13 <-7mm, the focal length f of the lens formed by the cementation of the twelfth lens 310 and the thirteenth lens 311 is... 123 Meets the requirement of 40mm <f 123 <43mm.

[0109] Using the above embodiments, the lens formed by cementing the twelfth and thirteenth lenses can correct astigmatism caused by the optical system, thereby improving image quality.

[0110] The fourteenth lens 312 is a biconvex lens, and its focal length is negative. The focal length f of the fourteenth lens 312 is... 14 Meets the requirement of 19mm <f 14 <20mm.

[0111] Using the above embodiments, the fourteenth lens, as the last lens in the optical system, can compensate for the remaining aberrations of the preceding lenses, thereby balancing the aberrations of the entire system and improving the imaging quality of the optical system.

[0112] The parameters of each lens in the optical system provided in Example 2 are shown in Table 3. The surface numbers in Table 3 are... Figure 6 The correspondence between the image side and object side of each lens and the parameters are described in the previous explanation of Table 1, and will not be repeated here.

[0113] Table 3 Parameters of each lens

[0114]

[0115]

[0116] Table 4 shows the variable interval (D(i)) of the second lens group in both the infinity focus state and the close-object-distance focus state in Embodiment 2:

[0117] Table 4 Variable Intervals of the Second Lens Group

[0118]

[0119] Figure 7a This is a fifth schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 7b This is a sixth schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 7c This is the seventh schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 7d This is the eighth schematic diagram of a longitudinal aberration map provided in an embodiment of the present invention. Figure 7a The image shown is an aberration diagram of the field curvature of the second lens group in the infinity focusing state in Embodiment 2. Figure 7b The image shown is an aberration diagram of the second lens group in the infinity focus state in Example 2. Figure 7c The image shown is an aberration diagram of the field curvature of the second lens group in the close-object-distance focusing state in Embodiment 2. Figure 7d The image shown is an aberration diagram of the second lens group in Example 2 when it is in a close-object-distance focusing state.

[0120] Figure 8a This is a third schematic diagram of the MTF curve provided in an embodiment of the present invention. Figure 8b This is a fourth schematic diagram of the MTF curve provided in an embodiment of the present invention. Figure 8c This is a third schematic diagram of relative illumination provided for an embodiment of the present invention. Figure 8d This is a fourth schematic diagram of relative illumination provided for an embodiment of the present invention. Wherein, Figure 8a This is the MTF curve of the second lens group in the infinity focus state in Example 2. Figure 8a This is the MTF curve of the second lens group in the close-object-distance focusing state in Example 2. Figure 8c This refers to the relative illumination of the second lens group in the infinity focus state in Example 2. Figure 8d This refers to the relative illumination of the second lens group in the near-object distance focusing state in Example 2.

[0121] Based on the aforementioned optical system, this invention also provides an endoscope adapter with a 90° image rotation, see [link to relevant documentation]. Figure 9 , Figure 9 This is a schematic diagram of the structure of an endoscope adapter provided in an embodiment of the present invention. The endoscope adapter includes a housing 2 and the aforementioned optical system 1.

[0122] The outer casing 2 includes a horizontal portion 21, a vertical portion 22, and a connecting portion 23. The included angle between the horizontal portion 21 and the vertical portion 22 is 90° to 100°, and the connecting portion 23 is used to connect the horizontal portion 21 and the vertical portion 22. Figure 9 The image only shows that the angle between the horizontal part 21 and the vertical part 22 is 90°.

[0123] The first lens group 100 in the optical system 1 is disposed inside the horizontal part 21, the second lens group 300 in the optical system 1 is disposed inside the vertical part 22, and the image-rotating prism 200 in the optical system 1 is disposed inside the connecting part 23.

[0124] Using the above embodiments, the endoscope adapter includes a housing and an optical system, realizing an image rotation function from 90° to 100°. The first lens group is disposed inside the horizontal part, the second lens group is disposed inside the vertical part, and the image rotation prism is disposed inside the connecting part. This reduces interference and loss of light during transmission, ensures stable propagation of light, thereby improving the quality of imaging and providing reliable visual evidence for medical diagnosis.

[0125] In one possible implementation, a gripping portion is provided on the outer side of the vertical portion 22.

[0126] By applying the above embodiments, compared with the traditional 0° bayonet lens, which has the problem of long distance between the doctor's hands and high operation difficulty in certain surgical scenarios (such as gynecological or urological stone surgery), the grip part is set on the outside of the vertical part. During the operation, the doctor can naturally place his hands on the grip part to achieve stable grip, reduce fatigue caused by holding the lens for a long time, and improve the efficiency of surgical operation.

[0127] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. An image-transfer optical system, characterized in that, The optical system includes: a first lens group, an image-rotating prism, and a second lens group arranged sequentially from the object side to the image side; The angle between the optical axis of the first lens group and the optical axis of the second lens group is equal to the turning angle of the light rays in the image-rotating prism, and the image-rotating prism is used to cause the light rays to deflect by 90° to 100° by folding the light rays. The focal length of the first lens group is negative; The second lens group can move along the optical axis of the second lens group; The entrance pupil diameter D of the optical system satisfies: 3mm <D<4mm; The maximum aperture F of the optical system satisfies: F≤7.5mm.

2. The optical system according to claim 1, characterized in that, The first lens group includes a first lens and a second lens arranged sequentially from the object side to the image side; The image-side surface of the first lens is bonded to the object-side surface of the second lens.

3. The optical system according to claim 2, characterized in that, The first lens is a biconcave lens, the second lens is a biconvex lens, the focal length of the first lens is negative, and the focal length of the second lens is positive.

4. The optical system according to claim 1, characterized in that, The second lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially from the object side to the image side; The image-side surface of the third lens is cemented to the object-side surface of the fourth lens; the focal length of the third lens is negative; the focal length of the fourth lens is positive; the refractive indices of the third lens and the fourth lens are different; the effective focal length of the lens formed by cementing the third lens and the fourth lens is negative. The focal length of the fifth lens is positive; The image-side surface of the sixth lens is cemented to the object-side surface of the seventh lens; the focal length of the sixth lens is positive; the focal length of the seventh lens is negative, and the focal length of the lens formed by cementing the sixth lens and the seventh lens is negative.

5. The optical system according to claim 4, characterized in that, The focal length f3 of the third lens satisfies: -13.0mm < f3 < -12.7mm, the focal length f4 of the fourth lens satisfies: 12.2mm < f4 < 14.2mm, the focal length f of the lens cemented by the third lens and the fourth lens 34 satisfies: -100.1mm < f 34 < -98.9mm, the focal length f5 of the fifth lens satisfies: 14.3mm < f5 < 15.6mm, the focal length f6 of the sixth lens satisfies: 7.1mm < f6 < 8.2mm, the focal length f7 of the seventh lens satisfies: -4.9mm < f7 < -4.2mm, the focal length f of the lens cemented by the sixth lens and the seventh lens 67 satisfies: -30.2mm < f 67 < -28.1mm.

6. The optical system according to claim 2, characterized in that, The first lens is a flat glass plate, the second lens is a plano-concave lens, and the focal length of the second lens is negative.

7. The optical system according to claim 1, characterized in that, The second lens group includes an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged sequentially from the object side to the image side; The eighth lens is a plano-concave lens, and the focal length of the eighth lens is positive; The image-side surface of the ninth lens is cemented to the object-side surface of the tenth lens; the ninth lens is a biconvex lens, the tenth lens is a biconvex lens, the focal length of the ninth lens is positive, and the focal length of the tenth lens is negative; the lens formed by cementing the ninth lens and the tenth lens has a positive focal length. The eleventh lens is a double meniscus lens, and the focal length of the eleventh lens is negative; The image-side surface of the twelfth lens is cemented to the object-side surface of the thirteenth lens; the twelfth lens is a biconvex lens, the thirteenth lens is a biconcave lens, the focal length of the twelfth lens is positive, and the focal length of the thirteenth lens is negative; the lens formed by cementing the twelfth and thirteenth lenses has a positive focal length. The fourteenth lens is a biconvex lens, and the focal length of the fourteenth lens is negative.

8. The optical system according to claim 7, characterized in that, The focal length f8 of the eighth lens satisfies: 35mm < f8 < 40mm, the focal length f9 of the ninth lens satisfies: 6mm < f9 < 6.5mm, the focal length f of the tenth lens 10 satisfies: -7.5mm < f 10 < -7mm, the focal length f of the lens cemented by the ninth lens and the tenth lens 910 satisfies: 17mm < f 910 < 19mm, the focal length f of the eleventh lens 11 satisfies: -10mm < f 11 < -5mm, the focal length f of the twelfth lens 12 satisfies: 7mm < f 12 < 7.2mm, the focal length f of the thirteenth lens 13 satisfies: -7.2mm < f 13 < -7mm, the focal length f of the lens cemented by the twelfth lens and the thirteenth lens 123 satisfies: 40mm < f 123 < 43mm, the focal length f of the fourteenth lens 14 satisfies: 19mm < f 14 < 20mm.

9. An image-converting endoscope adapter, characterized in that, The endoscope adapter includes a housing and an optical system as described in any one of claims 1-8; The outer casing includes a horizontal portion, a vertical portion, and a connecting portion. The angle between the horizontal portion and the vertical portion is 90° to 100°, and the connecting portion is used to connect the horizontal portion and the vertical portion. The first lens group in the optical system is disposed inside the horizontal part, the second lens group in the optical system is disposed inside the vertical part, and the image-rotating prism in the optical system is disposed inside the connecting part.

10. The endoscope adapter according to claim 9, characterized in that, A gripping part is provided on the outer side of the vertical part.

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