Optical system

Abstract

An optical system includes, in order from an object side to an image side along an optical axis, an objective optical module, an erecting lens optical module, and an eyepiece optical module. The objective optical module has positive refractive power. The erecting lens optical module has positive refractive power. The eyepiece optical module has positive refractive power. The objective optical module includes a first lens, a second lens, a third lens, and a fourth lens, the third lens and the fourth lens are cemented, or there is no air gap between the third lens and the fourth lens, and the combination of the third lens and the fourth lens has positive refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged in order from the object side to the image side along the optical axis.

Description

Technical Field

[0001] This invention relates to an optical system. Background Technology

[0002] The current development trend of optical systems used in sights is not only towards higher magnification, but also towards a larger field of view. Existing optical systems can no longer meet the current needs, and a new optical system architecture is needed to simultaneously meet the requirements of high magnification and a larger field of view. Summary of the Invention

[0003] In view of this, the main objective of the present invention is to provide an optical system comprising, sequentially from the object side to the image side along the optical axis, an objective lens optical module, an upright lens optical module, and an eyepiece optical module. The objective lens optical module, the upright lens optical module, and the eyepiece optical module all possess positive refractive power. The upright lens optical module includes a lens group movable along the optical axis to alter the magnification of the optical system, thus maintaining good optical performance even with high magnification, a large field of view, and a small displacement of 1 minute of angle (MOA).

[0004] The optical system of this invention includes an objective lens optical module, an upright lens optical module, and an eyepiece optical module. The objective lens optical module has positive refractive power. The upright lens optical module has positive refractive power. The eyepiece optical module has positive refractive power. The objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially along the optical axis from the object side to the image side. The objective lens optical module includes a first lens, a second lens, a third lens, and a fourth lens. The third lens and the fourth lens are cemented together, or there is no air gap between the third lens and the fourth lens. The combination of the third lens and the fourth lens has positive refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged sequentially along the optical axis from the object side to the image side.

[0005] The first lens has refractive power and includes a convex surface facing the image side; the second lens has refractive power and includes a concave surface facing the object side; the third lens has refractive power and includes a convex surface facing the object side; the fourth lens has refractive power; the upright lens optical module includes a first lens group, a second lens group, a third lens group, and a fourth lens group, wherein the second lens group and the third lens group are movable along the optical axis to change the magnification of the optical system; the first lens group has positive refractive power and includes a sixth lens, which is a meniscus lens with positive refractive power and includes a concave surface facing the object side and a convex surface facing the image side; the second lens group has positive refractive power; the third lens group has positive refractive power; the fourth lens group has negative refractive power; the first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side.

[0006] Another optical system of the present invention includes an objective lens optical module, an upright lens optical module, and an eyepiece optical module. The objective lens optical module has positive refractive power. The upright lens optical module has positive refractive power. The eyepiece optical module has positive refractive power. The objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially along the optical axis from the object side to the image side. The upright lens optical module includes a first lens group, a second lens group, a third lens group, and a fourth lens group. The second and third lens groups are movable along the optical axis to change the magnification of the optical system. The first lens group has positive refractive power and includes a sixth lens, which is a meniscus lens with positive refractive power and includes a concave surface facing the object side and a convex surface facing the image side. The second lens group has positive refractive power. The third lens group has positive refractive power. The fourth lens group has negative refractive power. The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side.

[0007] The objective lens optical module includes a first lens, a second lens, a third lens, and a fourth lens. The third lens and the fourth lens are cemented together, and there is no air gap between the third lens and the fourth lens. The combination of the third lens and the fourth lens has positive refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged sequentially along the optical axis from the object side to the image side.

[0008] The first lens has refractive power and includes a convex surface facing the image side; the second lens has refractive power and includes a concave surface facing the object side; the third lens has refractive power and includes a convex surface facing the object side; and the fourth lens has refractive power.

[0009] The second lens group includes a seventh lens and an eighth lens; the third lens group includes a ninth lens and a tenth lens; and the fourth lens group includes an eleventh lens, a twelfth lens, and a thirteenth lens.

[0010] The seventh and eighth lenses are cemented together, and there is no air gap between them. The seventh and eighth lenses can move along the optical axis to change the magnification of the optical system; the ninth and tenth lenses are cemented together, and there is no air gap between them. The ninth and tenth lenses can move along the optical axis to change the magnification of the optical system; and the eleventh and twelfth lenses are cemented together, and there is no air gap between them.

[0011] The seventh lens is a meniscus lens with positive refractive power, and includes a concave surface facing the object side and a convex surface facing the image side; the eighth lens is a meniscus lens with negative refractive power, and includes a concave surface facing the object side and a convex surface facing the image side; the ninth lens is a meniscus lens with negative refractive power, and includes a convex surface facing the object side and a concave surface facing the image side; the tenth lens is a biconvex lens with positive refractive power, and includes a convex surface facing the object side and another convex surface facing the image side; the eleventh lens is a biconcave lens with negative refractive power, and includes a concave surface facing the object side and another concave surface facing the image side; the twelfth lens is a meniscus lens with positive refractive power, and includes a convex surface facing the object side and a concave surface facing the image side; and the thirteenth lens is a meniscus lens with negative refractive power, and includes a concave surface facing the object side and a convex surface facing the image side.

[0012] The first lens is a biconvex lens with positive refractive power, and may further include another convex surface facing the object side; the second lens is a meniscus lens with negative refractive power, and may further include a convex surface facing the image side; the third lens is a biconvex lens with positive refractive power, and may further include another convex surface facing the image side; the fourth lens is a biconcave lens with negative refractive power, and includes a concave surface facing the object side and another concave surface facing the image side; the first lens and the second lens are cemented together, and there is no air gap between the first lens and the second lens; the combination of the first lens and the second lens has positive refractive power; the objective lens optical module may further include a fifth lens and a prism, the fifth lens being disposed between the second lens and the third lens, the fifth lens being a meniscus lens with positive refractive power, and including a convex surface facing the object side and a concave surface facing the image side; the prism being disposed between the fourth lens and the object side. The first lens group, consisting of the first lens, the second lens, the fifth lens, the third lens, the fourth lens, and the prism, is arranged sequentially along the optical axis from the object side to the image side; the eyepiece optical module includes the fourteenth lens, the fifteenth lens, and the sixteenth lens; the fourteenth lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; the fifteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; the sixteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; the fourteenth and fifteenth lenses are cemented together, and there is no air gap between the fourteenth and fifteenth lenses; the combination of the fourteenth and fifteenth lenses has positive refractive power; and the optical system satisfies at least one of the following conditions: 9 ≤ fCEEL / fCEEH ≤ 12; -0.01 mm ≤ fCEEH × tan(1° / 60) < 0 mm; 1 ≤∣fOBJ123 / fOBJ∣≤ 2; 10 ≤ VdEL2 / NdEL2 < VdEL1 / NdEL1 ≤ 45; 85% ≤ OD2 / OD3 ≤95%; 68% ≤ OD3 / OD1 ≤ 75%; 10 ≤ OD1 / ∣OD2-OD3∣≤ 30; 6 ≤ OD2 / (OD4-OD3) ≤15; where fCEEL is the combined effective focal length of the combination of the upright lens optical module and the eyepiece optical module at low magnification, fCEEH is the combined effective focal length of the combination of the upright lens optical module and the eyepiece optical module at high magnification, fOBJ is the effective focal length of the objective lens optical module, fOBJ123 is the combined effective focal length of the combination of the lens closest to the object side, the second lens closest to the object side, and the third lens closest to the object side in the objective lens optical module, and VdEL1 is the effective focal length of the second lens closest to the object side in the upright lens optical module. The Abbe coefficients of the lenses on the objective lens side are given by NdEL1, the refractive index of the second lens closest to the object side in the upright lens optical module, VdEL2, OD2, OD3, OD4, and OD4. OD2 represents the minimum effective optical diameter in the objective lens optical module, OD3 represents the effective optical diameter of the object-side surface of the sixth lens, OD1 represents the effective optical diameter of the object-side surface of the lens closest to the object side in the objective lens optical module, and OD4 represents the effective optical diameter of the image-side surface of the sixth lens.

[0013] The first lens is a biconvex lens with positive refractive power, and may further include another convex surface facing the object side; the second lens is a biconcave lens with negative refractive power, and may further include another concave surface facing the image side; the third lens is a meniscus lens with negative refractive power, and may further include a concave surface facing the image side; the fourth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; the first lens and the second lens are cemented together, and there is no air gap between the first lens and the second lens; the combination of the first lens and the second lens has negative refractive power; the objective lens optical module may further include a fifth lens and a prism, the fifth lens being disposed between the object side and the first lens, the fifth lens being a biconvex lens with positive refractive power, and including one convex surface facing the object side and another convex surface facing the image side; the prism being disposed between the fourth lens and the first lens. The optical system comprises a group of lenses; the fifth lens, the first lens, the second lens, the third lens, the fourth lens, and the prism are arranged sequentially along the optical axis from the object side to the image side; the eyepiece optical module includes a fourteenth lens, a fifteenth lens, and a sixteenth lens; the fourteenth lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; the fifteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; the sixteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; the fourteenth lens and the fifteenth lens are cemented together, and there is no air gap between the fourteenth lens and the fifteenth lens; the combination of the fourteenth lens and the fifteenth lens has positive refractive power; and the optical system satisfies at least one of the following conditions: 9 ≤ fCEEL / fCEEH ≤ 12; -0.01 mm ≤ fCEEH × tan(1° / 60) < 0 mm; 1 ≤∣fOBJ123 / fOBJ∣≤ 2; 10 ≤ VdEL2 / NdEL2 < VdEL1 / NdEL1 ≤ 45; 85% ≤ OD2 / OD3 ≤95%; 68% ≤ OD3 / OD1 ≤ 75%; 10 ≤ OD1 / ∣OD2-OD3∣≤ 30; 6 ≤ OD2 / (OD4-OD3) ≤15; where fCEEL is the combined effective focal length of the combination of the upright lens optical module and the eyepiece optical module at low magnification, fCEEH is the combined effective focal length of the combination of the upright lens optical module and the eyepiece optical module at high magnification, fOBJ is the effective focal length of the objective lens optical module, fOBJ123 is the combined effective focal length of the combination of the lens closest to the object side, the second lens closest to the object side, and the third lens closest to the object side in the objective lens optical module, and VdEL1 is the effective focal length of the second lens closest to the object side in the upright lens optical module. The Abbe coefficients of the lenses on the objective lens side are given by NdEL1, the refractive index of the second lens closest to the object side in the upright lens optical module, VdEL2, OD2, OD3, OD4, and OD4. OD2 represents the minimum effective optical diameter in the objective lens optical module, OD3 represents the effective optical diameter of the object-side surface of the sixth lens, OD1 represents the effective optical diameter of the object-side surface of the lens closest to the object side in the objective lens optical module, and OD4 represents the effective optical diameter of the image-side surface of the sixth lens.

[0014] The optical system of the present invention still has good optical performance even with high magnification, large field of view, and small displacement of 1 minute of angle (MOA). Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the lens configuration at low magnification and high magnification according to the first embodiment of the optical system of the present invention.

[0016] Figure 2 This is a schematic diagram of the lens configuration at low and high magnification according to a second embodiment of the optical system of the present invention.

[0017] Figure 3 This is a schematic diagram of the lens configuration at high magnification of a sight manufactured according to a first embodiment of the optical system of the present invention. Detailed Implementation

[0018] This invention provides an optical system comprising, sequentially from the object side to the image side along the optical axis, an objective lens optical module, an upright lens optical module, and an eyepiece optical module. All three modules possess positive refractive power. The upright lens optical module includes a lens array movable along the optical axis, allowing the optical system to change its magnification. Thus, even with high magnification, a large field of view, and a small displacement of 1 minute of angle (MOA), good optical performance is still maintained.

[0019] The present invention provides another optical system comprising: an objective lens optical module having positive refractive power; an upright lens optical module having positive refractive power; and an eyepiece optical module having positive refractive power; wherein the objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially from the object side to the image side along the optical axis; wherein the objective lens optical module includes a first lens, a second lens, a third lens, and a fourth lens, the third lens and the fourth lens being cemented together, or the third lens and the fourth lens not having an air gap between them, and the combination of the third lens and the fourth lens having positive refractive power; wherein the first lens, the second lens, the third lens, and the fourth lens are arranged sequentially from the object side to the image side along the optical axis.

[0020] This invention provides another optical system, comprising: an objective lens optical module having positive refractive power; an upright lens optical module having positive refractive power; and an eyepiece optical module having positive refractive power; wherein the objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially along the optical axis from the object side to the image side; wherein the upright lens optical module includes a first lens group, a second lens group, a third lens group, and a fourth lens group, wherein the second lens group and the first lens group are connected in series. The three lens groups can be moved along the optical axis to change the magnification of the optical system. The first lens group has positive refractive power and includes a sixth lens, which is a meniscus lens with positive refractive power and includes a concave surface facing the object side and a convex surface facing the image side. The second lens group has positive refractive power. The third lens group has positive refractive power. The fourth lens group has negative refractive power. The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side.

[0021] Please refer to Tables 1 and 3 below, which are parameter tables for each lens according to the first to second embodiments of the optical system of the present invention. The terms "first," "second," "third," "fourth," "fifth," "sixth," etc., used in the embodiments are only for distinguishing components and are not for ordering or limiting the number of components.

[0022] Figure 1 , Figure 2 These are schematic diagrams of lens configurations at low and high magnifications for the first and second embodiments of the optical system according to the present invention. The objective lens optical modules LGOBJ1 and LGOBJ2 have positive refractive power and respectively include first lenses L11 and L21, second lenses L12 and L22, third lenses L13 and L23, fourth lenses L14 and L24, fifth lenses L15 and L25, and prisms P1 and P2. The upright lens optical modules LGEL1 and LGEL2 have positive refractive power and respectively include first lens groups LG11 and LG21, second lens groups LG12 and LG22, third lens groups LG13 and LG23, and fourth lens groups LG14 and LG24. The first lens groups LG11 and LG21 have positive refractive power and respectively include sixth lenses L16 and L26. The second lens groups LG12 and LG22 have positive refractive power and respectively include seventh lenses L17 and L27 and eighth lenses L18 and L28. The third lens groups LG13 and LG23 have positive refractive power, and include the ninth lenses L19 and L29, and the tenth lenses L110 and L210, respectively. The fourth lens groups LG14 and LG24 have negative refractive power, and include the eleventh lenses L111 and L211, the twelfth lenses L112 and L212, and the thirteenth lenses L113 and L213, respectively. The eyepiece optical modules LGEYE1 and LGEYE2 have positive refractive power, and include the fourteenth lenses L114 and L214, the fifteenth lenses L115 and L215, and the sixteenth lenses L116 and L216, respectively.

[0023] The first lenses, L11 and L21, are biconvex lenses with positive refractive power, made of glass. Their object-side surfaces S11 and S23 are convex, and their image-side surfaces S12 and S24 are convex. Both object-side surfaces S11 and S23 and image-side surfaces S12 and S24 are spherical surfaces. The second lenses, L12 and L22, have negative refractive power, made of glass. Their object-side surfaces S12 and S24 are concave, and both object-side surfaces S12 and S24 and image-side surfaces S13 and S25 are spherical surfaces. The first lenses L11 and L21 are cemented together with the second lenses L12 and L22, and there is no air gap between them. The third lens, L13 and L23, has refractive power, made of glass. Its object-side surfaces S16 and S26 are convex, and both object-side surfaces S16 and S26 and image-side surfaces S17 and S27 are spherical surfaces. The fourth lenses L14 and L24 have refractive power and are made of glass. Their object-side surfaces S17 and S27, and image-side surfaces S18 and S28, are all spherical surfaces. The third lenses L13 and L23 are cemented together with the fourth lenses L14 and L24. There is no air gap between the third lenses L13 and L23 and the fourth lenses L14 and L24. The combination of the third lenses L13 and L23 and the fourth lenses L14 and L24 has positive refractive power. The fifth lenses L15 and L25 have positive refractive power and are made of glass. Their object-side surfaces S14 and S21 are convex, and their image-side surfaces S15 and S22 are all spherical surfaces. Prisms P1 and P2 are made of glass. Their object-side surfaces S19 and S29 are flat, and their image-side surfaces S110 and S210 are flat. Lenses L16 and L26 are meniscus lenses with positive refractive power, made of glass. Their object-side surfaces S111 and S211 are concave, and their image-side surfaces S112 and S212 are convex. Both object-side surfaces S111 and S211 and their image-side surfaces S112 and S212 are spherical surfaces. Lenses L17 and L27 are meniscus lenses with positive refractive power, made of glass. Their object-side surfaces S113 and S213 are concave, and their image-side surfaces S114 and S214 are convex. Both object-side surfaces S113 and S213 and their image-side surfaces S114 and S214 are spherical surfaces. The eighth lenses, L18 and L28, are meniscus lenses with negative refractive power, made of glass. Their object-side surfaces S114 and S214 are concave, and their image-side surfaces S115 and S215 are convex. Both object-side surfaces S114 and S214 and image-side surfaces S115 and S215 are spherical surfaces. The seventh lenses, L17 and L27, are cemented together with the eighth lenses, L18 and L28. There is no air gap between the seventh lenses, L17 and L27 and the eighth lenses, L18 and L28. The combination of the seventh lenses, L17 and L27 and the eighth lenses, L18 and L28, has positive refractive power.Lenses L19 and L29 are meniscus lenses with negative refractive power, made of glass. Their object-side surfaces S116 and S216 are convex, and their image-side surfaces S117 and S217 are concave. Both object-side surfaces S116 and S216 and their image-side surfaces S117 and S217 are spherical surfaces. Lenses L110 and L210 are biconvex lenses with positive refractive power, made of glass. Their object-side surfaces S117 and S217 are convex, and their image-side surfaces S118 and S218 are convex. Both object-side surfaces S117 and S217 and their image-side surfaces S118 and S218 are spherical surfaces. The ninth lenses L19 and L29 are cemented together with the tenth lenses L110 and L210. There is no air gap between the ninth lenses L19 and L29 and the tenth lenses L110 and L210. The combination of the ninth lenses L19 and L29 and the tenth lenses L110 and L210 has positive refractive power. The eleventh lenses L111 and L211 are biconcave lenses with negative refractive power. They are made of glass, and their object-side surfaces S119 and S219 are concave, as are their image-side surfaces S120 and S220. Both the object-side surfaces S119 and S219 and the image-side surfaces S120 and S220 are spherical surfaces. The twelfth lenses, L112 and L212, are meniscus lenses with positive refractive power. They are made of glass, with convex object-side surfaces S120 and S220, and concave image-side surfaces S121 and S221. Both object-side surfaces S120 and S220 and image-side surfaces S121 and S221 are spherical surfaces. The eleventh lenses, L111 and L211, are cemented together with the twelfth lenses, L112 and L212. There is no air gap between the eleventh lenses, L111 and L211, and the combination of the eleventh lenses, L111 and L211, and the twelfth lenses, L112 and L212, has negative refractive power. Lenses L113 and L213 are meniscus lenses with negative refractive power, made of glass. Their object-side surfaces S122 and S222 are concave, and their image-side surfaces S123 and S223 are convex. Both object-side surfaces S122 and S222 and their image-side surfaces S123 and S223 are spherical surfaces. Lenses L114 and L214 are biconcave lenses with negative refractive power, made of glass. Their object-side surfaces S125 and S225 are concave, and their image-side surfaces S126 and S226 are concave. Both object-side surfaces S125 and S225 and their image-side surfaces S126 and S226 are spherical surfaces. The fifteenth lenses, L115 and L215, are biconvex lenses with positive refractive power. They are made of glass, with the object-side surfaces S126 and S226 being convex and the image-side surfaces S127 and S227 being convex. Both the object-side surfaces S126 and S226 and the image-side surfaces S127 and S227 are spherical surfaces.The fourteenth lenses L114 and L214 are cemented together with the fifteenth lenses L115 and L215, without any air gap between them. This combination of lenses has positive refractive power. The sixteenth lenses L116 and L216 are biconvex lenses with positive refractive power, made of glass. Their object-side surfaces S128 and S228 are convex, and their image-side surfaces S129 and S229 are convex. Both object-side surfaces S128 and S228 and image-side surfaces S129 and S229 are spherical surfaces. Figure 3 This is a schematic diagram of the lens configuration at high magnification for a sight manufactured according to a first embodiment of the optical system of the present invention. The sight 3 includes a tube ST and an optical system 1. The optical system 1 is disposed inside the tube ST, and from the object side to the image side, it sequentially includes an objective lens optical module LGOBJ1, an upright lens optical module LGEL1, and an eyepiece optical module LGEYE1. The objective lens optical module LGOBJ1, from the object side to the image side, sequentially includes a first lens L11, a second lens L12, a fifth lens L15, a third lens L13, a fourth lens L14, and a prism P1. The upright lens optical module LGEL1, from the object side to the image side, sequentially includes a first lens group LG11, a second lens group LG12, a third lens group LG13, and a fourth lens group LG14. The first lens group LG11 includes a sixth lens L16, which can also be considered a light-gathering lens. The second lens group LG12, from the object side to the image side, sequentially includes a seventh lens L17 and an eighth lens L18. The third lens group LG13, from the object side to the image side, includes the ninth lens L19 and the tenth lens L110. The fourth lens group LG14, from the object side to the image side, includes the eleventh lens L111, the twelfth lens L112, and the thirteenth lens L113. The eyepiece optical module LGEYE1, from the object side to the image side, includes the fourteenth lens L114, the fifteenth lens L115, and the sixteenth lens L116. Wherein, OD1 is the effective optical diameter of the object side of the lens L11 closest to the object side in the objective lens optical module LGOBJ1, OD2 is the minimum effective optical diameter in the objective lens optical module LGOBJ1, OD3 is the effective optical diameter of the object side of the sixth lens (light-collecting lens) L16, and OD4 is the effective optical diameter of the image side of the sixth lens (light-collecting lens) L16. The aforementioned effective optical diameters OD1, OD2, OD3, and OD4 are limited by the inner diameter of the tube ST. For example, the inner diameter of the tube ST between the object side S11 (the object side of the lens L11 closest to the object side) and the object side is not a fixed value, but has different sizes. In this case, according to the characteristics of light propagation, the effective optical diameter OD1 will be equivalent to the minimum inner diameter of the tube ST between the object side S11 and the object side.

[0024] In addition, optical systems 1 and 2 satisfy at least one of the following conditions:

[0025] 9 ≤ fCEEL / fCEEH ≤ 12; (1)

[0026] -0.01 mm ≤ fCEEH × tan(1° / 60) < 0 mm; (2)

[0027] 1 ≤ |fOBJ123 / fOBJ|≤ 2;(3)

[0028] 10 ≤ VdEL2 / NdEL2 < VdEL1 / NdEL1 ≤ 45; (4)

[0029] 85% ≤ OD2 / OD3 ≤ 95%; (5)

[0030] 68% ≤ OD3 / OD1 ≤ 75%; (6)

[0031] 10 ≤ OD1 / ∣OD2-OD3∣≤ 30; (7)

[0032] 6 ≤ OD2 / (OD4-OD3) ≤ 15; (8)

[0033] Wherein, fCEEL is the combined effective focal length of the combination of upright lens optical modules LGEL1, LGEL2 and eyepiece optical modules LGEYE1, LGEYE2 in the first and second embodiments when the optical systems 1 and 2 are at low magnification; fCEEH is the combined effective focal length of the combination of upright lens optical modules LGEL1, LGEL2 and eyepiece optical modules LGEYE1, LGEYE2 in the first and second embodiments when the optical systems 1 and 2 are at high magnification; fOBJ is the effective focal length of the objective lens optical modules LGOBJ1, LGOBJ2 in the first and second embodiments; and fOBJ123 is the effective focal length of the objective lens optical modules LGOBJ1, LGOBJ2 in the first and second embodiments. In the optical modules LGOBJ1 and LGOBJ2, the combined effective focal length of the lenses L11 and L25 closest to the object side, the second lenses L12 and L21 closest to the object side, and the third lenses L15 and L22 closest to the object side are: VdEL1 is the Abbe coefficient of the second lenses L17 and L27 closest to the object side in the upright optical modules LGEL1 and LGEL2 in the first and second embodiments; NdEL1 is the refractive index of the second lenses L17 and L27 closest to the object side in the upright optical modules LGEL1 and LGEL2 in the first and second embodiments; and VdEL2 is the refractive index of the upright optical modules LGEL1 and LGOBJ2 in the first and second embodiments. In EL2, the Abbe coefficients of the third lenses L18 and L28 closest to the object side are NdEL2. In the first and second embodiments, LGEL1 and LGEL2 are the refractive indices of the third lenses L18 and L28 closest to the object side. OD2 is the minimum effective optical diameter in the objective lens modules LGOBJ1 and LGOBJ2 in the first and second embodiments. OD3 is the effective optical diameter of the object-side surfaces S111 and S211 of the sixth lenses (light-collecting lenses) L16 and L26 in the first and second embodiments. OD1 is the lens L closest to the object side in the objective lens modules LGOBJ1 and LGOBJ2 in the first and second embodiments. 11. The effective optical diameters of the object-side surfaces S11 and S21 of L25, OD4 is the effective optical diameter of the image-side surfaces S112 and S212 of the sixth lens (light-collecting lens) L16 and L26 in the first to second embodiments. The aforementioned effective optical diameters OD1, OD2, OD3, and OD4 are limited by the inner diameter of the tube ST. For example, the inner diameter of the tube ST between the object-side surfaces S11 and S21 of the lens L11 and L25 closest to the object side is not a fixed value, but has different sizes. At this time, according to the characteristics of light propagation, the effective optical diameter OD1 will be equivalent to the minimum inner diameter of the tube ST between the object-side surfaces S11 and S21 and the object side.This enables optical systems 1 and 2 to effectively increase the field of view, effectively reduce the displacement by 1 minute of angle (MOA), effectively correct aberrations, and effectively correct chromatic aberration.

[0034] The first embodiment of the optical system of the present invention will now be described in detail. Please refer to... Figure 1 , Figure 1This is a schematic diagram of the lens configuration at low and high magnification according to a first embodiment of the optical system of the present invention. The optical system 1, along the optical axis OA1 from the object side to the image side, sequentially includes an objective lens optical module LGOBJ1, an upright lens optical module LGEL1, and an eyepiece optical module LGEYE1. The objective lens optical module LGOBJ1, along the optical axis OA1 from the object side to the image side, sequentially includes a first lens L11, a second lens L12, a fifth lens L15, a third lens L13, a fourth lens L14, and a prism P1. The upright lens optical module LGEL1, along the optical axis OA1 from the object side to the image side, sequentially includes a first lens group LG11, a second lens group LG12, a third lens group LG13, and a fourth lens group LG14. The first lens group LG11 includes a sixth lens L16. The second lens group LG12 includes a seventh lens L17 and an eighth lens L18. The third lens group LG13 includes a ninth lens L19 and a tenth lens L110. The fourth lens group LG14 includes the eleventh lens L111, the twelfth lens L112, and the thirteenth lens L113. The eyepiece optical module LGEYE1 includes, along the optical axis OA1 from the object side to the image side, the fourteenth lens L114, the fifteenth lens L115, and the sixteenth lens L116. The first lens L11, the second lens L12, the fifth lens L15, the third lens L13, the fourth lens L14, the prism P1, the sixth lens L16, the seventh lens L17, the eighth lens L18, the ninth lens L19, the tenth lens L110, the eleventh lens L111, the twelfth lens L112, the thirteenth lens L113, the fourteenth lens L114, the fifteenth lens L115, and the sixteenth lens L116 are arranged along the optical axis OA1 from the object side to the image side. The seventh lens L17, the eighth lens L18, the ninth lens L19, and the tenth lens L110 can move along the optical axis OA1 to change the spacing between the sixth lens L16 and the seventh lens L17, the eighth lens L18 and the ninth lens L19, and the tenth lens L110 and the eleventh lens L111, thereby changing the magnification of the optical system 1. The optical system 1 of the first embodiment has a maximum magnification of 10 times, that is, a minimum magnification of 1 times and a maximum magnification of 10 times. During imaging, light from the object side first passes through the objective lens optical module LGOBJ1, forming an inverted image on the first imaging surface (not shown in the figure), then passes through the upright lens optical module LGEL1, forming an upright image on the second imaging surface S124, and finally passes through the eyepiece optical module LGEYE1 for human eye to view the image. In other words, the distinction between the objective lens optical module LGOBJ1 and the upright lens optical module LGEL1 is based on the first imaging surface, while the distinction between the upright lens optical module LGEL1 and the eyepiece optical module LGEYE1 is based on the second imaging surface S124.According to paragraphs 1 to 6 of the [Specific Implementation], wherein: the second lens L12 is a meniscus lens with its image-side surface S13 being convex; the combination of the first lens L11 and the second lens L12 has positive refractive power; the fifth lens L15 is a meniscus lens with its image-side surface S15 being concave; the third lens L13 is a biconvex lens with positive refractive power with its image-side surface S17 being convex; the fourth lens L14 is a biconcave lens with negative refractive power with its object-side surface S17 being concave and its image-side surface S18 being concave; by utilizing the above-mentioned objective lens optical module LGOBJ1, upright lens optical module LGEL1, eyepiece optical module LGEYE1 and at least satisfying one of the conditions (1) to (8), the optical system 1 can effectively increase the field of view, effectively reduce the displacement of 1 minute of angle (MOA), effectively correct aberrations, and effectively correct chromatic aberrations.

[0035] Table 1 is... Figure 1 Table of relevant parameters for each lens in optical system 1.

[0036]

[0037] Table 2 shows the relevant parameter values ​​of the optical system 1 in the first embodiment and the calculated values ​​of the corresponding conditions (1) to (8). As can be seen from Table 2, the optical system 1 in the first embodiment can meet the requirements of conditions (1) to (8).

[0038]

[0039] The second embodiment of the optical system of the present invention will now be described in detail. Please refer to [link to relevant documentation]. Figure 2 , Figure 2This is a schematic diagram of the lens configuration at low and high magnification according to a second embodiment of the optical system of the present invention. The optical system 2, along the optical axis OA2 from the object side to the image side, sequentially includes an objective lens optical module LGOBJ2, an upright lens optical module LGEL2, and an eyepiece optical module LGEYE2. The objective lens optical module LGOBJ2, along the optical axis OA2 from the object side to the image side, sequentially includes a fifth lens L25, a first lens L21, a second lens L22, a third lens L23, a fourth lens L24, and a prism P2. The upright lens optical module LGEL2, along the optical axis OA2 from the object side to the image side, sequentially includes a first lens group LG21, a second lens group LG22, a third lens group LG23, and a fourth lens group LG24. The first lens group LG21 includes a sixth lens L26. The second lens group LG22 includes a seventh lens L27 and an eighth lens L28. The third lens group LG23 includes a ninth lens L29 and a tenth lens L210. The fourth lens group LG24 includes the eleventh lens L211, the twelfth lens L212, and the thirteenth lens L213. The eyepiece optical module LGEYE2 includes, along the optical axis OA2 from the object side to the image side, the fourteenth lens L214, the fifteenth lens L215, and the sixteenth lens L216. The fifth lens L25, the first lens L21, the second lens L22, the third lens L23, the fourth lens L24, the prism P2, the sixth lens L26, the seventh lens L27, the eighth lens L28, the ninth lens L29, the tenth lens L210, the eleventh lens L211, the twelfth lens L212, the thirteenth lens L213, the fourteenth lens L214, the fifteenth lens L215, and the sixteenth lens L216 are arranged along the optical axis OA2 from the object side to the image side. The seventh lens L27, the eighth lens L28, the ninth lens L29, and the tenth lens L210 can move along the optical axis OA2 to change the spacing between the sixth lens L26 and the seventh lens L27, the eighth lens L28 and the ninth lens L29, and the tenth lens L210 and the eleventh lens L211, thereby changing the magnification of the optical system 2. The optical system 2 of the second embodiment has a maximum magnification of 10 times, that is, a minimum magnification of 1 times and a maximum magnification of 10 times. During imaging, light rays from the object side first pass through the objective lens optical module LGOBJ2, forming an inverted image on the first imaging plane (not shown in the figure), then pass through the upright lens optical module LGEL2, forming an upright image on the second imaging plane S224, and finally pass through the eyepiece optical module LGEYE2 for human eye to view the image. In other words, the distinction between the objective lens optical module LGOBJ2 and the upright lens optical module LGEL2 is based on the first imaging plane, while the distinction between the upright lens optical module LGEL2 and the eyepiece optical module LGEYE2 is based on the second imaging plane S224.According to paragraphs 1 to 6 of the [Specific Implementation], wherein: the second lens L22 is a biconcave lens with its image-side surface S25 being convex; the combination of the first lens L21 and the second lens L22 has negative refractive power; the fifth lens L25 is a biconvex lens with its image-side surface S22 being convex; the third lens L23 is a meniscus lens with negative refractive power with its image-side surface S27 being concave; the fourth lens L24 is a biconvex lens with positive refractive power with its object-side surface S27 being convex and its image-side surface S28 being convex; by utilizing the above-mentioned objective lens optical module LGOBJ2, upright lens optical module LGEL2, eyepiece optical module LGEYE2 and at least satisfying one of the conditions (1) to (8), the optical system 2 can effectively increase the field of view, effectively reduce the displacement of 1 minute of angle (MOA), effectively correct aberrations, and effectively correct chromatic aberrations.

[0040] Table 3 is... Figure 2 Table of relevant parameters for each lens in optical system 2.

[0041]

[0042] Table 4 shows the relevant parameter values ​​of the optical system 2 in the second embodiment and the calculated values ​​of the corresponding conditions (1) to (8). As can be seen from Table 4, the optical system 2 in the second embodiment can meet the requirements of conditions (1) to (8).

[0043]

[0044] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. An optical system, characterized in that, include: An objective lens optical module that has positive refractive power; An upright optical module, which has positive refractive power; as well as An eyepiece optical module that has positive refractive power; The objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially from the object side to the image side along the optical axis; The objective lens optical module includes a first lens, a second lens, a third lens, and a fourth lens. The third lens and the fourth lens are cemented together, or there is no air gap between the third lens and the fourth lens. The combination of the third lens and the fourth lens has positive refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged sequentially along the optical axis from the object side to the image side.

2. The optical system as described in claim 1, characterized in that: The first lens has refractive power and includes a convex surface facing the image side; The second lens has refractive power and includes a concave surface facing the object side; The third lens has refractive power and includes a convex surface facing the object side; This fourth lens has refractive power; The upright lens optical module includes a first lens group, a second lens group, a third lens group, and a fourth lens group. The second and third lens groups can be moved along the optical axis to change the magnification of the optical system. The first lens group has positive refractive power and includes a sixth lens. The sixth lens is a meniscus lens with positive refractive power and includes a concave surface facing the object side and a convex surface facing the image side. This second lens group has positive refractive power; This third lens group has positive refractive power; This fourth lens group has negative refractive power; The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side.

3. An optical system, characterized in that, include: An objective lens optical module that has positive refractive power; An upright mirror optical module, which has positive refractive power; as well as An eyepiece optical module that has positive refractive power; The objective lens optical module, the upright lens optical module, and the eyepiece optical module are arranged sequentially from the object side to the image side along the optical axis; The upright lens optical module includes a first lens group, a second lens group, a third lens group, and a fourth lens group. The second and third lens groups can move along the optical axis to change the magnification of the optical system. The first lens group has positive refractive power and includes a sixth lens. The sixth lens is a meniscus lens with positive refractive power and includes a concave surface facing the object side and a convex surface facing the image side. This second lens group has positive refractive power; This third lens group has positive refractive power; This fourth lens group has negative refractive power; The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side.

4. The optical system as described in claim 3, characterized in that... : The objective lens optical module includes a first lens, a second lens, a third lens, and a fourth lens. The third lens and the fourth lens are cemented together, and there is no air gap between them. The combination of the third lens and the fourth lens has positive refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged sequentially along the optical axis from the object side to the image side.

5. The optical system as described in claim 4, characterized in that: The first lens has refractive power and includes a convex surface facing the image side; The second lens has refractive power and includes a concave surface facing the object side; The third lens has refractive power and includes a convex surface facing the object side; and The fourth lens has refractive power.

6. The optical system as described in claim 2 or 5, characterized in that: The second lens group includes a seventh lens and an eighth lens; This third lens group includes the ninth lens and the tenth lens; The fourth lens group includes the eleventh lens, the twelfth lens, and the thirteenth lens.

7. The optical system as claimed in claim 6, characterized in that: The seventh lens and the eighth lens are cemented together, and there is no air gap between the seventh lens and the eighth lens. The seventh lens and the eighth lens can move along the optical axis to change the magnification of the optical system. The ninth lens and the tenth lens are cemented together, and there is no air gap between the ninth lens and the tenth lens. The ninth lens and the tenth lens can move along the optical axis to change the magnification of the optical system. as well as The eleventh lens and the twelfth lens are cemented together, and there is no air gap between the eleventh lens and the twelfth lens.

8. The optical system as claimed in claim 7, characterized in that: The seventh lens is a meniscus lens with positive refractive power, and includes a concave surface facing the object side and a convex surface facing the image side; The eighth lens is a meniscus lens with negative refractive power, and includes a concave surface facing the object side and a convex surface facing the image side; The ninth lens is a meniscus lens with negative refractive power, and includes a convex surface facing the object side and a concave surface facing the image side; The tenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The eleventh lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; The twelfth lens is a meniscus lens with positive refractive power, and includes a convex surface facing the object side and a concave surface facing the image side; and The thirteenth lens is a meniscus lens with negative refractive power, and includes a concave surface facing the object side and a convex surface facing the image side.

9. The optical system as claimed in claim 8, characterized in that: The first lens is a biconvex lens with positive refractive power, and further includes another convex surface facing the object side; The second lens is a meniscus lens with negative refractive power, and further includes a convex surface facing the image side; The third lens is a biconvex lens with positive refractive power, and further includes another convex surface facing the image side; The fourth lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; The first lens and the second lens are cemented together, and there is no air gap between the first lens and the second lens. The combination of the first lens and the second lens has positive refractive power. The objective lens optical module further includes a fifth lens and a prism. The fifth lens is disposed between the second lens and the third lens. The fifth lens is a meniscus lens with positive refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The prism is disposed between the fourth lens and the first lens group. The first lens, the second lens, the fifth lens, the third lens, the fourth lens, and the prism are arranged sequentially along the optical axis from the object side to the image side; The eyepiece optical module includes the fourteenth lens, the fifteenth lens, and the sixteenth lens; The fourteenth lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; The fifteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The sixteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The fourteenth lens and the fifteenth lens are cemented together, and there is no air gap between the fourteenth lens and the fifteenth lens; the combination of the fourteenth lens and the fifteenth lens has positive refractive power; and The optical system satisfies at least one of the following conditions: 9 ≤ fCEEL / fCEEH ≤ 12; -0.01 mm ≤ fCEEH × tan(1° / 60) < 0 mm; 1 ≤ |fOBJ123 / fOBJ| ≤ 2; 10 ≤ VdEL2 / NdEL2 < VdEL1 / NdEL1 ≤ 45; 85% ≤ OD2 / OD3 ≤ 95%; 68% ≤ OD3 / OD1 ≤ 75%; 10 ≤ OD1 / ∣OD2-OD3∣≤ 30; 6 ≤ OD2 / (OD4-OD3) ≤ 15; Wherein, fCEEL is the combined effective focal length of the upright lens optical module and the eyepiece optical module at low magnification, fCEEH is the combined effective focal length of the upright lens optical module and the eyepiece optical module at high magnification, fOBJ is the effective focal length of the objective lens optical module, fOBJ123 is the combined effective focal length of the combination of the lens closest to the object side, the second lens closest to the object side, and the third lens closest to the object side in the objective lens optical module, and VdEL1 is the effective focal length of the second lens closest to the object side in the upright lens optical module. The Abbe coefficient of the lens, NdEL1 is the refractive index of the second lens closest to the object side in the upright lens optical module, VdEL2 is the Abbe coefficient of the third lens closest to the object side in the upright lens optical module, NdEL2 is the refractive index of the third lens closest to the object side in the upright lens optical module, OD2 is the minimum optically effective diameter in the objective lens optical module, OD3 is the optically effective diameter of the object side of the sixth lens, OD1 is the optically effective diameter of the object side of the lens closest to the object side in the objective lens optical module, and OD4 is the optically effective diameter of the image side of the sixth lens.

10. The optical system as claimed in claim 8, characterized in that: The first lens is a biconvex lens with positive refractive power, and further includes another convex surface facing the object side; The second lens is a biconcave lens with negative refractive power, and further includes another concave surface facing the image side; The third lens is a meniscus lens with negative refractive power, and further includes a concave surface facing the image side; The fourth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The first lens and the second lens are cemented together, and there is no air gap between the first lens and the second lens. The combination of the first lens and the second lens has negative refractive power. The objective lens optical module further includes a fifth lens and a prism. The fifth lens is disposed between the object side and the first lens. The fifth lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side. The prism is disposed between the fourth lens and the first lens group. The fifth lens, the first lens, the second lens, the third lens, the fourth lens, and the prism are arranged sequentially along the optical axis from the object side to the image side; The eyepiece optical module includes the fourteenth lens, the fifteenth lens, and the sixteenth lens; The fourteenth lens is a biconcave lens with negative refractive power, and includes one concave surface facing the object side and another concave surface facing the image side; The fifteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The sixteenth lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side; The fourteenth lens and the fifteenth lens are cemented together, and there is no air gap between the fourteenth lens and the fifteenth lens; the combination of the fourteenth lens and the fifteenth lens has positive refractive power; and The optical system satisfies at least one of the following conditions: 9 ≤ fCEEL / fCEEH ≤ 12; -0.01 mm ≤ fCEEH × tan(1° / 60) < 0 mm; 1 ≤ |fOBJ123 / fOBJ| ≤ 2; 10 ≤ VdEL2 / NdEL2 < VdEL1 / NdEL1 ≤ 45; 85% ≤ OD2 / OD3 ≤ 95%; 68% ≤ OD3 / OD1 ≤ 75%; 10 ≤ OD1 / ∣OD2-OD3∣≤ 30; 6 ≤ OD2 / (OD4-OD3) ≤ 15; Wherein, fCEEL is the combined effective focal length of the upright lens optical module and the eyepiece optical module at low magnification, fCEEH is the combined effective focal length of the upright lens optical module and the eyepiece optical module at high magnification, fOBJ is the effective focal length of the objective lens optical module, fOBJ123 is the combined effective focal length of the combination of the lens closest to the object side, the second lens closest to the object side, and the third lens closest to the object side in the objective lens optical module, and VdEL1 is the effective focal length of the second lens closest to the object side in the upright lens optical module. The Abbe coefficient of the lens, NdEL1 is the refractive index of the second lens closest to the object side in the upright lens optical module, VdEL2 is the Abbe coefficient of the third lens closest to the object side in the upright lens optical module, NdEL2 is the refractive index of the third lens closest to the object side in the upright lens optical module, OD2 is the minimum optically effective diameter in the objective lens optical module, OD3 is the optically effective diameter of the object side of the sixth lens, OD1 is the optically effective diameter of the object side of the lens closest to the object side in the objective lens optical module, and OD4 is the optically effective diameter of the image side of the sixth lens.

Images