An eyepiece system based on prism beam combining

Abstract

The present invention discloses an eyepiece system based on prism beam combining, comprising a low-light-level image source, an infrared image source, an infrared end lens, a low-light end lens, a prism assembly, and a shared lens group, wherein the shared lens group comprises a shared first lens and a shared second lens; the low-light-level image source is located on one side of the prism assembly, and the low-light end lens is located between the low-light-level image source and the prism assembly; the infrared image source is located above the prism assembly, and the infrared end lens is located between the infrared image source and the prism assembly. The present invention solves the problem that the low-light-level image and infrared image generated by a low-light-level night vision scope with an image intensifier as its core component cannot be merged. By using the eyepiece system of the present invention, the low-light-level image and the infrared image can be observed simultaneously. After the two images are physically merged at the eyepiece end, the target outline is highlighted, greatly improving the target recognition capability.

Description

Technical Field

[0001] The present invention belongs to the technical field of eyepiece imaging, and in particular relates to an eyepiece system based on prism beam combining. Background Art

[0002] The eyepiece system is a crucial component of a sight. During operation, the eyepiece magnifies the image already resolved by the objective lens, satisfying the human eye's need for target recognition. Conventional eyepiece systems only display the target image along a single optical path. For multi-optical systems, how to observe target images along multiple optical paths through the eyepiece is a pressing issue.

[0003] A low-light-level night vision riflescope consists of two optical paths: an infrared system and a low-light-level system. Typically, the infrared objective lens and the low-light-level objective lens each generate corresponding target images. A fusion circuit then fuses the infrared and low-light-level image data, outputting them to a display screen for observation through the eyepiece. However, this fusion method digitizes the image before performing image registration and fusion processing, making it applicable only to systems that can generate digital signal images. For low-light-level night vision riflescopes, which use image intensifiers as their core component, the low-light-level image they generate cannot be simply fused with the infrared image because the image generated by the image intensifier cannot be digitized. Summary of the Invention

[0004] In order to solve the problem that the low-light image and infrared image generated by the low-light night vision sight with the image intensifier as the core component cannot be merged, the purpose of the present invention is to provide an eyepiece system based on prism beam combining, which can observe the low-light image and infrared image at the same time. After the two images are physically merged at the eyepiece end, the target outline is highlighted, greatly improving the target recognition ability.

[0005] To achieve the above-mentioned object, the technical solution adopted by the present invention is: an eyepiece system based on prism beam combining, comprising a low-light image source, an infrared image source, an infrared end lens, a low-light end lens, a prism assembly, and a common lens group, wherein the common lens group comprises a common first lens and a common second lens;

[0006] The low-light image source is located on one side of the prism assembly, and the low-light end lens is located between the low-light image source and the prism assembly; the light emitted by the low-light image source passes through the low-light end lens, the prism assembly and the common lens group in sequence to reach the human eye; the infrared image source is located above the prism assembly, and the infrared end lens is located between the infrared image source and the prism assembly, and the light emitted by the infrared image source passes through the infrared end lens, the prism assembly and the common lens group in sequence to reach the human eye; the central axis of the infrared image source is perpendicular to the central axis of the low-light image source, and coincides with the vertical and horizontal central axes of the prism assembly respectively.

[0007] Furthermore, the prism assembly is a semi-transparent and semi-reflective structure. The prism assembly consists of two right-angled trapezoidal prisms, the hypotenuse of which is a glued surface and is at a 45° angle to the horizontal direction. It reflects the light beam emitted by the infrared image source and transmits the light beam emitted by the low-light image source; within the wavelength range of 420nm to 670nm, when the incident angle a=45°, the average transmittance of the coated film layer of the prism assembly is 50%.

[0008] Furthermore, the optical material of the prism assembly is H-K9L, the external dimensions are 20mm×20mm×12mm, and the four corners are all provided with 4×4 chamfers.

[0009] Furthermore, the infrared end lens is a plano-concave lens, the plane of which is close to the display screen, the center thickness is 2 mm, the refractive index of the optical material is 1.95, the Abbe coefficient is 17.9, and the concave curvature radius is 19.53 mm.

[0010] Furthermore, the micro-light end lens is a meniscus lens, the concave surface is close to the image intensifier screen, the center thickness is 2.9mm, the optical material refractive index is 1.70, the Abbe coefficient is 48.1, the front surface curvature radius is -28.41mm, and the rear surface curvature radius is -15.32mm.

[0011] Furthermore, the common first lens is a meniscus lens, the concave surface of which is close to the prism group, the center thickness is 1.8 mm, the refractive index of the optical material is 1.73, the Abbe coefficient is 54.7, the front surface curvature radius is -30.4 mm, and the rear surface curvature radius is -22.2 mm.

[0012] Furthermore, the shared second lens is a biconvex lens with a center thickness of 3.6 mm, an optical material refractive index of 1.62, an Abbe coefficient of 63.9, an aspherical front surface, and aspherical parameters: R=21.65, k=0, A=-1.85759E-004, B=6.69238E-006, C=-1.022398E-007, D=5.3279766E-010; the rear surface is aspherical, and aspherical parameters are: R=-97.034, k=0, A=-1.31254E-004, B=5.459155E-006, C=-9.188663E-008, D=5.216857E-010.

[0013] Furthermore, the distance between the infrared image source and the infrared end lens is 2.42 mm, the distance between the infrared end lens and the prism assembly is 2.5 mm, the distance between the low-light image source and the low-light end lens is 4 mm, the distance between the low-light end lens and the prism assembly is 1 mm, the distance between the prism assembly and the common first lens is 4.02 mm, the distance between the common first lens and the common second lens is 0.5 mm, and the distance between the common second lens and the human eye is 15 mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are embodied in the following aspects:

[0015] Different from traditional image fusion modes, the present invention physically fuses infrared images and low-light-level images at the eyepiece end to highlight the target outline and improve target recognition capabilities.

[0016] Compared with the existing prism assembly, the beam-combining prism assembly composed of right-angle trapezoidal prisms greatly reduces the length and weight of the eyepiece system.

[0017] The infrared image generated by the target has the same magnification as the low-light-level image, which improves the fusion matching of the infrared image and the low-light-level image. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an optical schematic diagram of an eyepiece system based on prism beam combining according to the present invention;

[0019] Figure 2 is a schematic diagram of a prism assembly of the present invention;

[0020] Figure 3 yes Figure 2 a cross-sectional view of the middle prism assembly;

[0021] Figure 4 This is a spot diagram of the infrared portion of the eyepiece system of the present invention;

[0022] Figure 5 This is the infrared distortion diagram of the eyepiece system of the present invention;

[0023] Figure 6 This is a spot diagram of the low-light portion of the eyepiece system of the present invention;

[0024] Figure 7 This is a diagram of the low-light part distortion of the eyepiece system of the present invention;

[0025] In the figure: 1—low-light image source, 2—infrared image source, 3—infrared end lens, 4—low-light end lens, 5—prism assembly, 6—common lens group, 7—common first lens, 8—common second lens. Implementation Method

[0026] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate one or more embodiments of the present invention to provide a more accurate and thorough understanding of the technical solutions disclosed herein. However, it should be understood that the present invention can be implemented in a variety of different forms and is not limited to the embodiments described below.

[0027] The same or similar numbers in the drawings of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] This embodiment provides an eyepiece system based on prism beam combining, which realizes the physical fusion of low-light-level image and infrared image at the eyepiece end. Figure 1 As shown in FIG, the structure of the eyepiece system based on prism beam combining is shown, which includes a low-light image source 1, an infrared image source 2, an infrared end lens 3, a low-light end lens 4, a prism assembly 5, and a shared lens group 6. The shared lens group 6 includes a shared first lens 7 and a shared second lens 8. The light emitted by the infrared image source 2 passes through the infrared end lens 3, the prism assembly 5, and the shared lens group 6 in sequence to reach the human eye; the light emitted by the low-light image source 1 passes through the low-light end lens 4, the prism assembly 5, and the shared lens group 6 in sequence to reach the human eye.

[0029] The infrared image source 2 is used to display the infrared image generated by the target object; the low-light image source 1 is used to display the low-light image generated by the target object under low-light conditions; the infrared end lens 3 is located between the infrared image source 2 and the prism assembly 5; the low-light end lens 4 is located between the low-light image source 1 and the prism assembly 5; the prism assembly 5 is a semi-transparent and semi-reflective structure, which reflects the light beam emitted by the infrared image source 2 and transmits the light beam emitted by the low-light image source 1, and the infrared image light and the low-light image light are combined through the prism assembly 5; the combined light is magnified by the common lens group 6 to generate an image that meets the visual recognition requirements of the human eye, so that the human eye can observe comfortably.

[0030] The low-light-level image source 1 is an image intensifier located to one side of the prism assembly 5. The target is imaged by the low-light-level objective lens and focused on the cathode surface of the image intensifier, stimulating photoelectrons. The photoelectrons are accelerated, focused, and imaged by the electron optical system within the image intensifier. They strike the image intensifier's fluorescent screen at extremely high speeds, stimulating sufficiently intense visible light, transforming the target image into a visible light image suitable for human observation, which is then displayed on the image intensifier's fluorescent screen.

[0031] The infrared image source 2 is an OLED display screen, or other display screens, located above the prism assembly 5. The target generates an optical image through the infrared objective lens and forms an image on the target surface of the infrared detector. After digital-to-electrical conversion, the target image is displayed on the OLED screen.

[0032] The prism assembly 5 is located below the infrared image source 2 and on one side of the low-light-level image source 1. The central axis of the infrared image source 2 and the central axis of the low-light-level image source 1 are perpendicular to each other and coincide with the vertical and horizontal central axes of the prism assembly 5 respectively.

[0033] like Figure 2 and 3 As shown, the prism assembly 5 is composed of two right-angled trapezoidal prisms, the hypotenuse of which is a glued surface and forms an angle of 45° with the horizontal direction. It reflects the light beam emitted by the infrared image source 2 and transmits the light beam emitted by the low-light image source 1. The requirements for the coating layer are: within the wavelength range of 420nm to 670nm, when the incident angle a=45°, the average transmittance is 50%.

[0034] The optical material of prism assembly 5 is H-K9L, and the overall dimensions are 20mm×20mm×12mm. All four corners have 4×4 chamfers to prevent damage to the optical prism due to bumps and other causes at the sharp corners of the edges.

[0035] The infrared end lens 3 is a plano-concave lens, with a plane close to the OLED display screen, a center thickness of 2 mm, an optical material refractive index of 1.95, an Abbe coefficient of 17.9, and a concave curvature radius of 19.53 mm.

[0036] The micro-light end lens 4 is a meniscus lens with a concave surface close to the image intensifier screen. The center thickness is 2.9 mm, the refractive index of the optical material is 1.70, the Abbe coefficient is 48.1, the front surface curvature radius is -28.41 mm, and the rear surface curvature radius is -15.32 mm.

[0037] The common lens group 6 includes a common first lens 7 and a common second lens 8 .

[0038] The shared first lens 7 is a meniscus lens with a concave surface close to the prism group 5, a center thickness of 1.8 mm, an optical material refractive index of 1.73, an Abbe coefficient of 54.7, a front surface curvature radius of -30.4 mm, and a rear surface curvature radius of -22.2 mm.

[0039] The shared second lens 8 is a biconvex lens with a center thickness of 3.6 mm, an optical material refractive index of 1.62, an Abbe coefficient of 63.9, an aspherical front surface, and aspherical parameters: R=21.65, k=0, A=-1.85759E-004, B=6.69238E-006, C=-1.022398E-007, D=5.3279766E-010; the rear surface is aspherical, and aspherical parameters are: R=-97.034, k=0, A=-1.31254E-004, B=5.459155E-006, C=-9.188663E-008, D=5.216857E-010.

[0040] The relative positional relationship between the various components of the present invention is as follows: the distance between the infrared image source 2 and the infrared end lens 3 is 2.42 mm, the distance between the infrared end lens 3 and the prism assembly 5 is 2.5 mm, the distance between the low-light image source 1 and the low-light end lens 4 is 4 mm, the distance between the low-light end lens 4 and the prism assembly 5 is 1 mm, the distance between the prism assembly 5 and the common first lens 7 is 4.02 mm, the distance between the common first lens 8 and the common second lens 8 is 0.5 mm, and the distance between the common second lens 8 and the human eye is 15 mm.

[0041] like Figure 4-7 As shown, the imaging quality of the optical system of the present invention is primarily evaluated by the point diagram and distortion diagram. As can be seen from these figures, the imaging quality of the optical system of the present invention is excellent. The optical system of the present invention has advantages such as compact structure, small size, and strong engineering feasibility, and has practical application value. During operation, the infrared end lens 3 and the low-light end lens 4 are combined with the shared lens group 6 and matched with the corresponding infrared objective lens and low-light objective lens, respectively, to obtain infrared images and low-light images with the same magnification. This avoids large deviations after image fusion, improves the fusion matching of the infrared and low-light images, and greatly enhances target recognition capabilities.

Claims

1. An eyepiece system based on prism beam combining, characterized in that: It comprises a low-light image source (1), an infrared image source (2), an infrared end lens (3), a low-light end lens (4), a prism assembly (5), and a shared lens group (6), wherein the shared lens group (6) is composed of a shared first lens (7) and a shared second lens (8); The low-light image source (1) is located on one side of the prism assembly (5), and the low-light end lens (4) is located between the low-light image source (1) and the prism assembly (5); the light emitted by the low-light image source (1) passes through the low-light end lens (4), the prism assembly (5) and the common lens group (6) in sequence to reach the human eye; the infrared image source (2) is located above the prism assembly (5), and the infrared end lens (3) is located between the infrared image source (2) and the prism assembly (5); the light emitted by the infrared image source (2) passes through the infrared end lens (3), the prism assembly (5) and the common lens group (6) in sequence to reach the human eye; the central axis of the infrared image source (2) is perpendicular to the central axis of the low-light image source (1), and coincides with the vertical and horizontal central axes of the prism assembly (5) respectively; The infrared end lens (3) is a plano-concave lens, with its plane close to the display screen; the micro-light end lens (4) is a meniscus lens, with its concave surface close to the image intensifier screen; the shared first lens (7) is a meniscus lens, with its concave surface close to the prism assembly (5); and the shared second lens (8) is a biconvex lens.

2. The eyepiece system based on prism beam combining according to claim 1, characterized in that: The prism assembly (5) is a semi-transparent and semi-reflective structure. The prism assembly (5) is composed of two right-angled trapezoidal prisms, the hypotenuse of which is a glued surface and is at an angle of 45° to the horizontal direction. It reflects the light beam emitted by the infrared image source (2) and transmits the light beam emitted by the low-light image source (1). In the wavelength range of 420nm to 670nm, when the incident angle a=45°, the average transmittance of the coating layer of the prism assembly (5) is 50%.

3. The eyepiece system based on prism beam combining according to claim 2, characterized in that: The optical material of the prism assembly (5) is H-K9L, the outer dimensions are 20mm×20mm×12mm, and the four corners are all provided with 4×4 chamfers.

4. The eyepiece system based on prism beam combining according to claim 1, wherein: The infrared end lens (3) has a center thickness of 2 mm, an optical material refractive index of 1.95, an Abbe coefficient of 17.9, and a concave curvature radius of 19.53 mm.

5. The eyepiece system based on prism beam combining according to claim 1, wherein: The center thickness of the micro-optical end lens (4) is 2.9 mm, the refractive index of the optical material is 1.70, the Abbe coefficient is 48.1, the front surface curvature radius is -28.41 mm, and the rear surface curvature radius is -15.32 mm.

6. The eyepiece system based on prism beam combining according to claim 1, wherein: The central thickness of the common first lens (7) is 1.8 mm, the refractive index of the optical material is 1.73, the Abbe coefficient is 54.7, the front surface curvature radius is -30.4 mm, and the rear surface curvature radius is -22.2 mm.

7. The eyepiece system based on prism beam combining according to claim 1, wherein: The center thickness of the shared second lens (8) is 3.6 mm, the refractive index of the optical material is 1.62, the Abbe coefficient is 63.9, the front surface is aspherical, and the aspherical parameters are: R=21.65, k=0, A=-1.85759E-004, B=6.69238E-006, C=-1.022398E-007, D=5.3279766E-010; the back surface is aspherical, and the aspherical parameters are: R=-97.034, k=0, A=-1.31254E-004, B=5.459155E-006, C=-9.188663E-008, D=5.216857E-010.

8. The eyepiece system based on prism beam combining according to claim 1, wherein: The distance between the infrared image source (2) and the infrared end lens (3) is 2.42 mm, the distance between the infrared end lens (3) and the prism assembly (5) is 2.5 mm, the distance between the low-light image source (1) and the low-light end lens (4) is 4 mm, the distance between the low-light end lens (4) and the prism assembly (5) is 1 mm, the distance between the prism assembly (5) and the shared first lens (7) is 4.02 mm, the distance between the shared first lens (7) and the shared second lens (8) is 0.5 mm, and the distance between the shared second lens (8) and the human eye is 15 mm.

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