Screen detection optical module and screen detection optical equipment

Abstract

The embodiment of the invention provides a screen detection optical module and screen detection optical equipment. The optical module comprises a first lens group, a second lens group and a triplet lens group, and a to-be-detected screen is arranged on the image surface side of the triplet lens group; the first lens group comprises a first lens and a second lens, and the focal power of the first lens and the focal power of the second lens are negative. The second lens group comprises a third lens, a fourth lens, a fifth lens and a sixth lens, and the focal power of the third lens to the sixth lens is positive; the third lens and the sixth lens are in mirror symmetry, and the fourth lens and the fifth lens are in mirror symmetry; the triplet lens group comprises a seventh lens, an eighth lens and a ninth lens, the seventh lens, the eighth lens and the ninth lens are optically cemented to form the triplet lens group, the triplet lens group is provided with a twelfth surface, a thirteenth surface, a fourteenth surface and a fifteenth surface, and the curvature radius of the triplet lens group meets the formula: R12gt; 0, R13lt; 0, R14gt; 0, R15gt; 0, and R14lt; r121t; R121t; r < 15lt >; and R13.

Description

Technical Field

[0001] This application relates to the field of screen detection technology, and more specifically, to a screen detection optical module and a screen detection optical device. Background Technology

[0002] In the field of extended reality (XR) display technology, silicon-based OLED (Micro-OLED) and micro-LED (Micro-LED) microdisplays have become the mainstream display solutions for XR devices. At the same time, to balance the requirements of thinness and lightness and wide field of view of XR devices, the folded optical path (Pancake) optical solution has become the mainstream design.

[0003] Such systems achieve optical path folding through a combination of semi-transparent and semi-reflective mirrors and polarizing elements, but require strict control of the main ray incident angle (CRA) distribution on the screen. Pancake modules typically require a CRA ≤ 15° at the screen edges and a CRA close to 0° in the center to avoid polarization degradation (causing ghosting) or brightness attenuation (typical attenuation rate > 30%) due to excessively large light incident angles. The selection of screen type and the adjustment of the main ray incident angle pose significant challenges to screen inspection.

[0004] In view of this, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this application is to provide a new technical solution for screen detection optical module and screen detection optical equipment.

[0006] According to a first aspect of the present application, a screen detection optical module is provided. The screen detection optical module comprises a negative power first lens group, a positive power second lens group, and a negative power cemented triplet lens group arranged sequentially along the optical axis from the object plane to the image plane, wherein the image plane side of the cemented triplet lens group is provided with the screen to be detected; The first lens group includes a first lens and a second lens arranged from the object plane to the image plane, and the optical power of both the first lens and the second lens is negative; The second lens group includes a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object plane to the image plane, wherein the optical power of the third lens to the sixth lens is positive; The third lens and the sixth lens are mirror-symmetric about the reference axis, and the fourth lens and the fifth lens are mirror-symmetric about the reference axis, which is perpendicular to the optical axis. The cemented triplet lens group includes a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object plane to the image plane. These three lenses are optically cemented together to form the cemented triplet lens group. The cemented triplet lens group has a twelfth, thirteenth, fourteenth, and fifteenth surface arranged sequentially from the side closest to the second lens group to the image plane side. The radii of curvature of these surfaces satisfy the following relationship: R12>0, R13<0, R14>0, R15>0, and R14... <R12<R15<|R13|。

[0007] Optionally, the first lens and the second lens are optically bonded together. The first lens group has a first surface, a second surface, and a third surface arranged sequentially from the object surface to the side closest to the second lens group, and their radii of curvature satisfy the following relationship: R1 < 0, R2 < 0, R3 < 0, and R1 > R3 > R2.

[0008] Optionally, both the first lens and the second lens are meniscus lenses.

[0009] Optionally, the seventh lens is a biconvex lens, the eighth lens is a biconcave lens, and the ninth lens is a meniscus lens.

[0010] Optionally, the third to the sixth lenses are all meniscus lenses, the concave surfaces of the third and fourth lenses face the object plane, and the concave surfaces of the fifth and sixth lenses face the image plane.

[0011] Optionally, the screen detection optical module satisfies: f3 < f4 and f6 < f5; Where f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens.

[0012] Optionally, the screen detection optical module satisfies: F1 / F2>3 and F3 / F2>3; Where F1 is the effective focal length of the first lens group, F2 is the effective focal length of the second lens group, and F3 is the effective focal length of the third lens group.

[0013] Optionally, the first lens group and the second lens group form a reverse telephoto structure.

[0014] Optionally, all lenses in the screen detection optical module are spherical lenses.

[0015] According to a second aspect of the present application, a screen detection optical device is provided, including the screen detection optical module as described in the first aspect.

[0016] One technical advantage of this application is: This application provides a screen inspection optical module that rationally distributes optical power through the coordinated operation of a first lens group, a second lens group, and a cemented triplet lens group. Simultaneously, the optical architecture of the second lens group is set as a mirror-symmetric architecture, and the curvature of each surface in the third lens group is limited. Through the above design, this optical module can fully meet the needs of defect detection in small-sized, high-pixel screens, effectively improving the accuracy and reliability of the detection results.

[0017] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0019] Figure 1 The diagram shown is an optical architecture diagram of the screen detection optical module provided in an embodiment of this application.

[0020] Figure 2 The figure shown is an MTF curve of the screen detection optical module provided in the embodiment of this application.

[0021] Figure 3 The diagram shown is a relationship between the main ray angle and image height of the screen detection optical module provided in this embodiment.

[0022] Figure 4 The image shown is a field curvature and distortion diagram of the screen detection optical module provided in an embodiment of this application.

[0023] Figure 5 The image shown is a relative illumination diagram of the screen detection optical module provided in an embodiment of this application.

[0024] Explanation of reference numerals in the attached figures: 100. First lens group; 200. Second lens group; 300. Cemented triplet lens group; 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Eighth lens; 9. Ninth lens; 10. Aperture; 11. Screen. Detailed Implementation

[0025] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0026] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0027] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0028] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0030] This application provides a screen inspection optical module. The screen inspection optical module is specifically designed for detecting screen defects in VR and MR devices. The optical architecture of this module is an eyepiece architecture. Currently, the screen sizes of VR and MR devices range from 0.39 inches to 0.55 inches, with a pixel density ≥500ppi. This screen inspection optical module can be used with small-sized, high-pixel screens to achieve high-definition imaging. Simultaneously, it can acquire a wide range of CRA (principal ray angle) distributions, thereby improving imaging resolution, uniformity, and edge sharpness, fully meeting the various requirements for screen defect detection.

[0031] Reference Figure 1 The screen detection optical module includes: a negative optical power first lens group 100, a positive optical power second lens group 200 and a negative optical power triplet lens group 300 arranged sequentially along the optical axis from the object plane to the image plane, wherein the image plane side of the triplet lens group 300 is provided with the screen to be detected 11.

[0032] The first lens group 100 includes a first lens 1 and a second lens 2 arranged from the object plane to the image plane, and the optical power of the first lens 1 and the second lens 2 is negative. The second lens group 200 includes a third lens 3, a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged sequentially from the object plane to the image plane, wherein the optical power of the third lens 3 to the sixth lens 6 is positive. The third lens 3 and the sixth lens 6 are mirror-symmetric about the reference axis, and the fourth lens 4 and the fifth lens 5 are mirror-symmetric about the reference axis, which is perpendicular to the optical axis. The cemented triplet lens group 300 includes a seventh lens 7, an eighth lens 8, and a ninth lens 9 arranged sequentially from the object plane to the image plane. These three lenses are optically cemented together to form the cemented triplet lens group 300. The cemented triplet lens group 300 has a twelfth, thirteenth, fourteenth, and fifteenth surface arranged sequentially from the side closest to the second lens group 200 to the image plane side. The radii of curvature of these surfaces satisfy the following relationship: R12>0, R13<0, R14>0, R15>0, and R14... <R12<R15<|R13|。

[0033] It is worth noting that the optical module design typically follows the principle of reverse light path in building the optical architecture. Therefore, the subsequent explanation of this optical module will also be based on the reverse light path principle.

[0034] In this embodiment, the screen detection optical module employs a multi-lens group collaborative configuration (achieving a 2+4+3 eyepiece architecture) and a symmetrical design. The multi-lens groups work closely together to optimize the optical path; the symmetrical design effectively reduces aberrations and improves image quality. These two aspects complement each other, enabling the optical module to meet the defect detection requirements of small-sized, high-pixel screens, thereby improving the accuracy and reliability of the detection results.

[0035] Specifically, please refer to Figure 1 Along the optical axis, the components of the screen detection optical module are arranged sequentially from the object plane to the image plane: the first lens group 100, the second lens group 200, and the cemented triplet lens group 300. During actual screen defect detection, the screen 11 to be inspected is placed on the image plane side of the cemented triplet lens. From an optical structural perspective, this means that the screen 11 to be inspected is on the side of the cemented triplet lens furthest from the second lens group 200.

[0036] The first lens group 100 is a negative power lens group, which consists of two negative lenses: the first lens 1 and the second lens 2. The main function of this lens group is to perform preliminary aberration correction on light rays incident at large angles, laying a good foundation for subsequent optical imaging and ensuring that the light rays have relatively ideal optical characteristics when entering the subsequent lens groups.

[0037] The second lens group 200 is a positive power lens group, composed of four positive lenses: the third lens 3 to the sixth lens 6. This lens group plays an important role in compressing the light beam, while also effectively correcting chromatic aberration and spherical aberration, further improving the transmission quality of light, making the light more concentrated and the imaging clearer and more accurate, thus improving the accuracy of detection on the screen 11.

[0038] The triple-cemented lens group 300 is also a negative power lens group, which tightly binds the seventh lens 7, the eighth lens 8, and the ninth lens 9 together through an optical cementing process. This lens group can further correct residual aberrations in the system and optimize imaging uniformity, thereby obtaining high-quality, uniform imaging results and improving the accuracy of screen 11 detection.

[0039] In this embodiment, the second lens group 200 adopts a mirror-symmetric lens group design. Specifically, the third lens 3 and the sixth lens 6 are mirror-symmetric about a reference axis (virtual axis) perpendicular to the optical axis, and the fourth lens 4 and the fifth lens 5 are also mirror-symmetric about this reference axis. This design architecture not only enables the second lens group 200 to bear the main optical power of the screen detection optical module, but also effectively reduces aberrations and significantly improves the clarity of the image.

[0040] The third lens 3 and the sixth lens 6 are identical in all parameters except for their orientation; the fourth lens 4 and the fifth lens 5 are also identical, differing only in orientation. According to the Seidel coefficient definition in the primary theory of aberrations, in the second lens group 200, the first two lenses closest to the object plane have the same orientation, resulting in less astigmatism and thus providing more design freedom for correcting spherical aberration, coma, and other aberrations. Meanwhile, the last two lenses closest to the image plane, while producing less spherical aberration, also have more freedom to correct coma and astigmatism, further optimizing image quality.

[0041] This architectural design of the second lens group 200 is beneficial for the optical module to detect the screen 11.

[0042] Specifically, since the second lens group 200 bears the main optical power of the screen detection optical module, it can efficiently converge light. In the detection of the screen 11, whether detecting uniformity, defects, or color performance, it is necessary to clearly and accurately focus the light emitted from the screen 11. This focusing capability ensures that the detection module can capture subtle features on the screen 11, providing high-quality raw images for subsequent image analysis and defect judgment.

[0043] In the inspection of screen 11, the accuracy of imaging is crucial. Only by accurately reproducing the true image of screen 11 can the existence, type, and location of defects in screen 11 be accurately determined. The mirror-symmetric design of the second lens group 200 helps to reduce aberrations. Reducing aberrations can avoid problems such as blurring, distortion, and color distortion in the image, thereby improving the reliability of the inspection results.

[0044] In the detection of the screen 11, reducing astigmatism, correcting spherical aberration and coma can ensure that the image is clear in all directions, avoiding detection errors. In the design of the second lens group 200, the first two lenses close to the object surface reduce astigmatism while providing more freedom for correcting spherical aberration and coma, improving the imaging quality and making the detection result of the screen 11 more accurate and reliable.

[0045] In the detection of the screen 11, reducing spherical aberration can make the light rays focus more accurately, improving the resolution and clarity of the image. In the design of the second lens group 200, the last two lenses close to the image surface reduce spherical aberration while having more freedom to correct coma and astigmatism, ensuring that the shape and contour of the image are accurate and improving the accuracy and reliability of the detection.

[0046] In this embodiment, the triplet lens group 300 defines the twelfth surface S12, the thirteenth surface S13, the fourteenth surface S14 and the fifteenth surface S15 in sequence from the side close to the second lens group 200 to the image surface side. These surfaces are the interfaces that the light rays pass through in sequence when propagating in the triplet lens group 300, and the design of their radii of curvature is beneficial to optimizing the propagation path of the light rays and improving the imaging quality.

[0047] Specifically, R12>0 indicates that the twelfth surface S12 is a convex surface (the seventh lens is a biconvex lens) facing the second lens group 200. The convex surface can gradually converge the incident light rays, guiding the subsequent propagation and focusing of the light rays in the lens group. R13<0 indicates that the thirteenth surface S13 is a concave surface (the eighth lens is a biconcave lens). The concave surface can further change the propagation direction of the light rays, diverging or adjusting the light rays appropriately, helping to balance the degree of light ray convergence in the lens group and avoiding excessive concentration of light rays resulting in large aberrations. R14>0, indicating that the fourteenth surface S14 is a convex surface. This convex surface can converge the light rays again, cooperating with the previous concave surface to control the propagation path of the light rays, enabling the light rays to transition more smoothly to the subsequent surfaces. R15>0, indicating that the fifteenth surface S15 is also a convex surface facing the image surface. This convex surface can finally converge the light rays adjusted by the previous several surfaces onto the image surface, forming a clear image.

[0048] In this embodiment, R14<R12<R15<|R13|. This specific radius of curvature can adjust the propagation angle of the light rays, making the chief ray incident on the image surface at an appropriate angle, thus better matching the CRA. In addition, the alternating use of convex and concave surfaces can balance the degree of light ray convergence and divergence on different surfaces, reducing spherical aberration; the specific radius of curvature relationship can adjust the propagation direction of the light rays, reducing the generation of coma and astigmatism; at the same time, this design also helps to control field curvature and distortion, making the imaging on the entire image surface clearer and more uniform.

[0049] Specifically, a smaller R14 means that the curvature of the fourteenth surface is relatively large, which can more strongly converge light rays; a larger R12 makes the curvature of the twelfth surface relatively small, resulting in a gentler initial convergence of light rays; R15 is of moderate size, ensuring that light rays can be accurately converged onto the image plane; and a larger |R13| (the absolute value of the radius of curvature of the thirteenth surface) makes the divergence of the concave surface moderate, coordinating with the convergence of the convex surface to achieve smooth propagation of light rays and reduction of aberrations.

[0050] This architecture design of the triple-bonded lens group 300 is beneficial for the optical module to inspect the screen 11.

[0051] Specifically, the curvature radius design of the triple-cemented lens group 300 enables light to converge accurately onto the image plane, achieving precise focusing. In the inspection of screen 11, this means that detailed information on screen 11 can be clearly captured. High-definition imaging helps inspectors to more accurately judge the quality of screen 11, improving the accuracy and reliability of the inspection.

[0052] The triple-layered lens group 300 can match the principal ray angle, ensuring that light is uniformly incident on the image surface. This avoids uneven image brightness caused by uneven light incident angles, ensuring consistent imaging brightness across the entire image surface, thereby improving the accuracy and reliability of screen 11 detection.

[0053] The curvature radius design of the triplet lens group 300 helps reduce field curvature and distortion, resulting in more uniform and accurate imaging across the entire image plane. In the inspection of screen 11, this ensures consistency and comparability of inspection results for different areas of screen 11, facilitating the overall quality assessment of screen 11.

[0054] The screen inspection optical module provided in this application embodiment achieves a reasonable distribution of optical power through the coordinated operation of the first lens group 100, the second lens group 200, and the cemented triplet lens group 300. Simultaneously, the optical architecture of the second lens group 200 is set as a mirror-symmetric architecture, and the curvature of each surface in the third lens group 3 is limited. Through the above design, this optical module can fully meet the needs of defect detection in small-sized, high-pixel screens 11, effectively improving the accuracy and reliability of the detection results.

[0055] According to an embodiment of this application, the first lens 1 and the second lens 2 are optically bonded together. The first lens group 100 has a first surface S1, a second surface S2, and a third surface S3 arranged sequentially from the object surface to the side closest to the second lens group 200. Their radii of curvature satisfy the following relationship: R1 < 0, R2 < 0, R3 < 0, and R1 > R3 > R2. Therefore, |R2| > |R3| > |R1|.

[0056] In this embodiment, the curvature of the first surface S1, the second surface S2, and the third surface S3 in the first lens group 100 is all less than 0, which indicates that the first surface S1, the second surface S2, and the third surface S3 are all concave surfaces.

[0057] Furthermore, by limiting R1>R3>R2, the convergence and divergence capabilities of the first surface S1, the second surface S2, and the third surface S3 are restricted. This progressive convergence design ensures that the propagation path of light within the first lens group 100 is precisely controlled, improving the stability and accuracy of light propagation, thereby enhancing the accuracy and reliability of the detection results of the screen 11.

[0058] In addition, R1, R2 and R3 are all negative and satisfy a certain magnitude relationship, so that the degree of refraction of light rays at different incident angles is reasonably adjusted when passing through various surfaces, reducing the difference in the convergence point of light rays at different heights, thereby effectively reducing spherical aberration and improving the clarity of the image.

[0059] According to a specific embodiment of this application, both the first lens 1 and the second lens 2 are meniscus lenses.

[0060] In this embodiment, the first lens 1 and the second lens 2 serve as meniscus lenses, which can work in conjunction with other lens groups to rationally distribute optical power. Combining the specific relationship between the radii of curvature of the surfaces of the first lens group 100, the meniscus lens can precisely adjust the convergence of light rays according to the optical characteristics of different surfaces, making the optical power distribution of the entire optical module more reasonable. This helps avoid the problem of increased aberrations caused by uneven optical power distribution, further improving image quality and meeting the demand for high-definition images in defect detection of small-sized, high-pixel screens 11.

[0061] Furthermore, the meniscus lens design possesses a certain degree of versatility and compatibility, enabling it to adapt to the inspection requirements of different types of screens 11. In the optical module of this application, the first lens 1 and the second lens 2 serve as meniscus lenses, and the optical module can meet the inspection requirements for small-sized, high-pixel screens.

[0062] According to a specific embodiment of this application, the seventh lens 7 is a biconvex lens, the eighth lens 8 is a biconcave lens, and the ninth lens 9 is a meniscus lens.

[0063] In this embodiment, the screen detection optical module is designed for defect detection on a small-sized, high-pixel screen 11, and the size of the optical module is strictly limited. The combined design of the seventh lens 7, the eighth lens 8, and the ninth lens 9 enables good optical performance within a relatively small space.

[0064] According to the embodiments of this application, the third lens 3 to the sixth lens 6 are all meniscus lenses, the concave surfaces of the third lens 3 and the fourth lens 4 are both facing the object plane, and the concave surfaces of the fifth lens 5 and the sixth lens 6 are both facing the image plane.

[0065] In this embodiment, the small-sized high-pixel screen 11 is characterized by its small size and high pixel density, which places extremely high demands on the imaging quality of the optical module. This design of the third to sixth lenses 6 in the second lens group 200 can provide high-quality imaging, further meeting the needs of defect detection for the small-sized high-pixel screen 11.

[0066] Furthermore, considering the mirror-symmetric design of the second lens group 200, the third lens 3 and the sixth lens 6 are identical lenses, and the fourth lens 4 and the fifth lens 5 are identical lenses. Specifically, for the second lens group 200, which is a mirror-symmetric lens group, the fourth surface S4 of the third lens 3 facing the object plane and the eleventh surface S11 of the sixth lens 6 facing the image plane have identical optical parameters. The fifth surface S5 of the third lens 3 facing the image plane and the tenth surface S10 of the sixth lens 6 facing the object plane have identical optical parameters. The sixth surface S6 of the fourth lens 4 facing the object plane and the ninth surface S9 of the fifth lens 5 facing the image plane have identical optical parameters. The seventh surface S7 of the fourth lens 4 facing the image plane and the eighth surface S8 of the fifth lens 5 facing the object plane have identical optical parameters. This design allows the second lens group 200 to perform aberration correction while reducing costs.

[0067] According to an embodiment of this application, the screen detection optical module satisfies: f3 < f4 and f6 < f5; Where f3 is the effective focal length of the third lens 3, f4 is the effective focal length of the fourth lens 4, f5 is the effective focal length of the fifth lens 5, and f6 is the effective focal length of the sixth lens 6.

[0068] In this embodiment, a specific focal length relationship is set for the second lens group 200. This focal length constraint ensures that the light deflection angles undertaken by each lens in the second lens group 200 remain relatively uniform. This design helps avoid drastic changes in the light propagation path caused by a single lens undertaking an excessive light deflection task, which could lead to complex aberrations. When the light deflection angle undertaken by each lens is relatively uniform, the light propagates more smoothly and orderly as it passes through the entire lens group, effectively reducing aberrations, improving image quality, and enhancing the accuracy and reliability of screen detection results.

[0069] At the same time, this focal length relationship also makes the distribution of optical power among the lenses more reasonable. Optical power reflects the lens's ability to converge or diverge light. A reasonable distribution of optical power can ensure that the entire lens group can achieve the required imaging function while optimizing the imaging quality to the greatest extent, thereby improving the accuracy and reliability of screen detection results.

[0070] According to an embodiment of this application, the screen detection optical module satisfies: F1 / F2>3 and F3 / F2>3; Wherein, F1 is the effective focal length of the first lens group 100, F2 is the effective focal length of the second lens group 200, and F3 is the effective focal length of the third lens group 3.

[0071] In this embodiment, the optical power of the first lens group 100 and the cemented triplet lens group 300 is negative, while the optical power of the second lens group 200 is positive. The ratio of the focal length F1 of the first lens group 100 to the focal length F2 of the second lens group 200 is greater than 3, and the ratio of the focal length F3 of the cemented triplet lens group 300 to the focal length F2 of the second lens group 200 is also greater than 3. The focal lengths of the first lens group 100 and the cemented triplet lens group 300 are much longer than those of the second lens group 200. In an optical system, the longer the focal length, the smaller the absolute value of the optical power (under the same optical structure). Therefore, the first lens group 100 and the cemented triplet lens group 300 bear relatively less optical power, while the second lens group 200 bears more. This allocation method helps to rationally control the propagation path of light and avoid excessive convergence or divergence of light due to a single lens group bearing too much optical power, thereby producing large aberrations.

[0072] Furthermore, combined with the mirror-symmetric design of the second lens group 200, the light rays passing through the entire optical module can be more accurately focused on the image plane, improving the clarity of the image and thus enhancing the accuracy and reliability of the screen detection results, given the higher optical power of the second lens group 200.

[0073] According to an embodiment of this application, the first lens group 100 and the second lens group 200 form a reverse telephoto structure.

[0074] In this embodiment, the first lens group 100 and the second lens group 200 form a reverse telephoto structure. In the reverse telephoto structure, the negative optical power of the first lens group 100 causes the light to diverge, while the positive optical power of the second lens group 200 converges the diverged light. This combination allows the system to effectively shorten the overall length of the optical module while maintaining a certain optical power.

[0075] For example, the total optical length TTL range of the optical module is 70mm-100mm, such as 70mm, 80mm, 90mm, or 100mm.

[0076] Furthermore, the first lens group 100 and the second lens group 200 form a reverse telephoto structure, which allows the optical module to extend the back focal length while maintaining a wide angle. For example, the field of view (FOV) of the optical module is greater than 50°, such as 55°, 60°, 65°, or 70°.

[0077] According to embodiments of this application, all lenses included in the screen detection optical module are spherical lenses, which facilitates lens manufacturing and reduces costs. Furthermore, in screen detection applications, spherical lenses provide stable optical performance; by combining multiple spherical lenses to correct aberrations, clear and accurate imaging is achieved, improving the accuracy and reliability of screen detection results.

[0078] According to another aspect of the embodiments of this application, a screen detection optical device is provided, which includes the screen detection optical module described above.

[0079] In one specific embodiment, refer to Figure 1 The screen detection optical module, from the object plane to the image plane, includes an aperture stop 10, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, and a ninth lens 9. The first lens 1 and the second lens 2 are both meniscus lenses and are cemented together. The third lens 3 through the sixth lens 6 are all meniscus lenses. The third lens 3 and the sixth lens 6 are mirror-symmetrical about the reference axis, and the fourth lens 4 and the fifth lens 5 are mirror-symmetrical about the reference axis. The seventh lens 7 is a biconvex lens, the eighth lens 8 is a biconcave lens, and the ninth lens 9 is a meniscus lens; all three are cemented together.

[0080] The parameters of each component in the optical module are shown in Table 1.

[0081] Table 1:

[0082] Reference Figure 2 The screen detection optical module achieves high imaging quality when detecting screen 11, with MTF>0.6 at 35lp / mm.

[0083] Reference Figure 3 When the screen detection optical module detects the screen 11, it obtains a wide CRA distribution, with CRA > 15° at a 16mm image height.

[0084] Reference Figure 4 When the screen detection optical module detects screen 11, the field curvature is less than 0.2mm and the distortion is less than 12%.

[0085] Reference Figure 5When the screen detection optical module detects screen 11, the relative illumination is greater than 0.9.

[0086] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0087] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A screen detection optical module, characterized in that, include: A negative optical power first lens group (100), a positive optical power second lens group (200), and a negative optical power cemented triplet lens group (300) are arranged sequentially along the optical axis from the object plane to the image plane. The image plane side of the cemented triplet lens group (300) is provided with a screen (11) to be tested. The first lens group (100) includes a first lens (1) and a second lens (2) arranged from the object plane to the image plane, and the optical power of the first lens (1) and the second lens (2) is negative; The second lens group (200) includes a third lens (3), a fourth lens (4), a fifth lens (5) and a sixth lens (6) arranged sequentially from the object plane to the image plane, wherein the optical power of the third lens (3) to the sixth lens (6) is positive; The third lens (3) and the sixth lens (6) are mirror-symmetric about the reference axis, and the fourth lens (4) and the fifth lens (5) are mirror-symmetric about the reference axis, which is perpendicular to the optical axis. The cemented triplet lens group (300) includes a seventh lens (7), an eighth lens (8), and a ninth lens (9) arranged sequentially from the object plane to the image plane. The three lenses are optically cemented together to form the cemented triplet lens group (300). The cemented triplet lens group (300) has a twelfth, thirteenth, fourteenth, and fifteenth surface arranged sequentially from the side closest to the second lens group (200) to the image plane side. The radii of curvature of these surfaces satisfy the following relationship: R12>0, R13<0, R14>0, R15>0, and R14 <R12<R15<|R13|。 2. The screen detection optical module according to claim 1, characterized in that, The first lens (1) and the second lens (2) are optically bonded together. The first lens group (100) has a first surface, a second surface and a third surface arranged sequentially from the object surface to the side near the second lens group (200), and their radii of curvature satisfy the following relationship: R1<0, R2<0, R3<0, and R1>R3>R2.

3. The screen detection optical module according to claim 1 or 2, characterized in that, Both the first lens (1) and the second lens (2) are meniscus lenses.

4. The screen detection optical module according to claim 1, characterized in that, The seventh lens (7) is a biconvex lens, the eighth lens (8) is a biconcave lens, and the ninth lens (9) is a meniscus lens.

5. The screen detection optical module according to claim 1, characterized in that, The third lens (3) to the sixth lens (6) are all meniscus lenses. The concave surfaces of the third lens (3) and the fourth lens (4) face the object plane, and the concave surfaces of the fifth lens (5) and the sixth lens (6) face the image plane.

6. The screen detection optical module according to claim 1 or 5, characterized in that, The screen detection optical module satisfies: f3 < f4 and f6 < f5; Where f3 is the effective focal length of the third lens (3), f4 is the effective focal length of the fourth lens (4), f5 is the effective focal length of the fifth lens (5), and f6 is the effective focal length of the sixth lens (6).

7. The screen detection optical module according to claim 1, characterized in that, The screen detection optical module satisfies: F1 / F2>3 and F3 / F2>3; Wherein, F1 is the effective focal length of the first lens group (100), F2 is the effective focal length of the second lens group (200), and F3 is the effective focal length of the third lens group (3).

8. The screen detection optical module according to claim 1, characterized in that, The first lens group (100) and the second lens group (200) form a reverse telephoto structure.

9. The screen detection optical module according to claim 1, characterized in that, All lenses in the screen detection optical module are spherical lenses.

10. A screen detection optical device, characterized in that, Includes the screen detection optical module as described in any one of claims 1-9.

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