A diabetic retinopathy detection device

Abstract

The utility model relates to a kind of diabetic retinopathy detection devices, including box and multi-frequency column, the bottom of multi-frequency column is provided with the rotating shaft for being rotatably mounted in the inside of box, box side is equipped with eye observation port, each circumferential side wall of multi-frequency column constitutes a test surface, each test surface is respectively provided with the test pattern of different spatial frequency, wherein, under the condition that multi-frequency column rotates around rotating shaft, multi-frequency column can make the test surface corresponding to the specified spatial frequency test pattern with the central axis of eye observation port relative, and other spatial frequency test pattern can be switched according to the rotating direction of multi-frequency column and detected. The device is aimed at the problem of contrast sensitivity decline of early diabetic retinopathy patients, through the special design of multi-frequency column and rotating structure, the rapid switching of different spatial frequency detection patterns is realized, the visual specificity damage of patients can be accurately identified, and the early home screening of diabetic retinopathy is assisted.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a device for detecting diabetic retinopathy. Background Technology

[0002] Complications of diabetes are often severe because metabolic abnormalities lead to neurotransmitter imbalances, affecting normal metabolism and damaging the nervous system. Diabetic retinopathy (DR), a common complication, often has a long incubation period, sometimes going years without obvious visual symptoms. This can cause patients and their families to neglect early intervention, significantly increasing the risk of diabetes-related blindness. Early detection and treatment of visual abnormalities through effective diagnostic methods can significantly slow or even halt disease progression.

[0003] Studies have shown that visual impairment in patients with early diabetic retinopathy typically manifests as decreased contrast sensitivity (CS), particularly noticeable in dimly lit scenes or when object edges are blurred. Notably, visual impairment caused by diabetes exhibits spatial frequency specificity. For example, a research team at Cangzhou Central Hospital in Hebei Province used a computer vision system to examine diabetic patients without retinopathy and found that contrast sensitivity was significantly reduced in high spatial frequency areas (6, 12, and 18 Hz / degree), while there was no statistically significant difference in low frequency areas (1.5 and 3 Hz / degree) compared to healthy individuals (World's Latest Medical Information Digest, 2016). This specific pattern of impairment makes it difficult for patients to recognize fine textures (such as small fonts) or the outlines of objects in low light. However, because conventional vision tests (such as the Snellen chart) rely on high-contrast, fixed-frequency testing conditions, these early symptoms are easily missed.

[0004] However, current home-based visual acuity testing tools have significant limitations. First, routine low-contrast vision tests require standard bright environments, which cannot simulate the low-light scenarios (such as evening or cloudy days) encountered in patients' daily lives. Decreased visual function in dark environments is a typical manifestation of early diabetic damage, but existing tools struggle to capture this change due to the limited lighting conditions. Second, diabetes-specific damage is concentrated in mid-to-high spatial frequencies (6–18 weeks / degree), while home-based testing tools often use fixed-frequency (e.g., low-to-mid-frequency) detection patterns, lacking test designs that target high-frequency details. For example, mainstream tools rely on single low-frequency stripes or grayscale gradients, failing to identify the patient's decreased ability to perceive fine textures and struggling to distinguish visual changes in diabetic damage from other eye diseases (such as glaucoma).

[0005] CN220832992U discloses a visual acuity and visual contrast sensitivity tester, which can simulate different detection distances by switching lens groups and supports far, intermediate, and near visual acuity and contrast sensitivity testing. However, this tester has some limitations: First, it does not have corresponding optotypes specifically designed for the medium-to-high spatial frequency needs of diabetic patients, which is not accurate enough for this specific patient group; second, due to the need for precision optical components such as a display, lens group, and reflector, the equipment is expensive and difficult to maintain, making it difficult to promote for home use. In addition, the operation requires manual lens replacement and optical path adjustment, and ordinary users may cause inaccurate measurement results due to improper operation (such as errors in setting the detection distance or angle).

[0006] To address the aforementioned issues, there is an urgent need to develop a dedicated self-examination device based on the characteristics of visual impairment in diabetes, providing a scientific basis for home screening of diabetic retinopathy.

[0007] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this utility model, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that this utility model does not have the features of these prior art. On the contrary, this utility model has all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Utility Model Content

[0008] To address the shortcomings of existing technologies, this application proposes a diabetic retinopathy detection device, particularly a diabetic retinopathy detection device for home self-testing, aiming to solve one or more technical problems in the prior art.

[0009] This utility model relates to a diabetic retinopathy detection device, which includes a housing and a multi-frequency column. The bottom of the multi-frequency column is provided with a rotating shaft for rotatably mounting it inside the housing. An eye observation port is provided on the side of the housing. Each circumferential sidewall of the multi-frequency column forms a test surface, and each test surface is provided with a test pattern of a different spatial frequency. When the multi-frequency column rotates around the rotating shaft, the multi-frequency column can align the test surface corresponding to the test pattern of the specified spatial frequency with the central axis of the eye observation port, and can switch to other spatial frequency test patterns for detection according to the rotation direction of the multi-frequency column.

[0010] This novel diabetic retinopathy detection device utilizes a multi-frequency column design and a rotating switching structure to achieve efficient and accurate detection of visual contrast sensitivity. The test patterns, arranged with monotonically varying spatial frequencies on each test surface of the multi-frequency column, cover the visual sensitivity decline characteristics in the early stages of diabetic retinopathy. Users can quickly switch test frequencies by rotating the column, significantly improving the continuity and efficiency of the detection process. The enclosed housing structure, combined with an integrated rotating drive component, effectively isolates external ambient light interference, ensuring the stability of the test pattern's illumination conditions while simplifying operation and reducing human adjustment errors. Furthermore, the monotonically varying spatial frequency arrangement of the test surfaces aligns with the visual function degeneration patterns in clinical diabetic retinopathy, meeting the needs of users in early home screening for subtle visual changes and providing quantitative detection data directly related to pathological progression for clinical use.

[0011] According to a preferred embodiment, a brightness adjuster is provided inside the enclosure between the multi-frequency column and the eye observation port. The adjuster includes a base and a filter assembly fixed to the upper surface of the base. The base is slidably connected to a slide rail located on the bottom surface of the enclosure and extending along a first direction X. This allows the filter assembly to be laterally adjusted relative to the multi-frequency column, thereby completely moving the filter assembly out of the optical path between the test surface and the eye observation port, providing an unobstructed light path detection scenario. The ability of the filter assembly to move laterally along the slide rail allows for rapid switching between an optical path adjustment scenario and an unobstructed detection scenario. This integrated brightness adjustment mechanism enables the same device to perform contrast sensitivity testing under standard lighting conditions and also supports simulated testing under special ambient light conditions, significantly improving the adaptability of the detection scenario and providing a reliable optical environment control basis for the refined screening of diabetic retinopathy.

[0012] According to a preferred embodiment, the filter assembly includes multiple filters with different transmittances. These filters are continuously arranged along the extension direction of the slide rail so that their corresponding transmittance exhibits a monotonically changing pattern from low to high or from high to low. The orderly arrangement of filters with different transmittances along the slide rail allows the operator to precisely match the target transmittance by linearly moving the base. This eliminates the need for repeatedly changing or stacking filters, covering the complete detection requirements from low illumination to high brightness, significantly improving detection efficiency. The monotonically changing transmittance distribution is compatible with clinical visual sensitivity testing standards, simulating the continuous variation of natural lighting conditions and accurately capturing the characteristics of visual function decline in patients under different brightness levels.

[0013] According to a preferred embodiment, when the base slides along the slide rail, the target filter in the filter group, whose transmittance corresponds to the moving distance, covers the forward projection area of ​​the test surface. This causes the light intensity in the optical path from the test surface to the eye observation port to change with the switching of the filter, thereby simulating detection scenarios under different ambient light conditions. The monotonically changing arrangement of the filter transmittance and the strict correspondence between the slide rail moving distance allow the operator to precisely cover the optical path with the target filter by linear sliding, achieving continuous switching of multiple light intensity adjustments and effectively simulating clinical detection scenarios from dark environments to strong light illumination.

[0014] According to a preferred embodiment, a closed-loop transmission chain is provided on the outer periphery of the rotating shaft. One end of the chain, away from the rotating shaft, is wound around a first gear inside the housing. A first rack, meshing with the first gear, is slidably disposed on the side wall of the housing along a second direction Y. A first actuating block, penetrating the housing, is connected to its back side. The first actuating block can be pushed to drive the first rack to move. Through the linkage between the first gear and the transmission chain, the rotating shaft is controlled, thereby controlling the rotation of the multi-frequency column and switching the test surface. The external driving method of the first actuating block allows the operator to convert manual input into precise angle switching of the test surface through simple linear push-pull actions, ensuring rapid and accurate positioning of test patterns for different spatial frequencies.

[0015] According to a preferred embodiment, the brightness adjuster includes: a second rack slidably disposed on the inner side wall of the housing along a second direction Y; a second gear meshing with the second rack; and a driven gear connected to the second gear via a toothed chain parallel to the slide rail. A second actuating block externally connected to the back side of the second rack can be pushed, so that the movement of the second rack can be converted into the rotation of the driven gear by the linkage of the second gear and the toothed chain, thereby driving the base to move along the slide rail through the toothed groove on the side of the base. The external linear drive of the second actuating block converts manual operation into precise meshing motion of the rack and gear. Combined with the linkage effect of the toothed chain and the driven gear, it ensures that the movement distance of the base along the slide rail strictly corresponds to the operation input, avoiding the positioning deviation that may occur with traditional manual pushing and pulling.

[0016] According to a preferred embodiment, each of the left and right eye positions in the eye observation port is equipped with an independent rotatable light shield. Each light shield is coaxially fixedly connected to a knob via a drive shaft passing through the side wall of the housing, with the knob exposed on the housing surface. When the knob rotates around its axis, the light shield simultaneously undergoes angular displacement, selectively isolating the light path of the non-detected eye by switching to a light-blocking or open position. This coaxial drive design of the left and right eye light shields allows the operator to simultaneously adjust the angular position of the light shields by rotating an external knob. This quickly blocks the light path of the non-detected eye to eliminate visual interference, while also fully opening the light path in binocular synchronous detection mode, significantly improving the accuracy of monocular testing and the efficiency of detection mode switching.

[0017] According to a preferred embodiment, each test surface of the multi-frequency column is arranged with multiple test patterns of different contrasts but maintaining the same spatial frequency along the axial direction. When the test surface is aligned with the central axis of the eye observation port, the current filter of the filter group completely covers the projection area of ​​all test patterns on that test surface, allowing test patterns of all contrast levels to be observed through the eye observation port. The monotonic axial contrast variation arrangement of the multi-frequency column enables full-range contrast detection corresponding to the target spatial frequency to be covered with a single test surface positioning, avoiding the repeated rotation of the test surface caused by contrast switching in traditional equipment, significantly improving detection efficiency and data acquisition integrity.

[0018] According to a preferred embodiment, the outer wall of the housing containing the first actuating block has a first set of scale lines along its moving direction, with each scale line indicating the spatial frequency parameter of the corresponding test surface; the outer wall of the housing containing the second actuating block has a second set of scale lines along its moving direction, with each scale line indicating the transmittance parameter of the corresponding filter. This solution, by setting parameter scale lines on the outer wall of the housing corresponding to the moving direction of the actuating blocks, enables precise setting of optical testing conditions without the need for auxiliary measuring tools, significantly improving the intuitiveness of equipment operation and the accuracy of parameter adjustment.

[0019] According to a preferred embodiment, the enclosure includes an openable lid, with a light source fixed inside the lid, and the light source's illumination direction is aligned with the multi-frequency column. The built-in directional illumination mechanism of the openable lid ensures that the test surface of the multi-frequency column is always in a uniform and stable lighting environment, avoiding detection errors caused by external light source interference or internal optical path deviation, and guaranteeing the repeatability and accuracy of visual function assessment. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a preferred detection device of this utility model;

[0021] Figure 2 This is a schematic diagram of the internal structure of a preferred detection device of this utility model from a first-view perspective;

[0022] Figure 3 This is a schematic diagram of the internal structure of a preferred detection device of this utility model from a second perspective;

[0023] Figure 4 This is a top-view schematic diagram of the internal structure of a preferred detection device of this utility model;

[0024] Figure 5 This is a schematic diagram of a preferred multi-frequency column test surface of this utility model after unfolding.

[0025] List of reference numerals

[0026] 100: Box body; 110: Box cover; 120: Light source; 130: Support leg; 200: Multi-frequency column; 201: Test surface; 210: Rotating shaft; 220: Transmission chain; 230: First gear; 240: First rack; 250: First actuating block; 300: Brightness adjuster; 310: Filter group; 320: Base; 330: Slide rail; 340: Second gear; 350: Second rack; 360: Second actuating block; 370: Driven gear; 400: Eye observation port; 410: Eye cover; 420: Knob; 430: Light shield. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings.

[0028] Location definition: combined with Figure 2 The direction of the short side of the box 100 is taken as the first direction X, and the direction of the long side of the box 100 is taken as the second direction Y.

[0029] This embodiment relates to a device for detecting diabetic retinopathy, such as... Figures 1-3 As shown, the device mainly includes a housing 100, a multi-frequency support column 200, a brightness adjuster 300, and an eye observation port 400. The housing 100 can be designed as a cuboid structure, assembled from an aluminum alloy frame and composite light-shielding material, with an openable lid 110 on top. A light source 120 is fixed in the center of the inner side of the lid 110, its light emission direction aligned with the multi-frequency support column 200 inside the housing 100 to provide stable light intensity. Furthermore, the interior of the housing 100 is coated with a matte black coating to reduce stray light interference. At the center of the front of the housing 100, two symmetrically distributed circular eye observation ports 400 are provided, their height flush with the central axis of the multi-frequency support column 200 to ensure optical path alignment accuracy. Each eye observation port 400 is covered with a silicone cushioning pad as an eye mask 410, which improves user comfort and effectively blocks external light. The brightness adjuster 300 is installed inside the housing 100, specifically between the multi-frequency column 200 and the eye observation port 400. With this layout, the light reflected from the multi-frequency column 200 is first adjusted by the brightness adjuster 300 before being transmitted to the eye observation port 400, thus providing a variety of different lighting scenarios for the detection process.

[0030] like Figure 2 , Figure 3As shown, the multi-frequency support column 200 can be a prism structure, rotatably mounted to the center of the bottom surface inside the housing 100 via the bottom pivot 210. It should be noted that the prism structure is not limited to a quadrangular prism; other polygonal prisms such as triangular, pentagonal, and hexagonal prisms can also be used. For ease of description, this embodiment uses a quadrangular prism as an example. Preferably, each of the four circumferential sidewalls of the multi-frequency support column 200 constitutes a test surface 201. Each test surface 201 is equipped with a test pattern of a specific spatial frequency using processes such as film application, etching, and printing. Multiple test patterns with gradient contrast but consistent spatial frequencies are arranged axially on the same test surface 201. The test pattern can be a Landolt ring, a checkerboard pattern, dark and bright stripes, standardized letters or numbers, etc. Figure 5 The test pattern on test surface 201 is shown to be in the form of dark and light stripes.

[0031] Preferably, the spatial frequencies of the test patterns distributed circumferentially on the multi-frequency pillar 200 are monotonically arranged in a clockwise or counterclockwise direction, thereby forming a mid-to-high frequency detection band covering 6–18 Hz / degree on different test surfaces 201. This range is set based on the characteristic of decreased mid-frequency contrast sensitivity in early diabetic retinopathy patients. The spatial frequencies of adjacent test surfaces 201 can be set arithmetically according to the number of test surfaces 201 on the multi-frequency pillar 200, and a stepped detection sequence of spatial frequencies can be achieved by switching circumferentially. Preferably, the contrast of the test patterns distributed axially on the same test surface 201 of the multi-frequency pillar 200 is monotonically arranged from high to low or from low to high, thereby covering standard test values ​​such as 1%, 5%, 10%, and 20%. This dual-dimensional detection mechanism allows users to complete the combined test of spatial frequency and contrast parameters with a single rotation, meeting the multi-dimensional visual function assessment requirements for early screening of diabetic retinopathy.

[0032] The multi-frequency column 200 can achieve rotation control using a closed chain drive structure. Preferably, such as... Figure 3 , Figure 4As shown, the multi-frequency column 200 is connected to a bearing seat at the center of the bottom surface of the housing 100 via a rotating shaft 210. A closed-loop transmission chain 220 is fitted around the outer circumference of the rotating shaft 210, and the other end of the transmission chain 220 is wound around a first gear 230 located near the side wall of the housing 100. The first gear 230 meshes with a first rack 240 that slides along the second direction Y. The back of the first rack 240 is connected to a first oscillating block 250 that penetrates the side wall of the housing 100. When the user pushes the first oscillating block 250 to move along the second direction Y, the linear motion of the first rack 240 is converted into the rotational motion of the transmission chain 220 through the first gear 230, thereby driving the rotating shaft 210 and the multi-frequency column 200 to rotate around the axis. The outer wall of the housing 100 where the first oscillating block 250 is located has a first set of scale lines along its direction of movement. Each scale line marks the spatial frequency parameter of the corresponding test surface 201. The spacing between adjacent scale lines is linearly proportional to the rotation angle required to switch the adjacent test surfaces 201 of the multi-frequency column 200. As the multi-frequency column 200 rotates, the four test surfaces 201 are aligned sequentially with the central axis of the eye observation port 400. When each test surface 201 is switched, the scale line on the side of the box 100 where the first fluctuation block 250 is located indicates the current spatial frequency parameter. The user can accurately select the target test surface 201 by observing the scale position.

[0033] like Figures 2-4As shown, the base 320 of the brightness adjuster 300 is slidably connected to a slide rail 330 on the bottom surface of the housing 100 via a slider at its bottom. The slide rail 330 extends along the first direction X, allowing the base 320 to move laterally. Preferably, a filter assembly 310 is fixed on the upper surface of the base 320, which includes multiple filters with different transmittances, arranged linearly from low to high transmittance from left to right. Preferably, the filter assembly 310 is implemented using a neutral density filter array, wherein the difference in transmittance of each filter is achieved by controlling the thickness gradient of the metal oxide coating on the surface of the glass substrate through a vacuum coating process. The base 320 has a toothed groove on its back, which can mesh with the driven gear 370. The driven gear 370 is connected to a second gear 340 located near the side of the housing 100 via a toothed chain. The second gear 340 meshes with a second rack 350 that slides along the second direction Y. The back of the second rack 350 is connected to a second actuating block 360 that passes through the side wall of the corresponding housing 100. When the second actuating block 360 is pushed to move along the second direction Y, the linear motion of the second rack 350 is converted into the rotation of the driven gear 370 through the second gear 340 and the toothed chain, thereby driving the base 320 to move laterally along the slide rail 330. The outer wall of the housing 100 where the second actuating block 360 is located has a second set of scale lines along its moving direction. Each scale line marks the transmittance parameter of the corresponding filter. The spacing between adjacent scale lines is linearly proportional to the displacement required for switching between adjacent transmittance units of the filter group 310. As the base 320 moves along the slide rail 330, the filter group 310 gradually blocks the effective optical path projection area of ​​the test surface 201 of the multi-frequency column 200, simultaneously triggering the transmittance scale on the outside of the second toggle block 360 to produce a corresponding displacement, forming a continuously adjustable mechanism for ambient light brightness. When the base 320 moves to the middle working area of ​​the slide rail 330, the stepped light-blocking characteristics of the filter group 310 can simulate different lighting conditions such as cloudy days and overcast days; when the base 320 moves to the extreme positions at both ends of the slide rail 330, the filter group 310 completely leaves the optical path channel, causing the intensity of reflected light from the test surface 201 to reach its maximum value, corresponding to the optical simulation of a sunny day.

[0034] Preferably, each test surface 201 of the multi-frequency column 200 has multiple sets of test patterns with different contrast ratios distributed along the axial direction. Each set of patterns maintains the same spatial frequency but has a contrast gradient from high to low. When the test surface 201 is rotated to align with the central axis of the eye observation port 400, the current filter of the brightness adjuster 300 exactly covers the projection area of ​​the entire test surface 201, ensuring that patterns of all contrast levels can be observed under uniform lighting conditions. The test patterns of the test surface 201 adopt a vertical field-of-view partitioning design: the high-contrast area is located in the upper part of the field of view, the medium-contrast area is in the center, and the low-contrast area is distributed in the lower part. The user can complete the full contrast threshold detection at a single spatial frequency by vertically moving the gaze point.

[0035] Preferably, such as Figures 2-4As shown, the left and right eye positions of the eye observation port 400 are each equipped with independently controlled light-shielding plates 430. The light-shielding plates 430 are circular metal sheets, coaxially connected to a knob 420 on the outside of the housing 100 via a drive shaft. The drive shaft passes through the side wall of the housing 100, with a rigid short rod extending radially from its inner end. The light-shielding plate 430 is fixed to the end of this short rod, and the knob 420 is fixed to the outer end of the drive shaft. When the knob 420 is rotated, the drive shaft causes the light-shielding plate 430 to rotate around its axis. Driven by the short rod, the light-shielding plate 430 gradually opens or closes the light path as the rotation angle changes. The knob 420 has anti-slip textures on its surface and angle indicator marks on its edges, allowing users to quickly identify the status of the light-shielding plate 430. When the knob 420 is rotated to the 0-degree position, the light-blocking plate 430 completely blocks the light path of the non-detected eye to eliminate the binocular visual superposition effect and realize single-eye detection; when the knob 420 is rotated to other angles, the light-blocking plate 430 exposes the light path and realizes simultaneous detection of both eyes.

[0036] Preferably, such as Figure 1 As shown, the bottom of the cabinet 100 is equipped with four sets of height-adjustable support legs 130. Each set of support legs 130 includes a telescopic mechanism consisting of inner and outer sleeves and a locking knob 420. By rotating the sleeves, the extension length of the support legs 130 can be adjusted, thereby changing the overall height of the cabinet 100 to accommodate the eye position of users of different heights. The bottom of the support legs 130 is equipped with anti-slip rubber pads, which provide stable support for the cabinet 100 on load-bearing surfaces such as desktops or floors.

[0037] During the user's test, firstly, the light source 120 of the box cover 110 is turned on. The user aligns both eyes with the eye observation port 400 and operates the knob 420 to adjust the light shield 430 to monocular detection mode. Then, the first oscillating block 250 is pushed to select the initial spatial frequency, and the scale lines are observed to confirm that the test surface 201 is aligned. Next, the second toggle block 360 is pushed to adjust the filter position to simulate the target ambient light conditions. The user then sequentially identifies different contrast patterns and manually records the minimum discernible contrast. After completing the current frequency test, the first oscillating block 250 is pushed to switch to the next spatial frequency, and the above steps are repeated. Finally, three-dimensional detection data containing spatial frequency, contrast threshold, and ambient light parameters are obtained, thereby quantitatively assessing the level of visual contrast sensitivity and providing a basis for early screening of diabetic retinopathy.

[0038] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this utility model, and these solutions all fall within the scope of this utility model and its protection scope. Those skilled in the art should understand that this utility model specification and its drawings are illustrative and do not constitute a limitation on the claims. The protection scope of this utility model is defined by the claims and their equivalents. Throughout the text, features introduced by "preferred" are merely optional and should not be construed as mandatory. Therefore, the applicant reserves the right to abandon or delete relevant preferred features at any time.

Claims

1. A diabetic retinopathy detection device, comprising a housing (100) and a multi-frequency column (200), wherein the bottom of the multi-frequency column (200) is provided with a rotating shaft (210) for rotatably mounting it inside the housing (100), and the side of the housing (100) is provided with an eye observation port (400), characterized in that, Each circumferential sidewall of the multi-frequency column (200) forms a test surface (201), and each test surface (201) is provided with a test pattern of a different spatial frequency. When the multi-frequency column (200) rotates around the pivot (210), the multi-frequency column (200) can make the test surface (201) corresponding to the specified spatial frequency test pattern align with the central axis of the eye observation port (400), and can switch to other spatial frequency test patterns for detection according to the rotation direction of the multi-frequency column (200).

2. The detection device according to claim 1, characterized in that, Inside the housing (100), between the multi-frequency column (200) and the eye observation port (400), a brightness adjuster (300) is provided, which includes a base (320) and a filter group (310) fixed to the upper surface of the base (320); The base (320) is slidably connected to a slide rail (330) located on the bottom surface inside the housing (100) and extending along the first direction X, so that the filter group (310) can be laterally adjusted relative to the multi-frequency column (200), thereby completely moving the filter group (310) out of the light path between the test surface (201) and the eye observation port (400), thus providing a detection scenario with an unobstructed light path.

3. The detection device according to claim 2, characterized in that, The filter group (310) includes multiple filters with different transmittances. Each filter is arranged continuously along the extension direction of the slide rail (330) so that the corresponding transmittance presents a monotonous change from low to high or from high to low.

4. The detection device according to claim 3, characterized in that, When the base (320) slides along the slide rail (330), the target filter in the filter group (310) with a transmittance corresponding to the moving distance covers the forward projection area of ​​the test surface (201), so that the light intensity in the optical path between the test surface (201) and the eye observation port (400) changes with the switching of the filter, thereby simulating the detection scene under different ambient light conditions.

5. The detection device according to claim 2, characterized in that, The outer periphery of the rotating shaft (210) is provided with a closed-loop transmission chain (220), one end of which is away from the rotating shaft (210) is wound around a first gear (230) inside the housing (100), and a first rack (240) meshing with the first gear (230) is slidably disposed on the side wall of the housing (100) along the second direction Y, and its back side is connected to a first actuating block (250) that penetrates the housing (100); The first actuating block (250) can be pushed to drive the first rack (240) to move, and through the first gear (230) and the transmission chain (220) linked shaft (210), the multi-frequency column (200) is controlled to rotate and the test surface (201) is switched.

6. The detection device according to claim 5, characterized in that, The brightness adjuster (300) includes: a second rack (350) slidably disposed on the inner side wall of the housing (100) along the second direction Y, a second gear (340) meshing with the second rack (350), and a driven gear (370) connected to the second gear (340) by a toothed chain parallel to the slide rail (330); The second actuating block (360) connected to the back side of the second rack (350) can be pushed, so that the movement of the second rack (350) can be converted into the rotation of the driven gear (370) by the linkage of the second gear (340) and the toothed chain, thereby driving the base (320) to move along the slide rail (330) through the toothed groove on the side of the meshing base (320).

7. The detection device according to claim 1, characterized in that, The left and right eye positions of the eye observation port (400) are respectively equipped with independent rotatable light shields (430). Each light shield (430) is coaxially fixedly connected to the knob (420) through a drive shaft that penetrates the side wall of the box (100). The knob (420) is exposed on the surface of the box (100). When the knob (420) rotates around its axis, the light shield (430) simultaneously generates an angular displacement, selectively isolating the optical path of the non-detection eye by switching to the light blocking position or the open position.

8. The detection device according to claim 4, characterized in that, Each test surface (201) of the multi-frequency column (200) has multiple test patterns with different contrasts but maintaining the same spatial frequency arranged along the axial direction. When the test surface (201) is aligned with the central axis of the eye observation port (400), the current filter of the filter group (310) completely covers all test pattern projection areas of the test surface (201), so that test patterns of all contrast levels can be observed through the eye observation port (400).

9. The detection device according to claim 6, characterized in that, The outer wall of the housing (100) where the first toggle block (250) is located is provided with a first set of scale lines along its moving direction, and each scale line is marked with the spatial frequency parameter of the corresponding test surface (201); the outer wall of the housing (100) where the second toggle block (360) is located is provided with a second set of scale lines along its moving direction, and each scale line is marked with the transmittance parameter of the corresponding filter.

10. The detection device according to claim 1, characterized in that, The enclosure (100) includes an openable cover (110), and a light source (120) is fixed on the inside of the cover (110), with the illumination direction of the light source (120) aligned with the multi-frequency column (200).

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