Eye vision light instrument for visual survey

Abstract

The invention relates to the field of ophthalmology instruments, in particular to an ophthalmology optical instrument for general vision survey. The eye vision light instrument for general vision survey comprises a measuring instrument body, a chin support, a forehead support, an adjusting frame, a driving assembly, a cleaning roller and a cleaning cylinder, a displayer used for displaying measured data is installed on one side of the measuring instrument body, and the chin supports used for supporting the chin of a subject are symmetrically arranged on the other side of the measuring instrument body; a forehead support used for abutting against the forehead of the examinee is arranged above the chin support. According to the eye sight light instrument for visual survey, through the design of the cleaning roller and the cleaning cylinder, the chin support and the forehead support are cleaned immediately after being used, workers do not need to manually clean the chin support and the forehead support, the physical strength and time cost of the workers is greatly reduced, the fatigue of the workers caused by frequent operation is avoided, and the working efficiency is improved. The working efficiency is improved, the potential sanitation and safety hazards in a multi-person continuous general survey scene are solved, and meanwhile the burden of workers is relieved.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic instruments, and more particularly to an ophthalmic optometry instrument for visual screening. Background Technology

[0002] Visual screening is a crucial means of early detection of eye problems such as refractive errors, amblyopia, and visual dysfunction. Its screening efficiency and testing standardization directly affect the quality of public eye health management. With the increasing attention paid to eye health by Chinese residents and the normalization of myopia prevention and control among children and adolescents, the population covered by visual screening is constantly expanding, which places higher demands on the efficiency, suitability, and hygiene and safety of optometric instruments used in the screening. Currently, most mainstream vision screening optometry instruments on the market (such as automatic refractometers and vision screening instruments) are equipped with a head positioning structure consisting of a chin rest and a forehead rest. The chin rest supports the vertical position of the head, while the forehead rest restricts forward, backward, left, and right displacement, forming a two-point fixed posture lock. This ensures that the examinee's eye position is precisely aligned with the instrument's measurement optical path, avoiding data errors such as refractive error and visual acuity caused by head movement. While this design solves the core problem of measurement accuracy, it still has shortcomings in actual screening scenarios. Existing instruments often use skin-friendly materials such as silicone and PU for the chin and forehead supports. Since these materials come into direct contact with the skin during use, they are prone to leaving behind contaminants such as sebum, sweat, and dead skin cells. Especially in multi-person, continuous screening scenarios, to avoid the risk of cross-infection, the positioning components need to be cleaned and disinfected after each use. However, current cleaning methods mainly rely on manual wiping. Staff must pause the screening process and use alcohol wipes or disinfectant wipes to clean the surface of the chin and forehead supports one by one. This increases the physical and time costs for staff, leading to fatigue and reduced work efficiency.

[0003] Therefore, it is necessary to provide a new optometry instrument for visual census to solve the above-mentioned technical problems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an optometry instrument for visual surveys. The ophthalmic instrument for visual screening provided by this invention includes: a measuring instrument body, a chin rest, a forehead rest, an adjustment frame, a drive assembly, a cleaning roller, and a cleaning cylinder. A display for displaying measurement data is installed on one side of the measuring instrument body. A chin rest for supporting the subject's chin is symmetrically provided on the other side of the measuring instrument body. A forehead rest for pressing against the subject's forehead is provided above the chin rest. An adjustment frame is installed on the side of the measuring instrument body near the chin rest. A drive assembly is installed between the adjustment frame and the chin rest. The drive assembly drives the chin rest to rotate to provide support for different subjects. A cleaning roller for cleaning the chin rest is provided below the chin rest. A cleaning cylinder for cleaning the forehead rest is provided on one side of the forehead rest.

[0005] Preferably, the drive assembly includes: a motor, a push rod, and a cam ring. The motor is fixedly connected inside the adjusting frame. Rotating plates are symmetrically rotatably connected to the top of the adjusting frame. One rotating plate has a driving pulley fixedly connected to its bottom, and the other rotating plate has a driven pulley fixedly connected to its bottom. The driving pulley and the driven pulley are connected by a belt drive. The output end of the motor passes through the top of the adjusting frame and is fixedly connected to the driving pulley. A push rod is fixedly connected to the top of the rotating plate away from the center. A T-shaped rod is slidably connected to the top of the adjusting frame. Cam rings are fixedly connected to both ends of the T-shaped rod. Both push rods are in contact with the concave surfaces of the corresponding cam rings.

[0006] Preferably, a spring is fitted around the bottom end of the T-shaped rod, with the top end of the spring fixedly connected to the outer wall of the T-shaped rod and the bottom end fixedly connected to the top of the adjustment frame.

[0007] Preferably, a vertical cylinder is fixedly connected to the top of each cam ring, and a round rod is fixedly connected to the center of the top of each rotating plate. A square groove is opened inside the round rod, and a square rod is rotatably connected inside the vertical cylinder. The bottom end of the square rod is placed in the square groove and is slidably connected to its inner wall. A driving bevel gear is fixedly connected to the top of the square rod, and a crossbar is symmetrically fixedly connected to the middle of the two chin supports. The other end of each crossbar extends into the interior of the vertical cylinder and is fixedly connected to a driven bevel gear. The driving bevel gear and the driven bevel gear are in a meshing state.

[0008] Preferably, a mounting plate is fixedly connected to one side of the adjustment frame, and an arc-shaped groove is opened inside the mounting plate. A transmission rod is slidably connected inside the arc-shaped groove, and the end of the transmission rod is fixedly connected to the cleaning roller.

[0009] Preferably, a second motor is fixedly connected to the side wall of the mounting plate, a second drive pulley is fixedly connected to the output end of the second motor, and a second driven pulley is fixedly connected to the other end of the transmission rod. The second drive pulley and the second driven pulley are connected by belt drive.

[0010] Preferably, a rotating frame is rotatably connected to the side wall of the mounting plate, a connecting rod is fixedly connected to the output end of the second motor, the other end of the connecting rod is placed inside the rotating frame and slidably connected to its inner wall, and a transmission rod is placed inside the rotating frame and slidably connected to its inner wall.

[0011] Preferably, the side walls of the adjustment frame are symmetrically fixedly connected with arc-shaped rods, and the top of the arc-shaped rods is fixedly connected with a mounting cover.

[0012] Preferably, one end of the forehead support and the cleaning cylinder are rotatably connected to the inner wall of the mounting cover. The inner wall of the mounting cover is fixedly connected to a motor three. The output end of the motor three is fixedly connected to the end of the cleaning cylinder. A drive gear is fixedly connected to the end of the cleaning cylinder near the motor three. A driven gear is fixedly connected to the end of the forehead support near the motor three. The drive gear and the driven gear are in a meshing state, and the outer diameter of the drive gear is smaller than the outer diameter of the driven gear.

[0013] Preferably, both the cleaning roller and the cleaning cylinder contain cleaning fluid.

[0014] Compared with related technologies, the optometry instrument for visual census provided by this invention has the following beneficial effects: The design of the cleaning roller and cleaning cylinder enables immediate cleaning of the chin rest and forehead rest after use, eliminating the need for staff to manually clean them. This greatly reduces the physical and time costs for staff, avoids staff fatigue caused by frequent operation, improves work efficiency, solves hygiene and safety hazards in multi-person continuous census scenarios, and reduces the burden on staff. The cleaning roller design effectively removes residual sebum, sweat, dander, and other contaminants from the chin rest after use, avoiding the risk of cross-infection due to chin rest contamination during continuous screening of multiple people and ensuring the health and safety of the examinees. The cleaning cylinder design thoroughly and effectively cleans the forehead rest, further improving the hygiene and safety of the instrument and providing examinees with a clean and hygienic examination environment. The head positioning structure of the chin rest and forehead rest can effectively support and restrict the subject's head, forming a stable posture lock, preventing the subject's head from shaking during the measurement process, thereby avoiding data errors such as refractive power and visual acuity caused by head shaking, and ensuring the accuracy and reliability of the measurement data. Both the cleaning roller and the cleaning cylinder contain cleaning fluid, which can better dissolve and remove contaminants during the cleaning process, enhance the cleaning effect, ensure the cleanliness of the chin rest and forehead rest, reduce bacterial growth, and provide reliable protection for the eye health of the examinee. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structure of the optometry instrument for visual census provided by the present invention; Figure 2 for Figure 1 The diagram shows the structure of the adjustment frame; Figure 3 for Figure 2 The diagram shows the structure at point A. Figure 4 for Figure 2 The diagram shows the structural schematic of the side of the mounting plate. Figure 5 for Figure 4 The diagram shows the structure at point B. Figure 6 for Figure 1 The diagram shows the structure of the mounting cover. Figure 7 for Figure 6 The diagram shows the structure at point C.

[0016] The following components are labeled in the diagram: 1. Measuring instrument body; 2. Display; 3. Chin rest; 4. Forehead rest; 5. Adjustment frame; 6. Cleaning roller; 7. Cleaning cylinder; 8. Motor 1; 9. Top rod; 10. Cam ring; 11. Rotating plate; 12. Driving pulley 1; 13. Driven pulley 1; 14. T-shaped rod; 15. Spring; 16. Vertical cylinder; 17. Round rod; 18. Square rod; 19. Driving bevel gear; 20. Driven bevel gear; 21. Mounting plate; 22. Arc groove; 23. Transmission rod; 24. Motor 2; 25. Driving pulley 2; 26. Driven pulley 2; 27. Rotating frame; 28. Arc rod; 29. ​​Mounting cover; 30. Motor 3; 31. Driving gear; 32. Driven gear; 33. Connecting rod. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0019] Example 1 Please see Figures 1 to 7An optometry instrument for visual census, comprising: a measuring instrument body 1, a chin rest 3, a forehead rest 4, an adjustment frame 5, a drive assembly, a cleaning roller 6, and a cleaning cylinder 7. A display 2 for displaying measurement data is mounted on one side of the measuring instrument body 1. A chin rest 3 for supporting the subject's chin is symmetrically arranged on the other side of the measuring instrument body 1. A forehead rest 4 for pressing against the subject's forehead is located above the chin rest 3. An adjustment frame 5 is mounted on the side of the measuring instrument body 1 closest to the chin rest 3. The adjustment frame 5 and the chin rest 3... A drive assembly is installed between the chin rests and the forehead support 4. The drive assembly drives the chin rest 3 to rotate, providing support for different subjects. A cleaning roller 6 for cleaning the chin rest 3 is located below the chin rest 3, and a cleaning cylinder 7 for cleaning the forehead support 4 is located on one side of the forehead support 4. The subject's chin is placed on the chin rest 3, and the forehead is pressed forward against the forehead support 4, forming a two-point fixation. The head posture is locked to ensure that the eyes are aligned with the optical path axis of the measuring instrument body 1. The measuring instrument body 1 starts the measurement program, collects data such as refractive power and visual acuity, and displays them on the display 2 in real time.

[0020] The drive assembly includes: a motor 8, a push rod 9, and a cam ring 10. The motor 8 is fixedly connected inside the adjusting frame 5. Rotating plates 11 are symmetrically rotatably connected to the top of the adjusting frame 5. One rotating plate 11 has a driving pulley 12 fixedly connected to its bottom, and the other rotating plate 11 has a driven pulley 13 fixedly connected to its bottom. The driving pulley 12 and the driven pulley 13 are connected by a belt drive. The output end of the motor 8 passes through the top of the adjusting frame 5 and is fixedly connected to the driving pulley 12. When the motor 8 starts, its output end drives the coaxially fixed driving pulley 12 to rotate. The driving pulley 12 is connected by a belt drive. The driven pulley 13 rotates synchronously, causing the two rotating plates 11 to rotate synchronously around their own axes. A push rod 9 is fixedly connected to the top of the rotating plate 11 away from the center. A T-shaped rod 14 is slidably connected to the top of the adjusting frame 5. Cam rings 10 are fixedly connected to both ends of the T-shaped rod 14. Both push rods 9 are in contact with the concave surface of the corresponding cam ring 10. The push rod 9 moves in a circular motion with the rotating plate 11. In the initial state, the push rod 9 is in contact with the concave surface of the cam ring 10. As the rotating plate 11 rotates, the push rod 9 gradually slides from the concave surface to the convex surface of the cam ring 10, pushing the cam ring 10 upward.

[0021] A spring 15 is sleeved on the bottom end of the T-shaped rod 14. The top end of the spring 15 is fixedly connected to the outer wall of the T-shaped rod 14, and the bottom end is fixedly connected to the top of the adjustment frame 5. When the spring 15 moves upward with the T-shaped rod 14, it stores elastic potential energy to provide power for subsequent reset.

[0022] A vertical cylinder 16 is fixedly connected to the top of each cam ring 10. A round rod 17 is fixedly connected to the center of the top of each rotating plate 11. A square groove is opened inside the round rod 17. A square rod 18 is rotatably connected inside the vertical cylinder 16. The bottom end of the square rod 18 is placed in the square groove and slidably connected to its inner wall. Since the square rod 18 is rotatably connected to the inner wall of the vertical cylinder 16, the square rod 18 can slide upward synchronously with the rise of the vertical cylinder 16 while rotating. A driving bevel gear 19 is fixedly connected to the top of the square rod 18. A crossbar is symmetrically fixedly connected to the middle of the two chin supports 3. The other end of each crossbar extends into the interior of the vertical cylinder 16 and is fixedly connected to a driven bevel gear 20. The driving bevel gear 19 and the driven bevel gear 20 are in a meshing state. The gear ratio of the driving bevel gear 19 and the driven bevel gear 20 is 1:2. Therefore, when the driving bevel gear 19 rotates 1 revolution, the driven bevel gear 20 only rotates 0.5 revolutions. The two chin supports 3 are fixed to the driven bevel gear 20 by a crossbar, and thus rotate 180° synchronously with the driven bevel gear 20.

[0023] An installation plate 21 is fixedly connected to one side of the adjustment frame 5. An arc-shaped groove 22 is provided inside the installation plate 21. A transmission rod 23 is slidably connected inside the arc-shaped groove 22. The end of the transmission rod 23 is fixedly connected to the cleaning roller 6.

[0024] A second motor 24 is fixedly connected to the side wall of the mounting plate 21. A second drive pulley 25 is fixedly connected to the output end of the second motor 24. A second driven pulley 26 is fixedly connected to the other end of the transmission rod 23. The second drive pulley 25 and the second driven pulley 26 are connected by belt drive.

[0025] A rotating frame 27 is rotatably connected to the side wall of the mounting plate 21. A connecting rod 33 is fixedly connected to the output end of the motor 24. The other end of the connecting rod 33 is placed inside the rotating frame 27 and is slidably connected to its inner wall. The transmission rod 23 is placed inside the rotating frame 27 and is slidably connected to its inner wall. The swing of the rotating frame 27 drives the transmission rod 23 to move back and forth along the trajectory of the arc groove 22. The cleaning roller 6 swings synchronously with the transmission rod 23. During the swing, the rotating cleaning roller 6 can cover the entire upper surface of the chin support 3, avoiding cleaning dead corners.

[0026] Example 2 Please see Figure 6 and Figure 7 The side wall of the adjustment frame 5 is symmetrically fixedly connected with an arc-shaped rod 28, and the top of the arc-shaped rod 28 is fixedly connected with a mounting cover 29.

[0027] Both the forehead support 4 and the cleaning cylinder 7 are rotatably connected to the inner wall of the mounting cover 29. The inner wall of the mounting cover 29 is fixedly connected to a motor 30. The output end of the motor 30 is fixedly connected to the end of the cleaning cylinder 7. A drive gear 31 is fixedly connected to the end of the cleaning cylinder 7 near the motor 30, and a driven gear 32 is fixedly connected to the end of the forehead support 4 near the motor 30. The drive gear 31 and the driven gear 32 are meshed, and the outer diameter of the drive gear 31 is smaller than the outer diameter of the driven gear 32. The rotation speed of the cleaning cylinder 7 is higher than that of the forehead support 4. The surface of the cleaning cylinder 7 is wetted with cleaning liquid and comes into close contact with the used surface of the forehead support 4 during rapid rotation, removing surface contaminants through friction. As the forehead support 4 rotates synchronously at a low speed, its used surface gradually and completely adheres to the surface of the cleaning cylinder 7, ensuring that the entire contact surface is wiped clean by the cleaning cylinder 7.

[0028] Cleaning liquid is placed inside both the cleaning roller 6 and the cleaning cylinder 7. The cleaning liquid slowly penetrates to the surface through the micropores of the roller body and the cylinder wall, ensuring that a moist cleaning layer can be formed during cleaning, while avoiding excessive dripping of cleaning liquid.

[0029] The working principle of the optometry instrument for visual census provided by this invention is as follows: In the initial state, of the two symmetrically arranged chin supports 3, one is in the working position, i.e., horizontally upward, for the subject to place their chin, and the other is in the cleaning position, i.e., horizontally downward, located directly above the cleaning roller 6; the working surface of the forehead support 4, i.e., the side that fits against the forehead, faces the subject, and the cleaning cylinder 7 is located on the non-working side of the forehead support 4; motor 1 8, motor 2 24, and motor 3 30 are all in standby state; the T-shaped rod 14 is in the lowest position under the natural contraction force of the spring 15, the top rod 9 fits against the concave surface of the cam ring 10, and the cam ring 10 and the vertical cylinder 16 have no upward displacement; the rotating frame 27 is located in the middle of the arc groove 22; The subject places their chin on the chin rest 3 and their forehead against the forehead rest 4, forming a two-point fixation, locking the head posture and ensuring that the eyes are aligned with the optical path axis of the measuring instrument body 1; the measuring instrument body 1 starts the measurement program, collects data such as refractive power and visual acuity, and displays them on the display 2 in real time. Once a subject has completed the measurement, the measuring instrument 1 completes data acquisition, sends a signal to the control system, and the cleaning process begins. When motor 8 starts, its output drives the coaxial fixed drive pulley 12 to rotate; the drive pulley 12 drives the driven pulley 13 to rotate synchronously through the belt, thereby causing the two rotating plates 11 to rotate synchronously around their own axes. The push rod 9, located at the top of the rotating plate 11 away from the center, moves in a circular motion with the rotating plate 11. Initially, the push rod 9 is in contact with the concave surface of the cam ring 10. As the rotating plate 11 rotates, the push rod 9 gradually slides from the concave surface to the convex surface of the cam ring 10, pushing the cam ring 10 upward. The T-shaped rod 14, which is fixedly connected to the two cam rings 10, moves upward accordingly, simultaneously stretching the spring 15 at the bottom. The vertical cylinder 16, fixed at the top of the cam ring 10, rises synchronously with the cam ring 10. At the same time, the round rod 17 at the center of the top of the rotating plate 11 rotates synchronously with the rotating plate 11. The square groove inside the round rod 17 drives the square rod 18 inserted into the groove to rotate. Since the square rod 18 is rotatably connected to the inner wall of the vertical cylinder 16, the square rod 18 can slide upward synchronously with the rise of the vertical cylinder 16 while rotating. The driving bevel gear 19 at the top of the square rod 18 moves upward with the square rod. 18. The active bevel gear 19 meshes with the driven bevel gear 20 at the end of the crossbar of the chin support 3. The gear ratio of the active bevel gear 19 and the driven bevel gear 20 is 1:2. Therefore, when the active bevel gear 19 rotates 1 revolution, the driven bevel gear 20 only rotates 0.5 revolutions. The two chin supports 3 are fixed to the driven bevel gear 20 through the crossbar. Therefore, they rotate 180° synchronously with the driven bevel gear 20. The chin supports 3 used in the working position are rotated to the position to be cleaned, and the unused chin supports 3 are rotated to the working position, completing the working position switching. When motor 8 drives rotating plate 11 to rotate 1 revolution, push rod 9 returns from the raised surface of cam ring 10 to the concave surface, spring 15 releases stored potential energy, pulls T-shaped rod 14 downward to reset, cam ring 10, vertical cylinder 16, square rod 18 move down accordingly, chin support 3 stays stably in the new working position and cleaning position, motor 8 stops rotating when power is cut off. Next, motor 24 starts, and its output drives the drive pulley 25 to rotate. The drive pulley 25 drives the driven pulley 26 at the end of the transmission rod 23 to rotate via a belt. The transmission rod 23 is fixed to the cleaning roller 6, so the cleaning roller 6 rotates synchronously with the transmission rod 23. The cleaning liquid on the surface of the cleaning roller 6 is evenly distributed during rotation and comes into contact with the surface of the chin rest 3, which has been flipped to the cleaning position, and begins to roll and wipe, removing residual sebum, dander, and bacteria. At the same time, the output of motor 24 drives the connecting rod 33 to rotate. The other end of the connecting rod 33 is inserted into the groove of the rotating frame 27 and rotates with motor 24. The rotating frame 27 is driven to swing back and forth around the rotation axis of the mounting plate 21. The swing angle is limited by the arc groove 22, covering the entire surface of the chin support 3. Since the transmission rod 23 passes through both the arc groove 22 and the groove of the rotating frame 27 and is slidably connected, the swing of the rotating frame 27 drives the transmission rod 23 to move back and forth along the trajectory of the arc groove 22. The cleaning roller 6 swings synchronously with the transmission rod 23. During the swing, the rotating cleaning roller 6 can cover the entire upper surface of the chin support 3, avoiding cleaning dead corners. When the cleaning time reaches the preset value, the motor 24 is de-energized and stops rotating, and the cleaning process of the chin support 3 ends. While the chin rest 3 is being cleaned, motor 30 starts. Its output end is fixed to the end of the cleaning cylinder 7, so motor 30 directly drives the cleaning cylinder 7 to rotate after starting. The drive gear 31 of the cleaning cylinder 7 near the end of motor 30 rotates synchronously with the cleaning cylinder 7. The drive gear 31 meshes with the driven gear 32 at the end of the forehead rest 4, and the outer diameter of the drive gear 31 is smaller than the outer diameter of the driven gear 32. Therefore, the rotation speed of the cleaning cylinder 7 is higher than that of the forehead rest 4. The surface of the cleaning cylinder 7 is soaked in cleaning liquid and comes into close contact with the used surface of the forehead rest 4 during rapid rotation, removing surface contaminants through friction. As the forehead rest 4 rotates synchronously at a low speed, its used surface gradually and completely adheres to the surface of the cleaning cylinder 7, ensuring that the entire contact surface is wiped clean by the cleaning cylinder 7. Motor 30 stops rotating after a preset time, the cleaning is completed, and the forehead rest 4 remains stably in a new working position, waiting for the next examinee to use it.

[0030] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0031] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An optometric instrument for visual census, characterized in that, include: The measuring instrument body (1) has a display (2) for displaying measurement data installed on one side of the measuring instrument body (1). Chin support (3): A chin support (3) is symmetrically provided on the other side of the measuring instrument body (1) to support the subject's chin. A forehead support (4) is provided above the chin support (3) to hold the forehead of the examinee. Adjustment frame (5), the measuring instrument body (1) is equipped with adjustment frame (5) on the side near the chin support (3); A drive assembly is installed between the adjustment frame (5) and the chin rest (3). The drive assembly drives the chin rest (3) to rotate to provide support for different subjects. A cleaning roller (6) is provided below the chin rest (3) for cleaning the chin rest (3); A cleaning cylinder (7) is provided on one side of the forehead support (4) for cleaning the forehead support (4). An arc rod (28) is symmetrically fixedly connected to the side wall of the adjustment frame (5). A mounting cover (29) is fixedly connected to the top of the arc rod (28). One end of the forehead support (4) and the cleaning cylinder (7) are rotatably connected to the inner wall of the mounting cover (29). A motor three (30) is fixedly connected to the inner wall of the mounting cover (29). The output end of the motor three (30) is fixedly connected to the shaft of the cleaning cylinder (7). A drive gear (31) is fixedly connected to one end of the cleaning cylinder (7) near the motor three (30). A driven gear (32) is fixedly connected to one end of the forehead support (4) near the motor three (30). The drive gear (31) and the driven gear (32) are in a meshing state, and the outer diameter of the drive gear (31) is smaller than the outer diameter of the driven gear (32).

2. The optometric instrument for visual census according to claim 1, characterized in that, The drive assembly includes: motor 1 (8), push rod (9) and cam ring (10). Motor 1 (8) is fixedly connected inside the adjustment frame (5). Rotating plates (11) are symmetrically rotatably connected to the top of the adjustment frame (5). One of the rotating plates (11) is fixedly connected to the bottom of the driving pulley 1 (12), and the other rotating plate (11) is fixedly connected to the bottom of the driven pulley 1 (13). The driving pulley 1 (12) and the driven pulley 1 (13) are connected by belt drive. The output end of motor 1 (8) passes through the top of the adjustment frame (5) and is fixedly connected to the driving pulley 1 (12). Push rod (9) is fixedly connected to the top of the rotating plate (11) away from the center. T-shaped rod (14) is slidably connected to the top of the adjustment frame (5). Cam rings (10) are fixedly connected to both ends of the T-shaped rod (14). Both push rods (9) are in contact with the concave surface of the corresponding cam rings (10).

3. The optometric instrument for visual census according to claim 2, characterized in that, A spring (15) is fitted on the outside of the bottom end of the T-shaped rod (14). The top end of the spring (15) is fixedly connected to the outer wall of the T-shaped rod (14), and the bottom end is fixedly connected to the top of the adjustment frame (5).

4. The optometric instrument for visual census according to claim 2, characterized in that, A vertical cylinder (16) is fixedly connected to the top of the cam ring (10), and a round rod (17) is fixedly connected to the axis of the rotating plate (11). A square groove is opened inside the round rod (17). A square rod (18) is rotatably connected inside the vertical cylinder (16). The bottom end of the square rod (18) is placed in the square groove and is slidably connected to its inner wall. A driving bevel gear (19) is fixedly connected to the top of the square rod (18). A crossbar is symmetrically fixedly connected to the middle of the two chin supports (3). The other end of the crossbar extends into the interior of the vertical cylinder (16) and is fixedly connected to a driven bevel gear (20). The driving bevel gear (19) and the driven bevel gear (20) are in a meshing state.

5. The optometric instrument for visual census according to claim 1, characterized in that, An installation plate (21) is fixedly connected to one side of the adjustment frame (5). An arc groove (22) is provided inside the installation plate (21). A transmission rod (23) is slidably connected inside the arc groove (22). The end of the transmission rod (23) is fixedly connected to the cleaning roller (6).

6. The optometric instrument for visual census according to claim 5, characterized in that, The side wall of the mounting plate (21) is fixedly connected to a motor (24), the output end of the motor (24) is fixedly connected to a drive pulley (25), and the other end of the transmission rod (23) is fixedly connected to a driven pulley (26). The drive pulley (25) and the driven pulley (26) are connected by belt drive.

7. The optometric instrument for visual census according to claim 6, characterized in that, The side wall of the mounting plate (21) is rotatably connected to a rotating frame (27), and the output end of the motor (24) is fixedly connected to a connecting rod (33). The other end of the connecting rod (33) is placed inside the rotating frame (27) and is slidably connected to its inner wall. The transmission rod (23) is placed inside the rotating frame (27) and is slidably connected to its inner wall.

8. The optometric instrument for visual census according to claim 1, characterized in that, Cleaning fluid is placed inside both the cleaning roller (6) and the cleaning cylinder (7).

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