CN221229308U - Visual acuity test is with visual acuity chart lamp house - Google Patents

Abstract

The utility model belongs to the field of vision testing, in particular to an eye chart lamp box for vision testing, which aims at solving the problems that the brightness of a rear side lamp of an existing eye chart is different and the existing eye chart lamp box is easy to damage after long-term use.

Description

Visual acuity test is with visual acuity chart lamp house

Technical Field

The utility model relates to the technical field of vision testing, in particular to an eye chart lamp box for vision testing.

Background

The visual chart lamp box is a common device for performing visual testing. It is typically composed of a panel with letters or symbols of different sizes. By adjusting the distance, letters or symbols on the panel can be observed and identified at a specific distance to evaluate vision, and when vision testing is performed, the letters or symbols which can be seen are reported one by one according to the instruction of a doctor or a professional, which needs to be seated at a proper distance. Based on the size and clarity of the correctly identified letters or symbols, the doctor or professional can then assess the vision condition.

When using the eye chart light box for vision testing, the following problems are encountered: the light brightness inside the lamp box is different, the recognition of letters or symbols can be influenced, the letters or symbols on the visual chart are more common after the visual chart is used for a long time, and related personnel can possibly realize the direction and the pattern of the backed letters or symbols.

Disclosure of utility model

The utility model aims to solve the problem that the brightness of the rear side lamp of an eye chart is different in the prior art, and provides an eye chart lamp box for vision testing.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

the visual testing chart lamp box comprises a shell for protecting an integral structure, a visual testing chart board for vision measurement and a backboard for connection and fixation, wherein the front side of the backboard is detachably connected with the rear side of the shell, the visual testing chart board is positioned on the front side of the shell, and the visual testing chart board is a transparent plastic board;

The front side of the shell is fixedly connected with a first limiting clamping plate for limiting the visual chart board, a supporting rod for supporting the visual chart board is arranged at the bottom of the visual chart board, and limiting structures for clamping in the first limiting clamping plate are arranged on two sides of the supporting rod;

The two sides of the front side of the backboard are movably connected with a lighting lamp rod for lighting the visual chart board, and the right side of the lighting lamp rod is fixedly connected with a positioning structure for positioning the lighting lamp rod;

The top and the bottom of backplate rear side all are provided with the hanging board that is used for hanging.

Preferably, the limit structure comprises a sliding plate sliding inside the supporting rod, one side, close to the first limit clamping plate, of the sliding plate is fixedly connected with a limit block used for connecting the supporting rod with the first limit clamping plate, one side, away from the sliding plate, of the limit block penetrates through the supporting rod and extends to the inside of the first limit clamping plate, the bottom of the sliding plate is fixedly connected with a pushing rod used for pushing the sliding plate, and the bottom of the pushing rod penetrates through the supporting rod and extends to the bottom of the supporting rod.

Preferably, the positioning structure comprises a connecting block fixedly connected with the illuminating lamp rod, a positioning pin inserted into the back plate for limiting is movably connected in the connecting block, and a pull ring used for pulling the positioning pin is fixedly connected on the front side of the positioning pin.

Preferably, the top and the bottom that the stopper one side was kept away from to the sliding plate are all fixedly connected with and are used for the reset spring that the sliding plate reset, one side that the sliding plate was kept away from to reset spring and the inner wall fixed connection of bracing piece, the opening that is used for the catch bar to remove has been seted up to the bottom of bracing piece, the bayonet socket that is used for the stopper card to go into has been seted up to the inside of first spacing cardboard.

Preferably, a tension spring for resetting the positioning pin is sleeved on the surface of the positioning pin, the front side of the tension spring is fixedly connected with the rear side of the pull ring, and the rear side of the tension spring is fixedly connected with the front side of the connecting block.

Preferably, the front side of the backboard is provided with a plurality of clamping grooves for clamping the locating pins, and the clamping grooves are uniformly distributed on the front side of the backboard.

Preferably, the top and the bottom of backplate front side are all fixedly connected with be used for spacing guide's guided way, the both sides on guided way surface are all swing joint has movable sleeve, the front side of movable sleeve and the rear side fixed connection of light stick.

Preferably, the surface of backplate front side is provided with a plurality of first screws, the screw thread end of first screw runs through the shell and extends to the inside of backplate, the front side fixedly connected with of bracing piece is used for the bracing piece to carry the pull rod that draws.

Preferably, the top and the bottom of shell both sides all are provided with communicating pipe, one side of communicating pipe runs through to the inside of shell, the opposite side fixedly connected with fixed plate of communicating pipe, the four corners that one side was kept away from communicating pipe to the fixed plate all is provided with the second screw, the screw thread end of second screw runs through the fixed plate and extends to the inside of shell, one side that the fixed plate kept away from communicating pipe is provided with and is used for communicating pipe protection filterable filter, the surface cover of filter is equipped with the spacing cardboard of second that is used for the filter, one side that the spacing cardboard of second is close to the fixed plate and the fixed surface fixedly connected of fixed plate.

Preferably, the inside of communicating pipe is provided with driving motor, driving motor's fixed surface is connected with four supporting shoe, one side that driving motor was kept away from to the supporting shoe and the inner wall fixed connection of communicating pipe, driving motor's output fixedly connected with is used for the flabellum of ventilation.

The visual chart lamp box for visual testing provided by the utility model has the following technical effects:

This kind of visual testing is with visual chart lamp house, through setting up the shell, visual chart board, the backplate, first spacing cardboard, the bracing piece, limit structure, the light stick, location structure and string board, can fix backplate and shell on the wall through string board, in first spacing cardboard is gone into to visual chart board card, support the visual chart board through the bracing piece, limit structure carries out spacingly to the position of bracing piece, if necessary, can also carry out quick replacement to visual chart board, simultaneously when the back side lamp brightness is dim and dim, through adjusting the light stick position, reach the purpose of adjusting luminance in the lamp house, location structure can carry out spacing fixedly to the position of light stick, prevent that the light stick from taking place the skew, influence light luminance, defect that there is visual chart because light stick skew to appear for a long time in the prior art is overcome.

In the preferred embodiment, through setting up limit structure, can remove the catch bar, the catch bar drives the sliding plate and removes in the inside of bracing piece, and the sliding plate can drive the stopper and get into the inside of bracing piece, goes into first spacing cardboard with the bracing piece card, makes the bracing piece support the visual chart board, and when the bracing piece card was gone into in the first spacing cardboard, removal catch bar drove the sliding plate and removes, and the sliding plate drives the stopper card and goes into the inside of first spacing cardboard, reaches the purpose that is fixed to visual chart board and bracing piece.

In the preferred embodiment, through setting up location structure, can be through being connected connecting block and light stick, pulling pull ring, pull ring drive locating pin breaks away from the backplate, when the light stick removes suitable position, push back pull ring, pull ring drive locating pin card goes into the backplate, realizes the purpose that the light stick position was fixed.

In the preferred embodiment, through setting up reset spring, opening and bayonet socket, can conveniently reset the sliding plate, increase the inside stability of stopper card income first spacing cardboard, the removal of catch bar can be conveniently carried to the opening, avoids the card of catch bar to die, and the bayonet socket can make things convenient for the stopper card to go into the inside of first limiting plate.

In the preferred embodiment, through setting up the extension spring, can play reset ability to the pull ring, make the pull ring drive the locating pin card and go into the inside of backplate, increase the fixed stability of light stick.

In the preferred embodiment, through setting up the draw-in groove, can be when the light stick removes suitable position, go into the draw-in groove of different positions through the locating pin card, can carry out spacing fixedly to the position of light stick to reach the purpose that provides same light luminance.

In the preferred embodiment, through setting up guide rail and movable sleeve, can drive the movable sleeve through the light stick and remove, make the movable sleeve remove on the guide rail surface, can realize the stable left and right movement of light stick.

In the preferred embodiment, through setting up first screw and lifting rod, can conveniently say that the backplate is connected with the shell, lifting rod can conveniently remove the bracing piece, and the user can be through the purpose of carrying the lifting rod, realizes carrying the bracing piece.

In the preferred embodiment, through setting up communicating pipe, fixed plate, second screw, filter and the spacing cardboard of second, can penetrate inside the shell through communicating pipe, pass through the surface of second screw fixation at the shell with the fixed plate, the filter filters the inside air of entering the shell, avoids the entering of impurity, and the spacing cardboard of second can carry out spacing fixedly to the position of filter, makes things convenient for the dismantlement clearance of filter simultaneously.

In the preferred embodiment, through setting up driving motor, supporting shoe and flabellum, can fix driving motor in communicating pipe's inside through the supporting shoe, through starting driving motor, driving motor drives the flabellum and rotates, realizes the purpose of cooling down to the inside light stick of shell.

Drawings

Fig. 1 is a schematic perspective view of an eye chart lamp box for vision testing according to the present utility model;

fig. 2 is a schematic perspective view of an eye chart board removed from the eye chart lamp box for vision testing according to the present utility model;

Fig. 3 is a schematic perspective view of a communicating tube, a fixing plate, a second screw, a filter plate and a second limiting clamping plate of the visual testing chart lamp box provided by the utility model;

fig. 4 is a schematic perspective view of a limiting structure of an eye chart lamp box for vision testing according to the present utility model;

FIG. 5 is an enlarged view of the portion A of FIG. 1 illustrating an eye chart lamp box for vision testing according to the present utility model;

fig. 6 is an enlarged schematic view of a portion B of fig. 2 of an eye chart lamp box for vision testing according to the present utility model.

In the figure: 1. a housing; 2. an eye chart board; 3. a back plate; 4. the first limiting clamping plate; 5. a support rod; 6. a lighting lamp rod; 7. hanging a plate; 8. a sliding plate; 9. a limiting block; 10. a push rod; 11. a connecting block; 12. a positioning pin; 13. a pull ring; 14. a return spring; 15. an opening; 16. a bayonet; 17. a tension spring; 18. a clamping groove; 19. a guide rail; 20. a movable sleeve; 21. a first screw; 22. a lifting rod; 23. a communicating pipe; 24. a fixing plate; 25. a second screw; 26. a filter plate; 27. the second limiting clamping plate; 28. a driving motor; 29. a support block; 30. and (3) a fan blade.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments.

Example 1

Referring to fig. 1-6, an eye chart lamp box for vision test comprises a shell 1 for protecting an integral structure, an eye chart board 2 for vision measurement and a backboard 3 for connecting and fixing, wherein the front side of the backboard 3 is detachably connected with the rear side of the shell 1, the eye chart board 2 is positioned on the front side of the shell 1, and the eye chart board 2 is a transparent plastic board;

The front side of the shell 1 is fixedly connected with a first limiting clamping plate 4 used for limiting the visual chart board 2, the bottom of the visual chart board 2 is provided with a supporting rod 5 used for supporting the visual chart board 2, and both sides of the supporting rod 5 are provided with limiting structures used for clamping in the first limiting clamping plate 4;

The two sides of the front side of the back plate 3 are both movably connected with a lighting lamp rod 6 for lighting the visual chart board 2, and the right side of the lighting lamp rod 6 is fixedly connected with a positioning structure for positioning the lighting lamp rod 6;

The top and the bottom of the back side of the back plate 3 are provided with hanging plates 7 for hanging.

Example two

Improvement on the basis of the first embodiment: comprises a shell 1 for protecting the whole structure, an eye chart 2 for vision measurement and a backboard 3 for connecting and fixing, wherein the front side of the backboard 3 is detachably connected with the rear side of the shell 1, the eye chart 2 is positioned at the front side of the shell 1, the eye chart 2 is a transparent plastic plate, the front side of the shell 1 is fixedly connected with a first limiting clamping plate 4 for limiting the eye chart 2, the bottom of the eye chart 2 is provided with a supporting rod 5 for supporting the eye chart 2, both sides of the supporting rod 5 are respectively provided with a limiting structure for clamping the first limiting clamping plate 4, the limiting structure comprises a sliding plate 8 sliding in the supporting rod 5, One side of the sliding plate 8, which is close to the first limiting clamping plate 4, is fixedly connected with a limiting block 9 used for connecting the supporting rod 5 with the first limiting clamping plate 4, one side of the limiting block 9, which is far away from the sliding plate 8, penetrates through the supporting rod 5 and extends to the inside of the first limiting clamping plate 4, the bottom of the sliding plate 8 is fixedly connected with a pushing rod 10 used for pushing the sliding plate 8, the bottom of the pushing rod 10 penetrates through the supporting rod 5 and extends to the bottom of the supporting rod 5, the pushing rod 10 can be moved, the pushing rod 10 drives the sliding plate 8 to move in the inside of the supporting rod 5, the sliding plate 8 can drive the limiting block 9 to enter the inside of the supporting rod 5, the supporting rod 5 is clamped into the first limiting clamping plate 4, Make the bracing piece 5 support the vision meter board 2, when bracing piece 5 card is gone into in the first spacing cardboard 4, remove push rod 10, push rod 10 drives slide plate 8 and moves, slide plate 8 drives stopper 9 card income first spacing cardboard 4's inside, reach the purpose of fixing vision meter board 2 and bracing piece 5, the top and the bottom that slide plate 8 is kept away from stopper 9 one side all fixedly connected with be used for slide plate 8 reset spring 14, one side that reset spring 14 kept away from slide plate 8 and the inner wall fixed connection of bracing piece 5, opening 15 that is used for push rod 10 to remove has been seted up to the bottom of bracing piece 5, the bayonet socket 16 that is used for stopper 9 card income has been seted up to the inside of first spacing cardboard 4, The utility model has the advantages of being capable of conveniently resetting the sliding plate 8, increasing the stability of the first limiting clamping plate 4 clamped by the limiting block 9, facilitating the movement of the pushing rod 10 by the opening 15, avoiding the clamping of the pushing rod 10, facilitating the clamping of the limiting block 9 in the first limiting plate by the bayonet 16, movably connecting the two sides of the front side of the back plate 3 with the illuminating lamp rod 6 for illuminating the visual chart plate 2, fixedly connecting the right side of the illuminating lamp rod 6 with a positioning structure for positioning the illuminating lamp rod 6, the positioning structure comprises a connecting block 11 fixedly connected with the illuminating lamp rod 6, movably connecting the inside of the connecting block 11 with a positioning pin 12 inserted into the back plate 3 for limiting, fixedly connecting the front side of the positioning pin 12 with a pull ring 13 for pulling the positioning pin 12, the connecting block 11 can be connected with the illuminating lamp rod 6, the pull ring 13 is pulled, the pull ring 13 drives the positioning pin 12 to be separated from the back plate 3, when the illuminating lamp rod 6 moves to a proper position, the back push-pull ring 13 is pulled, the pull ring 13 drives the positioning pin 12 to be clamped into the back plate 3, the purpose of fixing the position of the illuminating lamp rod 6 is realized, the surface of the positioning pin 12 is sleeved with the tension spring 17 for resetting the positioning pin 12, the front side of the tension spring 17 is fixedly connected with the rear side of the pull ring 13, the rear side of the tension spring 17 is fixedly connected with the front side of the connecting block 11, the resetting capability can be realized on the pull ring 13, the pull ring 13 drives the positioning pin 12 to be clamped into the back plate 3, the stability of fixing the illuminating lamp rod 6 is increased, the clamping grooves 18 for clamping the positioning pins 12 are formed in the front side of the back plate 3, the number of the clamping grooves 18 is a plurality, the clamping grooves 18 are uniformly distributed on the front side of the back plate 3, when the illuminating lamp rod 6 moves to a proper position, the clamping grooves 18 at different positions can be clamped through the positioning pins 12, the positions of the illuminating lamp rod 6 can be limited and fixed, the purpose of providing the same light brightness is achieved, the top and the bottom of the front side of the back plate 3 are fixedly connected with guide rails 19 for limiting and guiding, two sides of the surface of the guide rails 19 are movably connected with movable sleeves 20, the front side of each movable sleeve 20 is fixedly connected with the rear side of the illuminating lamp rod 6, The movable sleeve 20 can be driven to move through the illuminating lamp rod 6, the movable sleeve 20 can be moved on the surface of the guide rail 19, the stable left-right movement of the illuminating lamp rod 6 can be realized, the surface of the front side of the back plate 3 is provided with a plurality of first screws 21, the threaded ends of the first screws 21 penetrate through the shell 1 and extend into the back plate 3, the front side of the support rod 5 is fixedly connected with a lifting rod 22 for lifting the support rod 5, the back plate 3 can be conveniently connected with the shell 1, the lifting rod 22 can conveniently move the support rod 5, a user can carry the lifting rod 22 by hand, the purpose of lifting the support rod 5 is realized, the top and the bottom of two sides of the shell 1 are respectively provided with a communicating pipe 23, one side of the communicating pipe 23 penetrates into the shell 1, the other side of the communicating pipe 23 is fixedly connected with a fixing plate 24, four corners of one side of the fixing plate 24 far away from the communicating pipe 23 are respectively provided with a second screw 25, the threaded ends of the second screws 25 penetrate through the fixing plate 24 and extend into the shell 1, one side of the fixing plate 24 far away from the communicating pipe 23 is provided with a filter plate 26 for protecting and filtering the communicating pipe 23, the surface of the filter plate 26 is sleeved with a second limiting clamping plate 27 for limiting the filter plate 26, one side of the second limiting clamping plate 27 close to the fixing plate 24 is fixedly connected with the surface of the fixing plate 24 and can penetrate into the shell 1 through the communicating pipe 23, The fixing plate 24 is fixed on the surface of the shell 1 through the second screw 25, the filter plate 26 filters the air entering the shell 1 to avoid the entry of impurities, the second limiting clamping plate 27 can limit and fix the position of the filter plate 26 and facilitate the disassembly and cleaning of the filter plate 26, the driving motor 28 is arranged in the communicating pipe 23, the four supporting blocks 29 are fixedly connected with the surface of the driving motor 28, one side of the supporting block 29 away from the driving motor 28 is fixedly connected with the inner wall of the communicating pipe 23, the fan blade 30 for ventilation is fixedly connected with the output end of the driving motor 28, the driving motor 28 can be fixed in the communicating pipe 23 through the supporting blocks 29, Through starting driving motor 28, driving motor 28 drives flabellum 30 and rotates, realizes the purpose of cooling down to the inside light stick 6 of shell 1, and the top and the bottom of backplate 3 rear side all are provided with the string board 7 that is used for hanging.

However, as is well known to those skilled in the art, the working principle and wiring method of the illumination lamp bar 6 and the driving motor 28 are common, which are all conventional means or common knowledge, and are not described herein in detail, and any choice can be made by those skilled in the art according to their needs or convenience.

In the utility model, when the vision is required to be tested, the backboard 3 is fixed on the rear side of the shell 1 through the first screw 21, the whole device is hung on the wall through the hanging plate 7, the pull ring 13 is pulled forward, the pull ring 13 stretches the tension spring 17, the pull ring 13 simultaneously drives the locating pin 12 to be separated from the inside of the backboard 3, the position of the lighting rod 6 is adjusted, the lighting rod 6 drives the movable sleeve 20 to move, the movable sleeve 20 moves on the surface of the guide rail 19, when the lighting rod 6 moves to a proper position, as the connecting block 11 is fixedly connected with the lighting rod 6, the lighting rod 6 drives the connecting block 11 to move, when the lighting rod 6 moves to the proper position, the pull ring 13 is released, the tension spring 17 pulls the pull ring 13, the pull ring 13 drives the locating pin 12 to be clamped into the inside the backboard 3, the purpose of limiting and fixing the lighting rod 6 is achieved, meanwhile, the push rod 10 drives the sliding plate 8 to move inside the supporting rod 5, the sliding plate 8 extrudes the reset spring 14, the reset spring 14 is contracted, the sliding plate 8 drives the limiting block 9 to enter the supporting rod 5, the supporting rod 5 to be clamped into the first supporting rod 4, when the lighting rod 6 moves to the first limiting plate 4, the sliding plate 2 is clamped into the first supporting rod 4, the first limiting plate 2, when the first limiting plate 2 is clamped into the first limiting plate 2, the first limiting plate 2 is further clamped into the first limiting plate 2, the first limiting plate 2 is clamped 2, the first limiting plate 2 is further fixed into the visual table plate 2, and the visual table plate 2 is further damaged, and the visual table plate 2 is further is replaced by the first limiting plate 2, and the visual table plate 2 is further, and the visual table 2 is damaged, and the visual table plate 2 is further, and the visual table is damaged by the visual table plate 2, and is further, and is damaged by the visual table plate 2 and is further, and is damaged, the purpose that the surface pattern of the visual gauge board 2 was illuminated is achieved, penetrate inside the shell 1 through communicating pipe 23, fix fixed plate 24 on the surface of shell 1 through second screw 25, filter the inside air of entering shell 1 through filter 26, avoid the entering of impurity, the spacing fixed of position to filter 26 can be carried out to the spacing cardboard of second 27, make things convenient for the dismantlement clearance of filter 26 simultaneously, fix driving motor 28 in communicating pipe 23's inside through supporting shoe 29, through starting driving motor 28, driving motor 28 drives flabellum 30 and rotates, realize the purpose of cooling down to the inside light stick 6 of shell 1.

The foregoing is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art, who is within the scope of the present utility model, should make equivalent substitutions or modifications according to the technical scheme of the present utility model and the inventive concept thereof, and should be covered by the scope of the present utility model.

Claims (10)

1. The visual chart lamp box for visual testing comprises a shell (1) for protecting an integral structure, a visual chart board (2) for visual measurement and a backboard (3) for connecting and fixing, and is characterized in that the front side of the backboard (3) is detachably connected with the rear side of the shell (1), the visual chart board (2) is positioned on the front side of the shell (1), and the visual chart board (2) is a transparent plastic board;

The visual testing device is characterized in that a first limiting clamping plate (4) used for limiting the visual testing board (2) is fixedly connected to the front side of the shell (1), a supporting rod (5) used for supporting the visual testing board (2) is arranged at the bottom of the visual testing board (2), and limiting structures used for being clamped into the first limiting clamping plate (4) are arranged on two sides of the supporting rod (5);

The two sides of the front side of the back plate (3) are movably connected with a lighting lamp rod (6) for lighting the visual chart board (2), and the right side of the lighting lamp rod (6) is fixedly connected with a positioning structure for positioning the lighting lamp rod (6);

The top and the bottom of the rear side of the backboard (3) are respectively provided with a hanging board (7) for hanging.

2. The visual acuity test chart lamp box according to claim 1, characterized in that the limit structure comprises a sliding plate (8) sliding in the supporting rod (5), one side of the sliding plate (8) close to the first limit clamping plate (4) is fixedly connected with a limit block (9) used for connecting the supporting rod (5) with the first limit clamping plate (4), one side of the limit block (9) far away from the sliding plate (8) penetrates through the supporting rod (5) and extends to the inside of the first limit clamping plate (4), the bottom of the sliding plate (8) is fixedly connected with a pushing rod (10) used for pushing the sliding plate (8), and the bottom of the pushing rod (10) penetrates through the supporting rod (5) and extends to the bottom of the supporting rod (5).

3. The visual acuity test chart lamp box according to claim 2, characterized in that the top and the bottom of one side of the sliding plate (8) far away from the limiting block (9) are fixedly connected with a reset spring (14) for resetting the sliding plate (8), one side of the reset spring (14) far away from the sliding plate (8) is fixedly connected with the inner wall of the supporting rod (5), an opening (15) for pushing the rod (10) to move is formed in the bottom of the supporting rod (5), and a bayonet (16) for clamping the limiting block (9) is formed in the first limiting clamping plate (4).

4. The visual acuity chart lamp box for vision testing according to claim 1, characterized in that the positioning structure comprises a connecting block (11) fixedly connected with the illuminating lamp rod (6), a positioning pin (12) which is inserted into the back plate (3) for limiting is movably connected in the connecting block (11), and a pull ring (13) for pulling the positioning pin (12) is fixedly connected on the front side of the positioning pin (12).

5. The visual acuity chart lamp box for vision testing according to claim 4, characterized in that the surface of the locating pin (12) is sleeved with a tension spring (17) for resetting the locating pin (12), the front side of the tension spring (17) is fixedly connected with the rear side of the pull ring (13), and the rear side of the tension spring (17) is fixedly connected with the front side of the connecting block (11).

6. The visual acuity chart lamp box for vision testing according to claim 4, wherein the front side of the back plate (3) is provided with a clamping groove (18) for clamping the positioning pin (12), and the number of the clamping grooves (18) is a plurality and is uniformly distributed on the front side of the back plate (3).

7. The visual acuity chart lamp box for vision testing according to claim 1, characterized in that the top and the bottom of the front side of the back plate (3) are fixedly connected with guide rails (19) for limiting and guiding, two sides of the surface of the guide rails (19) are movably connected with movable sleeves (20), and the front side of each movable sleeve (20) is fixedly connected with the rear side of the illuminating lamp rod (6).

8. The visual acuity chart lamp box for vision testing according to claim 1, characterized in that the surface of the front side of the back plate (3) is provided with a plurality of first screws (21), the threaded ends of the first screws (21) penetrate through the shell (1) and extend into the back plate (3), and the front side of the support rod (5) is fixedly connected with a lifting rod (22) for lifting the support rod (5).

9. The visual acuity chart lamp box for vision testing according to claim 1, characterized in that the top and the bottom of the two sides of the casing (1) are respectively provided with a communicating pipe (23), one side of the communicating pipe (23) penetrates into the casing (1), the other side of the communicating pipe (23) is fixedly connected with a fixing plate (24), four corners of one side of the fixing plate (24) far away from the communicating pipe (23) are respectively provided with a second screw (25), the threaded ends of the second screws (25) penetrate through the fixing plate (24) and extend into the casing (1), one side of the fixing plate (24) far away from the communicating pipe (23) is provided with a filtering plate (26) for protecting and filtering the communicating pipe (23), a second limiting clamping plate (27) for limiting the filtering plate (26) is sleeved on the surface of the filtering plate (26), and one side of the second limiting clamping plate (27) close to the fixing plate (24) is fixedly connected with the surface of the fixing plate (24).

10. The visual acuity chart lamp box for vision testing according to claim 9, characterized in that a driving motor (28) is arranged in the communicating tube (23), four supporting blocks (29) are fixedly connected to the surface of the driving motor (28), one side of the supporting blocks (29) far away from the driving motor (28) is fixedly connected with the inner wall of the communicating tube (23), and a fan blade (30) for ventilation is fixedly connected to the output end of the driving motor (28).