Eyesight examination projector device for ophthalmology department

Abstract

The invention discloses a projector device for ophthalmology department vision examination, relates to the field of ophthalmology department vision examination, and solves the problem that a forehead rest of an existing vision projector is difficult to clean. The projector device comprises a projector body and an operation bottom plate, an adjusting grip is installed at the top of the operation bottom plate, and an eyepiece, a display screen and a printing port are installed on the outer side of the projector body; the inner side of the projector body is provided with a mounting box, and the inner side of the mounting box is provided with a forehead rest; the protective mechanism is used for cleaning grease impurities on the forehead rest, and the protective mechanism is mounted on the outer side of the forehead rest; by means of the protection mechanism, protection can be provided for the outer side of the forehead rest, the forehead patch of a user can conveniently and comfortably abut against the forehead rest, grease can be collected into the mounting box after vision examination of the user is completed, the cleanliness of the forehead rest is improved, repeated use is facilitated, and the problem that grease on the forehead rest is difficult to clean is solved; therefore, the cleaning and protection effects are achieved.

Description

Technical Field

[0001] The invention relates to the field of ophthalmic vision examination, in particular to an ophthalmic vision examination projector device. Background Art

[0002] Vision test is a method of checking vision. It determines the near and far vision of the human eye by measuring the eye chart and instrument examination. It can check the naked eye vision or the corrected vision with glasses. If the vision test result is not normal, a refractive examination can be performed to further understand the refractive state of the eye.

[0003] During vision examination, the eye chart projector is a key equipment. Through projection technology, the standard pattern of the eye chart is enlarged and displayed on the screen for vision examination. Its main functions include measuring the naked eye vision or corrected vision of the examinee and helping doctors evaluate the patient's vision condition. When in use, in order to ensure that the user's eyes can be aligned with the eyepiece of the projector, the user's forehead will be against the forehead rest, and the staff is required to frequently disinfect the forehead rest. Existing projectors mostly use ultraviolet disinfection lamps to disinfect the forehead rest. However, when the user's forehead is against the forehead rest, skin oil will overflow, and it is difficult for the ultraviolet disinfection lamp to clean the skin oil. Summary of the invention

[0004] The object of the present invention is to provide an ophthalmic vision testing projector device to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: An ophthalmic vision test projector device, comprising: a projector body and an operating base plate fixedly mounted on the outside of the projector body, an adjustment handle mounted on the top of the operating base plate, an eyepiece, a display screen and a printing port fixedly mounted on the outside of the projector body, a mounting box disposed on the inside of the projector body, a forehead rest mounted on the inside of the mounting box, the forehead rest being located above the eyepiece and extending to the outside of the projector body; Also includes: A protective mechanism, used for cleaning grease and impurities on the forehead support, wherein the protective mechanism is installed on the outer side of the forehead support; A replacement mechanism, used to enable the forehead support to automatically collect grease impurities, and the replacement mechanism is installed inside the installation box; The disassembly and assembly mechanism is used to remove and clean the grease impurities collected in the installation box, and the disassembly and assembly mechanism is installed inside the installation box.

[0006] Preferably, the protective mechanism includes a winding box fixedly mounted on the top of the forehead rest, the forehead rest is in a U-shaped structure, a rotating rod is rotatably mounted on the end of the forehead rest away from the mounting box, a first roller is fixedly mounted on the outer side of the rotating rod, a U-shaped frame is fixedly mounted on the end of the forehead rest away from the rotating rod, two symmetrically distributed mounting cylinders are rotatably mounted on the inner side of the U-shaped frame, a diamond rod is slidably mounted on the inner side of the mounting cylinder, a winding disk is fixedly mounted on the end of the diamond rod away from the mounting cylinder, a winding rod is arranged between the two winding disks, the winding box is connected to the winding rod via a protective cloth belt, the inner side of the protective cloth belt is in contact with the outer side of the first roller, and the outer side of the first roller is made of rubber.

[0007] Preferably, the switching mechanism comprises two U-shaped rods symmetrically fixedly mounted at two ends of the forehead rest, the U-shaped rod slidingly passes through the outer side of the mounting box, the outer side of the U-shaped rod is provided with two symmetrically distributed first springs, the first springs are fixedly mounted between the inner sides of the U-shaped rods and the outer side of the mounting box, the inner side of the mounting box is provided with two symmetrically distributed rack plates, the rack plate is located above the U-shaped frame, and two symmetrically distributed elastic telescopic rods are fixedly mounted between the top of the rack plate and the top inner wall of the mounting box, the top of the U-shaped frame is fixedly mounted with a mounting frame, the inner side of the mounting frame is mounted with a push rod, the outer side of the rack plate is provided with a frame-shaped groove for the push rod to limit sliding, the end of the frame-shaped groove away from the forehead rest is a slope structure, and the outer side of the mounting cylinder is fixedly mounted with a first gear, and the first gear is located directly below the rack plate.

[0008] Preferably, the disassembly and assembly mechanism includes a sleeve plate rotatably mounted on the side of the winding disk away from the winding rod, an installation groove for the sleeve plate to limit the sliding of the sleeve is opened on the outer side of the U-shaped frame, a movable rack is fixedly mounted on the end of the sleeve plate away from the winding disk, and the two movable racks are symmetrically distributed in the center, an adjusting grip rod is rotatably mounted on the inner side of the U-shaped frame, a second gear matching the two movable racks is fixedly mounted on the outer side of the adjusting grip rod, an insert block is fixedly mounted on the end of the winding disk away from the sleeve plate, the insert block is a prismatic structure, and slots for the insert block to limit the insertion are opened at both ends of the winding rod.

[0009] Preferably, two second rollers are rotatably mounted on the inner side of the forehead support, and the outer sides of the second rollers are in contact with the inner sides of the protective cloth belts.

[0010] Preferably, positioning rollers are rotatably mounted on the bottom and bottom of the forehead support, and the positioning rollers are in contact with the outer side of the protective cloth belt.

[0011] Preferably, a guide block is fixedly mounted on one end of the frame-shaped groove away from the forehead support, and the outer side of the guide block is a slope structure.

[0012] Preferably, a sliding block is fixedly mounted on the outer side of the support rod, a sliding cavity for limiting the sliding of the sliding block is opened on the inner side of the mounting frame, and a second spring is fixedly mounted between the sliding cavity and the outer side of the sliding block.

[0013] Preferably, a ratchet is fixedly mounted on the side of the winding disc away from the winding rod, an elastic tooth matching the ratchet is slidably mounted on the inner side of the sleeve plate, and a third spring is fixedly mounted between the ratchet and the mounting tube.

[0014] Preferably, two symmetrically distributed guide rods are fixedly installed in the installation groove of the U-shaped frame, and the guide rods slide through the sleeve plate and the movable rack.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention can provide protection for the outer side of the forehead rest through the protection mechanism, so that the user's forehead can rest comfortably on the forehead rest. After the user's vision test is completed, the protective cloth belt can absorb the grease overflowing from the forehead, and the protective cloth belt can be moved along the outer side of the forehead rest in a rotating manner, so that the position where the grease adheres to the protective cloth belt can be put into the installation box, thereby improving the cleanliness of the forehead rest, facilitating multiple uses, and solving the problem that the grease on the forehead rest is difficult to clean, thereby achieving the effect of cleaning and protection.

[0016] The present invention uses a switching mechanism and a thrust force of the user's forehead on the forehead rest to enable the forehead rest to move along the inner side of the installation box, so that the user's eyes can be aligned with the eyepiece. When the user's inspection is completed, the forehead rest is reset by utilizing the resilience of the first spring, and the push rod moves along the inner side of the frame-shaped groove to press the rack plate down close to the first gear. The first gear on the winding disk can move along the teeth of the rack plate, so that the winding rod automatically winds up the protective cloth belt, and the grease position of the protective cloth belt can be automatically collected into the installation box, thereby achieving an automatic cleaning effect and improving the convenience of grease cleaning.

[0017] The present invention uses a disassembly and assembly mechanism, and after multiple inspections, the adjusting handle can be rotated to make the two movable racks move away from each other, and the two winding discs can be synchronously moved away from the winding rod, which is convenient for taking out the winding rod equipped with the protective cloth belt and facilitating the rapid installation of the winding rod, thereby achieving the effect of rapid disassembly, cleaning and installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the winding box and the forehead support structure in the present invention; Figure 3 It is a schematic diagram of the protective cloth belt and the U-shaped frame structure in the present invention; Figure 4 It is a schematic diagram of the structure of the U-shaped rod and the winding disk in the present invention; Figure 5 It is a schematic diagram of the structure of the rack plate and the guide block in the present invention; Figure 6 It is a schematic diagram of the structure of the support rod and the mounting frame in the present invention; Figure 7 It is a schematic diagram of the structure of the diamond rod and the sleeve plate in the present invention; Figure 8 It is a schematic diagram of the movable rack and the plug block structure in the present invention.

[0019] In the figure: 1, projector body; 2, operating base plate; 3, adjustment handle; 4, eyepiece; 5, display screen; 6, print port; 7, installation box; 8, forehead support; 9, take-up box; 10, rotating rod; 11, first roller; 12, U-shaped frame; 13, installation cylinder; 14, diamond rod; 15, take-up reel; 16, take-up rod; 17, protective cloth belt; 18, U-shaped rod; 19, first spring; 20, rack plate; 21, elastic telescopic rod; 22, installation frame; 23, push rod; 24, frame groove; 25, first gear; 26, sleeve plate; 27, movable rack; 28, adjustment handle; 29, second gear; 30, plug block; 31, second roller; 32, positioning roller; 33, guide block; 34, slider; 35, second spring; 36, ratchet; 37, elastic clamping tooth; 38, guide rod; 39, third spring. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1: Please refer to Figure 1-Figure 8, an ophthalmic vision test projector device shown in the figure includes a projector body 1 and an operating base plate 2 fixedly installed on the outside of the projector body 1, an adjusting handle 3 is installed on the top of the operating base plate 2, an eyepiece 4, a display screen 5 and a printing port 6 are fixedly installed on the outside of the projector body 1, a mounting box 7 is arranged on the inside of the projector body 1, a forehead rest 8 is installed on the inside of the mounting box 7, the forehead rest 8 is located above the eyepiece 4, and the forehead rest 8 extends to the outside of the projector body 1, so that the user's forehead can be placed on the forehead rest 8 to align the eyes with the eyepiece 4, so that the vision test symbols in the projector body 1 can be observed, and the symbols that the user sees can be selected by adjusting the handle 3; it also includes: a protective mechanism for cleaning grease impurities on the forehead rest 8, and the protective mechanism is installed on the outside of the forehead rest 8; The protective mechanism includes a winding box 9 fixedly mounted on the top of the forehead support 8. The bottom of the winding box 9 can be connected to the forehead support 8 through a suction cup, which is convenient for installation and disassembly. The forehead support 8 is in a U-shaped structure. A rotating rod 10 is rotatably mounted on the end of the forehead support 8 away from the installation box 7. Both ends of the rotating rod 10 extend to the outside of the winding box 9 to facilitate the rotation of the rotating rod 10. A first roller 11 is fixedly mounted on the outside of the rotating rod 10. A U-shaped frame 12 is fixedly mounted on the end of the forehead support 8 away from the rotating rod 10. Two symmetrically distributed mounting cylinders 13 are rotatably mounted on the inner side, and a diamond rod 14 is slidably mounted on the inner side of the mounting cylinder 13. The diamond rod 14 can move along the inner side of the mounting cylinder 13 and can drive the mounting cylinder 13 to rotate. A winding disk 15 is fixedly mounted on one end of the diamond rod 14 away from the mounting cylinder 13. A winding rod 16 is arranged between the two winding disks 15. The winding box 9 is connected to the winding rod 16 through a protective cloth belt 17, so that the protective cloth belt 17 can be pulled out of the winding box 9 and wound around. The outer side of the reel 16 is received between the two reel discs 15, and the inner side of the protective cloth belt 17 is in contact with the outer side of the first roller 11, so that the protective cloth belt 17 can drive the first roller 11 to rotate when it moves, and the user's forehead can be against the protective cloth belt 17, so that the protective cloth belt 17 absorbs the grease on the user's forehead. The outer side of the first roller 11 is made of rubber material, which increases the friction between the first roller 11 and the protective cloth belt 17. Rotating the rotating rod 10 can make the first roller 11 drive the protective cloth belt 17 to move, thereby replacing the grease position on the protective cloth belt 17. Two second rollers 31 are rotatably installed on the inner side of the forehead rest 8, and the outer side of the second roller 31 is in contact with the inner side of the protective cloth belt 17, providing guidance and support for the movement of the protective cloth belt 17. The bottom and bottom of the forehead rest 8 are rotatably installed with positioning rollers 32, and the positioning rollers 32 are in contact with the outer side of the protective cloth belt 17, so that the protective cloth belt 17 is pulled out of the reel box 9 and received in the reel rod 16.

[0022] Example 2: Please refer to Figure 2-Figure 7, this embodiment further explains the first embodiment, the switching mechanism shown in the figure includes two U-shaped rods 18 symmetrically fixedly installed at both ends of the forehead rest 8, the outer side of the forehead rest 8 is provided with a wing plate for installing the U-shaped rod 18, the U-shaped rod 18 slides through the outer side of the installation box 7, so that the U-shaped rod 18 can move linearly along the outer side of the installation box 7, and the outer side of the U-shaped rod 18 is provided with two symmetrically distributed first springs 19, the first spring 19 is fixedly installed between the inner side of the U-shaped rod 18 and the outer side of the installation box 7, so that when the forehead rest 8 drives the U-shaped rod 18 to move, the first spring 19 can be compressed, and when the user's forehead is away from the protective cloth belt 17 on the forehead rest 8, the rebound force of the first spring 19 can be used to reset the U-shaped rod 18, so as to achieve the forehead To reset the frontal support 8, two symmetrically distributed rack plates 20 are arranged on the inner side of the mounting box 7, the rack plate 20 is located above the U-shaped frame 12, the teeth of the rack plate 20 face downward, and two symmetrically distributed elastic telescopic rods 21 are fixedly installed between the top of the rack plate 20 and the top inner wall of the mounting box 7 to provide support for the rack plate 20, and when the rack plate 20 moves, the rack plate 20 can be reset, and a mounting frame 22 is fixedly installed on the top of the U-shaped frame 12. When the frontal support 8 moves, the mounting frame 22 can be driven to move synchronously by the U-shaped frame 12, and a push rod 23 is installed on the inner side of the mounting frame 22, and a frame-shaped groove 24 for limiting the sliding of the push rod 23 is provided on the outer side of the rack plate 20, and the end of the frame-shaped groove 24 away from the frontal support 8 is an inclined structure, so that the push rod 23 can be moved synchronously. When the rod 23 moves to the left, it can move along the inclined surface of the frame-shaped groove 24 and press the rack plate 20 to move downward. A first gear 25 is fixedly installed on the outer side of the mounting cylinder 13. The first gear 25 is located directly below the rack plate 20, so that when the rack plate 20 moves downward, it can contact the first gear 25. A guide block 33 is fixedly installed at one end of the frame-shaped groove 24 away from the forehead 8. The outer side of the guide block 33 is a sloped structure, so that the push rod 23 can slide into the inclined end of the frame-shaped groove 24 when it contacts the guide block 33. A slider 34 is fixedly installed on the outer side of the push rod 23, and a sliding cavity for limiting the sliding of the slider 34 is opened on the inner side of the mounting frame 22. A second spring 35 is fixedly installed between the sliding cavity and the outer side of the slider 34, so that the push rod 23 can When the guide block 33 comes into contact, the slider 34 can be driven to contract the second spring 35, and the push rod 23 can move along the guide block 33, and when the push rod 23 is away from the guide block 33, the resilience of the second spring 35 is utilized to make the push rod 23 press against the inner side of the frame-shaped groove 24, and the guide block 33 can provide guidance for the movement of the push rod 23, so that the push rod 23 can move along the inclined end of the frame-shaped groove 24. A ratchet 36 is fixedly installed on the side of the winding disk 15 away from the winding rod 16, and an elastic tooth 37 cooperating with the ratchet 36 is slidably installed on the inner side of the sleeve plate 26, so that the winding disk 15 can drive the ratchet 36 to rotate synchronously when it rotates, and the cooperation of the ratchet 36 and the elastic tooth 37 can prevent the winding disk 15 and the winding rod 16 from rebounding.

[0023] Example 3: Please refer to Figure 1 , Figure 7 and Figure 8 , this embodiment further explains other embodiments. The disassembly and assembly mechanism shown in the figure includes a sleeve plate 26 rotatably installed on the side of the winding disk 15 away from the winding rod 16. The outer side of the U-shaped frame 12 is provided with an installation groove for the sleeve plate 26 to limit the sliding of the sleeve plate 26. The end of the sleeve plate 26 away from the winding disk 15 is fixedly installed with a moving rack 27, so that when the moving rack 27 moves, it can drive the sleeve plate 26 to move along the installation groove of the U-shaped frame 12. The sleeve plate 26 pulls the winding disk 15 away from the winding rod 16, and the winding rod 16 can be quickly installed and disassembled. The two moving racks 27 are distributed symmetrically with the center. An adjusting grip 28 is rotatably installed on the inner side of the U-shaped frame 12, and a second gear 29 matching the two moving racks 27 is fixedly installed on the outer side of the adjusting grip 28. When the adjusting grip 28 is rotated, the two moving racks 27 can be driven by the second gear 29 The movable rack 27 moves in the opposite direction. An insert block 30 is fixedly installed at one end of the winding disk 15 away from the sleeve plate 26. The insert block 30 is a prismatic structure. Both ends of the winding rod 16 are provided with slots for the insert block 30 to limit the insertion, so that the winding disk 15 can be connected to the winding rod 16 through the insert block 30, and when the winding disk 15 rotates, the winding rod 16 can be driven to rotate by the insert block 30. A third spring 39 is fixedly installed between the ratchet 36 and the mounting cylinder 13. When the winding disk 15 moves, the third spring 39 can be compressed by the ratchet 36, and when the adjustment handle 28 is released, the rebound force of the third spring 39 can be used to make the winding disk 15 drive the insert block 30 to quickly insert into the winding rod 16. A sealed sliding door is installed on the top of the projector body 1. The protective cloth belt 17 can be installed and removed by opening the sealed sliding door.

[0024] Working principle: First, the user places the forehead against the protective cloth belt 17 on the forehead rest 8 and leans forward, so that the forehead pushes the forehead rest 8 to move along the inner side of the installation box 7, and the wing plates on both sides of the forehead rest 8 pull the corresponding U-shaped rod 18 to move, so that the U-shaped rod 18 compresses the first spring 19, and the forehead rest 8 pushes the U-shaped frame 12 to move synchronously, so that the U-shaped frame 12 drives the two mounting frames 22 to move synchronously, and the mounting frame 22 drives the push rod 23 to move along the frame-shaped groove 24 on the rack plate 20, when the push rod 23 contacts the guide block 33 in the frame-shaped groove 24, the push rod 23 moves along the inclined surface of the guide block 33, and drives the slider 34 to compress the second spring 35, and the push rod 2 When the user moves away from the guide block 33, the rebound force of the second spring 35 is used to make the push rod 23 push against the inner side of the frame-shaped groove 24. At this time, the user's eyes are aligned with the eyepiece 4, and the vision test is performed through the projector body 1. The protective cloth belt 17 can absorb the grease overflowing from the user's forehead. After the user's vision test is completed, the user's forehead moves away from the forehead support 8. The rebound force of the first spring 19 is used to make the U-shaped rod 18 pull the forehead support 8 to move along the inner side of the installation box 7 to reset. The forehead support 8 drives the U-shaped frame 12 to move synchronously, so that the installation frame 22 drives the push rod 23 to move along the outer side of the guide block 33 and move to the inclined surface inside the frame-shaped groove 24, and the push rod 23 can pull The rack plate 20 moves downward, and the rack plate 20 stretches the two elastic telescopic rods 21, so that the teeth of the rack plate 20 contact the first gear 25 directly below. Subsequently, the push rod 23 moves from the inclined surface of the frame-shaped groove 24 to the plane of the frame-shaped groove 24, and the U-shaped frame 12 drives the first gear 25 on the mounting cylinder 13 to move along the teeth of the rack plate 20, so that the first gear 25 drives the mounting cylinder 13 to rotate, and the mounting cylinder 13 drives the winding disk 15 to rotate through the diamond rod 14, and the plug block 30 on the winding disk 15 drives the winding rod 16 to rotate, so that the winding rod 16 pulls the protective cloth belt 17 to move along the outer side of the first roller 11, and the grease on the protective cloth belt 17 can move The grease is collected and cleaned by the winding disk 15. At the same time, the winding disk 15 can drive the ratchet wheel 36 to rotate, so that the ratchet wheel 36 cooperates with the elastic tooth 37, so that the winding disk 15 will not rotate. When the push rod 23 moves to the left end of the frame-shaped groove 24, the elastic force of the telescopic rod 21 is used to reset the rack plate 20 upward. Therefore, when the forehead support 8 is under pressure, the first gear 25 will not rotate, and the one-way rotation of the winding rod 16 is realized. The grease of the protective cloth belt 17 will also be continuously collected between the winding rod 16 and the two winding disks 15, thereby achieving the effect of automatically cleaning the grease, ensuring the cleanliness of the forehead support 8, and facilitating multiple visual inspections. When cleaning the protective cloth tape 17, the staff opens the sealed sliding door on the projector body 1 and rotates the adjusting handle 28, so that the adjusting handle 28 drives the second gear 29 to rotate, and the second gear 29 drives the two movable racks 27 to move in opposite directions along the outer sides of the guide rod 38, and the movable rack 27 drives the winding disc 15 to move synchronously through the sleeve plate 26, and the winding disc 15 compresses the third spring 39 through the ratchet wheel 36, so that the plug block 30 on the winding disc 15 is pulled out from the slot of the winding rod 16, and the winding rod 16 equipped with the protective cloth tape 17 can be taken out from the installation box 7, and when the winding rod 16 is aligned with the two plug blocks 30 again, the staff releases the adjusting handle 28, and uses the resilience of the third spring 39 to move the winding disc 15 along the outer side of the diamond rod 14 to reset, and the plug block 30 can be inserted into the slot of the winding rod 16 again, so as to realize the rapid installation of the winding rod 16, thereby achieving the effect of rapid disassembly, cleaning and installation.

[0025] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ophthalmic vision test projector device, characterized in that: include: A projector body (1) and an operating base plate (2), wherein an adjustment handle (3) is mounted on the top of the operating base plate (2), an eyepiece (4), a display screen (5) and a printing port (6) are mounted on the outside of the projector body (1), an installation box (7) is arranged on the inside of the projector body (1), and a forehead support (8) is mounted on the inside of the installation box (7); Also includes: A protective mechanism, used for cleaning grease impurities on the forehead support (8), the protective mechanism being installed on the outer side of the forehead support (8); a replacement mechanism, used to enable the forehead support (8) to automatically collect grease impurities, the replacement mechanism being installed inside the installation box (7); The disassembly and assembly mechanism is used to remove and clean the grease impurities collected in the installation box (7); the disassembly and assembly mechanism is installed inside the installation box (7).

2. An ophthalmic vision testing projector device according to claim 1, characterized in that: The protective mechanism comprises a winding box (9) mounted on the top of the forehead support (8); a rotating rod (10) is rotatably mounted on one end of the forehead support (8) away from the mounting box (7); a first roller (11) is fixedly mounted on the outer side of the rotating rod (10); a U-shaped frame (12) is fixedly mounted on one end of the forehead support (8); two mounting cylinders (13) are rotatably mounted on the inner side of the U-shaped frame (12); a diamond rod (14) is mounted on the inner side of the mounting cylinder (13); a winding reel (15) is fixedly mounted on one end of the diamond rod (14); a winding rod (16) is arranged between the two winding reels (15); and the winding box (9) is butted against the winding rod (16) via a protective cloth belt (17).

3. An ophthalmic vision testing projector device according to claim 2, characterized in that: The exchange mechanism comprises two U-shaped rods (18) mounted at both ends of the forehead support (8), the U-shaped rods (18) slidingly passing through the mounting box (7), two first springs (19) being arranged on the outer side of the U-shaped rods (18), two rack plates (20) being arranged on the inner side of the mounting box (7), two elastic telescopic rods (21) being fixedly mounted between the rack plates (20) and the mounting box (7), a mounting frame (22) being fixedly mounted on the U-shaped frame (12), a push rod (23) being mounted on the inner side of the mounting frame (22), a frame-shaped groove (24) being arranged on the outer side of the rack plates (20), one end of the frame-shaped groove (24) being a slope structure, and a first gear (25) being fixedly mounted on the outer side of the mounting cylinder (13).

4. An ophthalmic vision testing projector device according to claim 3, characterized in that: The disassembly and assembly mechanism comprises a sleeve plate (26) rotatably mounted on one side of the winding disk (15), a movable rack (27) being fixedly mounted on one end of the sleeve plate (26), an adjustment handle (28) being rotatably mounted on the inner side of the U-shaped frame (12), a second gear (29) cooperating with the two movable racks (27) being fixedly mounted on the outer side of the adjustment handle (28), an insertion block (30) being fixedly mounted on one end of the winding disk (15), and slots for limiting insertion of the insertion block (30) being provided at both ends of the winding rod (16).

5. The ophthalmic vision testing projector device according to claim 2, characterized in that: Two second rollers (31) are rotatably mounted on the inner side of the forehead support (8).

6. The ophthalmic vision testing projector device according to claim 2, characterized in that: Positioning rollers (32) are rotatably mounted on the bottom and the bottom of the forehead support (8).

7. The ophthalmic vision testing projector device according to claim 3, characterized in that: A guide block (33) is fixedly mounted on one end of the frame-shaped groove (24), and the outer side of the guide block (33) is a slope structure.

8. The ophthalmic vision testing projector device according to claim 3, characterized in that: A sliding block (34) is fixedly mounted on the outer side of the support rod (23), and a second spring (35) is mounted between the inner side of the mounting frame (22) and the sliding block (34).

9. The ophthalmic vision testing projector device according to claim 4, characterized in that: A ratchet wheel (36) is fixedly mounted on one side of the winding disc (15), and an elastic locking tooth (37) matching with the ratchet wheel (36) is slidably mounted on the inner side of the sleeve plate (26).

10. The ophthalmic vision testing projector device according to claim 4, characterized in that: Two guide rods (38) are installed on the inner side of the U-shaped frame (12), and the guide rods (38) slide through the sleeve plate (26) and the movable rack (27).

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