A contact testing device for liquid crystal displays

Abstract

The application discloses a contact testing device for liquid crystal display screens, which comprises a backlight box body, a placing panel arranged on the backlight box body, fixing seats arranged on the two sides of the placing panel, a second shielding plate arranged on the top of the placing panel, a first shielding plate slidingly arranged on the side of the fixing seat opposite to the placing panel, the fixing seat being fixedly connected with the backlight box body, the second shielding plate being slidingly connected with the first shielding plate, the end of the first shielding plate close to the second shielding plate being provided with a transmission assembly, the transmission assembly being in transmission cooperation with the second shielding plate, and the first shielding plate being slid towards the display screen when the display screen is placed in the groove, so that the first shielding plate is attached to the side edge of the display screen, in the process, the first shielding plate drives the second shielding plate to move downwards and be attached to the top of the display screen through the transmission assembly, so that the interval between the display screen and the groove is blocked, and the strong light is prevented from being shot to the outside through the interval.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of display screen production, and particularly relates to a contact testing device for a liquid crystal display screen. BACKGROUND

[0002] In a display screen production and processing line, in order to ensure the quality of the display screen, the display screen needs to be subjected to light transmission detection. Light transmission testing is an important quality control step, and a backlight box is usually used in the process to test the display screen. Light transmission testing mainly detects bright spots, dark spots, bad spots and other defects on the display screen under high brightness. In some factories that do not apply full automation production and detection, when the display screen is subjected to backlight detection, the display screen is usually placed on the light source of the backlight box by manual operation, then the light source is started, and the unqualified product is removed by naked eye observation.

[0003] Chinese Patent Publication No. CN220438704U discloses a backlight detection device for a display screen backlight, which comprises a detection table, a movable groove, a through hole, a first fixing frame and a detection lens. The through hole is arranged at the top of the detection table, the movable groove is arranged at the bottom of the inner wall of the through hole, the first fixing frame is fixedly connected to the bottom of the right side of the inner wall of the through hole, and the detection lens is fixedly connected to the top of the detection table.

[0004] In the prior art, the size of the backlight box for backlight testing of the display screen is fixed, and the display screen has different sizes in the production process. Therefore, when the display screen is subjected to light transmission testing, the corresponding light shielding material needs to be attached or removed on the backlight box, so as to shield the excess light transmission area or leak the shielded light source, so as to realize the effect that the light source of the backlight box is completely irradiated on the display screen. However, according to the size of the display screen, the corresponding light shielding material needs to be attached or removed to adjust the light source to adapt to the display screen, and the operation is relatively cumbersome.

[0005] Therefore, it is necessary to provide a contact testing device for a liquid crystal display screen to solve the above technical problems. SUMMARY

[0006] The application aims to provide a contact testing device for a liquid crystal display screen to solve the problems in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a contact testing device for a liquid crystal display screen, comprising a backlight box body; a placement panel is provided on the backlight box body, fixed seats are provided on both sides of the placement panel, a second shielding plate is provided on the top of the placement panel, a first shielding plate is slidably disposed on one side of the fixed seat opposite to the placement panel, the fixed seat is fixedly connected to the backlight box body, the second shielding plate is slidably connected to the first shielding plate, a transmission component is provided at one end of the first shielding plate near the second shielding plate, the transmission component is in transmission cooperation with the second shielding plate, and when the first shielding plate moves toward the placement panel, the first shielding plate drives the second shielding plate to move toward the placement panel through the transmission component.

[0008] As a further aspect of the present invention: a protruding plate is provided at one end of the first shielding plate near the placement panel, the protruding plate being slidably attached to the top of the placement panel; a storage plate is fixedly provided at one end of the second shielding plate near the placement panel, and the storage plate being slidably attached to the top of the placement panel.

[0009] As a further aspect of the present invention: the bottom of the storage plate is provided with a sliding groove, and the two ends of the sliding groove are slidably connected to an extension plate. A locking block is fixedly connected to the end of the extension plate away from the storage plate. The end of the protruding plate near the extension plate is provided with a connecting groove that is slidably connected to the locking block. The bottom of the extension plate is slidably fitted to the top of the placement panel.

[0010] As a further embodiment of the present invention: a sealing cloth is fixedly provided at the bottom of one end of the storage plate near the first shielding plate, and the sealing cloth is provided on the side of the storage plate near the bottom of the backlight box body, and a slot is provided on the side wall of the extension plate to slide and fit with the sealing cloth.

[0011] As a further aspect of the present invention: square openings are provided on both sides of the top of the second shielding plate, and a mounting frame is elastically connected inside the square opening. The mounting frame is slidably connected to the inner wall of the second shielding plate. A rotating roller is rotatably connected to the side wall of the mounting frame near the extension plate. The end of the sealing cloth away from the storage plate slides through the side wall of the second shielding plate and extends into the square opening. The end of the sealing cloth extending into the square opening bypasses the mounting frame and is fixedly connected to the bottom of the inner wall of the square opening.

[0012] As a further embodiment of the present invention: a first trigger block is slidably disposed at the center of the side of the convex plate away from the fixed seat; a conveying groove is disposed in the side wall of the first shielding plate and extends to the convex plate; the first trigger block is slidably connected to the conveying groove; a sliding rod is fixedly disposed at the end of the first shielding plate away from the second shielding plate; the sliding rod is disposed on the side of the first shielding plate away from the placement panel; the end of the conveying groove away from the first trigger block extends into the side wall of the sliding rod; a placement groove communicating with the conveying groove is disposed at the bottom of the sliding rod; a limiting post is elastically connected in the placement groove; a limiting groove is disposed on the side wall of the backlight box body and is slidably adapted to the limiting post; the top of the limiting groove is communicating with the conveying groove; a vertical plate is fixedly disposed at the end of the sliding rod away from the first shielding plate; a first pressure relief hole communicating with the end of the conveying groove is disposed on the side wall of the vertical plate.

[0013] As a further aspect of the present invention: a second trigger block is slidably connected to the center of the storage plate; an airbag is fixedly connected to one end of the second trigger block near the storage plate; a first air tube is fixedly connected to both sides of the end of the airbag away from the second trigger block; an air cavity is provided inside the card block; a protruding post is elastically connected inside the air cavity; a circular groove adapted to slide with the protruding post is provided at the top of the inner wall of the connecting groove; the end of the first air tube away from the airbag is connected to the air cavity; and the end of the first air tube extends to the vertical plate after passing through the air cavity; a second pressure relief hole is provided on the vertical plate, which is connected to the first air tube; a valve is elastically connected to both the first and second pressure relief holes; and a square plate is fixedly connected to the end of each set of valves away from the slide rod.

[0014] As a further embodiment of the present invention: an auxiliary rod is fixedly provided at the bottom of the protruding post, and a sealing plate is fixedly connected to the bottom of the auxiliary rod. Both the auxiliary rod and the sealing plate are disposed in the air cavity, and the sealing plate is slidably connected to the air cavity.

[0015] As a further aspect of the present invention: the transmission assembly includes a rack; a second gear is driven between the opposite ends of the two sets of racks, the second gear is rotatably connected to the side wall of the backlight box body, a first gear is slidably connected to the top center of the second gear, a transmission groove is provided at the bottom center of the second shield, a tooth groove is provided on one side of the transmission groove to drive the first gear, a piston rod is fixedly connected to the bottom of the first gear, a circular plate is provided at the bottom of the piston rod to seal and slide against the inner wall of the second gear, and a through groove is provided at the bottom end of the piston rod, a second air pipe is rotatably connected to the center of the circular plate and communicates with the through groove, and the end of the second air pipe away from the circular plate communicates with the air chamber.

[0016] As a further aspect of the present invention: a baffle is fixedly connected to one end of the second baffle away from the storage plate, and a winding box is provided on the top of the backlight box body, and a winding roller for winding the baffle is provided inside the winding box.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: When in use, after the display screen is placed in the groove, the first shielding plate is slid towards the display screen so that the first shielding plate is in contact with the side of the display screen. During this process, the first shielding plate drives the second shielding plate to move downward and fit against the top of the display screen through the transmission component, thereby blocking the gap between the display screen and the groove and preventing strong light from shining out through the gap. Attached Figure Description

[0018] Figure 1 This is a frontal three-dimensional structural diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the rack structure in this invention.

[0020] Figure 3 For the present invention Figure 2 A schematic diagram of the structure at point A in the middle.

[0021] Figure 4 This is a schematic diagram of the structure of the sealing cloth and extension plate in this invention.

[0022] Figure 5 This is a schematic diagram of the cross-section of the middle part of the second shielding plate in this invention.

[0023] Figure 6 For the present invention Figure 5 A schematic diagram of the structure at point B.

[0024] Figure 7 This is a schematic diagram of the conveying trough in this invention.

[0025] Figure 8 This is a schematic diagram of the limiting post and limiting groove in this invention.

[0026] Figure 9 For the present invention Figure 8 A schematic diagram of the structure at point C.

[0027] Figure 10 This is a schematic diagram of the airbag structure in this invention.

[0028] Figure 11 This is a schematic diagram of the square opening structure in this invention.

[0029] Figure 12 This is a schematic diagram of the mounting frame and rotating roller in this invention.

[0030] In the diagram: 1. Backlight box body; 2. Placement panel; 3. Fixing base; 4. Second shield; 5. First shield; 6. First trigger block; 7. Slide rod; 8. Rewind box; 9. Cover cloth; 10. Rack; 11. Sealing cloth; 12. Extension plate; 13. Storage plate; 14. Second trigger block; 15. Airbag; 16. First air pipe; 17. First gear; 18. Second gear; 19. Connecting groove; 20. Mounting bracket; 21. Transmission groove; 22. Second air pipe; 23. Piston rod; 24. Conveying groove; 25. Limiting groove; 26. Limiting post; 27. Protruding post; 28. Circular groove; 29. ​​Locking block; 30. Locking slot; 31. Square opening; 32. Rotating roller; 33. Square plate; 34. Sealing plate. Detailed Implementation

[0031] Please see Figures 1-12 In this embodiment of the invention, a contact testing device for a liquid crystal display screen includes a backlight box body 1, a placement panel 2 is provided on the backlight box body 1, fixing seats 3 are provided on both sides of the placement panel 2, a second shielding plate 4 is provided on the top of the placement panel 2, a first shielding plate 5 is slidably provided on one side of the fixing seat 3 relative to the placement panel 2, the fixing seat 3 is fixedly connected to the backlight box body 1, the second shielding plate 4 is slidably connected to the first shielding plate 5, a transmission component is provided at one end of the first shielding plate 5 near the second shielding plate 4, the transmission component is in transmission cooperation with the second shielding plate 4, when the first shielding plate 5 moves toward the placement panel 2, the first shielding plate 5 drives the second shielding plate 4 to move toward the placement panel 2 through the transmission component.

[0032] Preferably, the backlight box body 1 includes a light source to provide uniform and stable backlighting, ensuring sufficient brightness for the display screen during testing. The backlight box body 1 is arranged in a right-angled trapezoidal shape, and the inclined angle of the backlight box body 1 facilitates the placement and observation of the display screen by personnel. The placement panel 2 is embedded in the center of the inclined surface on the backlight box body 1, and a groove structure is provided between the top of the inclined surface of the backlight box body 1 and the top of the placement panel 2. In use, the display screen can be stably placed on the placement panel 2 through the groove. The placement panel 2 is usually made of transparent plexiglass or acrylic material to ensure good light transmission and durability. The backlight box body 1 is also provided with a brightness switch button to facilitate the turning the light source on and off. The backlight box body 1 is a conventional device in the prior art for light transmission testing of the display screen. Its specific related structure and corresponding working principle will not be described in detail here.

[0033] In practical use, after the display screen is placed on the placement panel 2, in the initial state, the two sets of first shielding plates 5 are located on the sides of the groove, and the second shielding plate 4 is located on the top side of the groove. At this time, the groove is in its maximum exposed state. After the display screen is placed in the groove, if there is a gap between the exposed space of the groove and the display screen, in order to ensure that strong light does not pass through the gap and shine to the outside when the light source is turned on to perform light transmission detection on the display screen, because strong light shining to the outside will affect the personnel's observation of the light transmission of the display screen and may also cause damage to the personnel's eyes, after the display screen is placed in the groove, the first shielding plate 5 is slid towards the display screen so that the first shielding plate 5 is in contact with the side of the display screen. During this process, the first shielding plate 5 drives the second shielding plate 4 to move downward and fit with the top of the display screen through the transmission component, thereby blocking the gap between the display screen and the groove and preventing strong light from shining to the outside through the gap. Then, the light source is turned on by the switch button, so that the light source shines on the placement panel 2 to perform light transmission detection on the display screen on the placement panel 2. Finally, after the detection is completed, the light source is turned off and the display screen is removed to proceed to the detection of the next display screen.

[0034] Please see Figures 1-2 , Figure 4 , Figure 7 Preferably, the first shielding plate 5 has a protruding plate at one end near the placement panel 2, and the protruding plate is located in a groove at one end near the placement panel 2. The protruding plate slides and fits against the top of the placement panel 2. The second shielding plate 4 has a storage plate 13 fixedly installed at one end near the placement panel 2, and the storage plate 13 is located in a groove at one end near the placement panel 2. The storage plate 13 slides and fits against the top of the placement panel 2. In this way, during use, through the action of the protruding plate and the storage plate 13, after the first shielding plate 5 and the second shielding plate 4 are moved to adapt to the size of the display screen, strong light will not shine out from the gap between the first shielding plate 5, the second shielding plate 4 and the placement panel 2, affecting the personnel's observation and inspection of the display screen. The setting of the protruding plate and the storage plate 13 also prevents the first shielding plate 5 and the second shielding plate 4 from continuing to move past the display screen after the protruding plate and the storage plate 13 come into contact with the display screen, thus preventing the first shielding plate 5 and the second shielding plate 4 from fixing the display screen in the groove and making it impossible to remove.

[0035] Please see Figures 2-4 , Figures 10-11Preferably, the bottom of the storage plate 13 is provided with a groove, and the two ends of the groove are slidably connected to the extension plate 12 by springs. The end of the extension plate 12 away from the storage plate 13 is fixedly connected to the locking block 29. The end of the protruding plate near the extension plate 12 is provided with a connecting groove 19 that is slidably connected to the locking block 29. The bottom of the extension plate 12 is slidably attached to the top of the placement panel 2. In the initial state, the extension plate 12 protrudes from the groove under the action of the spring, and the bottom of the extension plate 12 is flush with the bottom of the storage plate 13, thereby achieving a fit with the placement panel 2. In use, when the two sets of first shielding plates 5 move closer to each other, the two sets of first shielding plates 5 push the two sets of extension plates 12 to move and retract into the groove, thereby making the protruding plate, extension plate 12, storage plate 13 fit the size of the display screen, thus providing a good light transmission detection environment.

[0036] Furthermore, preferably, a sealing cloth 11 is fixedly provided at the bottom of the end of the storage plate 13 near the first shielding plate 5, and the sealing cloth 11 is provided on the side of the storage plate 13 near the bottom of the backlight box body 1. A slot 30 is provided on the side wall of the extension plate 12 to slide and fit with the sealing cloth 11. When the sealing cloth 11 is fitted with the slot 30, the bottom of the sealing cloth 11 slides and fits with the placement panel 2, and the sealing cloth 11 slides and fits with the protrusion. The end of the sealing cloth 11 away from the storage plate 13 passes sequentially through the bottom of the extension plate 12 and the extension plate 13. The end of plate 12 near the convex plate avoids the problem of light leakage caused by the extension plate 12 and the storage plate 13 not being flush with the side of the backlight box body 1. The top of the sealing cloth 11 near the extension plate 12 is a semi-circular structure with a locking strip, and the slot 30 is provided with a semi-circular groove that matches the semi-circular structure, thereby limiting the sealing cloth 11 on the extension plate 12 and preventing the sealing cloth 11 from shifting during the movement of the extension plate 12. The side of the sealing cloth 11 away from the slot 30 is flush with the side wall of the storage plate 13.

[0037] Please see Figure 12Preferably, the top two sides of the second baffle plate 4 are provided with square openings 31. A mounting bracket 20 is elastically connected to the square opening 31 by a spring. The mounting bracket 20 is slidably connected to the inner wall of the second baffle plate 4. A rotating roller 32 is rotatably connected to the side wall of the mounting bracket 20 near the extension plate 12. The end of the sealing cloth 11 away from the storage plate 13 slides through the side wall of the second baffle plate 4 and extends into the square opening 31. The end of the sealing cloth 11 that extends into the square opening 31 passes around the mounting bracket 20 and is fixedly connected to the bottom of the inner wall of the square opening 31. In use, the mounting bracket 20 is set in an "L" structure. The corresponding spring on the mounting bracket 20 is set on the side of the mounting bracket 20 away from the extension plate 12. In the initial state, the mounting bracket 20 is in a square position. When the square opening 31 is close to one end of the extension plate 12, and the two sets of first baffles 5 move closer to each other, the first baffles 5 push the extension plate 12 into the slide groove. At this time, the sealing cloth 11 becomes loose. At the same time, the spring corresponding to the mounting bracket 20 pulls the mounting bracket 20 to move away from the sealing cloth 11 in the square opening 31. Since the end of the sealing cloth 11 is fixed to the square opening 31, the movement of the mounting bracket 20 will cause the extension plate 12 to move and retract into the slide groove, and the excess sealing cloth 11 will be stored in the square opening 31. This keeps the sealing cloth 11 corresponding to the slot 30 taut and prevents the sealing cloth 11 from becoming loose, which would affect the movement of the extension plate 12 and the subsequent light transmission detection of the display screen.

[0038] Please see Figures 1-5 , Figure 7 Preferably, a first trigger block 6 is slidably disposed at the center of the side of the convex plate away from the fixed base 3. A conveying groove 24 is disposed in the side wall of the first shielding plate 5, and the conveying groove 24 extends to the convex plate. The first trigger block 6 is slidably connected to the conveying groove 24, and the first trigger block 6 and the conveying groove 24 are elastically connected by a spring. A sliding rod 7 is fixedly disposed at the end of the first shielding plate 5 away from the second shielding plate 4. The sliding rod 7 is disposed on the side of the first shielding plate 5 away from the placement panel 2. The sliding rod 7 is elastically connected to the fixed base 3 by a spring. The end of the conveying groove 24 away from the first trigger block 6 extends to the sliding rod 7. Inside the side wall, the bottom of the slide rod 7 is provided with a placement groove that communicates with the conveying groove 24. The placement groove is elastically connected to the limiting post 26 by a spring. The side wall of the backlight box body 1 is provided with a limiting groove 25 that slides and adapts to the limiting post 26. Multiple sets of limiting grooves 25 are arranged in a horizontal array on the backlight box body 1. The top of the limiting groove 25 communicates with the conveying groove 24. A vertical plate is fixedly provided at the end of the slide rod 7 away from the first shielding plate 5. The side wall of the vertical plate is provided with a first pressure relief hole that communicates with the end of the conveying groove 24. The springs corresponding to the first trigger block 6 and the slide rod 7 are not shown in the figure.

[0039] In use, the first trigger block 6 is recessed within the groove, and in its initial state, the first trigger block 6 protrudes from the convex plate. The limiting post 26 is retracted into the placement groove, and the first pressure relief hole is closed. Thus, after the display screen is placed in the groove, to ensure that the first shielding plate 5 and the second shielding plate 4 are compatible with the size of the display screen and to cover any excess placement panel 2, the sliding rod 7 is used to move the first shielding plate 5 towards the display screen after the display screen is placed. This, in turn, causes the first trigger block 6 to move. Once the first trigger block 6 is in contact with the side of the display screen, it moves into the conveying groove 24. The movement of the first trigger block 6 causes the conveying groove 24 to... The moving gas inside is compressed, at which point the limiting post 26 will move downward in the placement groove and match a set of limiting grooves 25, thereby limiting the sliding rod 7 and limiting the position of the first shield 5. This avoids the problem of the first shield 5 being squeezed and damaged by the sliding rod 7 continuing to slide after it is attached to the side of the display screen. After all the display screen tests are completed, the pressure relief hole is opened to make the air pressure in the conveying groove 24 normal. Then the limiting post 26 and the first trigger block 6 automatically reset elastically, and the sliding rod 7 also automatically resets, thereby driving the first shield 5 to move and reset, ready for the next use.

[0040] Please see Figures 2-3 , Figures 8-9 Preferably, a second trigger block 14 is slidably connected to the center of the storage plate 13. An airbag 15 is fixedly connected to one end of the second trigger block 14 near the storage plate 13. A first air tube 16 is fixedly connected to both sides of the end of the airbag 15 away from the second trigger block 14. An air chamber is provided inside the locking block 29. A protruding post 27 is elastically connected to the air chamber by a spring. The protruding post 27 is slidably disposed on the top of the locking block 29. A circular groove 28 is provided on the top of the inner wall of the connecting groove 19 to slide and adapt to the protruding post 27. The circular groove 28 is along the connecting groove. The extension direction array of 19 is provided in multiple sets. The end of the first air tube 16 away from the airbag 15 passes through the extension plate 12 and the locking block 29 in sequence and communicates with the air chamber. After passing through the air chamber, the end of the first air tube 16 also passes through the protruding plate, the first shielding plate 5, and the side wall of the slide rod 7 and extends to the vertical plate. A second pressure relief hole is provided above the first pressure relief hole and communicates with the end of the first air tube 16. Valves are elastically connected in both the first pressure relief hole and the second pressure relief hole. The two sets of valves are fixedly connected to a square plate 33 at the end away from the slide rod 7.

[0041] Preferably, the bottom of the second trigger block 14 is flush with the bottom of the storage plate 13, and the two are connected in a sealed sliding manner. The airbag 15 has an elastic telescopic structure, that is, after the airbag 15 is compressed, it can automatically elastically return to its original position. In addition, the first air tube 16 is specifically divided into two sets. One set of the first air tube 16 connects the air chamber and the airbag 15, and the other set of the first air tube 16 extends from the side of the locking block 29 away from the airbag 15 to the second pressure relief hole at the end of the slide rod 7. Both sets of the first air tube 16 are connected to the air chamber. In use, when the second trigger block 14 slides into the storage plate 13, the second trigger block 14 squeezes the airbag 15 to contract, so that the gas in the airbag 15 enters the first air chamber. Inside the tube 16, the top of the protruding post 27 does not protrude from the top of the locking block 29 under the action of the corresponding spring in the initial state. At this time, the second pressure relief hole is blocked, so the gas enters the air chamber and pushes the protruding post 27 to move upward and cooperate with a set of circular grooves 28 to limit the position of the locking block 29, thereby limiting the position of the storage plate 13 and the extension plate 12. When the square plate 33 is pressed towards the sliding rod 7, the sliding rod 7 pushes the valve to open the second pressure relief hole, thereby connecting the first air tube 16 with the outside, and then the protruding post 27 elastically moves and resets, releasing the restriction on the locking block 29. Subsequently, the airbag 15 and the second trigger block 14 move and reset.

[0042] Furthermore, preferably, an auxiliary rod is fixedly provided at the bottom of the protruding post 27, and a sealing plate 34 is fixedly connected to the bottom of the auxiliary rod. Both the auxiliary rod and the sealing plate 34 are located inside the air cavity, and the sealing plate 34 is slidably connected to the air cavity. When the protruding post 27 moves upward, it drives the auxiliary rod and the sealing plate 34 to move upward. When the protruding post 27 is matched with the corresponding circular groove 28, the sealing plate 34 matches the end of a set of first air tubes 16 of the corresponding airbag 15, thereby blocking the first air tubes 16 from the air cavity. In this way, the gas entering the air cavity will not be automatically delivered to the airbag 15 after the second trigger block 14 is no longer under force after pushing the protruding post 27 upward. At the same time, the position of the second trigger block 14 is restricted to prevent the airbag 15 from moving and resetting after adjustment, which would affect the subsequent placement of the display screen.

[0043] Please see Figures 1-10 Preferably, the transmission assembly includes a rack 10 fixedly disposed at the end of the first baffle 5 away from the slide rod 7; a second gear 18 is driven between the opposite ends of the two sets of racks 10, and the second gear 18 is rotatably connected to the side wall of the backlight box body 1. There is a gap between the two sets of racks 10, and the teeth on the two sets of racks 10 are in a relative state. In this way, when one set of racks 10 moves, the other set of racks 10 moves synchronously through the second gear 18.

[0044] Furthermore, preferably, the first gear 17 is slidably connected to the top center of the second gear 18, and a spring is provided between the bottom of the first gear 17 and the second gear 18. A transmission groove 21 is provided at the bottom center of the second baffle plate 4, and a tooth groove that engages with the first gear 17 is provided on one side of the transmission groove 21. The size of the first gear 17 is larger than the size of the second gear 18, so that when the second gear 18 rotates, it synchronously drives the first gear 17 to rotate. The rotation of the first gear 17 causes the second baffle plate 4 to move through the tooth groove. When the two sets of first baffle plates 5 are relatively close, the second baffle plate 4 moves downward through the cooperation of the rack 10, the second gear 18, and the first gear 17. A fixing ring is provided in the middle of the second gear 18, and a spring is provided on the side of the fixing ring corresponding to the first gear 17.

[0045] Furthermore, preferably, a piston rod 23 is fixedly connected to the bottom of the first gear 17. A circular plate is provided at the bottom of the piston rod 23, which is in sealed sliding contact with the inner wall of the second gear 18. A through groove is provided at the bottom end of the piston rod 23. A second air pipe 22, which communicates with the through groove, is rotatably connected to the center of the circular plate. The end of the second air pipe 22 away from the circular plate passes through the side wall of the backlight box body 1 and the locking block 29 and communicates with the air chamber. The piston rod 23 is in sealed sliding contact with the fixing ring. A hole is provided on the side wall of the piston rod 23 to allow the through groove and the inside of the second gear 18 to communicate. In this way, when the airbag 15 is compressed during use, the gas in the airbag 15 enters the second air pipe 22 through the first air pipe 16 and the air chamber. Then the gas enters the through groove and the second gear 18. When the air pressure increases, the piston rod 23 moves away from the fixing ring, thereby driving the first gear 17 to separate from the tooth groove.

[0046] In practical use, when the first shielding plate 5 retracts into the fixed base 3, the second trigger block 14 protrudes from the side wall of the storage plate 13, the protrusion 27 retracts into the air cavity, the first gear 17 meshes with the tooth groove, and the second pressure relief hole is in a blocked state. When it is necessary to perform light transmission testing on the display screen, the display screen is placed on the placement panel 2, and then the first shielding plate 5 is slid towards the display screen. The movement of the first shielding plate 5 causes the rack 10 to move, which in turn drives another set of first shielding plates 5 to move towards the display screen synchronously through the second gear 18. The rotation of the second gear 18 drives the first gear 17 to rotate at the same time. The rotation of the first gear 17 causes the second shielding plate 4 to move towards the display screen through the tooth groove. When the first trigger block 6 and the second trigger block 14 are both in contact with the display screen and are pushed to retract into the protrusion plate and the storage plate 13 respectively, the adaptation of the display screen size is completed. The operation is simple. During this process, the second trigger block 14 moves and retracts into the storage plate. Within 13, the airbag 15 is compressed, causing the gas inside the airbag 15 to be transported to the air chamber through the first air tube 16, increasing the air pressure in the air chamber. This causes the protrusion 27 to move upward and engage with the circular groove 28 to limit the position of the locking block 29, thereby limiting the positions of the extension plate 12 and the storage plate 13. Subsequently, the piston rod 23 moves downward through the action of the second air tube 22, causing the first gear 17 to separate from the tooth groove, thus not hindering the continued movement of the first shielding plate 5 to adapt to the size of the display screen. When it is necessary to move and reset the first shielding plate 5 and the second shielding plate 4, pressing the square plate 33 connects the second pressure relief hole and the first pressure relief hole to the outside, thereby restoring the air pressure in the air chamber to normal. Then, the protrusion 27 moves and resets, and at the same time, the first gear 17 moves and resets and engages with the tooth groove again. Then, the first shielding plate 5 moves and resets, and the second shielding plate 4 moves and resets through the engagement of the rack 10 and the second gear 18.

[0047] Please see Figure 1Preferably, a baffle 9 is fixedly connected to the end of the second baffle 4 away from the storage plate 13. A winding box 8 is provided on the top of the backlight box body 1. A winding roller for winding the baffle 9 is provided inside the winding box 8. A coil spring is provided between the winding roller and the winding box 8. The automatic winding of the baffle 9 is achieved by the coil spring. A pressing block is slidably provided on the top of the second baffle 4. The pressing block is not shown in the figure, and the length of the pressing block matches the length of the transmission groove 21. In use, when the pressing block is driven to move towards the second baffle 4, the pressing block will cause the first gear 17 to move towards the second gear 18 and separate from the tooth groove, and then it can be driven towards the second baffle 4. The slider 7 slides the second shield 4, and the second shield 4 moves to pull the baffle 9 out of the take-up box 8. Before this, the first trigger block 6 needs to be pressed towards the first shield 5 so that the position of the first shield 5 is limited. When the second shield 4 moves so that the second trigger block 14 engages with the bottom edge of the groove, the second trigger block 14 squeezes the airbag 15 so that the protrusion 27 limits the position of the locking block 29. Thus, the second shield 4 and the baffle 9 work together to shield the placement panel 2, preventing dust or impurities from falling on the placement panel 2 due to long-term disuse, which would affect the subsequent testing of the display screen.

Claims

1. A contact testing device for a liquid crystal display screen, comprising a backlight box body; characterized in that, The backlight box body is provided with a placement panel, the placement panel is provided with fixed seats on both sides, the placement panel is provided with a second shielding plate on the top, the fixed seats are slidably provided with a first shielding plate on one side opposite to the placement panel, the fixed seats are fixedly connected to the backlight box body, the second shielding plate is slidably connected to the first shielding plate, and a transmission component is provided at one end of the first shielding plate near the second shielding plate. The transmission component is in transmission cooperation with the second shielding plate. When the first shielding plate moves toward the placement panel, the first shielding plate drives the second shielding plate to move toward the placement panel through the transmission component. A conveying groove is provided inside the side wall of the first shielding plate, and the conveying groove extends to the convex plate. A first trigger block is slidably provided at the center of the side of the convex plate away from the fixed base. The first trigger block is slidably connected to the conveying groove. A sliding rod is fixedly provided at the end of the first shielding plate away from the second shielding plate. The sliding rod is located on the side of the first shielding plate away from the placement panel. The end of the conveying groove away from the first trigger block extends into the side wall of the sliding rod. A placement groove communicating with the conveying groove is provided at the bottom of the sliding rod. A limiting post is elastically connected in the placement groove. A limiting groove is provided on the side wall of the backlight box body to slide and adapt to the limiting post. The top of the limiting groove is communicating with the conveying groove. A vertical plate is fixedly provided at the end of the sliding rod away from the first shielding plate. A first pressure relief hole communicating with the end of the conveying groove is provided on the side wall of the vertical plate. A storage plate is fixedly installed at one end of the second shielding plate near the placement panel. A second trigger block is slidably connected to the center of the storage plate. An airbag is fixedly connected to one end of the second trigger block near the storage plate. A first air tube is fixedly connected to both sides of the end of the airbag away from the second trigger block. A sliding groove is provided at the bottom of the storage plate. An extension plate is slidably connected to both ends of the sliding groove. A locking block is fixedly connected to one end of the extension plate away from the storage plate. An air cavity is provided in the locking block. A protruding column is elastically connected to the air cavity. The end of the first air tube away from the airbag is connected to the air cavity. The end of the first air tube extends to the vertical plate after passing through the air cavity. A second pressure relief hole is provided on the vertical plate, which is connected to the first air tube. A valve is elastically connected to both the first and second pressure relief holes. A square plate is fixedly connected to one end of each set of valves away from the sliding rod. The transmission assembly includes a rack; a second gear is driven between the opposite ends of two sets of racks, the second gear is rotatably connected to the side wall of the backlight box body, a first gear is slidably connected to the top center of the second gear, a transmission groove is provided at the bottom center of the second shield, a tooth groove is provided on one side of the transmission groove to drive the first gear, a piston rod is fixedly connected to the bottom of the first gear, a circular plate is provided at the bottom of the piston rod to seal and slide against the inner wall of the second gear, and a through groove is provided at the bottom end of the piston rod, a second air pipe is rotatably connected to the center of the circular plate and communicates with the through groove, the end of the second air pipe away from the circular plate communicates with the air chamber; a protruding plate is provided at the end of the first shield near the placement panel, the protruding plate is slidably attached to the top of the placement panel, and the storage plate is slidably attached to the top of the placement panel; the protruding plate extends near the extension One end of the plate is provided with a connecting groove that slides with the card block. The top of the inner wall of the connecting groove is provided with a circular groove that slides with the protrusion. The bottom of the extension plate slides against the top of the placement panel. A sealing cloth is fixedly provided at the bottom of the end of the storage plate near the first shielding plate. The sealing cloth is located on the side of the storage plate near the bottom of the backlight box body. A card groove that slides against the sealing cloth is provided on the side wall of the extension plate. Square openings are provided on both sides of the top of the second shielding plate. A mounting bracket is elastically connected to the square opening. The mounting bracket is slidably connected to the inner wall of the second shielding plate. A rotating roller is rotatably connected to the side wall of the mounting bracket near the extension plate. The end of the sealing cloth away from the storage plate slides through the side wall of the second shielding plate and extends into the square opening. The end of the sealing cloth that extends into the square opening bypasses the mounting bracket and is fixedly connected to the bottom of the inner wall of the square opening.

2. The contact testing device for a liquid crystal display screen according to claim 1, characterized in that, An auxiliary rod is fixedly installed at the bottom of the protruding post, and a sealing plate is fixedly connected to the bottom of the auxiliary rod. Both the auxiliary rod and the sealing plate are installed inside the air cavity, and the sealing plate is slidably connected to the air cavity.

3. The contact testing device for a liquid crystal display screen according to claim 1, characterized in that, The second shielding plate has a baffle cloth fixedly connected to one end away from the storage plate. The top of the backlight box body is provided with a winding box, and a winding roller for winding the baffle cloth is provided inside the winding box.

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