Printed matter quality detection device

Abstract

The embodiment of the invention discloses a printed matter quality detection device, and relates to the technical field of printed matter detection. The quality detection device comprises a replacement mechanism, the replacement mechanism comprises two supporting plates, a guide plate is arranged between the two supporting plates, the two ends of the guide plate are circular arcs, the bottom of the guide plate protrudes downwards to form a table top, and a plurality of connecting blocks are jointly fixed to the guide plate and the two supporting plates; wherein a plurality of fixing plates are arranged between the two supporting plates, and the replacement mechanism further comprises a driving assembly enabling each fixing plate to move along the outer contour of the guide plate. According to the embodiment of the invention, the conveying assembly and the replacement mechanism are arranged, the scanning modules are arranged above the conveying assembly and the replacement mechanism, the lower conveying belt scans one side of a printed matter, then the replacement mechanism replaces the printed matter to the upper side, and meanwhile, turn-over and scanning of the internal scanning modules are completed, so that double-sided detection is realized; and no obstacle hinders scanning during detection.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of printed matter detection, and in particular, to a printed matter quality detection device. Background Art

[0002] Printing is a technology that transfers ink to the surface of materials such as paper, fabric, plastic and leather through processes such as plate making, inking and pressurizing to copy the contents of original manuscripts in batches. With the development of printing technology, printed materials are used more and more widely in various fields, and the requirements for printing quality are getting higher and higher. It is usually necessary to test the printing quality (such as pattern or image quality). At present, most printed materials are printed on both sides, so it is necessary to test both sides of the printed materials.

[0003] At present, in order to facilitate the detection of double-sided printed products, some detection devices have been specifically set up, such as the Chinese invention patent with publication number CN117849060A; however, during the detection process, the detection is generally performed by scanning and identifying the printed pattern and printed color. At this time, the scanned surface of the printed product must be free of obstacles to ensure the accuracy of the recognition; but the conveyor belt of the above-mentioned device is likely to obstruct the printed product, thereby affecting the scanning and recognition, and affecting the detection results. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a printed product quality detection device to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above objectives, this application proposes the following technical solutions:

[0006] The embodiment of the present application provides a printed product quality inspection device, the quality inspection device includes a replacement mechanism, the replacement mechanism includes two support plates, a guide plate is arranged between the two support plates, both ends of the guide plate are arcs, and the bottom of the guide plate protrudes downward to form a table, and the guide plate and the two support plates are jointly fixed with a plurality of connection blocks;

[0007] Among them, multiple fixed plates are arranged between the two support plates, and the replacement mechanism also includes a driving assembly for moving each fixed plate along the outer contour of the guide plate, multiple suction cylinders are slidably inserted into the outer side of the fixed plate, and a pressure plate is commonly fixed at one end of each suction cylinder on each fixed plate, and a plurality of suction holes are opened on the plate surface of the pressure plate, and the plurality of suction holes are coaxially arranged one by one with the plurality of suction cylinders, and a cross bar is commonly fixed at the other end of each suction cylinder on each fixed plate, and an elastic structure for lifting the suction cylinder upward is arranged on the outer side of the fixed plate, and the cross bar on the suction cylinder contacts the guide plate with the aid of the elastic structure.

[0008] As an embodiment, the driving assembly includes two annular guide rails, which are respectively fixed to two support plates, and the two ends of the annular guide rails are respectively coaxially arranged with the two ends of the guide plate, and the two ends of the fixed plate are fixed with sliders adapted to the annular guide rails, and the two ends of each fixed plate are respectively slidably mounted on the two annular guide rails through the sliders.

[0009] As an embodiment, the drive assembly also includes a servo motor, and both ends of the support plate and the guide plate are provided with rotating holes, and each rotating hole on the same end is jointly rotatably mounted with a transmission rod, the servo motor is fixed to one of the support plates, and the output shaft of the servo motor is coaxially fixed to the transmission rod, and synchronous wheels coaxially arranged therewith are fixed to the outer sides of both ends of the transmission rod, and the two synchronous wheels on the same side are jointly sleeved with a synchronous belt, and the synchronous belt is fixed to each slider on the same side.

[0010] As an embodiment, the elastic structure includes a limit plate and a spring. The limit plate is fixed to the air cylinder. The limit plate is located between the cross bar and the fixed plate. The spring is sleeved on the air cylinder. The two ends of the spring are respectively in contact with the limit plate and the fixed plate and maintain a compressed state.

[0011] As an implementation mode, a roller is rotatably sleeved on the outer side of the cross bar, and the roller on the cross bar contacts the guide plate with the help of the elastic force of a spring.

[0012] As an implementation manner, two parallel strip-shaped air knives are fixed to the outer side of one of the support plates, and the air knife openings of the strip-shaped air knives are flush with the pressing plate.

[0013] As an implementation manner, a fixing frame is fixed to the outer side of one of the support plates, and a photoelectric sensor is fixed to the bottom end of the fixing frame.

[0014] As an embodiment, a conveying assembly is arranged below the replacement mechanism, and the conveying assembly includes an electric telescopic rod, a base frame, a first belt conveyor, a second belt conveyor and a third belt conveyor, the outer frame of the first belt conveyor and the outer frame of the third belt conveyor are both fixed on the base frame, the second belt conveyor is arranged between the first belt conveyor and the third belt conveyor, and one end of the outer frame of the second belt conveyor is rotatably mounted on the base frame, a first concave block is fixed inside the base frame, a second concave block is fixed at the bottom of the outer frame of the second belt conveyor, both ends of the electric telescopic rod are rotatably mounted on the first concave block and the second concave block respectively, a top support plate is fixed inside the outer frame of the third belt conveyor, the top support plate is arranged in the inner area of ​​the belt of the third belt conveyor, and the top support plate contacts the inner top of the belt.

[0015] As an embodiment, a first cover shell is fixed on the top of the outer frame of the first belt conveyor, a first scanning module is fixed inside the first cover shell, a second cover shell is fixedly installed on the top of the two support plates, and a second scanning module is fixedly installed inside the second cover shell.

[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0017] 1. The embodiment of the present application is provided with a conveying assembly and a replacement mechanism, and a scanning module is provided above the conveying assembly and the replacement mechanism. After the conveyor belt below scans one side of the printed matter, the replacement mechanism then replaces the printed matter to the top, and at the same time completes the flipping, and the internal scanning module performs scanning, thereby realizing double-sided detection, and there are no obstacles to hinder the scanning during the detection. During the replacement process of the replacement mechanism of the embodiment of the present application, the replacement plate in the replacement mechanism compacts the printed matter so that the printed matter can be evenly unfolded to prevent the printed matter from wrinkling, which then affects the scanning result.

[0018] 2. The replacement mechanism of the embodiment of the present application can work continuously, that is, it can continuously absorb the printed matter in the conveying component, so that the entire detection process has no pause process, which is in line with batch detection to ensure the efficiency of the printed matter detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the three-dimensional structure of an embodiment of the present application;

[0021] Figure 2 This is a front view structural schematic diagram of an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the three-dimensional structure of the replacement mechanism of an embodiment of the present application;

[0023] Figure 4 for Figure 3 A schematic diagram of the enlarged structure at point A;

[0024] Figure 5 A schematic diagram of the internal structure of the replacement mechanism of an embodiment of the present application;

[0025] Figure 6 A cross-sectional view of a replacement mechanism according to an embodiment of the present application;

[0026] Figure 7 It is a schematic diagram of the three-dimensional structure of the elastic structure, the air suction cylinder, the cross bar, the roller and the pressure plate of the embodiment of the present application;

[0027] Figure 8 This is a schematic diagram of the three-dimensional structure of the pressure plate according to an embodiment of the present application.

[0028] Reference numerals:

[0029] 1. Base frame; 2. First belt conveyor; 3. First cover shell; 4. Second belt conveyor; 5. Third belt conveyor; 6. Replacement mechanism; 7. Second cover shell; 8. Electric telescopic rod; 9. First concave block; 10. Second concave block; 11. Support plate; 12. Servo motor; 13. Transmission rod; 14. Synchronous wheel; 15. Synchronous belt; 16. Strip air knife; 17. Annular guide rail; 18. Photoelectric sensor; 19. Fixed frame; 20. Connecting block; 21. Slider; 22. Guide plate; 23. Cross bar; 24. Spring; 25. Limiting plate; 26. Suction cylinder; 27. Fixed plate; 28. Roller; 29. ​​Top support plate; 30. Pressing plate; 31. Suction hole. DETAILED DESCRIPTION

[0030] In order to more fully understand the technical content of the present application, the present application will be further introduced and explained in conjunction with the drawings and specific embodiments below; it should be noted that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate directions or positional relationships that are not given the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are used to distinguish different components, etc., and do not represent a sequence, nor do they limit "first" and "second" to being different types.

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments; based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the present application.

[0032] Example:

[0033] See also Figure 1 , Figure 3 and Figure 5 This embodiment provides a printed product quality inspection device, which includes a replacement mechanism 6. The replacement mechanism 6 includes two support plates 11. A guide plate 22 is arranged between the two support plates 11.

[0034] Combination Figure 5 and Figure 6 As shown, both ends of the guide plate 22 are arcs, and the bottom of the guide plate 22 protrudes downward to form a table surface. The guide plate 22 and the two support plates 11 are jointly fixed with a plurality of connection blocks 20 .

[0035] A plurality of fixing plates 27 are disposed between the two support plates 11 , and the replacement mechanism 6 further includes a driving assembly for moving each fixing plate 27 along the outer contour of the guide plate 22 .

[0036] Please continue reading Figure 7 and Figure 8 A plurality of suction cylinders 26 are slidably inserted on the outer side of the fixed plate 27, and a pressing plate 30 is fixed to one end of each suction cylinder 26 on each fixed plate 27. A plurality of suction holes 31 are opened on the surface of the pressing plate 30, and the plurality of suction holes 31 are coaxially arranged one by one with the plurality of suction cylinders 26. A cross bar 23 is fixed to the other end of each suction cylinder 26 on each fixed plate 27, and an elastic structure for lifting the suction cylinder 26 upward is arranged on the outer side of the fixed plate 27.

[0037] It can be understood that in this embodiment, the cross bar 23 on the suction cylinder 26 contacts the guide plate 22 with the help of an elastic structure; when the cross bar 23 passes through the downward protrusion of the guide plate 22, the cross bar 23 drives each suction cylinder 26 to move downward, and the pressure plate 30 on the suction cylinder 26 moves downward with the suction cylinder 26.

[0038] The quality inspection device of this embodiment is suitable for inspecting printed materials, such as advertising brochures, art books, magazines and periodicals, to ensure that the printed materials meet the expected visual effects and quality requirements by inspecting the image quality of the printed materials.

[0039] The driving assembly and the elastic structure of this embodiment will be described in detail below.

[0040] Please continue reading Figure 5 and Figure 6 As shown, the above-mentioned driving assembly includes two annular guide rails 17, and the two annular guide rails 17 are respectively fixed to the two support plates 11, and the two ends of the annular guide rails 17 are respectively coaxially arranged with the two ends of the guide plate 22, and the two ends of the fixed plate 27 are fixed with sliders 21 adapted to the annular guide rails 17, and the two ends of each fixed plate 27 are respectively slidably mounted on the two annular guide rails 17 through the sliders 21; the annular guide rails 17 and the sliders 21 are arranged to ensure that the fixed plate 27 can move along the outer contour of the guide plate 22.

[0041] It is understandable that the annular guide rail 17 and the slider 21 are both prior art. Figure 5 The structure of the annular guide rail 17 and the slider 21 is shown.

[0042] Please continue reading Figure 3 and Figure 5 As shown, the driving assembly also includes a servo motor 12, and both ends of the support plate 11 and the guide plate 22 are provided with rotating holes, and each rotating hole on the same end is rotatably mounted with a transmission rod 13, the servo motor 12 is fixed to one of the support plates 11, and the output shaft of the servo motor 12 is coaxially fixed to the transmission rod 13, and synchronous wheels 14 coaxially arranged therewith are fixed to the outer sides of both ends of the transmission rod 13, and the two synchronous wheels 14 on the same side are jointly sleeved with a synchronous belt 15, and the synchronous belt 15 is fixed to each slider 21 on the same side.

[0043] Based on the above structure, the servo motor 12 rotates the transmission rod 13 fixed thereto through the output shaft, and the synchronous wheel 14 on the transmission rod 13 rotates synchronously with the transmission rod 13. The synchronous wheels 14 on both sides of the same side rotate synchronously through the synchronous belt 15. It can be seen that the synchronous belt 15 performs transmission motion. Since the synchronous belt 15 is fixed to each slider 21 on the same side, the synchronous belt 15 slider 21 moves along the annular guide rail 17.

[0044] Please combine Figure 5 , Figure 6 and Figure 7 As shown, the elastic structure includes a limit plate 25 and a spring 24. The limit plate 25 is fixed to the air cylinder 26. The limit plate 25 is located between the cross bar 23 and the fixed plate 27. The spring 24 is sleeved on the air cylinder 26. The two ends of the spring 24 are respectively in contact with the limit plate 25 and the fixed plate 27 and maintained in a compressed state. A roller 28 is rotatably sleeved on the outer side of the cross bar 23. The roller 28 on the cross bar 23 is in contact with the guide plate 22 with the help of the elastic force of the spring 24.

[0045] It should be noted that this embodiment provides additional explanation for the suction cylinder 26. The suction cylinder 26 has a miniature vacuum pump inside (such as a miniature diaphragm vacuum pump of model VM7002, VAA6005, or PC3025); the spring 24 applies an upward thrust to the limit plate 25, and the limit plate 25 transfers the force to the suction cylinder 26. The suction cylinder 26 drives the cross bar 23 to move upward, and the roller 28 on the cross bar 23 maintains contact with the guide plate 22 at all times with the help of the elastic force of the spring 24.

[0046] Specifically, combined Figure 3 and Figure 5As shown, two parallel strip air knives 16 are fixed on the outside of one of the support plates 11, and the air knife opening of the strip air knife 16 is flush with the pressing plate 30; it should be noted that an air compressor is arranged outside the quality inspection device, and the air inlet end of the strip air knife 16 is connected to the air outlet end of the air compressor. The air compressor is a prior art, and the air compressor mainly compresses the air to form a high-speed airflow and sends it into the strip air knife 16. The strip air knife 16 blows away the printed matter on the pressing plate 30 by spraying strip compressed air. It can be understood that two guide hoppers are fixed on the other support plate 11, and the two guide hoppers are arranged one by one with the two strip air knives 16.

[0047] Specifically, combined Figure 3 and Figure 4 As shown, a fixing frame 19 is fixed to the outer side of one of the support plates 11, and a photoelectric sensor 18 is fixed to the bottom end of the fixing frame 19; the photoelectric sensor 18 is used to identify the position of the pressing plate 30; when the pressing plate 30 passes the photoelectric sensor 18, the micro vacuum pump inside the suction cylinder 26 is started.

[0048] The transmission component of this embodiment will be described in detail below.

[0049] Please continue reading Figure 1-Figure 4 A conveying assembly is arranged below the replacement mechanism 6, and the conveying assembly includes an electric telescopic rod 8, a base frame 1, a first belt conveyor 2, a second belt conveyor 4 and a third belt conveyor 5. The outer frame of the first belt conveyor 2 and the outer frame of the third belt conveyor 5 are both fixed on the base frame 1, the second belt conveyor 4 is arranged between the first belt conveyor 2 and the third belt conveyor 5, and one end of the outer frame of the second belt conveyor 4 is rotatably mounted on the base frame 1, a first concave block 9 is fixed inside the base frame 1, a second concave block 10 is fixed at the bottom of the outer frame of the second belt conveyor 4, two ends of the electric telescopic rod 8 are rotatably mounted on the first concave block 9 and the second concave block 10 respectively, and a top support plate 29 is fixed inside the outer frame of the third belt conveyor 5, the top support plate 29 is arranged in the inner belt area of ​​the third belt conveyor 5, and the top support plate 29 is in contact with the inner top of the belt.

[0050] Among them, the first belt conveyor 2, the second belt conveyor 4 and the third belt conveyor 5 are all existing technologies, and their specific structures and working principles are not elaborated in detail here.

[0051] It can be understood that the printed matter is intermittently fed onto the transport belt of the first belt conveyor 2. If the printed matter is detected as qualified, the printed matter is continuously fed to the third belt conveyor 5, at which time the moving speed of the pressing plate 30 is made the same as the belt transmission speed of the third belt conveyor 5; when the pressing plate 30 passes through the photoelectric sensor 18, the micro vacuum pump inside the suction cylinder 26 is started, and when the cross bar 23 passes through the downward protrusion of the guide plate 22, the cross bar 23 drives each suction cylinder 26 to move downward, and the pressing plate 30 on the suction cylinder 26 moves downward with the suction cylinder 26, and the pressing plate 30 presses the printed matter onto the belt, and the top support plate 29 provides a support surface, and the suction cylinder 26 generates negative pressure to adsorb the printed matter onto the pressing plate 30; when the printed matter is detected as unqualified, the electric push rod is shortened, and the second belt conveyor 4 is tilted to remove the unqualified printed matter.

[0052] Specifically, a first cover shell 3 is fixed on the top of the outer frame of the first belt conveyor 2, a first scanning module is fixed inside the first cover shell 3, a second cover shell 7 is fixedly installed on the top of the two support plates 11, and a second scanning module is fixedly installed inside the second cover shell 7; the first scanning module and the second scanning module can use existing CCD scanning modules, such as the TSL1401CL linear CCD module, which can efficiently and accurately collect image information of printed materials.

[0053] It can be understood that a controller is provided outside the entire device, and each of the above-mentioned electrical appliances (electrical components) is electrically connected to the controller.

[0054] The working principle of this embodiment will be further described below:

[0055] (1) The printed matter is intermittently fed onto the conveying belt of the first belt conveyor 2;

[0056] (2) The first scanning module on the first belt conveyor 2 detects the printed matter;

[0057] (3) When the printed product is detected as unqualified, the electric push rod is shortened, and the second belt conveyor 4 is tilted to remove the unqualified printed product;

[0058] When the printed product is detected as qualified, it is sent to the third belt conveyor 5. At this time, the moving speed of the pressing plate 30 is the same as the belt transmission speed of the third belt conveyor 5. When the pressing plate 30 passes through the photoelectric sensor 18, the photoelectric sensor 18 will detect the signal and transmit it to the controller, and the controller starts the micro vacuum pump inside the suction cylinder 26; when the cross bar 23 passes the downward protrusion of the guide plate 22, the cross bar 23 drives each suction cylinder 26 to move downward, and the pressing plate 30 on the suction cylinder 26 moves downward with the suction cylinder 26. The pressing plate 30 presses the printed product on the belt, and the top support plate 29 provides a supporting surface. The suction cylinder 26 generates negative pressure to suck the printed product Attached to the pressure plate 30, after the vacuum cylinder 26 is separated from the table of the guide plate 22, the vacuum cylinder 26 is reset and takes the printed matter away from the third belt conveyor 5. When the vacuum cylinder 26 is reset and moved upward, the other side of the printed matter passes through the second scanning module; at this time, the controller stops the vacuum machine inside the vacuum cylinder 26, and the second scanning module performs scanning. If the printed matter is detected as unqualified, the strip air knife 16 close to the second scanning module will spray air to spray the printed matter toward the guide hopper aligned with it; if the printed matter is detected as qualified, the strip air knife 16 away from the second scanning module will spray air to spray the printed matter toward the guide hopper aligned with it.

[0059] The technical solutions provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present application. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present application. At the same time, for those skilled in the art, according to the embodiments of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. A printed product quality inspection device, comprising a replacement mechanism (6), characterized in that: The replacement mechanism (6) comprises two support plates (11), a guide plate (22) is arranged between the two support plates (11), both ends of the guide plate (22) are arcs, and the bottom of the guide plate (22) protrudes downward to form a table, and the guide plate (22) and the two support plates (11) are jointly fixed with a plurality of connection blocks (20); A plurality of fixed plates (27) are arranged between the two support plates (11), the replacement mechanism (6) further comprises a driving assembly for moving each fixed plate (27) along the outer contour of the guide plate (22), a plurality of suction cylinders (26) are slidably inserted on the outer side of the fixed plate (27), and a pressing plate (30) is commonly fixed to one end of each suction cylinder (26) on each fixed plate (27); The plate surface of the pressure plate (30) is provided with a plurality of suction holes (31), and the plurality of suction holes (31) are coaxially arranged one by one with the plurality of suction cylinders (26); the other end of each suction cylinder (26) on each fixed plate (27) is commonly fixed with a cross bar (23); an elastic structure for lifting the suction cylinder (26) upward is arranged on the outer side of the fixed plate (27); the cross bar (23) on the suction cylinder (26) contacts the guide plate (22) with the aid of the elastic structure.

2. The printed matter quality detection device according to claim 1, characterized in that: The driving assembly comprises two annular guide rails (17), the two annular guide rails (17) are respectively fixed to the two support plates (11), and the two ends of the annular guide rails (17) are respectively coaxially arranged with the two ends of the guide plate (22), and the two ends of the fixed plate (27) are fixed with sliders (21) adapted to the annular guide rails (17), and the two ends of each fixed plate (27) are respectively slidably sleeved on the two annular guide rails (17) through the sliders (21).

3. The printed matter quality detection device according to claim 2, characterized in that: The driving assembly further comprises a servo motor (12), both ends of the support plate (11) and the guide plate (22) are provided with rotation holes, each rotation hole on the same end is provided with a transmission rod (13) for rotation therewith, the servo motor (12) is fixed to one of the support plates (11), the output shaft of the servo motor (12) is coaxially fixed to the transmission rod (13), both ends of the transmission rod (13) are fixed with synchronous wheels (14) coaxially arranged therewith, the two synchronous wheels (14) on the same side are jointly sleeved with a synchronous belt (15), and the synchronous belt (15) is fixed to each slider (21) on the same side.

4. The printed matter quality detection device according to claim 1, characterized in that: The elastic structure comprises a limit plate (25) and a spring (24); the limit plate (25) is fixed to the air suction cylinder (26); the limit plate (25) is located between the cross bar (23) and the fixed plate (27); the spring (24) is sleeved on the air suction cylinder (26); two ends of the spring (24) are respectively in contact with the limit plate (25) and the fixed plate (27) and are kept in a compressed state.

5. The printed matter quality detection device according to claim 1, characterized in that: The outer rotating sleeve of the cross bar (23) is provided with a roller (28), and the roller (28) on the cross bar (23) contacts the guide plate (22) by means of the elastic force of the spring (24).

6. The printed matter quality detection device according to claim 1, characterized in that: Two parallel strip-shaped air knives (16) are fixed on the outer side of one of the support plates (11), and the air knife openings of the strip-shaped air knives (16) are flush with the pressing plate (30).

7. The printed matter quality inspection device according to claim 1, characterized in that: A fixing frame (19) is fixed to the outer side of one of the support plates (11), and a photoelectric sensor (18) is fixed to the bottom end of the fixing frame (19).

8. The printed matter quality detection device according to claim 7, characterized in that: A conveying assembly is arranged below the replacement mechanism (6), and the conveying assembly comprises an electric telescopic rod (8), a base frame (1), a first belt conveyor (2), a second belt conveyor (4) and a third belt conveyor (5); the outer frame of the first belt conveyor (2) and the outer frame of the third belt conveyor (5) are both fixed on the base frame (1); the second belt conveyor (4) is arranged between the first belt conveyor (2) and the third belt conveyor (5); one end of the outer frame of the second belt conveyor (4) is rotatably mounted on the base frame (1); a first concave block (9) is fixed inside the base frame (1); a second concave block (10) is fixed at the bottom of the outer frame of the second belt conveyor (4); two ends of the electric telescopic rod (8) are rotatably mounted on the first concave block (9) and the second concave block (10) respectively; a top support plate (29) is fixed inside the outer frame of the third belt conveyor (5); the top support plate (29) is arranged in the inner area of ​​the belt of the third belt conveyor (5), and the top support plate (29) is in contact with the inner top of the belt.

9. The printed matter quality detection device according to claim 8, characterized in that: A first cover shell (3) is fixed on the top of the outer frame of the first belt conveyor (2), a first scanning module is fixed inside the first cover shell (3), a second cover shell (7) is fixedly installed on the top of the two support plates (11), and a second scanning module is fixedly installed inside the second cover shell (7).

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