Laser printer imaging quality detection device and method thereof

Abstract

The application discloses a kind of laser printer imaging quality detection device and method thereof, wherein device includes first high-speed camera, control system, drive mechanism being arranged in the support shaft of photosensitive roller two ends;First high-speed camera is used to the image acquisition of the content that has been printed on paper and is transmitted to control system;Control system is used to obtain the image transmission of first high-speed camera and carries out paper surface defect detection, if detecting there is black dot, control system controls laser printer body to stop running;If detecting that handwriting is not the same in depth, control system controls laser printer body to stop running, and sends drive signal to drive mechanism;Drive mechanism is fixedly connected with photosensitive roller, for controlling photosensitive roller reciprocating sliding after receiving drive signal, so that carbon powder on photosensitive roller is evenly distributed.The application can implement the automatic detection of imaging quality when printing, and according to detection result, corresponding processing is carried out, avoid continuously printing low-quality data or improve printing quality.

Description

Technical Field

[0001] This invention relates to the field of laser printer technology, and in particular to a laser printer imaging quality testing device and method. Background Technology

[0002] A laser printer is a printing output device that combines laser scanning technology and electrophotographic technology. Its basic working principle is that binary data information from a computer is converted into a video signal by a video controller, then the video interface / control system converts the video signal into a laser drive signal, the laser scanning system generates a laser beam carrying character information, and finally the electrophotographic system images the laser beam and transfers it onto paper.

[0003] As laser printers are used more frequently and for longer periods, black spots or uneven ink density can sometimes occur on the paper during laser imaging, resulting in poor print quality. Therefore, there is a need to improve the laser printer imaging quality detection device and method to optimize laser printer performance. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention provides a laser printer imaging quality detection device and method to solve the problem that existing laser printers cannot automatically identify imaging quality.

[0005] In a first aspect, a laser printer imaging quality detection device is provided, including a first high-speed camera, a control system, and a drive mechanism disposed in the support shafts at both ends of the photosensitive roller;

[0006] The first high-speed camera is used to capture images of the printed content on the paper and transmit them to the control system;

[0007] The control system is used to acquire images transmitted by the first high-speed camera and perform paper surface defect detection. If black spots are detected, the control system controls the laser printer to stop running. If uneven writing is detected, the control system controls the laser printer to stop running and sends a drive signal to the drive mechanism.

[0008] The drive mechanism is fixedly connected to the photosensitive roller and is used to control the photosensitive roller to slide back and forth after receiving the drive signal sent by the control system, so that the toner on the photosensitive roller is evenly distributed.

[0009] Furthermore, the drive mechanism is symmetrically arranged within the support shafts at both ends of the photosensitive roller, and the drive mechanism includes:

[0010] Miniature push rod, fixedly installed on the inner wall of the support shaft;

[0011] The support block is connected to the output end of the miniature actuator.

[0012] A connecting column, one end of which is connected to a support block;

[0013] A square cylinder is fixedly installed on the inner wall of the support shaft. It has long grooves symmetrically arranged on both sides and a conductive plate at its bottom. A sliding electromagnet is installed inside. The other end of the connecting column passes through one long groove and is fixedly connected to one end of the electromagnet. The other end of the electromagnet is fixedly connected to a round rod, and the other end of the round rod passes through the other long groove and is fixedly connected to the photosensitive roller.

[0014] The miniature push rod and electromagnet are both electrically connected to the control system.

[0015] Furthermore, the electromagnet is adapted to the conductive plate, and the sum of the heights of the conductive plate and the electromagnet is equal to the cavity height of the square tube.

[0016] Furthermore, the miniature push rods of the two drive mechanisms operate synchronously.

[0017] Furthermore, it also includes a display screen electrically connected to the control system, the display screen being used to display the types of paper surface defects detected by the control system.

[0018] Furthermore, it also includes a second high-speed camera electrically connected to the control system. The second high-speed camera is used to acquire images on the photosensitive roller and transmit them to the control system. The control system is also used to compare the image on the photosensitive roller with the content image on the transferred paper to determine whether the quality of the printed content on the paper is up to standard.

[0019] Furthermore, it also includes a support set inside the laser printer, on which a detection box is fixedly installed, the second high-speed camera is installed on the detection box, and the control system is set inside the detection box.

[0020] Secondly, a method for detecting the imaging quality of a laser printer is provided, which utilizes the laser printer imaging quality detection device described above, and includes the following steps:

[0021] The first high-speed camera captures images of the printed content on the paper and transmits them to the control system.

[0022] The control system detects paper surface defects based on images transmitted from the first high-speed camera.

[0023] If a black dot is detected, the control system will stop the laser printer from running.

[0024] If uneven ink density is detected, the control system stops the laser printer and controls the drive mechanism to drive the photosensitive roller to slide back and forth, so that the toner on the photosensitive roller is evenly distributed.

[0025] Furthermore, it also includes displaying the detected paper surface defect types on a display screen.

[0026] Furthermore, before capturing images of the printed content on the paper using the first high-speed camera, the process also includes:

[0027] After the photosensitive roller is irradiated by the laser emitter and an image is formed, the image on the photosensitive roller is captured and transmitted to the control system.

[0028] After the first high-speed camera captures images of the printed content on the paper and transmits them to the control system, the system also includes:

[0029] The control system compares the image from the photosensitive roller with the image of the content on the transferred paper to determine whether the quality of the printed content on the paper is up to standard.

[0030] This invention proposes a laser printer imaging quality detection device and method. By acquiring images of paper, the device automatically detects paper imaging defects based on the acquired images. When black spots are detected, the control system stops the laser printer to prevent the continuous printing of low-quality data and facilitates the handling of defects by staff. Similarly, when inconsistent text depth is detected, the control system stops the laser printer to prevent the continuous printing of low-quality data. Simultaneously, the control system activates the drive mechanism to drive the photosensitive roller to slide back and forth, evenly distributing the toner on the roller and improving the uneven text depth. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the laser printer imaging quality detection device provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the photosensitive roller and driving mechanism provided in an embodiment of the present invention.

[0034] In the diagram: 1. Display screen; 2. Laser printer body; 3. Support; 4. Detection box; 5. Laser emitter; 7. Control system; 8. Second high-speed camera; 12. Charging roller; 13. Support shaft; 14. Photosensitive roller; 15. Paper; 16. First high-speed camera; 17. Miniature push rod; 18. Conductive plate; 19. Support block; 20. Connecting column; 21. Electromagnet; 22. Round rod; 23. Long groove; 24. Square cylinder; 25. Developing roller. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "center," "longitudinal," "lateral," "vertical," and "horizontal," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. When an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present.

[0037] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or order.

[0038] Example 1

[0039] like Figure 1 , Figure 2 As shown, this embodiment provides a laser printer imaging quality detection device, including a first high-speed camera 16, a control system 7, and a drive mechanism disposed in the support shafts 13 at both ends of the photosensitive roller 14;

[0040] The first high-speed camera 16 is used to capture images of the printed content on the paper and transmit them to the control system 7;

[0041] The control system 7 is used to acquire images transmitted by the first high-speed camera 16 and perform paper surface defect detection. If black spots are detected, the control system 7 controls the laser printer to stop running. If uneven writing is detected, the control system 7 controls the laser printer to stop running and sends a drive signal to the drive mechanism.

[0042] The drive mechanism is fixedly connected to the photosensitive roller 14 and is used to control the photosensitive roller 14 to slide back and forth after receiving the drive signal sent by the control system, so that the toner on the photosensitive roller 14 is evenly distributed.

[0043] Specifically, the laser printer body 2 is equipped with a developing roller 25, and a photosensitive roller 14 is mounted above the developing roller 25. A charging roller 12 is rotatably connected to the right side of the photosensitive roller 14. Support shafts 13 are provided at both ends of the photosensitive roller 14. The interior of the support shafts is a hollow structure, and drive mechanisms are symmetrically arranged inside the two support shafts. The first high-speed camera 16 is located on the paper output side of the photosensitive roller 14 and can be fixed inside the laser printer body 2 by a bracket. It should be noted that... Figure 1 The paper 15 shown does not move within the laser printer body 2. Figure 1 As shown, Figure 1 This is for illustrative purposes only. Inside the laser printer body 2, there is also a support 3. A detection box is fixedly connected to one side of the support 3. A laser emitter 5 is set on the side of the detection box corresponding to the photosensitive roller. The control system 7 is set inside the detection box.

[0044] More specifically, the drive mechanism is symmetrically arranged inside the support shafts at both ends of the photosensitive roller. The drive mechanism includes: a miniature push rod 17, fixedly installed on the inner wall of the support shaft 13; a support block 19, connected to the output end of the miniature push rod 17; a connecting column 20, one end of which is connected to the support block 19; a square cylinder 24, fixedly installed on the inner wall of the support shaft 13, with long grooves 23 symmetrically arranged on both sides of the cylinder, a conductive plate 18 at the bottom of the cylinder, and a slidable electromagnet 21 inside the cylinder. The other end of the connecting column 20 passes through one long groove 23 and is fixedly connected to one end of the electromagnet 21. The other end of the electromagnet 21 is fixedly connected to a round rod 22, and the other end of the round rod 22 passes through the other long groove 23 and is fixedly connected to the photosensitive roller 14. The miniature push rod 17 and the electromagnet 21 are both electrically connected to the control system. It should be noted that during normal printing, the electromagnet 21 is energized and is fixed to the conductive plate 18, and the two cannot move. The rotating mechanism inside the laser printer body drives the photosensitive roller to rotate through the two support shafts 13, and the laser printer can print normally. When a defect of uneven text depth is detected, the control system controls the electromagnet 21 to be de-energized. At this time, the electromagnet 21 is released from the conductive plate and can slide inside the square cylinder 24. At this time, the control system controls the two micro push rods 17 to run synchronously, which can drive the photosensitive roller to slide back and forth, so that the toner on the photosensitive roller is evenly distributed, thereby improving the uneven text depth of the printed text.

[0045] In this embodiment, the electromagnet is adapted to the conductive plate. The square cylinder 24 has a hollow cuboid shape inside, and the sum of the heights of the conductive plate and the electromagnet inside is equal to the height of the cavity in the square cylinder, which allows the electromagnet 21 to be stabilized in the square cylinder 24. The miniature push rods of the two drive mechanisms operate synchronously, ensuring that the movement of both ends of the photosensitive roller remains consistent, thus realizing the reciprocating sliding of the photosensitive roller.

[0046] Preferably, the system also includes a display screen 1 electrically connected to the control system 7. The display screen 1 is mounted on the upper surface of the laser printer body 2. The display screen 1 is used to display the type of paper surface defects detected by the control system 7, such as black spots or uneven writing.

[0047] Preferably, the system further includes a second high-speed camera 8 electrically connected to the control system 7. The second high-speed camera 8 is used to acquire images of the photosensitive roller 14 and transmit them to the control system 7. The image acquired by the second high-speed camera 8 represents the graphic patterns or even text content that should be printed on the subsequent paper. This image can serve as a standard for determining whether the quality of the printed content on the paper is up to standard. If the content quality is not up to standard, there may be a malfunction in the transfer process, and the control system 7 can control the laser printer to stop for inspection.

[0048] In one specific implementation, the control system can detect paper surface defects based on images transmitted by the first high-speed camera using a convolutional neural network model. A large number of paper images, including those with black spot defects, uneven handwriting depth, and normal paper, can be pre-collected and labeled with defect type tags to construct training and testing sets. Then, the convolutional neural network model is trained based on the training and testing sets to obtain a paper printing defect detection model. The input of this model is the image collected by the first high-speed camera, and its output is the defect type tag corresponding to the image.

[0049] In another specific implementation, the control system processes the image transmitted from the first high-speed camera using Gaussian filtering, dilation erosion, and median filtering. Any black spots in the processed image will be eliminated. Therefore, comparing the processed image with the original image transmitted from the first high-speed camera will reveal the differences in black spots, thus achieving black spot defect detection. Furthermore, since the image itself should be continuous, gradient and edge detection algorithms are applied to the image, and its continuity is compared. If it is discontinuous, it indicates inconsistent depth, thus achieving inconsistent handwriting defects detection.

[0050] Example 2

[0051] Based on the laser printer imaging quality detection device as described in Example 1, this embodiment provides a laser printer imaging quality detection method, including the following steps:

[0052] The first high-speed camera captures images of the printed content on the paper and transmits them to the control system.

[0053] The control system detects paper surface defects based on images transmitted from the first high-speed camera.

[0054] If a black dot is detected, the control system will stop the laser printer from running.

[0055] If uneven ink density is detected, the control system stops the laser printer and controls the drive mechanism to drive the photosensitive roller to slide back and forth, so that the toner on the photosensitive roller is evenly distributed.

[0056] More specifically, a complete laser printer image quality inspection process includes:

[0057] S1: The charging roller 12 rotates close to the photosensitive roller 14 and applies charge to the surface of the photosensitive roller 14 to prepare for the imaging process;

[0058] S2: The photosensitive roller 14 is irradiated by the light from the laser emitter 5 to form an image. The second high-speed camera 8 captures the image on the photosensitive roller 14, and the irradiated area of ​​the photosensitive roller 14 shows a positive charge. This image is the graphic pattern or even text content that should be printed on the paper. The image serves as the standard for the image processing module to determine whether the content on the paper is up to standard.

[0059] S3: The toner moves to the surface of the developing roller 25. During the movement, the toner becomes negatively charged and is attracted by the positively charged part of the photosensitive roller 14.

[0060] S4: The toner on the photosensitive roller 14 is transferred to the paper 15, and the toner melts and is fixed on the paper 15.

[0061] S5: The first high-speed camera 16 continuously captures images on the surface of the paper 15, and the control system automatically detects defects on the paper surface.

[0062] S6: When black spots are detected, the control system stops the laser printer body 2, allowing the operator to handle the defect. When uneven ink density is detected, the control system stops the laser printer body 2. Simultaneously, the electromagnet 21 is de-energized, and the micro push rod 17 operates, causing the photosensitive roller 14 to slide back and forth, ensuring even distribution of toner in the roller. Since toner is crucial for printing, it's essential to ensure even ink distribution to prevent uneven ink density. The reciprocating motion of the photosensitive roller 14 further disperses toner in areas with high concentrations. The system also displays the detected paper surface defects on the screen, such as black spots or uneven ink density. Furthermore, the control system compares the image from the photosensitive roller with the image of the printed content on the paper to determine if the quality is acceptable. If the content quality is unacceptable, a malfunction in the transfer process may exist, and the control system can stop the laser printer body 2 for inspection.

[0063] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A laser printer imaging quality inspection device, characterized in that, It includes a first high-speed camera, a control system, and a drive mechanism located within the support shafts at both ends of the photosensitive roller; The first high-speed camera is used to capture images of the printed content on the paper and transmit them to the control system; The control system is used to acquire images transmitted by the first high-speed camera and perform paper surface defect detection. If black spots are detected, the control system controls the laser printer to stop running. If uneven writing is detected, the control system controls the laser printer to stop running and sends a drive signal to the drive mechanism. The drive mechanism is fixedly connected to the photosensitive roller and is used to control the photosensitive roller to slide back and forth after receiving the drive signal sent by the control system, so that the toner on the photosensitive roller is evenly distributed. The drive mechanism is symmetrically arranged within the support shafts at both ends of the photosensitive roller, and the drive mechanism includes: Miniature push rod, fixedly installed on the inner wall of the support shaft; The support block is connected to the output end of the miniature actuator. A connecting column, one end of which is connected to a support block; A square cylinder is fixedly installed on the inner wall of the support shaft. It has long grooves symmetrically arranged on both sides and a conductive plate at its bottom. A sliding electromagnet is installed inside. The other end of the connecting column passes through one long groove and is fixedly connected to one end of the electromagnet. The other end of the electromagnet is fixedly connected to a round rod, and the other end of the round rod passes through the other long groove and is fixedly connected to the photosensitive roller. The miniature push rod and electromagnet are both electrically connected to the control system.

2. The laser printer imaging quality inspection device according to claim 1, characterized in that, The electromagnet is adapted to the conductive plate, and the sum of the heights of the conductive plate and the electromagnet is equal to the cavity height of the square tube.

3. The laser printer imaging quality inspection device according to claim 1, characterized in that, The miniature push rods of the two drive mechanisms operate synchronously.

4. The laser printer imaging quality inspection device according to claim 1, characterized in that, It also includes a display screen electrically connected to the control system, the display screen being used to display the types of paper surface defects detected by the control system.

5. The laser printer imaging quality inspection device according to claim 1, characterized in that, It also includes a second high-speed camera electrically connected to the control system. The second high-speed camera is used to acquire images on the photosensitive roller and transmit them to the control system. The control system is also used to compare the image on the photosensitive roller with the content image on the transferred paper to determine whether the quality of the printed content on the paper is up to standard.

6. The laser printer imaging quality inspection device according to claim 5, characterized in that, It also includes a support set inside the laser printer, on which a detection box is fixedly installed, the second high-speed camera is installed on the detection box, and the control system is set inside the detection box.

7. A method for detecting the imaging quality of a laser printer, characterized in that, The laser printer imaging quality inspection device as described in any one of claims 1 to 6 is used to achieve the following steps: The first high-speed camera captures images of the printed content on the paper and transmits them to the control system. The control system detects paper surface defects based on images transmitted from the first high-speed camera. If a black dot is detected, the control system will stop the laser printer from running. If uneven ink density is detected, the control system stops the laser printer and controls the drive mechanism to drive the photosensitive roller to slide back and forth, so that the toner on the photosensitive roller is evenly distributed.

8. The laser printer imaging quality detection method according to claim 7, characterized in that, Also includes: The detected paper surface defects are displayed on the screen.

9. The laser printer imaging quality detection method according to claim 7, characterized in that, Before capturing images of the printed content on the paper using a first high-speed camera, the process also includes: After the photosensitive roller is irradiated by the laser emitter and an image is formed, the image on the photosensitive roller is captured and transmitted to the control system. After the first high-speed camera captures images of the printed content on the paper and transmits them to the control system, the system also includes: The control system compares the image from the photosensitive roller with the image of the content on the transferred paper to determine whether the quality of the printed content on the paper is up to standard.

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