A galvanometer LSU control method

Abstract

The present invention provides a galvanometer LSU control method, comprising the following steps: S1. Acquiring a print instruction issued by a user via a client; S2. Generating corresponding print data on the client based on the received print instruction; S3. The client or printer driver reversely converts the print data output from right to left; S4. The client or printer driver transmits the print data to the printer; S5. The printer program controls the oscillation of the galvanometer according to the type of the printed document, such as text or image, to execute the print task. The present invention applies a galvanometer LSU to a laser printer. Prior to exposure, the print data direction is pre-converted, and programming is used to synchronize the galvanometer's swing amplitude and period with the data direction of the content to be printed. This ensures that the printed image is normal. Compared to traditional LSUs, the galvanometer LSU has the advantages of lower cost, lower noise, and lower energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of laser printing, and in particular to a galvanometer laser unit (LSU) control method. Background Art

[0002] The galvanometer is an excellent vector scanning device that is driven by an oscillating motor. The basic principle is that an energized coil generates torque in a magnetic field. However, unlike a rotating motor, a restoring torque is applied to the rotor through a mechanical torsion spring or electronic means. The magnitude of the restoring torque is proportional to the angle at which the rotor deviates from the equilibrium position. When a certain current is passed through the coil and the rotor deflects to a certain angle, the electromagnetic torque is equal to the restoring torque. Therefore, it cannot rotate like an ordinary motor and can only deflect, and its deflection angle is proportional to the current. Since the galvanometer LSU has the advantages of lower cost, lower noise and lower energy consumption compared to the traditional LSU, the galvanometer LSU has a good application prospect in laser printers. When a laser printer uses a galvanometer LSU to print, the laser source emits light to the galvanometer, and the galvanometer reflects the light and hits the photosensitive drum through the lens to form an electrostatic latent image. Since the galvanometer can only deflect, the light reflected by the galvanometer sweeps back and forth on the photosensitive drum. This method is very different from the traditional LSU. The traditional LSU reflects light in only one direction and does not change direction, while the galvanometer LSU sweeps back and forth from left to right and from right to left. The order of output data is different, and it is difficult to continue to use the data control method of the traditional LSU. Summary of the Invention

[0003] In view of the above problems, the present invention provides a galvanometer LSU control method.

[0004] The present invention is implemented through the following technical solution: A galvanometer LSU control method includes the following steps:

[0005] S1. Obtain the printing instruction issued by the user through the client;

[0006] S2. Generate corresponding print data on the client according to the received print instruction;

[0007] S3: The client side or printer side driver reversely converts the print data output from right to left;

[0008] S4. The client side or the printer side driver transmits the print data to the printer;

[0009] S5. The printer program controls the swing of the galvanometer according to the type of the printed document, such as text or image, to execute the printing task.

[0010] Furthermore, the client is a mobile phone, a PC or an embedded device with a printing function.

[0011] Furthermore, the step S5 specifically includes the following steps:

[0012] Use image processing or text recognition technology to extract text or image information from printed documents;

[0013] According to the document type, set the oscillation frequency, direction and amplitude parameters of the galvanometer;

[0014] Use programming language to write the control program of the galvanometer, and control the swing of the galvanometer according to the document type and control parameters;

[0015] The oscillation mode of the galvanometer is tested and optimized by adjusting control parameters or modifying the program.

[0016] Furthermore, the client-side or printer-side driver transmits the processed print data to the printer via a network, a data cable or Bluetooth transmission.

[0017] Furthermore, the printing instruction includes the content to be printed in documents, images and other formats, as well as the output format, color, resolution, paper size and other printing parameters of the content.

[0018] Furthermore, the programming language is Python or MATLAB.

[0019] Furthermore, it also includes using an edge detection algorithm to extract edge information of the content to be printed, and determining the swing angle and speed of the galvanometer according to the edge information. The specific steps are:

[0020] Extract edge information of the content to be printed by edge detection algorithm;

[0021] Identifying the extracted edge information and determining the edges related to the printed content;

[0022] Calculate the swing amplitude and period of the galvanometer based on the identified edge position and intensity;

[0023] According to the calculated galvanometer swing amplitude and period, the swing angle and speed of the galvanometer are controlled.

[0024] Furthermore, the swing amplitude and period of the galvanometer are synchronized with the data direction of the content to be printed.

[0025] Furthermore, the edge detection algorithm is a Canny algorithm.

[0026] Furthermore, the specific steps of using the Canny algorithm to extract edge information of the content to be printed are:

[0027] T1. Grayscale the content to be printed, converting the color content to be printed into black and white content to be printed;

[0028] T2. Perform Gaussian blur filtering on the content to be printed to reduce noise in the content to be printed;

[0029] T3. Perform dual threshold processing on the content to be printed, dividing the content to be printed into two areas: a high threshold area and a low threshold area;

[0030] T4. For the high threshold area, calculate the gradient between adjacent pixels and determine whether they are edge pixels; for the low threshold area, similarly calculate the gradient between adjacent pixels and determine whether they are edge pixels;

[0031] T5. For the detected edge pixels, calculate the gradient direction and gradient magnitude around them to determine the direction and strength of the edge;

[0032] T6. Connect the detected edge pixels to form an edge curve;

[0033] T7. Smooth the edge curve to remove noise on the edge, and output the extracted edge curve and edge intensity.

[0034] The beneficial effects of the present invention are:

[0035] The present invention applies a galvanometer LSU to a laser printer. Before exposure, the printing data direction is converted in advance, and the swing amplitude and period of the galvanometer are synchronized with the data direction of the content to be printed through programming, so that the printed image is a normal image. Compared with the traditional LSU, the galvanometer LSU has the advantages of lower cost, lower noise, and lower energy consumption. The Canny algorithm is used to extract edge information of the content to be printed, and the swing of the galvanometer is controlled according to the edge of the document content, which can increase the printing speed and reduce the ineffective swing of the galvanometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the laser printing principle based on the galvanometer LSU according to an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the data conversion process on a PC or mobile phone according to an embodiment of the present invention;

[0038] Figure 3 Schematic diagram of the process of data conversion on the printer side according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] like Figure 1 The figure shows a schematic diagram of the laser printing principle based on a galvanometer LSU according to an embodiment of the present invention. During printing, a laser source emits light onto the galvanometer, which reflects the light and impinges on the photosensitive drum through a lens, forming an electrostatic latent image. Unlike a conventional LSU, which reflects light in a single direction and does not change direction, a galvanometer LSU sweeps back and forth, outputting data in a different order from left to right and from right to left. Therefore, the data control method used by conventional LSUs cannot be used. Therefore, this embodiment proposes a galvanometer LSU control method that converts the print data before exposure. Specifically, when the galvanometer LSU sweeps from left to right, the data is processed normally; however, when sweeping from right to left, the entire row of data needs to be mirrored. This ensures that the printed image is normal.

[0041] A galvanometer LSU control method comprises the following steps:

[0042] S1. Obtain the printing instruction issued by the user through the client;

[0043] S2. Generate corresponding print data on the client according to the received print instruction; wherein the print instruction includes the content to be printed in documents, images, or other formats, as well as the output format, color, resolution, paper size, and other printing parameters of the content; the client is a mobile phone, PC, or embedded device with printing function;

[0044] S3, the client side or printer side driver reversely converts the print data output from right to left; specifically, Figure 2 As shown, the data conversion method on the PC or mobile phone side is as follows: before sending the print data to the printer, the PC or mobile phone side will reversely convert all the print data output from right to left, and then send it to the printer to execute the printing action;

[0045] like Figure 3 As shown, the data conversion method on the printer side is as follows: No special processing is required on the PC or mobile phone side. After receiving the data, the printer will reverse the print data output from right to left and then send it to the printer to execute the printing action. It should be noted that the data reversal operation involved is implemented by the relevant image-text conversion software installed on the client or printer.

[0046] S4. The client-side or printer-side driver transmits the print data to the printer; optionally, the client-side or printer-side driver transmits the processed print data to the printer via a network, a data cable, or Bluetooth transmission;

[0047] S5. The printer program controls the oscillation of the galvanometer according to the type of the printed document, such as text or image, and executes the printing task. The specific steps are:

[0048] Use image processing or text recognition technology to extract text or image information from printed documents;

[0049] According to the document type, set the oscillation frequency, direction and amplitude parameters of the galvanometer;

[0050] Use programming language to write the control program of the galvanometer, and control the swing of the galvanometer according to the document type and control parameters;

[0051] The oscillation mode of the galvanometer is tested and optimized by adjusting control parameters or modifying the program.

[0052] A preferred solution of this embodiment is to further use an edge detection algorithm to extract edge information of the content to be printed, and determine the swing angle and speed of the galvanometer according to the edge information. The specific steps are as follows:

[0053] (1) Extracting edge information of the content to be printed using an edge detection algorithm; the edge detection algorithm is the Canny algorithm. Specifically, the steps for extracting edge information of the content to be printed using the Canny algorithm are:

[0054] T1. Grayscale the content to be printed, converting the color content to be printed into black and white content. In image processing, grayscale conversion is a technique for converting a color image into a black and white image. This is done by multiplying each pixel in the color image by a value of one of the three primary colors, summing the values, and then dividing the result by 3 to convert the RGB value of each pixel into its grayscale value. This allows the color image to be converted into a black and white image, where each pixel contains information about only one color.

[0055] T2. Perform a Gaussian blur filter on the content to be printed to reduce the noise in the content to be printed. By applying a Gaussian kernel to each pixel in the image, the pixel values ​​around the pixel are weighted averaged to reduce the influence of noise, making the image clearer while retaining the image's detail information.

[0056] T3. Perform dual threshold processing on the content to be printed, dividing the content to be printed into two areas: a high threshold and a low threshold. By setting two thresholds, the pixels in the image are divided into two categories: pixels above the threshold and pixels below the threshold, so as to separate different areas in the image.

[0057] T4. For the high threshold area, calculate the gradient between adjacent pixels and determine whether they are edge pixels; for the low threshold area, similarly calculate the gradient between adjacent pixels and determine whether they are edge pixels; gradient refers to the rate of change of pixel values ​​in an image. In the Canny algorithm, gradient is used to detect edges in an image. For the high threshold area, pixels with a gradient greater than a certain threshold are considered edge pixels, and for the low threshold area, pixels with a gradient less than or equal to a certain threshold are also considered edge pixels;

[0058] T5. For the detected edge pixels, calculate the gradient direction and gradient magnitude around them to determine the direction and strength of the edge. For the detected edge pixels, the Canny algorithm calculates the gradient direction and gradient magnitude around them to determine the direction and strength of the edge. The gradient direction indicates the direction of the edge, and the gradient magnitude indicates the strength of the edge.

[0059] T6. Connect the detected edge pixels to form an edge curve. The edge curve is formed by connecting adjacent edge pixels. During the connection process, if the distance between two edge pixels is less than a threshold, they are considered to be adjacent.

[0060] T7. Smooth the edge curve to remove noise on the edge, and output the extracted edge curve and edge strength;

[0061] (2) Identify the extracted edge information and determine the edges related to the printed content;

[0062] (3) calculating the swing amplitude and period of the galvanometer based on the identified edge position and intensity; the swing amplitude and period of the galvanometer are synchronized with the data direction of the content to be printed, and the identified edge position and intensity parameters of the content to be printed correspond to the width of the galvanometer on the printing paper after passing through the lens;

[0063] (4) Based on the calculated galvanometer swing amplitude and period, the programming language is Python or MATLAB to control the swing angle and speed of the galvanometer.

[0064] The above-described embodiments merely represent preferred embodiments of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications, improvements, and substitutions without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A galvanometer LSU control method, characterized in that: The following steps are involved: S1. Obtain the printing instruction issued by the user through the client; S2. Generate corresponding print data on the client according to the received print instruction; S3: The client side or printer side driver reversely converts the print data output from right to left; S4. The client side or the printer side driver transmits the print data to the printer; S5. The printer program controls the oscillation of the galvanometer according to the type of the print document and executes the print task; It also includes using an edge detection algorithm to extract edge information of the content to be printed, and determining the swing angle and speed of the galvanometer based on the edge information. The specific steps are: Extract edge information of the content to be printed by edge detection algorithm; Identifying the extracted edge information and determining the edges related to the printed content; Calculate the swing amplitude and period of the galvanometer based on the identified edge position and intensity; According to the calculated galvanometer swing amplitude and period, the swing angle and speed of the galvanometer are controlled; The swing amplitude and period of the galvanometer are synchronized with the data direction of the content to be printed; The edge detection algorithm is the Canny algorithm; The specific steps of using the Canny algorithm to extract edge information of the content to be printed are: T1. Grayscale the content to be printed, converting the color content to be printed into black and white content to be printed; T2. Perform Gaussian blur filtering on the content to be printed to reduce noise in the content to be printed; T3. Perform dual threshold processing on the content to be printed, dividing the content to be printed into two areas: a high threshold area and a low threshold area; T4. For the high threshold area, calculate the gradient between adjacent pixels and determine whether they are edge pixels; for the low threshold area, similarly calculate the gradient between adjacent pixels and determine whether they are edge pixels; T5. For the detected edge pixels, calculate the gradient direction and gradient magnitude around them to determine the direction and strength of the edge; T6. Connect the detected edge pixels to form an edge curve; T7. Smooth the edge curve to remove noise on the edge, and output the extracted edge curve and edge intensity.

2. A galvanometer LSU control method according to claim 1, characterized in that: The client is a mobile phone, PC or an embedded device with printing function.

3. A galvanometer LSU control method according to claim 1, characterized in that: The step S5 specifically includes the following steps: Use image processing or text recognition technology to extract text or image information from printed documents; According to the document type, set the oscillation frequency, direction and amplitude parameters of the galvanometer; Use programming language to write the control program of the galvanometer, and control the swing of the galvanometer according to the document type and control parameters; The oscillation mode of the galvanometer is tested and optimized by adjusting control parameters or modifying the program.

4. The galvanometer LSU control method according to claim 1, characterized in that: The client-side or printer-side driver transmits the processed print data to the printer via a network, a data cable or Bluetooth transmission.

5. The galvanometer LSU control method according to claim 1, characterized in that: The printing instruction includes the content to be printed in documents, images and other formats, as well as the output format, color, resolution, paper size and other printing parameters of the content.

6. A galvanometer LSU control method according to claim 3, characterized in that: The programming language is Python or MATLAB.

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