Color correction method, image forming apparatus, and storage medium

Abstract

The invention relates to the technical field of image forming, in particular to a color correction method, an image forming device and a storage medium. The color correction method comprises the following steps: a control unit controls a plurality of image forming units to form a first correction pattern transferred by using different colors of carbon powder on an intermediate transfer belt, the first correction pattern includes a first correction mark extending linearly and perpendicular to a transport direction of the intermediate transfer belt, a second correction mark, and a third correction mark extending linearly and inclined with respect to the transport direction of the intermediate transfer belt. The problem that in the prior art, the calculation result of position deviation calculation is not accurate is solved.

Description

Technical Field

[0001] This application relates to the field of image forming technology, and more specifically to a color correction method, an image forming apparatus, and a storage medium. Background Technology

[0002] Auto Color Registration (ACR) correction is performed to correct the relative positions of the four colors formed in a color image forming device, ensuring precise alignment of the four colors and improving image quality. During ACR, the color image forming device forms correction patterns of different colors on an intermediate transfer belt (e.g., an image carrier drum) using an image carrier. The actual positions of these correction patterns on the intermediate transfer belt are compared with their preset positions to determine any deviations during formation, and then corrections are applied to correct these deviations.

[0003] Current technologies typically use a single color correction image to correct positional deviations in color correction. Furthermore, the design and composition of the correction images used in current color correction methods are not sufficiently refined. Therefore, this can negatively impact space utilization and correction quality to some extent. Summary of the Invention

[0004] This invention provides a color correction method, an image forming apparatus, and a storage medium to address the problem of insufficient accuracy in calculating positional deviations in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a color correction method applied to an image forming apparatus. The image forming apparatus includes a detection unit, a control unit, and multiple image forming units. The multiple image forming units are used to form a first correction pattern transferred using different colored toners on an intermediate transfer belt. The detection unit is used to detect the first correction pattern formed on the intermediate transfer belt and feed the detection result back to the control unit. The method is characterized by comprising:

[0006] The control unit controls multiple image forming units to form a first correction pattern on the intermediate transfer belt using different colored toners. The first correction pattern includes a first correction mark, a second correction mark, and a third correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt.

[0007] The control unit performs color position registration based on the detection results of the detection unit on the first correction pattern.

[0008] Optionally, the order of the correction marks in the first correction pattern is as follows: second correction mark, first correction mark, second correction mark, and third correction mark.

[0009] Optionally, the control unit performs color position registration based on the detection result of the detection unit on the first correction pattern, including:

[0010] The positional deviation is determined based on the color blocks in the first correction pattern;

[0011] Color position registration is performed based on positional deviation.

[0012] Optionally, determining the positional deviation based on the color blocks in the first correction pattern includes:

[0013] Based on the detection results of the detection unit, the control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the first and third correction marks of the first correction pattern on the intermediate transfer belt.

[0014] The control unit determines the positional deviation in the main scanning direction based on the calculation results.

[0015] Optionally, the first and third correction marks are composed of a reference color block and a correction color block, respectively, and the second correction mark is composed of a reference color block.

[0016] Optionally, based on the detection results of the detection unit, the control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the first and third correction marks of the first correction pattern on the intermediate transfer belt, including:

[0017] The control unit calculates the first distance between the correction color blocks of the same color at corresponding positions in the first correction mark and the third correction mark through the signal collected by the detection unit, and calculates the second distance between the reference color blocks at corresponding positions in the first correction mark and the third mark;

[0018] The control unit determines the positional deviation in the main scanning direction based on the actual calculation results, including:

[0019] The control unit determines the positional deviation of the correction color block in the main scanning direction based on the first distance and the second distance.

[0020] Optionally, the control unit calculates the first distance between the correction color patches of the same color at corresponding positions in the first and third correction marks based on the signals collected by the detection unit, including:

[0021] The control unit calculates the first distance by using the signal acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the positions of two adjacent correction color blocks in the first correction mark and the corresponding correction color blocks of the same color in the third correction mark; or

[0022] The control unit calculates a second distance between reference color patches of the same color at corresponding positions in the first and third correction marks based on the signals acquired by the detection unit, including:

[0023] The control unit calculates the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks in the first correction mark and the corresponding reference color block in the third correction mark based on the signals collected by the detection unit, and determines the second distance.

[0024] Optionally, determining the positional deviation based on the color blocks in the first correction pattern further includes:

[0025] The control unit calculates the third distance between the correction color block in the first correction mark and the reference color block in the corresponding position of the second correction mark based on the signal collected by the detection unit;

[0026] The control unit determines the positional deviation of the correction color block in the sub-scanning direction based on the third distance and the preset fourth distance between the correction color block in the first correction mark and the reference color block in the second correction mark at the corresponding position.

[0027] Optionally, the control unit calculates the third distance between the correction color block in the first correction mark and the reference color block in the corresponding position of the second correction mark based on the signal collected by the detection unit. This specifically includes:

[0028] The control unit calculates the position between two adjacent correction color blocks in the first correction mark relative to the vertical distance in the sub-scanning direction of the reference color block in the second correction mark at the corresponding position using the signal collected by the detection unit, and determines the third distance. Alternatively, the control unit calculates the position between two adjacent reference color blocks in the second correction mark relative to the vertical distance in the sub-scanning direction of the correction color block in the first correction mark at the corresponding position using the signal collected by the detection unit, and determines the third distance.

[0029] Secondly, embodiments of the present invention provide a color correction method applied to an image forming apparatus. The image forming apparatus includes a detection unit, a control unit, and multiple image forming units. The multiple image forming units are used to form a second correction pattern transferred using different colored toners on an intermediate transfer belt. The detection unit is used to detect the second correction pattern formed on the intermediate transfer belt and feed the detection result back to the control unit. The method is characterized by comprising:

[0030] The control unit controls multiple image forming units to form a second correction pattern on the intermediate transfer belt using different colored toners. The second correction pattern includes a fourth correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt, and a fifth correction mark that extends linearly and is inclined relative to the transport direction of the intermediate transfer belt.

[0031] The control unit performs color position registration based on the detection results of the detection unit on the second correction pattern.

[0032] Optionally, the control unit performs color registration based on the detection result of the detection unit on the second correction pattern, including:

[0033] The control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the fourth and fifth correction marks of the second correction pattern on the intermediate transfer belt, based on the detection results of the detection unit.

[0034] The control unit determines the positional deviation in the main scanning direction based on the actual calculation results.

[0035] Optionally, the control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the fourth and fifth correction marks of the second correction pattern on the intermediate transfer belt, based on the detection results of the detection unit, including:

[0036] The control unit calculates the fifth distance between the correction color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit, and calculates the sixth distance between the reference color blocks at corresponding positions in the fourth and fifth correction marks.

[0037] The control unit determines the positional deviation in the main scanning direction based on the actual calculation results, including:

[0038] The control unit determines the positional deviation of the correction color block in the main scanning direction based on the fifth and sixth distances.

[0039] Optionally, the control unit calculates the fifth distance between the correction color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit. This specifically includes:

[0040] The control unit calculates the fifth distance by using the signal acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the positions of two adjacent correction color blocks in the fourth correction mark and the corresponding correction color blocks of the same color in the fifth correction mark; or

[0041] The control unit calculates the sixth distance between the reference color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit, including:

[0042] The control unit calculates the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks in the fourth correction mark and the corresponding reference color block in the fifth correction mark based on the signals collected by the detection unit, and determines the sixth distance.

[0043] Optionally, the control unit performs color registration based on the detection result of the detection unit on the second correction pattern, and further includes:

[0044] The control unit calculates the seventh distance between the correction color block in the fourth correction mark and the reference color block in the fourth correction mark at the relative position based on the signal collected by the detection unit;

[0045] The control unit determines the positional deviation of the correction color block in the sub-scanning direction based on the seventh distance and the preset eighth distance between the correction color block in the fourth correction mark and the reference color block in the fourth correction mark at the relative position.

[0046] Optionally, the control unit calculates the seventh distance between the correction color patch in the fourth correction mark and the reference color patch in the fourth correction mark at a relative position based on the signal acquired by the detection unit. This specifically includes:

[0047] The control unit calculates the seventh distance by measuring the vertical distance in the sub-scanning direction between the correction color block in the fourth correction mark and the reference color block in the adjacent fourth correction mark, based on the signal collected by the detection unit.

[0048] Thirdly, embodiments of the present invention also provide an image forming apparatus, comprising:

[0049] At least one control unit; and

[0050] At least one memory that is communicatively connected to the control unit, wherein:

[0051] The memory stores program instructions that can be executed by the control unit, and the control unit can call the program instructions to perform the aforementioned color correction method.

[0052] Fourthly, embodiments of the present invention also provide a storage medium, the storage medium including a stored program, wherein, when the program is running, the device where the storage medium is located is controlled to execute the method as described in either the first or second aspect above.

[0053] Compared with the prior art, the present invention has at least the following technical effects:

[0054] By setting the first calibration pattern to include a first calibration mark, a second calibration mark, and a third calibration mark that extend linearly and are perpendicular to the transport direction of the intermediate transfer belt, and extends linearly and are inclined relative to the transport direction of the intermediate transfer belt, the control unit can perform color position registration based on the detection result of the detection unit on the first calibration pattern. During this process, the first and third calibration marks can be used for color position registration in the main scanning direction, and the first and second calibration marks can be used for color position registration in the sub-scanning direction. This helps to improve the utilization rate of the first calibration mark and shorten the length of the calibration pattern. Furthermore, it effectively utilizes internal space while reducing the time required to detect longer calibration patterns, thus improving the efficiency of color position registration. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 The diagram shown is a flowchart of a color correction method provided in an embodiment of the present invention;

[0057] Figure 2 The image shown is a partial schematic diagram of a first correction pattern provided in an embodiment of the present invention;

[0058] Figure 3 The image shown is an example of a complete first correction pattern provided by an embodiment of the present invention;

[0059] Figure 4 The diagram shows a flowchart of another color correction method provided in an embodiment of the present invention;

[0060] Figure 5 The image shown is an example of a complete second correction pattern provided by an embodiment of the present invention;

[0061] Figure 6 The image shown is an example of a correction pattern formed on an intermediate transfer belt according to an embodiment of the present invention;

[0062] Figure 7 The diagram shown is a schematic diagram of calculating the sub-scanning direction deviation provided by an embodiment of the present invention;

[0063] Figure 8 The diagram shown is a schematic diagram of calculating the main scanning direction deviation provided by an embodiment of the present invention;

[0064] Figure 9The diagram shown is a structural schematic of an image forming apparatus provided in an embodiment of the present invention;

[0065] Figure 10 The diagram shown is a structural schematic of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0066] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0067] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0068] Color image forming equipment (also known as color image forming apparatus) uses four colors—cyan (C), magenta (M), yellow (Y), and black (K)—to superimpose on a printing medium to form a color image. To ensure image quality, color registration is necessary to ensure the four colors are superimposed in the correct positions. Automatic Color Registration (ACR) is performed to perform color registration on the image. ACR correction corrects the relative positions of the four colors, ensuring precise alignment and improving image quality. When the color image forming equipment uses CMYK colors for image formation, ACR aligns cyan, magenta, and yellow with black. Misalignment, such as when using yellow and cyan to form a green image, will result in discrepancies, creating separate yellow and cyan images, partial overlap of the two colors, or partial separation of the two colors.

[0069] When performing ACR, the color image forming equipment forms correction patterns of different colors on the intermediate transfer belt through the organic sensitive drum (OPC). The actual position of the correction pattern on the intermediate transfer belt is compared with the preset position on the intermediate transfer belt to determine the deviation of each color during formation, and then the deviation is corrected.

[0070] However, current technologies generally use a single color correction image to correct positional deviations in color correction, and the design and composition of the correction images used in current color correction are not perfect. Therefore, this will affect space utilization and correction efficiency to some extent.

[0071] To solve the above problems, such as Figure 1 As shown, this embodiment of the invention provides a color correction method applied to an image forming apparatus. The image forming apparatus includes a detection unit, a control unit, and multiple image forming units. The multiple image forming units are used to form a first correction pattern transferred using different colored toners on an intermediate transfer belt. The detection unit is used to detect the first correction pattern formed on the intermediate transfer belt and feed the detection result back to the control unit. This method is applied to the control unit of the image forming apparatus, which executes a color correction method, including the following steps:

[0072] S110 controls multiple image forming units to form a first correction pattern on the intermediate transfer belt using different colored toners.

[0073] Figure 3 An example of a complete first correction pattern provided for an embodiment of the present invention, such as... Figure 3 The first correction pattern shown includes a first correction mark, a second correction mark, and a third correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt.

[0074] Specifically, color image forming apparatuses typically employ C-color, M-color, Y-color, and K-color image forming units to create toner images by overlaying four colors of toner onto the printing medium. To perform the ACR correction process, an IDC (Image Density Control) sensor, also known as a CTD (Counterpoint sensor), color block sensor, or color block density sensor, is used to detect the toner concentration on the intermediate transfer belt and the position and concentration of color blocks on the ITB (Intermediate Transfer Belt) for image density correction. The detected image is generally a monochrome image, meaning the CMYK colors are separate. If image density is being detected, each color has varying concentrations from dark to light. If it is a color image forming device, two transfers are required. An intermediate transfer belt is used to transfer the image on the photosensitive drum to the intermediate transfer belt and then to the paper. If it is a black and white image forming device, only one transfer is required. There is no intermediate transfer belt. Therefore, if it is a black and white printer, a sensor is required to detect the density.

[0075] Before performing ACR correction, i.e. color correction, a test pattern needs to be issued by the control unit to control the four-color image forming unit to form a correction pattern on the intermediate transfer belt.

[0076] In one implementation of this invention, the first correction pattern may consist of a first correction mark, a second correction mark, and a third correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt. For example, the first and second correction marks may be correction marks composed of horizontal color blocks, and the third correction mark may be correction marks composed of diagonal color blocks.

[0077] In the color correction method of this invention, the first correction pattern is configured as including a first correction mark, a second correction mark, and a third correction mark that extend linearly and are perpendicular to the transport direction of the intermediate transfer belt. Furthermore, the first and third correction marks can be used for color position registration in the main scanning direction, and then the first and second correction marks can be used for color position registration in the sub-scanning direction. This helps to improve the utilization rate of the first correction mark and shorten the length of the correction pattern. Furthermore, it effectively utilizes internal space while reducing the time required for detecting longer correction patterns, thus improving the efficiency of color position registration.

[0078] In a specific embodiment, such as Figure 3 As shown, the vertical direction (or perpendicular direction) is the transport direction (sub-scanning direction) of the intermediate transfer belt, that is, parallel to the transport direction of the intermediate transfer belt, and the horizontal direction (or main scanning direction) is perpendicular to the transport direction of the intermediate transfer belt. The first correction pattern includes:

[0079] The first correction mark is a first linear mark composed of continuous straight line segments, and the extension direction of the first linear mark is perpendicular to the transmission direction of the intermediate transfer belt;

[0080] The second correction mark is a second linear mark composed of continuous straight line segments. The extension direction of the second linear mark is perpendicular to the transmission direction of the intermediate transfer belt, and is spaced at a preset distance from the first correction mark along the transmission direction.

[0081] The third correction mark is a third linear mark composed of continuous straight line segments. The extension direction of the third linear mark forms a non-orthogonal tilt angle θ with the transmission direction of the intermediate transfer belt. Preferably, it can be 45°, or it can be 50° or other angles. The present invention does not limit this.

[0082] Furthermore, in the first correction pattern, the line segment lengths of the first linear marker, the second linear marker, and the third linear marker are all L, and the line width is W. Those skilled in the art can set the size of the markers according to actual needs, and the present invention does not limit this.

[0083] Furthermore, in the first correction pattern, there may be multiple first linear markers, second linear markers, and third linear markers. Those skilled in the art can set the number of markers according to actual needs, and the present invention does not limit this.

[0084] Furthermore, the first and third correction marks are each composed of a reference color block and correction color blocks of multiple colors, while the second correction mark is composed of a reference color block. The reference color blocks and correction color blocks are distinguished by color. Preferably, the reference color block is a black color block, and the correction color block is any one or more of cyan, magenta, and yellow color blocks. Figure 3 For example, the color blocks in the first and third correction marks can be arranged in the order of cyan, magenta, yellow, and black, while the second correction mark consists of multiple black blocks. The color blocks in the first and third correction marks can also be arranged in the order of yellow, magenta, cyan, and black, or any other arrangement easily conceived by those skilled in the art. This invention does not limit this, as long as the color arrangement order of the first and third correction marks is the same. In the embodiments of this application, by arranging the color blocks of the first, second, and third correction marks, color position registration in the main scanning direction can be performed using the first and third correction marks, and then color position registration in the sub-scanning direction can be performed using the first and second correction marks. This helps improve the utilization rate of the first correction mark and shorten the length of the correction pattern. Furthermore, it effectively utilizes internal space while reducing the time spent detecting longer correction patterns and improving the efficiency of color position registration.

[0085] In one specific implementation, there can be multiple correction color patches of the same color as the first and third correction marks, which together constitute a correction color patch group, such as... Figure 3 As shown, the first calibration mark contains one set of calibration color blocks each for cyan, magenta, and yellow, and one set of black reference color blocks. The cyan calibration color block set includes four cyan calibration color blocks: C1, C2, C3, and C4. The reference color block set includes three black calibration color blocks: K12, K13, and K14.

[0086] In one specific implementation, there can be multiple first correction marks and third correction marks, and the number of first correction marks and third correction marks is equal. Those skilled in the art can design the number of first correction marks and third correction marks according to actual needs, and the present invention does not limit this.

[0087] In one specific implementation, the arrangement of the first, second, and third correction marks in the first correction pattern can be in various combinations. For example, the order of the correction marks in the first correction pattern can be the second correction mark, the first correction mark, the second correction mark, and the third correction mark. By setting the order of the correction marks in the first correction pattern to the second correction mark, the first correction mark, the second correction mark, and the third correction mark, that is, arranging the second correction mark at the upper and lower ends of the first correction mark, the same position on the first correction mark can be calculated twice with the two second correction marks above and below, thus doubling the number of calculations and improving the accuracy of the calculation results. That is, in this embodiment, while making full use of the first correction mark to perform color position deviation correction in the main scanning direction and the sub-scanning direction, thereby improving space utilization and correction efficiency, it can also help improve correction accuracy.

[0088] Understandably, the arrangement order can also be set as first correction mark, second correction mark, third correction mark, or other arrangements that are easily conceived by those skilled in the art. This invention does not limit this.

[0089] In one specific implementation, there can be more than one first correction pattern formed on the intermediate transfer belt, such as... Figure 3 As shown, there can be two first correction patterns, distributed on the left and right sides of the secondary scanning direction of the intermediate transfer belt. Those skilled in the art can design the number and arrangement of the first correction patterns according to actual needs, and this invention does not impose any limitations on this. In the embodiments of this application, the first correction patterns can be set on the left and right sides of the secondary scanning direction of the intermediate transfer belt, thereby allowing the calculation of the color position deviation between the two positions. This further enables full utilization of the space of the intermediate transfer belt, improves the rationality of the correction pattern layout, and thus helps to improve correction accuracy and efficiency.

[0090] S120: Perform color position registration based on the detection result of the detection unit on the first correction pattern. Specifically, this includes the following steps: step S102 and step S103.

[0091] S102, determine the positional deviation based on the color blocks in the first correction pattern. The positional deviation includes the positional deviation in the sub-scanning direction and the positional deviation in the main scanning direction.

[0092] Specifically, when determining the positional deviation, it is necessary to determine the deviation of the color patch in the main scanning direction and the deviation of the color patch in the secondary scanning direction. For example... Figure 6 As shown, Figure 6 To correct the example of pattern formation on the intermediate transfer belt, from Figure 6It can be seen that the main scanning direction is perpendicular to the transmission direction of the intermediate transfer belt, and the secondary scanning direction is parallel to the transmission direction of the intermediate transfer belt. The deviation of the formed correction pattern in the horizontal direction is judged based on the deviation in the main scanning direction, and the deviation of the formed correction pattern in the vertical direction is judged based on the deviation in the secondary scanning direction.

[0093] The method for calculating the deviation in the main scanning direction is as follows:

[0094] When calculating the deviation in the main scanning direction, it is necessary to use the color blocks of the same color that meet the preset conditions in the first and third correction marks, that is, it is necessary to use the horizontal line in the first correction mark and the diagonal line in the third correction mark together.

[0095] Specifically, a counterpoint sensor (CTD) deployed at a fixed position on the intermediate transfer belt detects color blocks on the moving intermediate transfer belt. The control unit acquires the detection results from the counterpoint sensor and determines the distance between the color blocks based on the detection results. Here, the detection result refers to the detection signal corresponding to the color block acquired by the counterpoint sensor, such as the color block's density signal, which is usually the signal value of specular reflection from the counterpoint sensor.

[0096] Specifically, in S102, the positional deviation is determined based on the color blocks in the first correction pattern, including:

[0097] When calculating the main scanning deviation, the control unit calculates the distance between the same color blocks in the first and third correction marks of the first correction pattern on the intermediate transfer belt, which meet the preset conditions in terms of their position, based on the detection results of the detection unit. The control unit then determines the position deviation in the main scanning direction based on the actual calculation results.

[0098] In one possible implementation, the preset condition can be that the position of a color block of the same color in the first correction mark is the same as its position in the third correction mark. In another possible implementation, the preset condition is that the distance between the positions of the color blocks of the same color in the first correction mark and their positions in the third correction mark satisfies a preset distance; their positions may be different. In yet another possible implementation, the preset condition can be that, for color blocks of the same color, the position between two adjacent color blocks in the first correction mark is the same as the position of a color block of the same color in the third correction mark, or the distance between them satisfies a preset distance. In yet another possible implementation, the preset condition is that, for color blocks of the same color, the position of a color block in the first correction mark is the same as the position between two adjacent color blocks in the third correction mark, or the distance between them satisfies a preset distance. In yet another possible implementation, the preset condition is that, for color blocks of the same color, the positions between two adjacent color blocks in the first correction mark are the same as the positions between two adjacent color blocks in the third correction mark, or the distance between them satisfies a preset distance. Understandably, the present invention does not limit the preset conditions, which can be set according to the actual calibration environment and requirements of the image forming apparatus, with the aim of reducing interference factors in color position registration.

[0099] Specifically, in one possible implementation, the control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the first and third correction marks of the first correction pattern on the intermediate transfer belt, based on the detection results of the detection unit, including:

[0100] When there are multiple correction color blocks in the correction color block group of the first correction mark and the third correction mark, the control unit calculates the first distance between the correction color blocks of the same color at corresponding positions in the first correction mark and the third correction mark through the signal collected by the detection unit, and calculates the second distance between the reference color blocks at corresponding positions in the first correction mark and the third correction mark.

[0101] The control unit determines the positional deviation in the main scanning direction based on the actual calculation results, including:

[0102] The control unit determines the positional deviation of the correction color block in the main scanning direction based on the first distance and the second distance.

[0103] Specifically, the control unit calculates the first distance between the correction color blocks of the same color at corresponding positions in the first and third correction marks based on the signals collected by the detection unit, including:

[0104] The control unit calculates the first distance by using the signal acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the positions of two adjacent correction color blocks at the corresponding positions in the first correction mark and the corresponding correction color blocks of the same color at the corresponding positions in the third correction mark. Alternatively, the control unit calculates the first distance by using the signal acquired by the detection unit to determine the first distance by calculating the vertical distance in the sub-scanning direction between the positions of two adjacent correction color blocks at the corresponding positions in the first correction mark and the corresponding correction color blocks of the same color at the corresponding positions in the third correction mark. Alternatively, the control unit calculates the first distance by using the signal acquired by the detection unit to determine the first distance by calculating the vertical distance in the sub-scanning direction between the positions of two adjacent correction color blocks at the corresponding positions in the first correction mark and the corresponding correction color blocks of the same color at the corresponding positions in the third correction mark.

[0105] The control unit calculates a second distance between reference color patches of the same color at corresponding positions in the first and third correction marks based on the signals acquired by the detection unit, including:

[0106] The control unit calculates the second distance by using the signals acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the first correction mark and the corresponding reference color block at the corresponding positions in the first correction mark. Alternatively, the control unit calculates the second distance by using the signals acquired by the detection unit to determine the second distance by using the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the first correction mark and the corresponding reference color block at the corresponding positions in the third correction mark. Alternatively, the control unit calculates the second distance by using the signals acquired by the detection unit to determine the second distance by using the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the first correction mark and the corresponding positions of two adjacent reference color blocks at the corresponding positions in the third correction mark.

[0107] In this embodiment, by utilizing the positions of adjacent color blocks of the same color in the correction markers—for example, by using the position between two adjacent correction color blocks in the first correction marker and the corresponding correction color block of the same color in the third correction marker to perform color position registration—the utilization rate of the correction markers can be improved, and the number of calculations can be increased. Therefore, this embodiment can calculate the deviation more conveniently and accurately.

[0108] like Figure 3As shown, when there are multiple cyan correction patches in the cyan correction patch group of the first and third correction marks, the control unit calculates the distance between the midpoints of the cyan patch C1 (correction patch) at the first position and the cyan patch C2 (correction patch) at the second position in the vertical direction (understandably, it can also be set to one-third, one-quarter, etc., which is not limited in this invention) and the corresponding position of the cyan patch LC1 (correction patch) at the first position in the third correction mark, using the signal collected by the detection unit as the first distance. For example, the first distance can be the distance between the midpoints of the cyan patches C1 and C2 in the vertical direction in the first correction mark (understandably, it can also be set to one-third). The distance in the horizontal direction between the midpoint of the cyan patch LC1 in the third calibration mark (e.g., a quarter-distance, etc., which is not limited by this invention) and the distance in the vertical direction is determined. Understandably, the distance between other calibration patches of the same color can also be used as the first distance (actual detection distance). For example, the first distance D1 is determined as the actual detection distance (not shown in the figure) by the distance in the vertical direction between the midpoints of the magenta patches M1 and M2 in the first calibration mark (understandably, it can also be set as a third-degree distance, a quarter-degree distance, etc., which is not limited by this invention) and the midpoint of the magenta patch LM1 in the third calibration mark. This invention does not limit this.

[0109] Similarly, the horizontal distance (which can be set to one-third, one-quarter, etc., in the vertical direction between the midpoints of black blocks K12 and K13 in the first correction mark, and the vertical distance between the midpoints of the black blocks LK1 in the third correction mark) can be calculated to determine the second distance D2 as a reference distance (not shown in the figure). Theoretically, if the correction blocks have no positional deviation in the main scanning direction relative to the reference blocks, the first and second distances should be equal. However, if the correction image is offset, the first and second distances may have a certain deviation. When calculating the main scan deviation, the deviation in the main scan direction can be determined by calculating the difference or ratio between the first distance and the second distance. For example, when the second distance is approximately 42.3 mm (approximately 1000 600 dpi pixels), and the calculated first distance is approximately 42 mm, then the first distance is offset by approximately 0.3 mm relative to the second distance (approximately 7.1 600 dpi pixels). The deviation of the first distance of multiple cyan blocks relative to the second distance of the black block can also be calculated and averaged to determine the actual deviation. Similarly, the deviation of magenta and yellow blocks in the main scan direction can be calculated using a similar method, which will not be elaborated here. When actually calculating the deviation in the main scan direction, if first correction patterns are formed on both sides of the middle transfer belt, the deviation in the main scan direction of each color correction block calculated based on the left correction pattern and the deviation in the main scan direction of each color correction block calculated based on the right correction pattern are averaged to obtain the final adjustment amount of the main scan deviation.

[0110] S102, determining the positional deviation based on the color blocks in the first correction pattern, also includes the following calculation method for the deviation in the sub-scanning direction:

[0111] The control unit calculates the third distance between the correction color block in the first correction mark and the reference color block in the corresponding position of the second correction mark based on the signal collected by the detection unit.

[0112] The control unit determines the positional deviation of the correction patch in the sub-scanning direction based on a third distance and a preset fourth distance between the correction patch in the first correction mark and the reference patch in the corresponding position of the second correction mark. In one possible implementation, there is at least one second correction mark, distributed at corresponding positions on the intermediate transfer belt. In this embodiment, the third distance between the correction patch in the first correction mark and the reference patch in one or more of the second correction marks can be calculated.

[0113] Specifically, the control unit calculates a third distance between the correction color block in the first correction mark and the reference color block in the corresponding position of the second correction mark based on the signal acquired by the detection unit, including:

[0114] The control unit calculates a third distance by using the signal acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the position between two adjacent correction color blocks in the first correction mark and the corresponding reference color block in the second correction mark. Alternatively, the control unit calculates a third distance by using the signal acquired by the detection unit to determine the third distance by using the vertical distance in the sub-scanning direction between the position between two adjacent correction color blocks in the second correction mark and the corresponding correction color block in the first correction mark. Or, the control unit calculates a third distance by using the signal acquired by the detection unit to determine the third distance by using the vertical distance in the sub-scanning direction between the position between two adjacent correction color blocks in the first correction mark and the corresponding position between two adjacent reference color blocks in the second correction mark.

[0115] Two correction patches of the same color from the first correction mark and one reference patch from the second correction mark, or two reference patches from the second correction mark and one correction patch from the first correction mark, or two correction patches of the same color from the first correction mark and two reference patches from the second correction mark, are used to calculate the positional deviation in the sub-scanning direction.

[0116] like Figure 2As shown, for example, the control unit calculates the distance S between the black block K1 (reference block) at the first position of the second correction mark in the second correction mark at the front end, relative to the cyan blocks C1 and C2 at the first and second positions of the first correction mark in the vertical direction (understandably, it can also be set to one-third, one-quarter, etc., which is not limited in this invention) as the third distance. The third distance is the actual calculated deviation of the cyan block relative to the black block in the sub-scanning direction, i.e., the actual detection distance. It is necessary to compare the actual detection distance of the deviation in the sub-scanning direction with the preset fourth distance to determine the position deviation of the correction block in the sub-scanning direction. Similarly, the third distance between the correction blocks of other colors and the reference block can also be compared with the preset fourth distance to determine the position deviation of the correction blocks of other colors in the sub-scanning direction. The preset fourth distance can be stored in the storage unit of the control unit in advance. In actual calculations, the control unit also calculates the distance 3S between the midpoints of the black block K21 (reference block) at the first position of the second correction mark at the tail end and the cyan blocks C1 (correction block) and C2 (correction block) at the first and second positions of the first set of first correction marks in the vertical direction (understandably, it can also be set to one-third, one-quarter, etc., which is not limited in this invention) as the third distance. In actual calculations, the deviation values ​​of the actual detected third distance S and 3S from the design distance can be averaged, or other algorithms can be used to calculate the deviation in the sub-scanning direction multiple times to improve the accuracy of the calculation results.

[0117] When calculating the sub-scan deviation, the deviation in the sub-scanning direction can be determined by calculating the difference between the third distance and the preset fourth distance. For example, the preset fourth distance is approximately 21.15mm (approximately the distance of 500 600dip pixels). If the third distance at the actual detected cyan patch position is 21.1923mm, then the third distance has shifted by 0.0423mm (approximately the distance of one 600dip pixel) relative to the fourth distance. The deviations of the third distances of multiple cyan patches relative to the black patch from the preset fourth distance can also be calculated and averaged to determine the actual deviation. Similarly, the deviations of magenta and yellow patches in the sub-scanning direction can be calculated using a similar method, which will not be elaborated upon here.

[0118] When actually calculating the deviation in the sub-scanning direction, if the first correction pattern is formed on both the left and right sides of the middle transfer belt, the deviation in the sub-scanning direction of each color correction patch calculated based on the left correction pattern and the deviation in the sub-scanning direction of each color correction patch calculated based on the right correction pattern are averaged to obtain the final adjustment amount of the sub-scanning deviation.

[0119] Using two correction blocks of the same color from the first correction mark and a reference block from the second correction mark, or using two reference blocks from the second correction mark and a correction block from the first correction mark, to calculate the positional deviation in the sub-scanning direction can better and more accurately calculate the positional deviation. That is, the positional deviation in the sub-scanning direction can be calculated using two correction blocks and a reference block, or two reference blocks and a correction block. Therefore, the control unit can also calculate the distance S between the midpoint distance (understandably, it can also be set to one-third, one-quarter, etc., distances, etc., at the first and second positions of the second correction mark in the vertical direction) relative to the cyan block C1 at the first position of the first correction mark, based on the signal acquired by the detection unit, as a third distance. The third distance is the actual calculated deviation of the cyan patch relative to the black patch in the sub-scanning direction, i.e., the actual detection distance. This actual detection distance in the sub-scanning direction needs to be compared with a preset fourth distance to determine the positional deviation of the correction patch in the sub-scanning direction. Similarly, the third distance between the correction patches of other colors and the reference patches can be compared with the preset fourth distance to determine the positional deviation of the correction patches of other colors in the sub-scanning direction. The preset fourth distance can be pre-stored in the storage unit of the control unit. In actual calculations, the control unit also calculates the distance 3S between the black patches K21 (reference patch) and K22 (reference patch) at the first and second positions of the second correction mark at the tail end, and the cyan patch C1 at the first position of the first correction mark in the first group, as the third distance. This invention does not limit this.

[0120] Figure 7 This is a schematic diagram illustrating the calculation of sub-scanning direction deviation provided in an embodiment of the present invention. Figure 8 The diagram illustrates a method for calculating the main scanning direction deviation according to an embodiment of the present invention. The specific calculation method is described above and will not be repeated here. The midpoint, one-third, or one-quarter positions of the two color blocks can be used in the deviation calculation; the present invention does not impose any limitations on this.

[0121] S103, perform color position registration based on position deviation. Specifically, if it is determined that any one or both of the position deviations in the main scanning direction and the sub-scanning direction are consistent with the previously detected position deviation, then the same value as when the deviation was adjusted last time can be applied.

[0122] Compared to existing technologies, this invention adjusts the calibration pattern by setting the first calibration pattern to include a first calibration mark extending linearly and perpendicular to the transmission direction, a second calibration mark, and a third calibration mark extending linearly and inclined relative to the transmission direction. Color position registration in the main scanning direction can be performed using the first and third calibration marks, and then color position registration in the sub-scanning direction can be performed using the first and second calibration marks. This helps improve the utilization rate of the first calibration mark, shortening the length of the calibration pattern. Furthermore, it effectively reuses internal space while reducing the time required for detecting longer calibration patterns, thus improving the efficiency of color position registration. Further, by arranging the calibration marks in the calibration pattern in a specific order, the number of calculations can be increased, thereby improving the accuracy of positional correction deviations. Calculating the deviations in the main scanning direction and the sub-scanning direction based on the positions between adjacent color blocks further improves the utilization rate of the calibration marks and increases the number of calculations, thus making full use of internal space while conveniently and accurately calculating positional deviations.

[0123] Optionally, in some embodiments, as another implementation of the present invention, in some scenarios with high correction accuracy, it is necessary to use an ACR long correction pattern for color correction. As an example of an ACR long correction pattern, refer to the first correction pattern.

[0124] like Figure 4 As shown, this embodiment of the invention provides another color correction method. This method is applied to an image forming apparatus, which includes a detection unit, a control unit, and multiple image forming units. The multiple image forming units are used to sequentially form correction patterns transferred using different colored toners on an intermediate transfer belt. The detection unit is used to detect the correction patterns formed on the intermediate transfer belt and feed the detection results back to the control unit, including:

[0125] S410 controls multiple image forming units to sequentially form a second correction pattern using different colored toners on the intermediate transfer belt.

[0126] Figure 5 An example of a complete second correction pattern provided for an embodiment of the present invention, such as... Figure 5The second correction pattern shown includes a fourth correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt, and a fifth correction mark that extends linearly and is inclined relative to the transport direction of the intermediate transfer belt.

[0127] In one implementation of this invention, the second correction pattern can be composed of a fourth correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt, and a fifth correction mark that extends linearly and is inclined relative to the transport direction of the intermediate transfer belt. For example, the fourth correction mark is a correction mark composed of horizontal color blocks, and the fifth correction mark is a correction mark composed of diagonal color blocks. The fourth correction mark is a fourth linear mark composed of continuous straight line segments, and the extension direction of the fourth linear mark is perpendicular to the transport direction of the intermediate transfer belt. The fifth correction mark is a fifth linear mark composed of continuous straight lines, and the extension direction of the fifth linear mark forms a non-orthogonal inclination angle θ with the transport direction of the intermediate transfer belt. Preferably, it can be 45°, or 50° or other angles; this invention does not limit this.

[0128] The fourth and fifth correction marks are composed of reference color blocks and correction color blocks of multiple colors, respectively. The control unit determines the arrangement order of the color blocks in the fourth and fifth correction marks. In the arrangement order, the correction color blocks and reference color blocks in the fourth and fifth correction marks are arranged alternately.

[0129] The reference color block is a black color block, and the correction color block is any one or more of the following: cyan, magenta, and yellow color blocks.

[0130] The arrangement of the fourth and fifth correction marks in the second correction pattern can be in various combinations. For example, the order of the correction marks in the second correction pattern can be fourth correction mark, fifth correction mark, fourth correction mark, fifth correction mark, fourth correction mark, and fifth correction mark. Understandably, the arrangement order can also be fifth correction mark, fourth correction mark, fifth correction mark, fourth correction mark, fifth correction mark, and fourth correction mark, or other arrangements readily conceived by those skilled in the art. This invention does not limit this arrangement.

[0131] The arrangement order of the color blocks in the fourth and fifth correction marks can be black (K, Black), cyan (C, Cyan), black (K, Black), magenta (M, Magenta), black (K, Black), and yellow (Y, Yellow). The arrangement order of the color blocks in the fourth correction mark is KKCCKKMMKKYY, and the arrangement order in the fifth correction mark is KCKMKY. The arrangement order of the color blocks in the fourth and fifth correction marks can also be black, yellow, black, magenta, black, cyan, or any other arrangement order that is easily conceived by those skilled in the art; this invention does not limit this. Generally, the black color block is set as the reference color block, and the other three colors—cyan, magenta, and yellow—are set as correction color blocks. This invention, by repeating the pattern in the order of reference color block, first correction color block, reference color block, second correction color block, reference color block, and third correction color block, compared to the prior art's pattern of repeating the pattern in the order of reference color block, first correction color block, second correction color block, third correction color block, reference color block, first correction color block, second correction color block, and third correction color block (e.g., black, cyan, magenta, yellow), can more accurately calculate the deviation in the main scanning and sub-scanning directions, thereby reducing the impact of the deviation. Furthermore, previous pattern arrangements used KCMY, calculating the offset of the three CMY color blocks relative to K separately. This would affect the function and effect due to the different instantaneous speeds of OPC.

[0132] In a specific embodiment, such as Figure 5 As shown, the vertical direction (or perpendicular direction) is the transport direction (sub-scanning direction) of the intermediate transfer belt, that is, parallel to the transport direction of the intermediate transfer belt. The horizontal direction (or main scanning direction) is perpendicular to the transport direction of the intermediate transfer belt. See also... Figure 5 The second correction pattern includes multiple sets of diagonal lines extending linearly relative to the transfer direction of the intermediate transfer belt and inclined relative to the transfer direction, i.e., multiple sets of diagonal lines inclined at 45°, which are the fifth correction marks, and multiple sets of horizontal lines perpendicular to the direction of the intermediate transfer belt, which are the fourth correction marks. Understandably, the tilt angle of each color block in the fifth correction mark can also be set to 50° or other angles, and the present invention does not limit this.

[0133] S420, perform color position registration based on the detection result of the detection unit on the second correction pattern. Specifically, this includes the following steps: steps S402 and S403.

[0134] S402, determine the positional deviation based on the color blocks in the second correction pattern. The positional deviation includes the positional deviation in the sub-scanning direction and the positional deviation in the main scanning direction.

[0135] The control unit performs color position registration based on the position deviation in the sub-scanning direction and the position deviation in the main scanning direction. The position deviation in the main scanning direction and the position deviation in the sub-scanning direction are calculated and adjusted together. When it is determined that either the position deviation in the main scanning direction or the position deviation in the sub-scanning direction is consistent with the previously detected position deviation, the same value as when the deviation was adjusted last time can be applied.

[0136] Specifically, when determining the positional deviation, it is necessary to determine the deviation of the color block in the main scanning direction and the deviation of the color block in the secondary scanning direction.

[0137] The method for calculating the deviation in the main scanning direction is as follows:

[0138] When calculating the deviation in the main scanning direction, it is necessary to use the color blocks of the same color that meet the preset conditions in the fourth and fifth correction marks. That is, it is necessary to use the horizontal line in the fourth correction mark and the diagonal line in the fifth correction mark together.

[0139] Specifically, a counterpoint sensor (CTD) deployed at a fixed position on the intermediate transfer belt detects color blocks on the moving intermediate transfer belt. The control unit acquires the detection results from the counterpoint sensor and determines the distance between the color blocks based on the detection results. Here, the detection result refers to the detection signal corresponding to the color block acquired by the counterpoint sensor, such as the color block's density signal, which is usually the signal value of specular reflection from the counterpoint sensor.

[0140] Specifically, S402, determining the positional deviation based on the color blocks in the second correction pattern includes:

[0141] When calculating the main scanning deviation, the control unit calculates the distance between the same color blocks in the fourth and fifth correction marks of the second correction pattern on the intermediate transfer belt, which meet the preset conditions in terms of their position, based on the detection results of the detection unit. The control unit then determines the position deviation in the main scanning direction based on the actual calculation results.

[0142] In one possible implementation, the preset condition can be that the position of a color block of the same color in the fourth correction mark is the same as its position in the fifth correction mark. In another possible implementation, the preset condition is that the distance between the positions of the color blocks of the same color in the fourth correction mark and their positions in the fifth correction mark satisfies a preset distance; their positions may be different. In yet another possible implementation, the preset condition can be that, for color blocks of the same color, the position between two adjacent color blocks in the fourth correction mark is the same as the position of the color block of the same color in the fifth correction mark, or the distance between them satisfies a preset distance. In yet another possible implementation, the preset condition is that, for color blocks of the same color, the position of a color block in the fourth correction mark is the same as the position between two adjacent color blocks in the fifth correction mark, or the distance between them satisfies a preset distance. In yet another possible implementation, the preset condition is that, for color blocks of the same color, the position between two adjacent color blocks in the fourth correction mark is the same as the position between two adjacent color blocks in the fifth correction mark, or the distance between them satisfies a preset distance. Understandably, the present invention does not limit the preset conditions, which can be set according to the actual calibration environment and requirements of the image forming apparatus, with the aim of reducing interference factors in color position registration.

[0143] Specifically, the control unit calculates the distance between color blocks of the same color and whose positions meet preset conditions in the fourth and fifth correction marks of the second correction pattern on the intermediate transfer belt, based on the detection results of the detection unit, including:

[0144] The control unit calculates the fifth distance between the correction color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit, and calculates the sixth distance between the reference color blocks at corresponding positions in the fourth and fifth correction marks.

[0145] The control unit determines the positional deviation in the main scanning direction based on the actual calculation results, including:

[0146] The control unit determines the positional deviation of the correction color block in the main scanning direction based on the fifth and sixth distances.

[0147] Specifically, the control unit calculates the fifth distance between the correction color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit, including:

[0148] When there are multiple correction color blocks in the correction color block group of the fourth and fifth correction marks, the control unit calculates the vertical distance in the sub-scanning direction between the position of two adjacent correction color blocks in the fourth correction mark and the corresponding correction color block of the same color in the fifth correction mark based on the signal collected by the detection unit; or, the control unit calculates the vertical distance in the sub-scanning direction between the position of two adjacent correction color blocks at the corresponding position in the fifth correction mark and the corresponding correction color block of the same color in the fourth correction mark based on the signal collected by the detection unit; or, the control unit calculates the vertical distance in the sub-scanning direction between the position of two adjacent correction color blocks at the corresponding position in the fourth correction mark and the corresponding position of two adjacent correction color blocks of the same color in the fifth correction mark based on the signal collected by the detection unit.

[0149] The control unit calculates the sixth distance between the reference color blocks of the same color at corresponding positions in the fourth and fifth correction marks based on the signals collected by the detection unit, including:

[0150] The control unit calculates the sixth distance by using the signals acquired by the detection unit to determine the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the fourth correction mark and the corresponding reference color blocks at the corresponding positions in the fifth correction mark. Alternatively, the control unit calculates the sixth distance by using the signals acquired by the detection unit to determine the sixth distance by calculating the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the fourth correction mark and the corresponding reference color blocks at the corresponding positions in the fifth correction mark. Alternatively, the control unit calculates the sixth distance by using the signals acquired by the detection unit to determine the sixth distance by calculating the vertical distance in the sub-scanning direction between the positions of two adjacent reference color blocks at the corresponding positions in the fourth correction mark and the corresponding positions of two adjacent reference color blocks at the corresponding positions in the fifth correction mark.

[0151] In this embodiment, by utilizing the positions of adjacent color blocks of the same color in the correction marks—for example, by using the positions between two adjacent color blocks in the fourth correction mark and the corresponding color blocks of the same color in the fifth correction mark to perform color position registration—the utilization rate of the correction marks can be improved, and the number of calculations can be increased. Therefore, this embodiment can calculate the deviation more conveniently and accurately.

[0152] like Figure 5As shown, for example, the control unit calculates the distance between the midpoints of the cyan patch C1 (correction patch) at the first position and the cyan patch C2 (correction patch) at the second position in the vertical direction of the fourth correction mark (understandably, it can also be set to one-third, one-quarter, etc., the present invention does not limit this) and the distance at the corresponding position of the cyan patch LC1 (correction patch) at the first position of the fifth correction mark, as the fifth distance. For example, the fifth distance can be the distance between the midpoints of the cyan patches C1 and C2 in the vertical direction of the fourth correction mark (understandably, it can also be set to one-third, one-quarter, etc., the present invention does not limit this) and the distance at the corresponding position of the cyan patch LC1 (correction patch) at the first position of the fifth correction mark. The fifth distance (actual detection distance) is determined by the vertical distance between the horizontal position of the cyan patch LC1 in the fifth calibration mark and the midpoint of the cyan patch LC1 in the fifth calibration mark. Understandably, the distance between other calibration patches of the same color can also be used as the fifth distance (actual detection distance). For example, the fifth distance D5 is determined by the vertical distance between the midpoints of the magenta patches M1 and M2 in the fourth calibration mark (understandably, it can also be set to one-third, one-quarter, etc., which is not limited by the present invention) and the midpoint of the magenta patch LM1 in the fifth calibration mark. The present invention does not limit this.

[0153] Similarly, the horizontal distance (which can be set to one-third, one-quarter, etc., in the vertical direction between the midpoints of black blocks K1 and K2 in the fourth correction mark, and the vertical distance between the midpoints of black block LK1 in the fifth correction mark) can be used to determine the sixth distance D6 as a reference distance. Theoretically, if the correction blocks have no positional deviation in the main scanning direction relative to the reference blocks, the fifth and sixth distances should be equal. However, if the correction image shifts, the fifth and sixth distances may have some deviation. When calculating the main scan deviation, the deviation in the main scan direction can be determined by calculating the difference between the fifth distance and the sixth distance. For example, when the sixth distance is approximately 42.3mm (approximately the distance of 1000 600dpi pixels), and the actual calculated fifth distance is approximately 42.1944mm, then the fifth distance is offset by approximately 0.1057mm (approximately the distance of 2.5 600dpi pixels) relative to the sixth distance. The deviation of the fifth distance of multiple cyan patches relative to the preset sixth distance of the black patch can also be calculated, and the average value can be taken to determine the actual deviation. Similarly, the deviation of magenta and yellow patches in the main scan direction can be calculated using a similar method, which will not be elaborated upon here.

[0154] When actually calculating the deviation in the main scanning direction, since second correction patterns are formed on both the left and right sides of the middle transfer belt, it is necessary to take the average of the deviation in the main scanning direction of each color correction patch calculated based on the left correction pattern and the deviation in the main scanning direction of each color correction patch calculated based on the right correction pattern to obtain the final adjustment amount of the main scanning deviation.

[0155] S402, determining the positional deviation based on the color blocks in the second correction pattern, also includes the following calculation method for the deviation in the sub-scanning direction:

[0156] The control unit calculates the seventh distance between the correction color block in the fourth correction mark and the reference color block in the fourth correction mark at the relative position based on the signal collected by the detection unit;

[0157] The control unit determines the positional deviation of the correction color block in the sub-scanning direction based on the seventh distance and the preset eighth distance between the correction color block in the fourth correction mark and the reference color block in the fourth correction mark at the relative position.

[0158] The control unit calculates the seventh distance by measuring the vertical distance in the sub-scanning direction between the correction color block in the fourth correction mark and the reference color block in the adjacent fourth correction mark, based on the signal collected by the detection unit.

[0159] like Figure 5 As shown, for example, the control unit calculates the distance S1 between the black block K1 (reference block) at the first position of the fourth correction mark in the first group and the cyan block C1 at the first adjacent position of the fourth correction mark, using the signal acquired by the detection unit. This distance is used as the seventh distance. The seventh distance is the actual calculated deviation of the cyan block relative to the black block in the sub-scanning direction, i.e., the actual detection distance. The actual detection distance in the sub-scanning direction needs to be compared with a preset eighth distance to determine the positional deviation of the correction block in the sub-scanning direction. Similarly, the seventh distance between the correction blocks of other colors and the reference block can be compared with the preset eighth distance to determine the positional deviation of the correction blocks of other colors in the sub-scanning direction. The preset eighth distance can be stored in the storage unit of the control unit.

[0160] When calculating the sub-scan deviation, the deviation in the sub-scan direction can be determined by calculating the difference between the seventh distance and the preset eighth distance. For example, the preset eighth distance is approximately 33.84mm (approximately the distance of 800 600dP pixels). If the seventh distance at the actual detected cyan patch position is 32.994mm, then the seventh distance is offset by approximately 0.846mm (approximately the distance of 2 pixels) relative to the eighth distance. The deviations of the seventh distance relative to the black patch from multiple sets of cyan patches relative to the preset eighth distance can also be calculated and averaged to determine the actual deviation. Similarly, the deviations of magenta and yellow patches in the sub-scan direction can be calculated using a similar method, which will not be elaborated upon here.

[0161] When actually calculating the deviation in the sub-scanning direction, since second correction patterns are formed on both the left and right sides of the middle transfer belt, it is necessary to take the average of the deviation in the sub-scanning direction of the correction patch of each color calculated based on the left correction pattern and the deviation in the sub-scanning direction of the correction patch of each color calculated based on the right correction pattern to obtain the final adjustment amount of the sub-scanning deviation.

[0162] S403 performs color position registration based on the detected positional deviation.

[0163] Compared with the prior art, the present invention can more accurately calculate the deviation in the main scanning direction and the deviation in the sub-scanning direction by setting the second correction pattern to include a fourth correction mark that extends linearly and is perpendicular to the transmission direction and a fifth correction mark that extends linearly and is inclined relative to the transmission direction.

[0164] Optionally, in some embodiments, as another implementation of the present invention, in some scenarios with low correction accuracy, it is necessary to use an ACR short correction pattern for color correction. As an example of an ACR short correction pattern, refer to the second correction pattern.

[0165] Corresponding to the above color correction method, this application also provides an image forming apparatus. See [link to previous document]. Figure 9 This is a schematic diagram of the structure of an image forming apparatus provided in an embodiment of this application. The image forming apparatus may include: a detection unit 902, a control unit 903, and a plurality of image forming units 901.

[0166] Multiple image forming units 901 are used to sequentially form a first correction pattern on an intermediate transfer belt using toner of different colors;

[0167] The detection unit 902 is used to detect the first correction pattern formed on the intermediate transfer belt and feed the detection result back to the control unit so that the control unit can perform color position registration based on the detection result.

[0168] The control unit 903 is used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an intermediate transfer belt. The first correction pattern includes a first correction mark, a second correction mark, and a third correction mark that extends linearly and is perpendicular to the transport direction of the intermediate transfer belt. The control unit 903 is also used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an intermediate transfer belt. The first correction pattern includes a first correction mark, a second correction mark, and a third correction mark that extends linearly and is inclined relative to the transport direction of the intermediate transfer belt. The control unit 903 is also used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an intermediate transfer belt. The control unit 903 is used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an intermediate transfer belt. The control unit 903 is used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an intermediate transfer belt. The first correction pattern includes a first correction mark, a second correction mark, and a third correction mark that extends linearly and is inclined relative to the transport direction of the intermediate transfer belt. The control unit 903 is used to control multiple image forming units to form a first correction pattern for toner transfer of different colors on an ...

[0169] The first and third calibration marks are each composed of a reference color block and calibration color blocks of various colors, while the second calibration mark is composed of a reference color block. The reference and calibration color blocks are distinguished by color. The control unit determines the arrangement order of the color blocks in the first and third calibration marks. In this arrangement, the calibration color blocks and reference color blocks in the first and third calibration marks are arranged sequentially. The reference color block is a black color block, and the calibration color block is any one of a cyan color block, a magenta color block, or a yellow color block.

[0170] Additionally, in this embodiment of the invention, another image forming apparatus (not shown) corresponding to the color correction method for the second correction pattern is also included, the apparatus comprising:

[0171] Multiple image forming units are used to form a second correction pattern on the intermediate transfer belt using toner of different colors;

[0172] The detection unit is used to detect the second correction pattern formed on the intermediate transfer belt and feed the detection result back to the control unit so that the control unit can perform color position registration based on the detection result;

[0173] The control unit controls multiple image forming units to form a second correction pattern for toner transfer of different colors on an intermediate transfer belt. The second correction pattern may consist of a fourth correction mark that extends linearly and is perpendicular to the transmission direction of the intermediate transfer belt, and a fifth correction mark that extends linearly and is inclined relative to the transmission direction of the intermediate transfer belt. The control unit also performs color position registration based on the inspection result of the first correction pattern by the detection unit.

[0174] The fourth and fifth correction marks are composed of reference color blocks and correction color blocks of multiple colors, respectively. The control unit determines the arrangement order of the color blocks in the fourth and fifth correction marks. In the arrangement order, the correction color blocks and reference color blocks in the fourth and fifth correction marks are arranged alternately.

[0175] The reference color block is a black color block, and the correction color block is any one of cyan, magenta, or yellow color blocks.

[0176] The specific implementation methods of the two image forming devices are the same as those of the two color correction methods mentioned above, and will not be repeated here.

[0177] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device can be the image forming apparatus described above. Figure 10 As shown, the image forming apparatus may include at least one control unit; and at least one memory communicatively connected to the control unit, wherein the memory stores program instructions executable by the control unit, and the control unit can execute at least one color correction method provided in this embodiment by calling the program instructions.

[0178] The aforementioned electronic device can be a device capable of intelligent dialogue with the user, such as a cloud server. This specification does not limit the specific form of the electronic device in the embodiments. It is understood that the electronic device here refers to the machine mentioned in the method embodiments.

[0179] Figure 10 A block diagram of an exemplary electronic device suitable for implementing embodiments of this specification is shown. Figure 10 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments described in this specification.

[0180] like Figure 10 As shown, the electronic device is represented in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: one or more processors 1010, communication interface 1020, memory 1030, and communication bus 1040 connecting different system components (including memory 1030, communication interface 1020 and processor 1010).

[0181] The communication bus 1040 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0182] Electronic devices typically include a variety of computer-readable media. These media can be any available media that can be accessed by the electronic device, including volatile and non-volatile media, and removable and non-removable media.

[0183] Memory 1030 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory. The electronic device may further include other removable / non-removable, volatile / non-volatile computer system storage media. Memory 1030 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein.

[0184] A program / utility having a set (at least one) of program modules can be stored in memory 1030. Such program modules include—but are not limited to—an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. The program modules typically perform the functions and / or methods described in the embodiments of this specification.

[0185] The processor 1010 executes various functional applications and data processing by running programs stored in the memory 1030, such as implementing the color correction method provided in the embodiments shown in this specification.

[0186] This specification provides a non-transitory computer-readable storage medium that stores computer instructions that cause a computer to execute the color correction method provided in the embodiments shown in this specification.

[0187] The aforementioned non-transitory computer-readable storage medium may be any combination of one or more computer-readable media. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or flash memory, optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in connection with an instruction execution system, apparatus, or device.

[0188] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including—but not limited to—electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0189] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0190] Computer program code for performing the operations described herein can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0191] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0192] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0193] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this specification includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which the embodiments of this specification pertain.

[0194] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0195] It should be noted that the terminals involved in the embodiments of this specification may include, but are not limited to, personal computers (hereinafter referred to as PCs), personal digital assistants (hereinafter referred to as PDAs), wireless handheld devices, tablet computers, mobile phones, MP3 players, MP4 players, etc.

[0196] In the embodiments provided in this specification, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0197] Furthermore, the functional units in the various embodiments of this specification can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in a combination of hardware and software functional units.

[0198] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of this specification.

[0199] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A color correction method applied to an image forming apparatus including a detection unit, a control unit, and a plurality of image forming units for forming a first correction pattern transferred using different color toners on an intermediate transfer belt, the detection unit for detecting the first correction pattern formed on the intermediate transfer belt and feeding back a detection result to the control unit, characterized in that, The method comprises: The control unit controls the plurality of image forming units to form a first correction pattern on the intermediate transfer belt, the first correction pattern comprising a first correction mark linearly extending and perpendicular to a transport direction of the intermediate transfer belt, a second correction mark, and a third correction mark linearly extending and inclined with respect to the transport direction of the intermediate transfer belt, the first correction pattern being transferred using different color toners; The control unit performs color position registration based on a detection result of the first correction pattern by the detection unit.

2. The method of claim 1, wherein, The arrangement order of the correction marks in the first correction pattern is the second correction mark, the first correction mark, the second correction mark, and the third correction mark in sequence.

3. The method of claim 1, wherein, The color position registration based on the detection result of the first correction pattern by the detection unit comprises: determining a position deviation according to color blocks in the first correction pattern; and performing color position registration according to the position deviation.

4. The method of claim 3, wherein, The determination of the position deviation according to the color blocks in the first correction pattern comprises: The control unit calculates, according to the detection result of the detection unit, a distance between color blocks of the same color and at positions satisfying a preset condition in the first correction mark and the third correction mark in the first correction pattern on the intermediate transfer belt; The control unit determines a position deviation in a main scanning direction according to the calculation result.

5. The method of claim 4, wherein, The first correction mark and the third correction mark are respectively composed of reference color blocks and correction color blocks, and the second correction mark is composed of reference color blocks.

6. The method of claim 5, wherein, The calculation of the distance between the color blocks of the same color and at the positions satisfying the preset condition in the first correction mark and the third correction mark in the first correction pattern on the intermediate transfer belt according to the detection result of the detection unit comprises: The control unit calculates, according to the signal collected by the detection unit, a first distance between correction color blocks of the same color at corresponding positions in the first correction mark and the third correction mark, and a second distance between reference color blocks at corresponding positions in the first correction mark and the third correction mark; The determination of the position deviation in the main scanning direction according to the actual calculation result comprises: The control unit determines a position deviation of the correction color blocks in the main scanning direction according to the first distance and the second distance.

7. The method of claim 6, wherein, The calculation of the first distance between the correction color blocks of the same color at the corresponding positions in the first correction mark and the third correction mark according to the signal collected by the detection unit comprises: The control unit calculates the first distance by calculating, according to the signal collected by the detection unit, a vertical distance in a sub-scanning direction between two adjacent correction color blocks in the first correction mark relative to correction color blocks of the same color at corresponding positions in the third correction mark; or The calculation of the second distance between the reference color blocks of the same color at the corresponding positions in the first correction mark and the third correction mark according to the signal collected by the detection unit comprises: The control unit determines the second distance by calculating, according to the signals collected by the detection unit, a vertical distance between positions of two adjacent reference color blocks in the first correction mark relative to reference color blocks at corresponding positions in the third correction mark in the sub-scanning direction.

8. The method of claim 5, wherein, The method further comprises: The control unit calculates, according to the signals collected by the detection unit, a third distance between a correction color block in the first correction mark and a reference color block at a corresponding position in the second correction mark; The control unit determines the position deviation of the correction color block in the sub-scanning direction according to the third distance and a preset fourth distance between the correction color block in the first correction mark and the reference color block at the corresponding position in the second correction mark.

9. The method of claim 8, wherein, The control unit calculates, according to the signals collected by the detection unit, a third distance between a correction color block in the first correction mark and a reference color block at a corresponding position in the second correction mark; The control unit determines the third distance by calculating, according to the signals collected by the detection unit, a vertical distance between positions of two adjacent correction color blocks in the first correction mark relative to reference color blocks at corresponding positions in the second correction mark in the sub-scanning direction, or a vertical distance between positions of two adjacent reference color blocks in the second correction mark relative to correction color blocks at corresponding positions in the first correction mark in the sub-scanning direction.

10. A color correction method applied to an image forming apparatus including a detection unit, a control unit, and a plurality of image forming units for forming a second correction pattern transferred using different color toners on an intermediate transfer belt, the detection unit for detecting the second correction pattern formed on the intermediate transfer belt and feeding back a detection result to the control unit, characterized in that, The method comprises: The control unit controls the plurality of image forming units to form a second correction pattern on the intermediate transfer belt, the second correction pattern comprising fourth correction marks linearly extending and perpendicular to a conveying direction of the intermediate transfer belt and fifth correction marks linearly extending and inclined relative to the conveying direction of the intermediate transfer belt; The control unit performs color position registration based on a detection result of the second correction pattern by the detection unit.

11. The method of claim 10, wherein, The control unit performs color registration based on a detection result of the second correction pattern by the detection unit, comprising: The control unit calculates, according to the detection result by the detection unit, a distance between color blocks of the same color and at positions satisfying a preset condition in the fourth correction marks and the fifth correction marks of the second correction pattern on the intermediate transfer belt; The control unit determines the position deviation in the main scanning direction according to the actual calculation result.

12. The method of claim 11, wherein, The control unit calculates, according to the detection result by the detection unit, a distance between color blocks of the same color and at positions satisfying a preset condition in the fourth correction marks and the fifth correction marks of the second correction pattern on the intermediate transfer belt, comprising: The control unit calculates, according to the detection result by the detection unit, a distance between color blocks of the same color and at positions satisfying a preset condition in the fourth correction marks and the fifth correction marks of the second correction pattern on the intermediate transfer belt, comprising: The control unit calculates a fifth distance between correction patches of the same color at corresponding positions in the fourth correction mark and the fifth correction mark, and a sixth distance of reference patches at corresponding positions in the fourth correction mark and the fifth correction mark, according to signals collected by the detection unit. The control unit determines the position deviation in the main scanning direction according to the actual calculation result, including: The control unit determines the position deviation of the correction patch in the main scanning direction according to the fifth distance and the sixth distance.

13. The method of claim 12, wherein, The control unit calculates the fifth distance between correction patches of the same color at corresponding positions in the fourth correction mark and the fifth correction mark according to signals collected by the detection unit, including: The control unit calculates the fifth distance between correction patches of the same color at corresponding positions in the fourth correction mark and the fifth correction mark according to signals collected by the detection unit, including: The control unit calculates the sixth distance of reference patches of the same color at corresponding positions in the fourth correction mark and the fifth correction mark according to signals collected by the detection unit, including: The control unit calculates the sixth distance of reference patches of the same color at corresponding positions in the fourth correction mark and the fifth correction mark according to signals collected by the detection unit, including:

14. The method of claim 10, wherein, The control unit performs color registration based on the detection result of the second correction pattern by the detection unit, further including: The control unit calculates a seventh distance between a correction patch in the fourth correction mark and a reference patch in the fourth correction mark at a relative position according to signals collected by the detection unit; The control unit determines the position deviation of the correction patch in the sub-scanning direction according to the seventh distance and a preset eighth distance between the correction patch in the fourth correction mark and the reference patch in the fourth correction mark at a relative position.

15. The method of claim 14, wherein, The control unit calculates the seventh distance between a correction patch in the fourth correction mark and a reference patch in the fourth correction mark at a relative position according to signals collected by the detection unit, including: The control unit calculates the seventh distance between a correction patch in the fourth correction mark and a reference patch in the fourth correction mark at a relative position according to signals collected by the detection unit, including:

16. An image forming apparatus characterized by comprising: including: at least one control unit; and at least one memory in communication connection with the control unit, wherein: the memory stores program instructions executable by the control unit, and the control unit calling the program instructions can execute the method of any one of claims 1 to 9 or claims 10 to 15.

17. A storage medium, characterized by The storage medium includes a stored program, wherein the storage medium controls the device where the storage medium is located to execute the method of any one of claims 1 to 9 or claims 10 to 15 when the program is running.

Images