JP2013218283A - Image forming apparatus, and control method of image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of performing color shift correction without performing image formation and detection of a detection pattern that requires color shift correction, and a control method of an image forming apparatus.SOLUTION: An image forming apparatus includes: an image forming unit that forms an image on a sheet; a temperature sensor that detects a temperature in the apparatus; a shift amount table that stores shift amount of color of an image formed to a reference color for each temperature; and a control unit that calculates the correction amount of color shift on the basis of the temperature in the apparatus detected by the temperature sensor and the shift amount for each temperature read out from the shift amount table.

Description

  Embodiments described herein relate generally to an image forming apparatus and an image forming apparatus control method.

  Some image forming apparatuses such as printers and copiers perform color printing. In this model, an image is formed by an image forming unit for each color using a plurality of color developers, and one image is generated. Therefore, high-quality images cannot be formed unless the image forming positions of the respective colors are accurate.

  A conventional image forming apparatus includes a color misregistration correction device that detects an image forming position of each color and corrects the image forming position when it is determined that a misregistration has occurred in order to match the image forming positions of the respective colors.

  The color misregistration correction apparatus includes a detection pattern forming unit that forms an image of a detection pattern on an image carrier that carries a developer image, and a detection sensor that detects the detection pattern.

  Therefore, the conventional image forming apparatus not only increases the manufacturing cost, but also consumes the developer, and it takes time to form and detect the detection pattern, which is inconvenient for the user.

JP 2009-64016 A

  Accordingly, there is a need for an image forming apparatus and a control method for the image forming apparatus that can perform color misregistration correction without performing image formation and detection of a detection pattern that is essential for color misregistration correction.

  In order to solve the above-described problem, an embodiment of the present invention provides an image forming unit that forms an image on a sheet, a temperature sensor that detects a temperature inside the apparatus, and a temperature for each color of an image that is formed with respect to a reference color. Image formation comprising: a deviation amount table that stores deviation amounts; and a controller that calculates a color deviation correction amount based on a temperature detected by the temperature sensor and a deviation amount for each temperature read from the deviation amount table. Providing equipment.

1 is a diagram illustrating a configuration of an image forming apparatus. 1 is a block diagram illustrating a configuration of an image forming apparatus. 6 is a graph showing a relationship between a temperature and a color shift amount for image formation with respect to a reference color. It is a graph which shows the calculation method of correction amount. 3 is a flowchart illustrating an operation of the image forming apparatus.

  Hereinafter, an embodiment of an image forming apparatus and a method for controlling the image forming apparatus will be described in detail with reference to the drawings.

  The image forming apparatus according to the present exemplary embodiment includes an image forming unit that forms an image on a sheet, a temperature sensor that detects a temperature inside the apparatus, and a shift amount table that stores a shift amount of each color of the image forming color with respect to a reference color. And a controller that calculates a correction amount of color misregistration based on the temperature in the machine body detected by the temperature sensor and the deviation amount for each temperature read from the deviation amount table.

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 includes an automatic document feeder 11, an image reading unit 12, an image forming unit 13, a paper feeding unit 16, a sheet conveying mechanism 18, and a control unit 19. Including.

  The automatic document feeder 11 is installed at the top of the main body of the image forming apparatus 1 so as to be openable and closable. The automatic document feeder 11 includes a document conveyance mechanism that takes out documents one by one from a paper feed tray and conveys them to a paper discharge tray.

  The automatic document feeder 11 conveys documents one by one to the document reading unit of the image reading unit 12 by the document conveying function. It is also possible to open the automatic document feeder 11 and place the document on the document table of the image reading unit 12.

  The image reading unit 12 includes an exposure lamp that exposes a document and a carriage including a first reflection mirror, a plurality of second reflection mirrors that move in accordance with the movement of the carriage, a lens block, and a CCD ( Charge Coupled Device).

  The carriage rests on the document reading unit or reciprocates under the document table to reflect the light of the exposure lamp reflected by the document to the first reflecting mirror. The plurality of second reflection mirrors reflects the reflected light of the first reflection mirror to the lens block. The lens block changes the magnification of the reflected light and outputs it to the CCD. The CCD converts incident light into an electrical signal and outputs it as an image signal to the image forming unit 13.

  The image forming unit 13 includes a registration roller 13A that corrects the orientation of the sheet so that the side in the width direction of the sheet conveyed obliquely is parallel to the sheet conveyance direction.

  The image forming apparatus 1 forms an image on the sheet whose orientation is corrected by the registration roller 13 </ b> A by the image forming unit 13.

  The image forming method of the image forming unit 13 does not matter. The image forming method of the image forming unit 13 can be selected from methods such as an electronic method and an ink jet method.

  In the case of an electronic system, the image forming unit 13 includes a laser irradiation unit 13D, a photosensitive drum 13B, a developer supply unit 13C, a transfer unit 14, and a yellow Y, a magenta M, a cyan C, and a black K. Is provided.

  The laser irradiation unit 13D irradiates the photosensitive drum 13B with laser light based on the image signal, and forms an electrostatic latent image on the photosensitive drum 13B. The developer supply unit 13C supplies the developer to the photosensitive drum 13B and forms a developer image from the electrostatic latent image.

  The paper feed unit 16 takes out the sheets one by one from the paper feed cassette and delivers them to the paper transport mechanism. The paper transport mechanism transports the sheet to the transfer unit 14.

  The transfer unit 14 includes a transfer belt 14B and a transfer roller 14A. The transfer belt 14B receives and carries the developer image on the photosensitive drum 13B. The transfer roller 14A applies a voltage to transfer the developer image on the transfer belt to the conveyed sheet.

  Here, the image carrier refers to a member that carries a developer image. In other words, in the case of a model having the transfer belt 14B, the transfer belt 14B does not have the transfer belt 14B, and in the model in which the developer image is directly transferred from the photosensitive drum 13B to the sheet, the photosensitive drum 13B has the image carrier. Is the body.

  The image forming apparatus 1 includes a fixing device 14 </ b> C downstream of the transfer unit 14 in the sheet conveyance direction. The fixing device 14C heats and pressurizes the developer image to fix it on the sheet.

  In the case of an ink jet type, the image forming unit 13 includes a head that sprays ink onto a sheet.

  The head has an ink supply chamber in which piezo elements of different polarities are attached in the longitudinal direction, and the set of the attached piezo elements are arranged in a comb tooth shape, an ink discharge hole, and covers the ink supply chamber A cover is provided. The image forming unit 13 deforms the ink supply chamber by alternately applying a voltage to the head, and repeats the suction of the ink and the discharge from the ink discharge hole. The ejected ink adheres to the sheet and image formation is performed.

  The image forming apparatus 1 includes a paper feed cassette opening / closing sensor 51 that is installed in the paper feed cassette and detects opening / closing of the paper feed cassette, and a size sensor 52 that detects the size of sheets accumulated in the paper feed cassette.

  The image forming apparatus 1 includes a temperature sensor 31 that detects the temperature of the image forming apparatus 1.

  FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus 1. As shown in FIG. 2, the image forming apparatus 1 includes a main CPU 201 that is a control unit 19 that performs overall control of the entire image forming apparatus 1, a ROM and RAM 202 that are memories, a storage device 215 such as a hard disk drive, and image processing. An image processing unit 204 that performs communication, and a communication interface (hereinafter referred to as I / F) 214 that communicates information with an external device.

  The main CPU 201 is connected to a print CPU 205 that controls each part of the image forming system, a scan CPU 209 that controls each part of the image reading system, and a drive controller 212 that controls the drive unit.

  The storage device 215 includes a deviation amount table 215 </ b> A that stores a deviation amount of a color for image formation for each temperature of the image forming apparatus 1.

  In the case of an electronic system, the print CPU 205 controls a print engine 206 that forms an electrostatic latent image on the photosensitive drum 13B and a process unit 207 that forms a developer image.

  The print CPU 205 is connected to the temperature sensor 31.

  The scan CPU 209 controls the CCD drive circuit 210 that drives the CCD 211. A signal from the CCD 211 is output to the image forming unit 13.

  The drive controller 212 is connected to the drive unit 213.

  FIG. 3 is a graph showing the relationship between the temperature and the amount of color shift for image formation with respect to the reference color. The shift amount is represented by a distance that a certain color is shifted from the reference color.

  As shown in FIG. 3, the amount of deviation changes as the temperature changes. The correspondence between this temperature and the amount of deviation is determined for each aircraft. Therefore, it is possible to predict the deviation amount from the temperature by measuring the temperature and the deviation amount in advance.

  The image forming apparatus 1 stores the correspondence between the previously measured temperature and the deviation amount in the deviation amount table 215A.

  An example of the deviation amount table is as follows.

(Temperature, deviation) = {(10, y10), (20, y20), (30, y30), (40, y40)}
Here, y10 to y40 represent numerical values indicating distance.

  In FIG. 3, the temperature interval for measuring the deviation is 10 ° C. It is assumed that the amount of deviation during this measurement interval is proportional to the temperature.

  FIG. 4 is a graph showing a correction amount calculation method. As shown in FIG. 4, it is assumed that the previous temperature T1, which is the temperature of the image forming apparatus 1 measured last time, is between 20 ° C. and 30 ° C.

  Further, it is assumed that the current temperature T2 that is the temperature of the image forming apparatus 1 measured this time is also 20 ° C. or higher and lower than 30 ° C.

  The image forming apparatus 1 stores the previous temperature T1 in the RAM 202.

  In the case of the first temperature measurement after the assembly adjustment of the image forming apparatus 1, the correction amount Δy is calculated by the equation (1) which is a linear equation for the following temperatures.

(Correction amount Δy) = {(y30−y20) / (30 ° C.−20 ° C.)} × (T2−20 ° C.) (1)
In the second and subsequent temperature measurement, the image forming apparatus 1 first sets a correction amount calculation formula according to the formula (2) which is a linear formula for the following temperatures.

(Correction amount Δy) = {(yk−yl) / (k ° C.−1 ° C.)} × (T 2 −T 1) (2)
However, k = 30 and l = 20. When the temperature range changes, the values of k and l change. For example, when both the previous temperature T1 and the current temperature T2 are 10 ° C. or higher and lower than 20 ° C., k = 20 and l = 10.

  Next, the image forming apparatus 1 calculates the correction amount Δy by substituting T1 and T2 into the set equation (2). The image forming apparatus 1 stores the current temperature T2 in the RAM 202 as a new previous temperature T1.

  The image forming apparatus 1 calculates the correction amount Δy every certain time and when the temperature change amount exceeds the threshold value.

  FIG. 5 is a flowchart showing the operation of the image forming apparatus 1. As shown in FIG. 5, in step 501, the image forming apparatus 1 starts time measurement.

  In step 502, the image forming apparatus 1 calculates the current temperature T2 by the temperature sensor 31, and determines whether the temperature change amount, that is, the difference between T2 and T1 exceeds the threshold value.

  If the image forming apparatus 1 determines that the temperature change amount exceeds the threshold value, the process proceeds to step 504. If the image forming apparatus 1 determines that the temperature change amount does not exceed the threshold value, the process proceeds to step 503.

  In step 503, the image forming apparatus 1 determines whether the elapsed time exceeds a threshold value. If the image forming apparatus 1 determines that the elapsed time has exceeded the threshold value, the process proceeds to step 504. If the image forming apparatus 1 determines that the elapsed time has not exceeded the threshold value, the process returns to step 502.

  In step 504, the image forming apparatus 1 measures the temperature of the image forming apparatus 1 with the temperature sensor 31.

  In step 505, the image forming apparatus 1 sets a correction amount calculation formula according to the above-described formula (1) or formula (2).

  In step 506, the image forming apparatus 1 calculates the correction amount Δy according to the set correction amount calculation formula.

  In step 507, the image forming apparatus 1 corrects the shift amount based on the calculated correction amount, and returns to step 501.

  As described above, the image forming apparatus 1 according to the present embodiment includes the image forming unit 13 that forms an image on a sheet, the temperature sensor 31 that detects the temperature inside the apparatus, and the temperature of each color that forms an image with respect to the reference color. A deviation amount table 215A for storing the deviation amount of the image, and a control unit 19 for calculating a correction amount of the color deviation based on the temperature in the body detected by the temperature sensor 31 and the deviation amount for each temperature read from the deviation amount table 215A; Prepare.

  Accordingly, since color misregistration correction can be performed without performing image formation and detection of a detection pattern that is essential for color misregistration correction, the manufacturing cost can be reduced, the consumption of developer can be suppressed, and the color misregistration correction time can be shortened. effective.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

13: Image forming unit 19: Control unit

Claims (5)

An image forming unit for forming an image on a sheet;
A temperature sensor that detects the temperature inside the aircraft,
A deviation amount table for storing deviation amounts for each temperature of the color of the image to be formed with respect to the reference color;
A controller that calculates a color misregistration correction amount based on the temperature detected by the temperature sensor and the deviation amount for each temperature read from the deviation amount table;
An image forming apparatus. The controller is
The image forming apparatus according to claim 1, wherein the correction amount is calculated every time a threshold time elapses. The controller is
The image forming apparatus according to claim 1, wherein the correction amount is calculated when a temperature change amount exceeds a threshold value. The temperature sensor detects the temperature inside the aircraft,
Calculating a correction amount of color misregistration based on the deviation amount read from the deviation amount table storing the deviation amount for each temperature of the color to be imaged with respect to the detected temperature inside the machine body and the reference color;
A control method for an image forming apparatus, wherein color misregistration is corrected based on the correction amount.   The image forming apparatus control method according to claim 4, wherein the correction amount is calculated every time a threshold time elapses.

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