JP2006171634A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method using a process cartridge having at least an image carrier, the process cartridge being capable of highly accurately positioning images in different colors in the system in which the images in the different colors are superposed and transferred onto a transfer medium. <P>SOLUTION: In the image forming method using the process cartridge having at least the image carrier, the process cartridge has a memory storing information about color deviation, such as mechanical differences and accuracy, caused during the manufacture or assembly of the process cartridge. When the process cartridge is replaced, an arithmetic operation is performed such that the memory information is read and combined with information about color misalignment stored in the memory of the main body of the apparatus. When it is determined as a result that the process cartridge is one that can be adjusted in registration, the process cartridge is subject to an initializing operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that forms an electrostatic latent image on an image carrier by electrophotography and obtains a desired output image.

  In a conventional image forming apparatus, a photosensitive drum as an image carrier and a peripheral charging device, a developing device, a cleaning device, and the like are unitized (hereinafter, the unitized unit is referred to as a process cartridge) and is detached from the apparatus main body. A device that enables the replacement of consumables by a user or the like has been developed.

  In addition, with the colorization of the image, a plurality of image forming stations for forming an image are provided, and each color image of a cyan image, a magenta image, a yellow image, and a black image is formed on each photoconductor. There has been proposed a tandem color image forming apparatus that forms a full-color image by superimposing and transferring each color image on a transfer medium at the transfer position. Such a tandem type color image forming apparatus has an image forming unit for each color, which is very advantageous for speeding up. However, in the tandem image forming apparatus, the problem of how well the registration (registration) of the images formed by different image forming units is very large. This is because a shift in the image forming positions of the four colors transferred to the transfer medium will eventually appear as a color shift or a change in color tone.

In a tandem type color image forming apparatus, a method for preventing color misregistration is described in Japanese Patent Laid-Open No. 2000-250285. In the present invention, a registration pattern is formed on each of four photoconductors each having an independent drive motor, and transferred onto the intermediate transfer belt in an overlapping manner. In addition to the widely used method of calculating the amount of misregistration of each color with respect to the set value from the information read from the pattern on the intermediate transfer belt by the CCD sensor, a filter is further added from the information read from the CCD sensor. By applying it, it is possible to extract the eccentric information of the photoconductor, and to prevent color shift with higher accuracy.
JP 2000-250285 A

  However, in the image forming apparatus disclosed in the above-mentioned publication, in addition to the eccentricity of the photosensitive member at each image forming station, variations in the photosensitive member diameter and mechanical accuracy in assembling the photosensitive member all appear as color misregistration. Therefore, it is expected that it is very difficult to correct by separating each contribution.

  The present invention solves the above-described problems of the prior art and includes a process cartridge including at least an image carrier capable of highly accurately aligning images of each color in a system in which images of a plurality of colors are transferred onto a transfer medium. An object of the present invention is to provide an image forming method to be used.

  According to the first aspect of the present invention, in the image forming method using at least a process cartridge provided with an image carrier, the process cartridge has a memory in which information relating to color misregistration such as mechanical variation and accuracy generated during manufacture or assembly is stored. And when the process cartridge is replaced, the memory information is subjected to arithmetic processing in combination with information information relating to color misregistration of the reading apparatus main body memory, and as a result, it is confirmed that the process cartridge is capable of registration adjustment. The initialization operation is performed.

  The second invention is characterized in that in the image forming method of the first invention, the memory of the process cartridge is read wirelessly.

  The third invention is characterized in that in the image forming method of the first invention, the memory of the process cartridge is read in a wired manner.

  According to a fourth aspect of the present invention, in the image forming method according to any one of the first to third aspects of the invention, the replacement of the process cartridge is prohibited when the power is turned off.

In an image forming method using at least a process cartridge provided with an image carrier, the process cartridge has a memory in which information relating to color deviation such as mechanical variation and accuracy generated during manufacture or assembly is stored, and the process cartridge The above-mentioned memory information is combined with the information in the reading device main body memory at the time of replacement, and as a result, when it is confirmed that the process cartridge is capable of registration adjustment, the process cartridge is initialized to perform the process. Since the color misregistration information on the cartridge side and the color misregistration information on the apparatus main body side are calculated together, highly accurate color misregistration information can be obtained and a high quality color image can be obtained.
With the configuration in which the memory of the process cartridge is read wirelessly, the color misregistration information of the process cartridge can be read simultaneously with the mounting of the process cartridge to the apparatus main body, and the combination calculation with the color misregistration information on the apparatus main body side can be performed quickly.
With the configuration in which the memory of the process cartridge is read in a wired manner, the color misregistration information of the process cartridge can be read simultaneously with the mounting of the process cartridge to the apparatus main body, and the combination calculation with the color misregistration information on the apparatus main body side can be performed quickly.
Since the replacement of the process cartridge is prohibited when the power is turned off, it is not necessary to perform arithmetic processing every time the power is turned on, and a user-friendly device can be provided.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of one embodiment of a color image forming apparatus used in the image forming method of the present invention. In the following description, the same numbers may be assigned between the drawings, and the description may be omitted. In this embodiment, an intermediate transfer belt is used as the transfer belt.

  In FIG. 1, an image forming apparatus 1 according to the present embodiment includes a housing body 2, and an image forming unit 6, a transfer belt unit 9, and a paper feeding unit 10 are disposed in the housing body 2. A transfer unit 11, a fixing unit 12, and a recording medium transport unit 13 are provided. The consumables in the image forming unit 6 and the paper feeding unit 10 are configured to be detachable from the main body. In this case, the configuration including the transfer belt unit 9 can be removed and repaired or replaced. It has become.

  The transfer belt unit 9 includes a driving roller 14, a driven roller 15 disposed obliquely above the driving roller 14, and an intermediate belt that is stretched between the two rollers 14 and 15 and circulated in the direction of the arrow shown in the figure. A transfer belt 16 and a cleaning means 17 that contacts the surface of the intermediate transfer belt 16 are provided, and the driven roller 15 and the intermediate transfer belt 16 are disposed in a direction inclined to the left in the drawing with respect to the drive roller 14. Yes. As a result, the belt surface 16a with the belt conveyance direction downward when the intermediate transfer belt 16 is driven is positioned below. In the present embodiment, the belt surface 16a is a belt tension surface (surface pulled by the drive roller 14) when the belt is driven.

  The primary transfer member 21 is elastically applied to the back surface 16a of the intermediate transfer belt 16 facing the image carrier 20 of each image forming station Y, M, C, K, which will be described later. A transfer bias is applied to the primary transfer member 21.

  A registration sensor 18 is installed on the support frame of the transfer belt unit 9 in the vicinity of the drive roller 14. This test pattern sensor 18 is a sensor for positioning each color toner image on the intermediate transfer belt 16, detecting the density of each color toner image, and correcting the color shift and image density of each color image.

  The image forming unit 6 includes image forming stations Y (for yellow), M (for magenta), C (for cyan), and K (for black) that form a plurality (four in this embodiment) of different color images. Each of the image forming stations Y, M, C, and K includes an image carrier 20 formed of a photosensitive drum, and a charging unit 22, an image writing unit 23, and a developer disposed around the image carrier 20. Means 24 are provided. In the developing unit 24, only the image forming station K is assigned a drawing number, and the other image forming stations have the same configuration, and thus the drawing number is omitted. Further, the arrangement order of the image forming stations Y, M, C, and K is arbitrary.

  Then, the image carrier 20 of each of the image forming stations Y, M, C, and K is brought into contact with the belt surface 16a facing downward in the transport direction of the intermediate transfer belt 16, and as a result, each of the image forming stations Y, M. , C and K are also arranged in a direction inclined to the left in the drawing with respect to the drive roller 14. The image carrier 20 is rotationally driven in the conveyance direction of the intermediate transfer belt 16 as indicated by the arrows in the figure.

  The developing unit 24 includes a toner storage container 26 that stores toner (hatched portion in the drawing), a toner storage part 27 formed in the toner storage container 26, and a toner stirring member disposed in the toner storage part 27. 29, a partition member 30 partitioned at the upper portion of the toner storage portion 27, a toner supply roller 31 disposed above the partition member 30, and abutment against the toner supply roller 31 provided on the partition member 30. The blade 32, the developing roller 33 disposed so as to be in contact with the toner supply roller 31 and the image carrier 20, and the regulation blade 34 that is in contact with the developing roller 33. The toner is a negatively charged toner made of a one-component nonmagnetic toner. The toner supply roller 31 and the developing roller 33 rotate in the same direction.

  The image carrier 20 is rotated in the conveying direction of the intermediate transfer belt 16, and the developing roller 33 and the supply roller 31 are rotationally driven in a direction opposite to the rotation direction of the image carrier 20, as shown by the arrows in the figure. The stirring member 29 is driven to rotate in the direction opposite to the direction of rotation of the supply roller 31. The toner stirred and carried up by the stirring member 29 in the toner storage unit 27 is supplied to the toner supply roller 31 along the upper surface of the partition member 30, and the supplied toner is rubbed against the blade 32 and slid on the supply roller 31. The toner is supplied to the surface of the developing roller 33 by a mechanical adhesion force to the surface uneven portion and an adhesion force by frictional band power. The toner supplied to the developing roller 33 is regulated to a predetermined thickness by the regulating blade 34, and the thinned toner layer is conveyed to the image carrier 20 so that the developing roller 33 and the image carrier 20 come into contact with each other. The latent image portion of the image carrier 20 is developed at the nip portion configured as described above and in the vicinity thereof.

  The paper feed unit 10 includes a paper feed unit including a paper feed cassette 35 in which the recording media P are stacked and held, and a pickup roller 36 that feeds the recording media P from the paper feed cassette 35 one by one. In the first opening / closing member 3, a registration roller pair 37 that defines the feeding timing of the recording medium P to the secondary transfer unit, and a secondary transfer unit that is pressed against the drive roller 14 and the intermediate transfer belt 16. A secondary transfer unit 11, a fixing unit 12, a recording medium conveyance unit 13, a paper discharge roller pair 39, and a duplex printing conveyance path 40 are provided.

  The secondary transfer unit 11 includes a secondary transfer roller 19, and normally, the secondary transfer roller 19 can be pressed against the intermediate transfer belt 16 and the driving roller 14.

  The fixing unit 12 includes a heating roller 45 that includes a heating element such as a halogen heater and is rotatable, a pressure roller 46 that presses and biases the heating roller 45, and is swingable on the pressure roller 46. The belt tension member 47, and the heat-resistant belt 49 stretched between the pressure roller 45 and the belt tension member 47, and the color image secondarily transferred to the recording medium are the heat roller 45 and the heat-resistant belt 49. The toner image is fixed on the recording medium at a predetermined temperature at the nip portion formed in step (b). In the present embodiment, the fixing unit 12 can be disposed in a space formed obliquely above the intermediate transfer belt 16, in other words, in a space opposite to the image forming unit 6 with respect to the intermediate transfer belt 16. Thus, heat transfer to the electrical component box, the image forming unit 6 and the intermediate transfer belt 16 can be reduced, and the frequency of performing the color misregistration correction operation for each color can be reduced.

  FIG. 2 is a diagram illustrating a state in which the process cartridge 50 that is replaceably mounted in each image forming station is attached to the apparatus main body. The process cartridge 50 shown in this embodiment includes a photosensitive drum 51 at the center, a female coupling 52 to which driving force is transmitted to one end of the photosensitive drum 51, and the other end. A plurality of positioning pins 53 for positioning in the apparatus main body, and an electronic module 54 incorporating a memory and the like are provided. A photoreceptor gear 56 is disposed on the rear side 55 of the apparatus main body, and a male coupling 57 that engages with the female coupling 52 of the process cartridge 50 is formed on the photoreceptor gear 56, and rotational force is applied to the photoreceptor drum 51. To communicate. A positioning hole 59 for inserting a positioning pin 53 formed at the other end of the photosensitive drum 51 is formed on the front side 58 of the apparatus main body, and a connector or a transmission / reception unit is disposed at a position facing the electronic module 54. Is done. The electronic module 54 includes a memory that stores color misregistration information such as mechanical variation and accuracy generated when the process cartridge 50 is manufactured or assembled. The connector or the transmission / reception unit arranged in the apparatus main body is connected to the CPU of the apparatus main body by wire or wirelessly. The CPU of the apparatus main body is provided with a memory that stores color misregistration information such as a position error of the coupling 57, a position error of the positioning hole 59, and an exposure position error, and further includes a memory built in the electronic module 54 of the process cartridge 50. An arithmetic device is provided that calculates by combining color misregistration information and color misregistration information in the memory on the main body side. Further, an organic EL line head 60 as an image writing unit is disposed at a position corresponding to the photosensitive drum 51 in the apparatus main body.

  FIG. 3 is a view showing a method of mounting the process cartridge 50 of the present invention on the apparatus main body. The process cartridge 50 is moved in the axial direction and attached to the apparatus main body.

  FIG. 4 is a diagram showing a mounting abnormality of the process cartridge 50 mounted on the apparatus main body. The first process cartridge 50 is mounted with the photosensitive drum 51 shifted in the sub-scanning direction, and the second process cartridge 50 from the top is mounted with the photosensitive drum 51 twisted. Such a mounting abnormality occurs when the error of the process cartridge 50 and the error of the apparatus main body are added together.

  FIGS. 5A and 5B are diagrams showing a state in which the wired electronic module 54 is mounted on the apparatus main body. In this case, the electronic module 54 includes an electrode 64, a connector 62 is disposed on the front side 58 of the apparatus main body, and the electrode 64 is inserted into the connector 62 when the process cartridge 50 is attached to the apparatus main body. Memory in the electronic module 54 is connected by wire.

  FIGS. 6A and 6B are views showing a mounting state of the wireless electronic module 54 in the apparatus main body. In this case, the electronic module 54 includes transmission means, and a transmission / reception unit 63 is disposed on the front side 58 of the apparatus main body. When the process cartridge 50 is mounted on the apparatus main body, the electronic module 54 and the transmission / reception unit 63 are positioned close to each other. The CPU of the apparatus main body and the memory in the electronic module are connected wirelessly.

  FIG. 7 is a diagram showing the inside of the wired electronic module 54. In the wired electronic module 54, ROM storing color shift information such as mechanical variation and accuracy generated at the time of manufacturing or assembling of the process cartridge 50, and writing / erasing by commands from the computer of the apparatus main body The control circuit is provided with a signal / power supply by wire, and the control circuit is connected to GND.

  FIG. 8 is a diagram showing the inside of the wireless electronic module 54. In the wireless electronic module 54, ROM that stores color misregistration information such as mechanical variation and accuracy generated at the time of manufacturing or assembling the process cartridge 50, and writing / erasing by commands from the computer of the apparatus main body The control circuit is connected to a transmission / reception antenna, and the transmission / reception antenna is connected to a CPU in the apparatus body via a transmission / reception unit 63 disposed on the front side 58 of the apparatus body.

  In the present invention, measures are taken so that the process cartridge 50 cannot be replaced when the power is turned off. Since the calculation is performed after confirming that the process cartridge is mounted on the apparatus main body at the time of replacement, it is not necessary to perform the calculation every time the power is turned on.

  FIG. 9 is a block diagram showing an electrical configuration of the process cartridge 50 and the apparatus main body of each image forming station Y, M, C, K.

  FIG. 10 is a flowchart showing registration correction according to the present invention. In the present invention, the process cartridge 50 cannot be replaced when the power is turned off. When the power is turned on, it is confirmed that the process cartridge 50 is mounted on the apparatus main body. Next, the color misregistration information is read from the memory in the electronic module 54 of the process cartridge 50. Subsequently, the color misregistration information is read from the memory of the apparatus main body, and the two color misregistration information is synthesized and calculated to calculate the color misregistration correction amount. It is determined whether or not the calculated color misregistration correction amount is within a correctable range. If the determination result is YES, the process cartridge initialization sequence is executed, and if the determination result is NO, a warning is displayed on the display panel.

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Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Image forming apparatus 2: Housing main body 9: Transfer belt unit 10: Paper feed unit 11: Secondary transfer unit 12: Fixing unit 13: Recording medium conveyance means 14: Transfer belt drive roller 15: Driven roller 16: Intermediate transfer belt 17: Cleaning means 18: Test pattern sensor 19: Secondary transfer roller 20: Image carrier 21: Primary transfer member 22: Charging means 23: Image writing means 24: Developing means 26: Toner storage container 27: Toner storage section 29: Toner stirring member 30: Partition member 31: Toner supply roller 32: Blade 33: Development roller 34: Restriction blade 35: Paper feed set 36: Pickup roller 37: Registration roller pair 39: Paper discharge roller pair 40: For duplex printing Conveying path 45: heating roller 46: pressure roller 47: belt stretching member 4 9: Heat-resistant belt 50: Process cartridge 51: Photoconductor drum 52: Female coupling 53: Positioning pin 54: Electronic module 55: Rear side of the apparatus main body 56: Photoconductor gear 57: Male coupling 58: Front side of the apparatus main body 59: Positioning hole 60: Reading head 61: Organic EL line head 62: Connector 63: Transmission / reception unit 64: Electrode

Claims (4)

In an image forming method using a process cartridge having at least an image carrier, the process cartridge has a memory storing information on color misregistration, and the memory information is read when the process cartridge is replaced. An image forming method characterized by performing an initialization process of a process cartridge when it is confirmed that the process cartridge is capable of performing registration processing and register adjustment can be performed. 2. The image forming method according to claim 1, wherein the memory of the process cartridge is read wirelessly. 2. The image forming method according to claim 1, wherein reading of the memory of the process cartridge is performed by wire. 4. The image forming method according to claim 1, wherein replacement of the process cartridge is prohibited when the power is turned off.

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