JP2010039280A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress image density variation by performing an image density adjustment operation, when updating toner container ID information and by setting an image forming condition optimum for each toner. <P>SOLUTION: The image forming apparatus has a toner supply device for supplying a toner to a developing device. The toner supply device has a toner container storage part for storing a toner container. The toner container has a storage means 222 into/from which data can be input/output. The body of the image forming apparatus has a data processing device that reads data for the storage means 222; and when the data held by the toner container is updated, the apparatus performs the image density adjustment operation for adjusting the image forming conditions so that the image density becomes a predetermined density. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that performs image formation using toner.

  In general, in an image forming apparatus using toner, image forming conditions are greatly influenced by a difference in toner characteristics. In particular, when the coloring degree of the toner varies from lot to lot, the image density varies greatly, the color is different, and the image density becomes unstable.

  The prior art will be disclosed next in relation to the above problems.

  In the image forming apparatus described in Patent Document 1, a timer for measuring the driving time of the developing drive motor is installed in the image forming apparatus, and the driving time of the developing drive motor measured by the timer is accumulated in the EEPROM. The control unit confirms that the drive time of the development drive motor stored and stored in the EEPROM has reached the drive time of the development drive motor until calibration of the image density stored in the ROM is executed. Then, it is disclosed that calibration of image density is executed. By determining the timing of image density calibration execution based on the driving time of the developing device, it is possible to prevent a reduction in the quality of the output image.

  A color image forming apparatus described in Patent Document 2 includes a plurality of photosensitive drums, an optical writing unit that forms a latent image on the photosensitive drum, and a developing unit that develops the latent image formed by the optical writing unit. A color image forming apparatus comprising: transfer means for transferring image data developed by the developing means onto an intermediate transfer body; and a toner for detecting a change in toner density of an image developed on the photosensitive drum. It is disclosed that a density detecting unit is provided, and the writing intensity of the optical writing unit is changed according to the change in the toner density detected by the toner density detecting unit to correct the image density fluctuation. This determines the timing for executing image density calibration based on the driving time of the developing device.

In the image forming apparatus and the process cartridge described in Patent Document 3, a photoconductive drum and an ID chip are provided in the process cartridge, a writing CPU is connected to an LD driver IC that adjusts the light quantity of the LD, and an ID chip is connected to the writing CPU. Communicate non-contact with. The eccentricity data of the photosensitive drum is stored in the ID chip, and the writing CPU reads the eccentricity data of the photosensitive drum from the ID chip in a non-contact manner, and calculates the LD light amount corresponding to the eccentricity. . A signal indicating the LD light amount is sent to the LD driver IC, and the LD driver IC adjusts the light amount of the LD. Further, it is disclosed that the writing CPU calculates the eccentric amount of the photosensitive drum based on the reading value of the sensor that reads the toner pattern of the photosensitive drum and stores it in the ID chip. As described above, the process cartridge includes the storage unit that stores the eccentric amount of the photosensitive drum, and adjusts the light amount of the writing light source based on the read eccentric amount. Thereby, even if the process cartridge is replaced, the printed image can be made uniform.
JP 2006-330424 A JP-A-2005-25031 JP 2006-79010 A

  However, there are various causes of color unevenness and density unevenness. Patent Document 1 described above is a technique for color unevenness and density unevenness due to speed fluctuation of the sleeve surface, and color unevenness before and after toner replacement. There is no description regarding the description corresponding to the density unevenness.

  In addition, the above-described Patent Document 2 does not describe the description about the calibration execution of the image density when the toner is replaced. In addition, when the same lot of toner is used, the image density calibration based on the driving time is effective, but when the toner of a different lot is introduced, the image density calibration is surely executed. Not exclusively. As a result, image density variation occurs before and after toner replacement.

  Further, as described above, Patent Document 3 discloses that the process cartridge includes a storage unit that stores the eccentric amount of the photosensitive drum, and adjusts the light amount of the writing light source based on the read eccentric amount. Has been. The light amount of the writing light source is adjusted based on the amount of drum eccentricity as in the above document, but there is no description regarding the description of the adjustment operation before and after toner replacement.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming image forming apparatus that executes an image density adjusting operation in order to set an image forming condition suitable for toner when the ID information of the toner container is updated. .

  To achieve the above object, the invention described in claim 1 has a toner replenishing device for replenishing toner to the developing device, and the toner replenishing device has a toner container accommodating portion for accommodating a toner container, The toner container has storage means capable of data input / output, and the image forming apparatus main body has a data processing device for reading data into the storage means, and data held in the toner container is updated. In this case, an image density adjusting operation for adjusting image forming conditions so that the image density becomes a predetermined density is executed.

  The invention described in claim 2 is characterized in that the image density is adjusted by adjusting the developing potential.

  The invention described in claim 3 is characterized in that the image density is adjusted by controlling the write laser light quantity of the writing means.

  According to a fourth aspect of the present invention, the image density is adjusted by controlling the transfer bias of the transfer means.

  The invention according to claim 5 is characterized in that the image density is adjusted by controlling the charging bias of the charging means.

  The invention described in claim 6 is characterized in that the image forming apparatus main body reads data in a non-contact manner by using an ID chip as the storage means.

  According to the present invention, it is possible to provide an image forming apparatus that suppresses image fluctuation due to toner replacement and maintains stable image quality even after toner replacement.

  In general, in an image forming apparatus using toner, image forming conditions are greatly influenced by a difference in toner characteristics. In particular, when the degree of coloration of the toner varies from lot to lot, the image density varies greatly, the color is different, and the image density becomes unstable. In order to avoid such a situation, the present invention provides a storage device that stores unique ID information in the toner container, reads the toner container ID information from the main body of the image forming apparatus, and updates the toner container ID information. An object of the present invention is to execute an image density adjustment operation (when different toner is introduced), set an optimal image forming condition for each toner, and suppress fluctuations in image density.

  Hereinafter, embodiments of the present invention that solve the above-described problems will be described with reference to the drawings.

  FIG. 1 is a cross-sectional configuration diagram showing a color copying machine as an example of an image forming apparatus according to the present invention. In this color copying machine, a copying machine main body 100 is arranged at the center, and a sheet feeding unit 200 configured in a table shape is arranged below the copying machine main body 100, a scanner 300 above the copying machine main body 100, and an automatic document feeder 400 above the scanner 300. It is the composition which arranged.

  The copying machine main body 100 is provided with an intermediate transfer belt 10 as an image carrier constituted by a flexible endless belt wound around a plurality of rollers 14, 15, 16. In the intermediate transfer belt 10, one of the plurality of rollers 14, 15, and 16 is rotationally driven by a driving device (not shown), whereby the intermediate transfer belt 10 is driven to run clockwise in the figure indicated by an arrow. The other rollers are driven to rotate. Black, cyan, magenta, and yellow image forming units 18 are arranged side by side on the upper traveling side of the intermediate transfer belt 10 that travels in this way. That is, four image forming means 18 are arranged on the belt running side between the roller 14 and the roller 15 to constitute the tandem image forming unit 20.

  The four image forming units 18 include a photosensitive drum 40 as a latent image carrier in contact with the intermediate transfer belt 10. Around the photosensitive drum 40, a charging device, a developing device, a cleaning device, a static eliminator, and the like are disposed. Further, a transfer device is disposed inside the intermediate transfer belt 10 at a position where the photosensitive drum 40 contacts the intermediate transfer belt 10. 62 is provided. In the present embodiment, the four image forming units 18 have the same structure, but the color of the toner of the developing device is different to four colors of black, cyan, magenta, and yellow.

  Further, an exposure device 21 for irradiating the surface of each photosensitive drum with light-modulated laser light is disposed above each image forming unit 18, and this laser light is applied to the photosensitive drum between the charging device and the developing device. To do. Although the exposure apparatus 21 may be provided for each image forming unit 18, using the common exposure apparatus 21 is advantageous in terms of cost.

  A secondary transfer device 22 is provided on the opposite side of the intermediate transfer belt 10 from the tandem image forming unit 20. In the illustrated example, the secondary transfer device 22 is arranged such that a secondary transfer belt 24 that is an endless belt is wound around two rollers 23 and the belt is pressed against the roller 16 via the intermediate transfer belt 10. Has been.

  In FIG. 1, a fixing device 25 for fixing a transfer image carried on a sheet is provided on the left side of the secondary transfer device 22. The fixing device 25 of this embodiment includes a pressure roller 27 and a fixing belt 26 that is an endless belt pressed against the pressure roller 27.

  The secondary transfer device 22 described above also has a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a non-contact charger may be disposed as the secondary transfer device 22. In such a case, it is necessary to separately provide a sheet conveying device for conveying the transferred sheet to the fixing device 25.

  In the illustrated example, a sheet reversing device 28 for reversing the sheet so as to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. It has.

  Now, a case where copying is performed using the color copying machine configured as described above will be described. First, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  Further, when a start switch (not shown) is pressed, the intermediate transfer belt 10 is rotated, and at the same time, the photosensitive member 40 is rotated by each image forming unit 18 so that each black, yellow, A magenta / cyan monochrome image is formed. Then, as the intermediate transfer belt 10 travels, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

  Further, by pressing the start switch, one of the paper feed rollers 42 of the paper feed unit 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller The sheet is separated one by one at 45 and put into the sheet feeding path 46, conveyed by the conveying roller 47, guided to the sheet feeding path 48 in the copying machine main body 100, abutted against the registration roller 49 and stopped.

  Alternatively, when manual feeding is selected, the sheet feeding roller 50 is rotated to feed out the sheets on the manual tray 51, separated one by one by the separation roller 52, and put into the manual feeding path 53. Stop by hitting.

  Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. Full color images are recorded on the sheet at once.

  The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image. Are discharged and stacked on the discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.

  On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming unit 20 prepares for another image formation.

  FIG. 2 is a perspective view showing a toner supply mechanism that supplies toner to the developing device of the image forming unit 18. In this figure, reference numeral 60 denotes a developing device provided for each color image forming unit 18, and a toner container 80 as a toner storage means for storing toner to be supplied to each developing device 60 is shown in the lower left of FIG. From right to left, four of black, magenta, cyan, and yellow are set and arranged in a set unit (not shown) provided in the copying machine main body 100. Since the mechanism for supplying toner from each color toner container 80 to each developing device 60 is the same, the black device located in the foreground in FIG.

  A nozzle 90 to be inserted into the container 80 is provided in a machine frame (not shown) in the setting portion for setting the toner container 80, and the nozzle 90 and the powder pump 70 are connected by a toner supply tube 91. Yes. By setting the toner container 80 in the setting portion, the nozzle tip is inserted into the valve chamber of the mounting member 101 attached to the lower part of the toner container 80, and the powder container 70 communicates with the toner container 80.

  The powder pump 70 is driven via a connection gear 74 from a drive shaft gear 73 mounted on a drive shaft 72 that is rotationally driven by a drive motor 71. As the powder pump 70, a well-structured MONO pump can be employed. The toner transferred by the powder pump 70 is temporarily stored in the sub hopper 75, and is supplied to the developing device 60 from the toner replenishing port 76 below the sub hopper.

  FIG. 3 is a perspective view of the toner container 80. The toner container 80 includes a bag-like toner container 81 and a mounting member 101 (a discharging member). The toner storage body 81 is formed of a resin, which is formed into a bag shape by welding a film-like resin having a thickness of about 50 to 300 μm, called a soft packaging material, or a molding resin.

  The storage unit 222 stores ID information unique to the toner container. In the unique information, for example, information unique to the toner contained in the toner container, such as the production date of the toner and the production lot, is recorded. The storage means 222 is preferably an ID chip, a barcode, or the like that can be automatically read in cooperation with a reading device on the main body side.

  According to the present embodiment, by performing the image density adjustment operation at the time of toner replacement, it is possible to suppress the density fluctuation at the time of toner replacement, and the stability of the image density can be maintained for a long time.

  Further, by using the ID chip, the image forming apparatus main body side can read data without contact.

  Furthermore, not only the image forming apparatus using toner but also replacement of supplies such as an ink cartridge is executed.

  FIG. 4 is a flowchart when image density adjustment is performed by developing potential control of the developing means.

  In the control flow, first, a density adjustment operation is executed (step S401). When the ID information of the toner container is updated, an execution command is issued from the control unit that executes the image density adjustment. Next, a process for uniformly charging the photosensitive member (step S402) and a reference pattern exposure (step S403) are performed. As an image density adjustment operation, a reference pattern is developed on the photoreceptor. Here, the solid pattern image is used as the reference pattern. However, the present invention is not limited to this, and a halftone pattern or the like is also possible.

  When the reference pattern is developed on the photosensitive member, the development bias potential applied to the developing roller is appropriately changed for development (step S404). Then, the developed reference pattern density is read by the optical sensor (step S405), and it is possible to select a development potential at which a desired image density is obtained (step S406). End of the density adjustment operation (step S407).

  According to this embodiment, by adjusting the developing bias, fluctuations in image density can be suppressed regardless of toner replacement.

  FIG. 5 is a flowchart when image density adjustment is performed by controlling the write laser light quantity of the writing means.

  In the control flow, first, a density adjustment operation is executed (step S501). First, when the ID information of the toner container is updated, an execution command is issued from the control unit that executes the image density adjustment. Next, reference pattern exposure (step S503) processing is performed by uniformly charging the photoconductor (step S502) and adjusting the amount of writing light. As an image density adjustment operation, an electrostatic latent image serving as a reference pattern is written on a uniformly charged photoconductor. Here, the solid pattern image is used as the reference pattern. However, the present invention is not limited to this, and a halftone pattern or the like is also possible.

  When writing the reference pattern, the electrostatic latent image is written while appropriately changing the laser light amount of the exposure apparatus. Thereafter, development is performed along the electrostatic latent image by the developing device (step S504). Then, the developed reference pattern density is read by the optical sensor (step S505), and it is possible to select the laser light quantity that provides the desired image density (step S506). End of the density adjustment operation (step S507).

  According to this embodiment, by controlling the write laser light amount of the writing means, fluctuations in image density can be suppressed regardless of toner replacement.

  FIG. 6 is a flowchart when image density adjustment is performed by controlling the transfer bias of the transfer means.

  In the control flow, first, a density adjustment operation is executed (step S601). When the ID information of the toner container is updated, an execution command is issued from the control unit that executes the image density adjustment. Next, a process of uniformly charging the photoconductor (step S602) and a reference pattern exposure (step S603) are performed. As the image density adjustment operation, the reference pattern is developed on the photoconductor (step S604). Here, the solid pattern image is used as the reference pattern. However, the present invention is not limited to this, and a halftone pattern or the like is also possible.

  The developed image developed on the photosensitive member is transferred onto the intermediate transfer member using a transfer unit (step S605). The transfer bias used when transferring to this intermediate transfer member is applied with varying it appropriately. Then, the reference pattern density transferred onto the intermediate transfer member is read by an optical sensor (step S606), and a transfer bias that can obtain a desired image density can be selected (step S607). End of the density adjustment operation (step S608).

  According to the present embodiment, by controlling the transfer bias of the transfer unit, fluctuations in image density can be suppressed regardless of toner replacement.

  FIG. 7 is a flowchart when image density adjustment is performed by controlling the charge amount of the charging means.

  In the control flow, first, a density adjustment operation is executed (step S701). First, when the ID information of the toner container is updated, an execution command is issued from the control unit that executes the image density adjustment. Next, the photosensitive member uniform charging (step S702) and reference pattern exposure (step S703) are performed by adjusting the charging bias. As the image density adjustment operation, the reference pattern is developed on the photoconductor (step S704).

  Here, the solid pattern image is used as the reference pattern. However, the present invention is not limited to this, and a halftone pattern or the like is also possible. Here, before the reference pattern is developed on the photosensitive member, when the photosensitive member is uniformly charged by the charging unit, the charging bias is appropriately changed and applied. Then, the reference pattern density developed by the developing device is read by the optical sensor (step S705), and the charging bias can be selected so as to obtain a desired image density (step S706). End of the density adjustment operation (step S707).

  According to the present embodiment, by controlling the charging bias of the charging unit, fluctuations in image density can be suppressed regardless of toner replacement.

1 is a schematic configuration diagram of a copier as an image forming apparatus. FIG. 3 is a perspective view of a toner supply device. FIG. 6 is a perspective view of a toner container. FIG. 6 is a flowchart of image density adjustment by developing potential adjustment. It is a flowchart figure of image density adjustment by write laser light quantity adjustment. FIG. 10 is a flowchart of image density adjustment by transfer bias adjustment. It is a flowchart figure of the image density adjustment by charging bias adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intermediate transfer belt 11 Lubricant press spring 12 Lubricant case 13 Secondary transfer power supply 14 First support roller 15 Second support roller 16 Backup roller 17 Belt cleaning device 18 Image forming unit 20 Tandem image forming unit 21 Exposure device 22 Cleaning blade 23 Secondary Transfer Roller 24 Solid Lubricant 25 Fixing Device 40 Photosensitive Drum 61 Development Unit 62 Primary Transfer Roller 63 Photoconductor Cleaning Device 100 Printer Unit 200 Paper Feeding Unit 222 Storage Unit 300 Scanner Unit 400 Document Conveying Unit

Claims (6)

A toner supply device for supplying toner to the developing device;
The toner replenishing device has a toner container accommodating portion for accommodating a toner container,
The toner container has storage means capable of data input / output,
The image forming apparatus main body has a data processing device for reading data into the storage means,
An image forming apparatus that executes an image density adjusting operation for adjusting an image forming condition so that an image density becomes a predetermined density when data held in the toner container is updated. Writing means for forming a latent image on the image carrier;
Developing means for developing the latent image formed by the writing means with a developing device;
The image forming apparatus according to claim 1, wherein the image density adjusting operation is control of a developing potential of the developing unit. Writing means for forming a latent image on the image carrier;
Developing means for developing the latent image formed by the writing means with a developing device;
The image forming apparatus according to claim 1, wherein the image density adjusting operation is control of a writing laser light amount of the writing unit. Writing means for forming a latent image on the image carrier;
Developing means for developing the latent image formed by the writing means with a developing device;
Transfer means for transferring the toner image developed by the developing means to a transfer medium,
The image forming apparatus according to claim 1, wherein the image density adjustment operation is control of a transfer bias of the transfer unit. Writing means for forming a latent image on the image carrier;
Developing means for developing the latent image formed by the writing means with a developing device;
Charging means for uniformly charging the surface of the image carrier,
The image forming apparatus according to claim 1, wherein the image density adjusting operation is control of a charging bias of the charging unit.   6. The image forming apparatus according to claim 1, wherein the storage unit is an ID chip.

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