JP2005084494A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus having a parameter regarding an image forming means for each surface to be transferred to a sheet of paper, for keeping uniformity in image quality of images to be formed on the front side and the back side of the sheet of paper that is the recording medium. <P>SOLUTION: The polarity of toner formed on a first image carrier 1 is minus, and the toner formed on the first image carrier 1 is transferred to a second image carrier 10, by providing a plus electric charge to a first transfer means 20. By providing the plus electric charge to a second transfer means 120, the toner formed on the second image carrier is transferred to a third image carrier 100. Further, the toner on the surface of the second image carrier is transferred to one side of the recording medium. By providing the electric charge of the plus polarity from a charger CH, the toner of the minus polarity on the third image carrier 100 is attracted, and is transferred to the other side of the recording medium. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of forming images on both sides of a recording medium almost simultaneously.

  In recent electrophotographic apparatuses such as copying machines and printers, double-sided transfer images onto a recording medium (paper) are already common. However, as a transfer method to the recording medium (paper), after transferring and fixing the first surface to the recording medium (paper), transfer and fixing to the second surface of the recording medium (paper) using a double-side reversing device or the like. The process is going on.

However, in double-sided printing on a recording medium (paper) by the above method, a double-sided reversing device or the like is indispensable, and it cannot be denied that the first print on both sides is delayed.
In addition, there is an image forming apparatus that performs double-sided printing without using a double-sided reversing device or the like in order to achieve the above problem (see Patent Document 1).

Also, there is an image forming apparatus that performs double-sided printing by changing the running condition of the second image carrier after transferring the visible image from the first image carrier to the second image carrier (Patent Document). 2).
JP 2000-352889 A JP 2003-233287 A

  However, the image forming device is provided for each of the first side and the second side of the recording medium (paper), and space-saving is required, but the machine size is large, and the image forming device is further used as the recording medium. Since it is necessary for each side of the (paper), it is very disadvantageous in terms of cost.

  The present invention has been made in view of such problems, and in order to maintain the uniformity of image quality formed on the front and back surfaces of the recording medium (paper), image formation is performed for each surface to be transferred to the recording medium (paper). An object of the present invention is to provide an image forming apparatus having parameters relating to the means.

  In addition, in order to maintain the uniformity of the image quality formed on the front and back surfaces of the recording medium (paper), the parameter relating to the image forming means for each surface to be transferred to the recording medium (paper) is the image forming printer γ. Objective.

  In order to achieve the above object, an image forming apparatus according to claim 1 includes a first image carrier, a second image carrier, and a third image carrier, and the first image carrier to the first image carrier. The image transferred to the second image carrier and further transferred from the second image carrier to the third image carrier is transferred to one surface of the recording medium, and from the first image carrier. An image forming apparatus capable of transferring a visible image on both sides of a recording medium by transferring the visible image transferred to the second image carrier onto the other side of the paper, and developing the read original into RGB image data. In addition, a color original reading apparatus capable of color-converting RGB image data into KCMY image data, and an image forming apparatus having an image forming unit that visualizes KCMY image data with a plurality of first image carriers. RGB image data read by the Holding means for holding conversion parameters for conversion to image data that matches the output characteristics when outputting the image data corrected by the color correction means for conversion to MY image data, and settings for converting the conversion parameters It has the setting means to perform, It is characterized by the above-mentioned.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the holding unit holds different conversion parameters according to the front and back image formation of the paper as the recording medium.

  According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the setting unit sets a conversion parameter corresponding to the front and back image formation of a sheet as a recording medium.

  A fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein the conversion parameter is an image forming printer γ.

  From the above description, the image forming apparatus of the present invention maintains the uniformity of the image quality formed on the recording medium (paper) by having the parameters related to the image forming means for each surface to be transferred to the recording medium (paper). be able to. In addition, since the image forming printer γ is provided as a unique parameter relating to the image forming unit for each surface to be transferred to the recording medium (paper), uniformity of image quality formed on the recording medium (paper) can be maintained. .

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic central sectional view of an image forming apparatus capable of forming images almost simultaneously on both sides of a recording medium of the present invention.

  A neutralizing device L, a cleaning device 2, a charging device 3, and a developing device 5 are arranged on the outer periphery of a first image carrier (photosensitive member) 1 that is rotatably supported and rotates in the direction of an arrow. A space for storing optical information emitted from the exposure device 4 is secured between the charging device 3 and the developing device 5. There are four (a, b, c, d) first image carriers (photoconductors) 1, but the components for image formation provided around are the same.

  The color of the color material (toner) handled by the developing device 5 is different. The first image carrier 1 is a photoreceptor in which an organic semiconductor layer, which is a photoconductive substance, is provided on the surface of an aluminum cylinder having a diameter of about 30 to 100 mm. A part thereof is in contact with the second image carrier (intermediate transfer belt) 10. A belt-like photoreceptor can also be employed.

  The second image carrier 10 is supported and stretched between rollers 11, 12, and 13 that rotate so as to be movable in the direction of the arrow. On the back side (inside the loop), the first transfer means 20 is the first transfer unit 20. In the vicinity of the image carrier 1.

  A second image carrier cleaning device 25 is disposed outside the belt loop. After the transfer from the second image carrier 10, unnecessary toner remaining on the surface is wiped off.

  The exposure device 4 irradiates the uniformly charged surface of the photoconductor as a latent image with optical information corresponding to full-color image formation by a known laser method. An exposure apparatus comprising an LED array and an image forming means can also be employed.

  The second image carrier (intermediate transfer member) 10 is a belt having a base of a resin film or rubber having a substrate thickness of 50 μm to 600 μm, and has a resistance value capable of transferring toner from the first image carrier. .

  The belt-like third image carrier 100 is supported and stretched between the rotating rollers 111, 112, and 113 so as to be movable in the direction of the arrow, and on the back side (inside the loop), the second transfer means is provided. 120 is deployed. A third image carrier cleaning device 250, a charger CH, and the like are arranged outside the belt loop. The cleaning device 250 transfers the toner onto the paper and then wipes off any remaining unnecessary toner.

  The second image carrier 10 and the third image carrier 100 are brought into contact with each other by the transfer means 120, the roller 113, and the roller 11 that supports the second image carrier 10 to form a predetermined transfer nip.

  The third image carrier (intermediate transfer member) 100 is a belt having a base of a resin film or rubber having a thickness of 50 μm to 600 μm, and a belt having a resistance value capable of transferring toner from the second image carrier. It is.

  The recording medium (paper) P is housed in paper feeding devices (paper feeding cassettes) 26-1 and 26-2, and the uppermost paper is fed by a paper feeding roller 27 one by one, and a plurality of guides 29 are passed through registration rollers. Transported to pair 28.

  In the upper part of the figure, a fixing heating unit 30, a paper discharge guide pair 31, a paper discharge roller pair 32, and a paper discharge stack unit 40 are provided.

  A storage unit TS that can store replenishment toner is provided above the second image carrier 10 and below the paper discharge unit 40. There are four toner colors, magenta, cyan, yellow, and black, which are in the form of a cartridge TC. The developing device for the corresponding color is appropriately supplied by a powder pump or the like.

  The frame 50, which is a part of the main body, has a structure that can be rotated and opened around the opening / closing support shaft 50A. Therefore, the conveyance path of the recording medium (paper) P is greatly opened, and the jammed recording medium (paper) The processing of P is facilitated.

Next, a processing operation when images are obtained on both sides of the recording medium (paper) P will be described.
First, an image is formed by the first image carrier 1 (photosensitive member). As a result of the operation of the exposure device 4, light from an LD light source (not shown) passes through optical parts (not shown) and is denoted as a in the first image carrier (photoconductor) 1 uniformly charged by the charging device 3. A latent image corresponding to the writing information (information corresponding to the color) is formed on the photosensitive member.

  The latent image on the first image carrier 1 is developed by the developing device 5, and a visible image by the toner is transferred to the surface of the second image carrier 10 that moves in synchronization with the first image carrier. The remaining toner on the surface of the first image carrier 1 is cleaned by the cleaning device 2 and discharged by the charge removing device L to prepare for the next image forming cycle.

  The second image carrier 10 carries the toner image transferred to the surface and moves in the direction of the arrow. A latent image corresponding to another color is written on the first image carrier (photosensitive member) 1 marked b, and developed with a toner of the corresponding color to become a visible image. This image is superimposed on the previous color image already on the second image carrier, and finally four colors are superimposed.

  At this time, the third image carrier 100 is moved in the direction of the arrow in synchronism, and the second transfer means 120 acts on the surface of the third image carrier 100 and the surface of the second image carrier. The created image is transferred. While the images are formed on the four photoconductors in the so-called tandem format, the second and third image carriers move and the image formation proceeds, so the time can be shortened.

  When the second image carrier 10 moves to a predetermined position, a toner image to be created on another surface of the recording medium (paper) P is again produced by the first image carrier 1 in the process as described above. And feeding is started. When the paper feed roller 27 rotates counterclockwise, the uppermost recording medium (paper) P in the paper feed device (paper feed cassette) 26 is pulled out and conveyed to the registration roller pair 28.

  A toner image on the surface of the second image carrier 10 is formed on one surface of a recording medium (paper) P sent between the second image carrier 10 and the third image carrier 100 through the registration roller pair 28. Is transferred by the second transfer means 120.

  Further, the recording medium (paper) P is conveyed upward, and the toner image on the surface of the third image carrier 100 is transferred to the other surface of the recording medium (paper) P by the charger CH. At the time of transfer, the recording medium (paper) P is conveyed at a timing so that the position of the image is normal.

  In this embodiment, the polarity of the toner formed on the first image carrier 1 is negative. By applying a positive charge to the first transfer unit 20, the toner formed on the first image carrier is transferred to the second image carrier 10.

By applying a positive charge to the second transfer unit 120, the toner formed on the second image carrier is transferred to the third image carrier 100. Further, the toner on the surface of the second image carrier is also transferred to one surface of the recording medium (paper) P.
By applying a positive polarity charge from the charger CH, the negative polarity toner on the surface of the third image carrier 100 is sucked and transferred to the other surface of the recording medium (paper) P.

  The recording medium (paper) P on which the toner images are transferred on both sides in the above steps is sent to the fixing means 30, and the toner images (both sides) on the recording medium (paper) P are melted and fixed at one time. After 31, the paper is discharged to the paper discharge stack 40 at the upper part of the main body frame by the paper discharge roller pair 32.

  As shown in FIG. 1, when the paper discharge unit 40 is configured, the side (page) of the double-sided image that is transferred from the back to the recording medium (paper) P, that is, from the second image carrier 10 to the recording medium ( Since the surface directly transferred to the sheet (P) is the lower surface and is placed on the paper discharge stack unit 40, the second page image is created first and the third image is prepared for page alignment. The toner image may be held on the carrier 100 and the image of the first page may be directly transferred from the second image carrier 10 to the recording medium (paper) P.

The image transferred from the second image carrier 10 to the recording medium (paper) P becomes a normal image on the surface of the first image carrier, and is transferred from the third image carrier 100 to the recording medium (paper) P. The toner image is exposed so as to be a reverse image (mirror image) on the surface of the first image carrier (photoconductor).
Such an image forming order for page alignment is a known technique for storing image data in a memory, and exposure for switching between a normal image and a reverse image (mirror image) can also be realized by a known image processing technique.

After transferring from the third image carrier 100 to the recording medium (paper) P, the cleaning device 250 having a brush roller, a collection roller, a blade, and the like inside the unnecessary toner remaining on the surface of the third image carrier And remove paper dust.
As shown in FIG. 1, the roller 250A is in a state of being separated from the surface of the third image carrier. The structure can swing around the fulcrum 250A and can contact and separate from the surface of the third image carrier. Before the image is transferred to the recording medium (paper) P, it is released when the third image carrier carries a toner image, and when cleaning is required, it swings counterclockwise as shown in FIG. Let The toner thus removed is collected in the toner storage unit 250B.

Next, a processing operation when an image is obtained on one side of the recording medium (paper) P will be described.
In the case of the single side, there are two methods, but a case where the step of transferring the toner to the third image carrier 100 is omitted and the transfer from the second image carrier to the recording medium (paper) P will be described.

The toner image formed on the surface of the first image carrier 1 is transferred to a recording medium (paper) P while being transferred to the second image carrier.
In FIG. 1, in order to align with the toner image formed on the second image carrier 10, the recording medium (paper) P is synchronized with the second image carrier 10 and the third image carrier. The toner is transferred between the bodies 100, and the toner is transferred from the second image carrier 10 to the recording medium (paper) P by the second transfer unit 120.

  The charger CH, which is a transfer unit, does not operate, and the recording medium (paper) P moves together with the third image carrier 100 and is sent to a region where the fixing unit 30 is located, and the toner is fixed. Thereafter, the recording medium (paper) P is separated from the third image carrier 100 and is discharged in the direction of arrow A through the guide pair 31 and the discharge roller pair 32, and the image surface is face down (face down). ). With such a configuration, even if documents of several pages are processed in order from one page, the printed matter is in page order when taken out from the paper discharge stack unit 40.

Next, the processing operation of the read image processing will be described with reference to FIG.
RGB, which is image data of a document read by a reading device (not shown), corrects non-uniformity of image data in the main scanning direction caused by the reading device by shading correction, and is the same image data for the same document. RGB is output (step S1).

  Next, the image data is converted into linear image data normalized by the scanner γ (step S2). Next, in ACC (automatic color correction), the image data is output without being processed (step S3). Next, in color correction, image data is converted from R, G, B to K, C, M, Y, and image data that can be output to a printer is generated (step S4).

  Next, in main scanning scaling, image data is processed according to the scaling ratio in the main scanning direction (step S5). In the sub-scanning direction, image data can be obtained by changing the reading speed of the document according to the magnification. Finally, the printer γ holds the conversion parameters for converting the image data after color correction into output characteristics that match the printer engine characteristics, and makes settings for conversion (step S6).

  The image data generated by the image processing is written according to the image data by an exposure device (not shown) of the first image carrier 1. The conversion parameters of the image data in the printer γ hold different conversion parameters according to the front and back image formation of the recording medium (paper) P, and set the conversion parameters according to the front and back image formation of the recording medium. Note that the conversion parameter switching is based on an instruction from a device control unit (not shown).

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. 5 is a flowchart illustrating processing operations of the image forming apparatus according to the exemplary embodiment of the present invention.

Explanation of symbols

1 First image carrier (photoreceptor)
2 First image carrier (photosensitive times)
3 Charging device 4 Exposure device 5 Development device 10 Second image carrier (intermediate transfer belt)
11, 12, 13 Roller (support shaft of second image carrier)
20 First transfer means 25 Cleaning device (for second image carrier)
26-1, 26-2 Paper feeding device (paper feeding cassette)
27 Feed roller 28 Registration roller pair 29 Conveying guide 30 Heating device 31 Guide pair 32 Paper discharge roller pair 40 Paper discharge stack unit 50 Opening / closing frame 50A Opening / closing support shaft 100 Third image carrier (intermediate transfer belt)
111, 112, 113 Roller 120 Second transfer means 250 Cleaning device (for third image carrier)
250A Cleaning rocking fulcrum 250B Toner storage part A Paper discharge direction L Discharge lamp P Recording medium (paper)
CH charger TS toner storage TC toner (cartridge)

Claims (4)

A first image carrier, a second image carrier, and a third image carrier; transfer from the first image carrier to the second image carrier; The visible image transferred to the third image carrier is transferred to one side of a sheet as a recording medium, and the visible image transferred from the first image carrier to the second image carrier is transferred to the other side of the sheet. An image forming apparatus capable of transferring a visible image to both sides of the recording medium by transferring to the surface of
A color original reading device capable of developing the read original into RGB image data and color-converting the RGB image data into KCMY image data;
In an image forming apparatus having image forming means for visualizing KCMY image data on the plurality of first image carriers,
Conversion parameters for converting the RGB image data read by the color document reading device into the image data that matches the output characteristics when outputting the image data corrected by the color correction unit that converts the image data into KCMY image data. Holding means for holding;
An image forming apparatus comprising: a setting unit configured to perform a setting for converting the conversion parameter.   The image forming apparatus according to claim 1, wherein the holding unit holds different conversion parameters according to front and back image formation of a sheet as the recording medium.   The image forming apparatus according to claim 1, wherein the setting unit sets the conversion parameter according to front and back image formation of a sheet as the recording medium.   The image forming apparatus according to claim 1, wherein the conversion parameter is an image forming printer γ.

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