JPH0883032A - Color image forming device - Google Patents

Abstract

PURPOSE: To correct and adjust the change of a regist, which is caused by the replacement of an image forming body or image exposure means, by applying a simple correction means. CONSTITUTION: In the process of a test pattern mode, a linear image is formed by linearly exposing for every LED unit in which an LED array composing each of yellow(Y), magenta(M), cyan(C), and black(K) exposure optical system is divided in four in order from the upstream side in a main scanning direction, and the level difference (displacement) >= of each image is read. The level differences >= are inputted to the main body of the device by storing them in a RAM card C4 as code numbers or specified marks, and the set value of regist in image exposure is automatically corrected in an image formation process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic system in which a plurality of image exposing means and developing means are arranged on the peripheral surface of an image forming body so that toner images are superposed during one rotation of the image forming body. The present invention relates to a color image forming apparatus.

[0002]

2. Description of the Related Art As a method for forming a multicolor image, a monochromatic toner image formed on each photoconductor is intermediately transferred by equipping the photoconductor with the same number of images as necessary, a charger and a developing device. A device that creates a color image by superimposing it on an image (A)
An apparatus (B) for forming a color image by repeating charging, image exposure and development for each color by rotating one photoreceptor a plurality of times, or similarly, charging and image exposure for each color within one rotation of one photoreceptor. An apparatus (C) and the like for forming a color image by sequentially performing development are known.

However, the above-mentioned device (A) has a drawback that the volume of the device is increased because a plurality of photoconductors and intermediate transfer members are required, while the device (B) has a charging means, an image exposing means and a photoconductor. However, there is a restriction that the size of the formed image is limited to the surface area of the photoreceptor or less, though the volume is reduced.

Although the device (C) enables high-speed image formation, it is necessary to dispose a plurality of sets of a charger, an image exposing means and a developing device within one circumference of the photosensitive member. A function and performance capable of superimposing the toner images of the respective colors formed by the image exposing means and the developing device with high accuracy are required.

[0005]

The accuracy of superimposing a plurality of toner images depends mainly on the accuracy of the image exposure timing by the image exposing means on the image forming body when forming the respective toner images. The image exposure timing itself also changes due to changes in the peripheral length of the image forming body, and due to changes in the exposure positional relationship of the LED arrays used as a plurality of exposure optical systems, the overlay becomes incomplete, which is a so-called color shift. And a high quality color image cannot be obtained.

As a result of solving these problems and improving the present invention, a plurality of image exposure means are used to change the peripheral length of the image forming body and LE.
Color image formation in which high-quality color images can be formed by automatically adjusting the timing of image exposure individually in response to changes in the exposure position relationship of the D array, thereby accurately superimposing toner images of respective colors The purpose is to provide a device.

[0007]

SUMMARY OF THE INVENTION The above-mentioned object is a color in which a toner image is superposed on the image forming body by repeating charging, image exposure and development on the image forming body, and then collectively transferring to a transfer material. In the image forming apparatus, the image forming body has a plurality of image exposing means, and at least one of the image forming body and the image exposing means can be exchanged together with corresponding resist management data. An image forming apparatus (first invention) and a color image formation in which a toner image is superimposed on the image forming body by repeating charging, image exposure and development on the image forming body, and then collectively transferring to a transfer material. The apparatus has a test pattern mode for resist adjustment and a storage means capable of exchanging or rewriting the resist set value, and the resist adjustment obtained from the printing by the test pattern. A color image forming apparatus (second invention), which exchanges or rewrites the resist setting value of the storage means according to the value, and a plurality of charging means, image exposing means, and developing means in the vicinity of the image forming body. In a color image forming apparatus in which toner images are superposed and formed on the image forming body by repeating charging, image exposure and development after being arranged, a plurality of writing timings for resist adjustment are used in a color image forming apparatus for collectively transferring to a transfer material. This is achieved by a color image forming apparatus (third invention) having a test pattern mode, selecting a specific resist pattern from prints by the plurality of test patterns, and resetting as a resist timing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of each embodiment of the present invention, the structure of a color image forming apparatus common to each invention will be described with reference to FIGS.

Reference numeral 10 denotes a drum-shaped image forming body, that is, a photosensitive drum, which is coated with a transparent conductive layer and an organic photosensitive layer (OPC) on the outer periphery of a cylindrical substrate formed of a transparent member such as optical glass or transparent acrylic resin. It was done.

A flange 10A at one end of the photosensitive drum 10 has a guide pin 30 provided in a cartridge 30 described later.
The flange 10B at the other end is supported by P, and the flange 10B at the other end is externally fitted to a plurality of guide rollers 40R included in a support plate 40A attached to the substrate 40 of the apparatus main body to mesh the outer peripheral gear 10G with the drive gear 40G. The transparent conductive layer is grounded by power in a clockwise direction.

Reference numeral 11 denotes a scorotron charger, which is a photosensitive drum 10.
The above-mentioned organic photoconductor layer is charged by a grid held at a predetermined potential and corona discharge by a discharge wire to give a uniform potential to the photoconductor drum 10.

Reference numeral 12 denotes L arranged in the axial direction of the photosensitive drum 10.
In an exposure optical system composed of an ED array and a Selfoc lens, image signals of respective colors read by a separate image reading device are sequentially taken out from a memory and inputted to the respective exposure optical systems 12 as electric signals. To be done.

Each of the exposure optical systems 12 is mounted on a cylindrical support member 20 which is fixed to the support plate 40A using guide pins 40P1 as guides, and is mounted on the photosensitive drum 10.
Is housed inside the base body of.

Numerals 13Y to 13K are developing units for accommodating each of yellow (Y), magenta (M), cyan (C) and K (black) developers, and each has a predetermined gap with respect to the peripheral surface of the photosensitive drum 10. Development sleeve 13 that keeps the same and rotates in the same direction
Equipped with 0.

Each of the developing devices is in a non-contact state by applying a developing bias voltage to the electrostatic latent image formed on the photosensitive drum 10 formed by the charging by the charging device 11 and the image exposure by the exposure optical system 12 described above. Reverse development with.

Next, the process of the color image forming apparatus in this apparatus will be described.

The original image is temporarily stored in an image reading device, which is separate from this apparatus, as an image read by an image pickup device or an image edited by a computer as an image signal for each color of Y, M, C and K. Are stored and stored in.

When the photoconductor drive motor is started by the start of image recording, the drive gear 40G is rotated to rotate the photoconductor drum 10 in the clockwise direction, and at the same time, the photoconductor is driven by the charging action of the charger 11 (Y). Application of electric potential to the drum 10 is started.

After the photosensitive drum 10 is applied with an electric potential,
In the exposure optical system 12 (Y), the exposure by the electric signal corresponding to the first color signal, that is, the yellow (Y) image signal is started, and the yellow (Y) of the original image is formed on the photosensitive layer on the surface by the rotational scanning of the drum. ) Form an electrostatic latent image corresponding to the image.

The latent image is reversely developed by the developing device 13 (Y) with the developer on the developing sleeve in a non-contact state, and a yellow (Y) toner image is formed in accordance with the rotation of the photosensitive drum 10.

Next, the photosensitive drum 10 is further given a potential on the yellow (Y) toner image by the charging action of the charger 11 (M), and the second color signal of the exposure optical system 12 (M), that is, Exposure with an electric signal corresponding to the magenta (M) image signal is performed, and non-contact reversal development by the developing device 13 (M) causes a magenta (M) toner image on the yellow (Y) toner image. Will be sequentially stacked.

By a similar process, a cyan (C) toner image corresponding to the third color signal is further generated by the charger 11 (C), the exposure optical system 12 (C) and the developing device 13 (C), and the charger also. 11 (K), exposure optical system 12 (K) and developing unit 13
By (K), a black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed, and a color toner image is formed on the peripheral surface of the photosensitive drum 10 within one rotation.

Photoreceptor drum 10 by each of these exposure optical systems
The exposure of the organic photosensitive layer is conducted from the inside of the drum through the above-mentioned transparent substrate. Therefore, the exposure of the images corresponding to the second, third and fourth color signals is performed without any influence of the toner image previously formed.
It is possible to form an electrostatic latent image equivalent to the image corresponding to the color signal of. The stabilization of the temperature inside the photosensitive drum 10 and the prevention of the temperature rise due to the heat generation of each exposure optical system 12 use a material having good thermal conductivity for the supporting member 20, and use a heater 201 when the temperature is low, When the temperature is high, it can be suppressed to a level without any trouble by taking measures such as radiating heat to the outside through the heat pipe 202. Further, during the developing operation by each developing device, a developing bias in which a direct current or an alternating current is applied to the developing sleeve 103 is applied, and jumping development is performed by the one-component or two-component developer accommodated in the developing device, and the transparent Non-contact reversal development is performed on the photoconductor drum 10 whose grounding is carried out on the conductive layer.

Thus, the color toner image formed on the peripheral surface of the photosensitive drum 10 is transferred to the transfer paper which is conveyed from the paper feed cassette 15 in the transfer device 14A and is fed in synchronization by the driving of the timing roller 16. It

The transfer paper on which the toner image has been transferred is a static eliminator.
In 14B, the charge is removed and the toner is separated from the peripheral surface of the drum. After the toner is fused in the fixing device 17, the toner is discharged via the paper discharge roller 18 onto the tray above the device.

On the other hand, the photosensitive drum 10 from which the transfer paper has been separated removes and cleans the residual toner in the cleaning device 19 to continue the formation of the toner image of the original image, or temporarily stops the toner image of the new original image. Formation.

The photoconductor drum 10, the charging devices 11, the developing devices 13, and the cleaning device 19 are housed in a cartridge 30 and integrated with each other, except for a supporting member 20 having an exposure optical system 12. It is configured to be removable inside.

That is, the cartridge 30 is housed in the frame 50 shown in FIG.

The structure in which the supporting member 20 is left at the time of attachment / detachment is a heater.
201, heat pipe 202, lead wire 20 for operating the LED
It has a feature that the optical system 12 and the optical system 12 can be fixed to the supporting member 20 despite the rotation of the photoconductor and the attachment / detachment of the photoconductor. It can also be used to determine the axis of the photosensitive drum 10 as described below.

When mounted, the gantry 50 comprises a side plate 50A and a pair of support pedestals 50B. The cartridge 30 is placed and slid horizontally along the guide rails 51 inside the main body in a locked state.

The mount 50 is a guide pin that supports the photosensitive drum 10 in the cartridge 30 when it is inserted into the apparatus.
30P is engaged with the supporting member 20 for mounting the above-mentioned exposure optical system 12, and the flange 10B is provided with the supporting plate before and after this engaging member.
After being fitted onto the guide roller 40R of 40A, the side plate 50A is tightly fixed to the abutting portion 53 of the apparatus main body by using the tightening screw 52 as a fixing means. As a result, the axial center and the axial center position of the photosensitive drum 10 with respect to the image forming portion are determined.

When the pedestal 50 is pulled out from the inside of the apparatus at the time of dismounting, the photoconductor drum 10 causes the exposure optical system 12 described above.
The slide is stopped at a position separated from the support member 20 to which the guide is attached, and the guide rail 51 supports the slide rail.

The flange 10B of the photosensitive drum 10 which is disengaged from the guide roller 40R of the support plate 40A when the frame 50 is pulled out is supported by the folding portions 30A at several places integrally formed by the cartridge 30. Maintain the same axial center position as when inserting. Therefore, when the frame 50 is inserted again, the flange 10B is easily fitted on the guide roller 40R to set the photosensitive drum 10 at the normal axial position.

Although the above-described embodiment is an example in which the photosensitive drum 10 can be replaced as a cartridge, the exposure optical system can also be replaced as a cartridge in the apparatus main body. That is, the exposure optical system 12 is the mount
After pulling out 50 from the inside of the device, the above-mentioned support plate 40A
By removing from the substrate 40 of the main body of the apparatus, the cartridge can be taken out from the inside of the apparatus similarly to the cartridge 30.

(Embodiment 1) An embodiment of the first invention of the present invention will be described with reference to FIGS.

In the cartridge 30, the RO in which the outer diameter size, the sensitivity, the potential characteristics, the usage history and the like of the photoconductor of the photoconductor drum 10 to be stored are stored as resist management data.
As shown in FIG. 4A, the M card C1 is mounted on a card mounting portion 301 provided on the outer wall of the M card C1 to be integrated.

The ROM card C1 is a cartridge 30.
When installing the card into the main body of the device, pull it out from the above-mentioned card mounting part 301, and as shown in FIG.
When it is inserted into 400, the outer diameter dimension, characteristics, history, etc. of the photosensitive drum 10 described above are used as resist management data as shown in FIG.
As shown in the block diagram of (b), it is input to the CPU on the apparatus main body side.

On the other hand, the control system on the main body side of the apparatus has the image exposure timing and the exposure light amount of each of the exposure optical systems 12 corresponding to the variation of the above-mentioned characteristic values on the side of the photoconductor drum 10 of the ROM card C1 inputted. A ROM storing the correction values of the above is stored, the image exposure timing and the exposure light amount of each exposure optical system 12 are corrected based on the information from the ROM card C1, and the above-mentioned image forming process is performed. To be done.

In the above embodiment, the outer diameter of the photosensitive drum is classified into a plurality of levels, and the ROM card C is used.
1 stores the classification level number of the photoconductor drum 10, while the ROM on the apparatus main body side stores the classification level number and the exposure timing table corresponding thereto, and the ROM read by the apparatus main body It is also possible that the image forming process is performed at the exposure timing on the exposure timing table corresponding to the classification level number of the card C1.

Therefore, in this apparatus, even if the replaced photosensitive drum 10 has a different outer diameter, there is no deviation in the toner images of the respective colors to be superposed, and the sensitivity and potential characteristics of the photosensitive member are slightly deteriorated. It is possible to form a color image with a good color balance by using an appropriate exposure light amount.

In this apparatus, the image forming process is put in a standby state by mounting both the cartridge 30 and the ROM card C1 attached thereto, and when either one of them is not mounted, a warning lamp is provided. When L is turned on, the process operation is prohibited.

FIG. 5 shows an example of an apparatus in which each of the above-mentioned exposure optical systems 12 can be replaced as a cartridge. The above-mentioned support member 20 is used to register the distance between each of the exposure optical systems 12 held and the light-emitting characteristics. The ROM card C2 stored as management data is attached to the card attaching portion 302 provided on the outer wall of the ROM card C2 as shown in FIG.

When the ROM card C2 is inserted into the card insertion portion 400 of the main body of the apparatus, the resist management data such as the intervals between the exposure optical systems 12 held by the ROM card C2 and the light emission characteristics are shown in the block of FIG. 5B. As shown in the figure, it is input to the CPU on the apparatus main body side.

On the other hand, in the control system of the main body of the apparatus, the ROM which stores the correction values of the image exposure timing and the amount of emitted light corresponding to the fluctuation of the above-mentioned characteristic values of the input side of the exposure optical system 12 of the ROM card C2. Is stored in the ROM
The image exposure timing and the amount of light emitted from each exposure optical system 12 are corrected based on the information from the card C2, and then the above-described image forming process is performed.

Further, when a pair of the photoconductor drum 10 and each exposure optical system 12 is replaced as a cartridge, one RO is used.
The M card C3 stores the above-described resist management data for the pair of the photoconductor drum 10 and each exposure optical system 12 and inserts them into the card insertion portion 400 of the apparatus main body, so that they can be stored as shown in FIG. Information of the CPU at the same time
To the peripheral speed of the photoconductor drum 10 or the exposure optical system 12
It is also possible to adjust the image exposure timing.

(Embodiment 2) An embodiment of the second invention of the present invention will be described with reference to FIGS.

The control system of this apparatus is C as shown in FIG.
In addition to the regular image forming process described above, the PU stores a test mode process for obtaining a test pattern print, which will be described later, and further inserts a RAM card C4 as a non-volatile storage unit so that the resist set value is input. It has become.

When the test mode process described above is selected by mode switching, each exposure optical system 12 described above is selected.
For (Y), 12 (M), 12 (C) and 12 (K), for example, as shown in FIG. 8 (a), image exposure is performed in units of four units which are sequentially divided from the upstream side in the main scanning direction, and development is performed. As a result, a test pattern print in which each line of yellow (Y), magenta (M), cyan (C) and black (K) is formed in series on the transfer paper is obtained as shown in FIG. 8B.

If all the above lines are on a straight line, the registration setting stored in the inserted RAM card C4 is correct and does not need to be corrected. If it is recognized, the service engineer analyzes the test pattern print, and operates the numeric keypad based on the analysis result to perform R according to the amount of the step difference Δ.
The registration set value stored in the AM card C4 is corrected so that the above lines are aligned, and the corrected R is corrected.
By inserting the AM card C4, it is possible to obtain a color image with good color balance by superimposing the toner images of the respective colors without deviation.

Since the RAM card C4 is designed to be inserted and stored in the card insertion portion 400 of the apparatus main body as shown in FIG. 7, a corresponding resist adjustment value is newly set by analysis of the test pattern print. It is also possible to separately create the above RAM card C4 and replace it with the previous RAM card C4.

(Embodiment 3) An embodiment of the third invention of the present invention will be described with reference to FIG.

The control system of this apparatus stores a test mode process for obtaining a test pattern print, which will be described later, in addition to the regular image forming process described above, as shown in FIG.
Further, a RAMC 5 is provided as a non-volatile storage means so that the resist set value can be stored and a new resist set value can be input.

When the test mode process is selected by mode switching, each of the exposure optical systems 12 described above is selected.
9 (Y), 12 (M), 12 (C) and 12 (K) form three sets of test patterns that are line-shaped in the main scanning direction as shown in FIG. 9A, for example, according to the test mode program. The upper test pattern is a test pattern set for detecting the amount of deviation based on the image exposure of black (K) and yellow (Y), and the intermediate test pattern is the image exposure of black (K) and magenta (M). Is a test pattern set for detecting the amount of deviation based on image exposure, and the lower test pattern is a test pattern set for detecting the amount of deviation based on image exposure of black (K) and cyan (C). Each test pattern set is composed of a plurality of test patterns in which the exposure timings of the other exposure optical systems forming a pair are changed in the (+) and (-) directions with reference to the exposure timing of black (K).
A code number is added to each test pattern,
Alternatively, marking can be done.

The user checks the test pattern print obtained in the test print mode, selects a specific pattern in which two lines match for each test pattern set, and provides this code number in, for example, the operating section of the apparatus main body. Enter with the numeric keypad. The apparatus body stores a code number and the exposure timing of each exposure optical system corresponding thereto as a table, and the CPU reads the exposure timing of each exposure optical system corresponding to the inputted code number from the table and The resist information is stored in RAMC5. When the user cancels the test mode and performs copying, image formation is performed according to the exposure timing of the exposure optical system newly stored in the RAMC 5, so that the resist adjustment is completed and good color without deviation is obtained. An image is obtained.

With respect to the copying machine, the resist adjustment can be performed as follows. That is, in the test print mode in which the marking is added to the test pattern, the user checks the obtained test pattern print, selects a specific pattern in which two lines match for each test pattern set, and Marking is performed, the marked test print pattern is placed on the platen, and the reading operation is performed to read the marking. The CPU exposes each exposure optical system corresponding to the read marking information. The timing is read from the table and the resist information is stored in the RAMC5. In this embodiment also, when the user cancels the test mode and performs copying, the exposure optical system newly stored in the RAMC5. Image formation is performed according to the exposure timing of That.

[0056]

According to the present invention, the amount of change in the resist caused by the replacement of the image forming body or the image exposing means is corrected by the ROM card which is simultaneously replaced, and it is properly grasped by the test pattern print obtained in the test mode. As a result, it is possible to provide a color image forming apparatus capable of forming a high-quality image with high accuracy in superimposing toner images.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus of the present invention.

FIG. 2 is a cross-sectional configuration diagram of an image forming unit.

FIG. 3 is a perspective view showing attachment / detachment formation of an image forming unit.

FIG. 4 is an explanatory diagram showing a resist management system associated with replacement of an image forming body.

FIG. 5 is an explanatory view showing a method of resist management accompanying replacement of image exposure means.

FIG. 6 is an explanatory diagram showing a resist management system accompanying simultaneous replacement of an image forming body and an image exposing unit.

FIG. 7 is a perspective view showing an insertion portion of a ROM card.

FIG. 8 is an explanatory diagram showing a method of adjusting a resist set value according to the second embodiment.

FIG. 9 is an explanatory diagram showing a method of adjusting a resist set value according to a third embodiment.

[Explanation of symbols]

 10 Photoconductor drum 11 Charging device 12 Exposure optical system 13 Developing device 14A Transfer device 14B Static eliminator 17 Fixing device 19 Cleaning device 20 Supporting member 30 Cartridge 301, 302 Card mounting part 400 Card insertion part C ROM card

Claims (8)

[Claims] 1. A color image forming apparatus, wherein a toner image is superposedly formed on an image forming body by repeating charging, image exposure and development on the image forming body, and then a batch transfer is performed on a transfer material. The body has a plurality of image exposing means, and at least one of the image forming body and the image exposing means can be exchanged together with corresponding resist management data. 2. A ROM for exchanging the resist management data.
The color image forming apparatus according to claim 1, wherein the color image forming apparatus is performed by replacing a card. 3. The color image forming apparatus according to claim 1, wherein when the replacement part is an image forming body, the resist management data of the image forming body is an outer dimension of the image forming body. 4. The color image forming apparatus according to claim 1, wherein when the replacement part is an image exposure unit, the resist management data of the image exposure unit is an image exposure interval of the image exposure unit. 5. A color image forming apparatus for carrying out batch transfer to a transfer material after repeatedly forming a toner image on the image forming body by repeating charging, image exposure and development on the image forming body, and adjusting the resist. Of the test pattern mode and a storage unit capable of exchanging or rewriting the resist setting value, and exchanging or rewriting the resist setting value of the storage unit with a resist adjustment value obtained from printing by the test pattern. Color image forming apparatus. 6. A plurality of charging means, image exposing means, and developing means are provided in the vicinity of the image forming body, and after charging, image exposing and developing are repeated, a toner image is formed on the image forming body in a superposed manner. In a color image forming apparatus that performs batch transfer to a transfer material, a test pattern mode with a plurality of writing timings for resist adjustment is provided, and a specific resist pattern is selected from prints with the plurality of test patterns, and the resist timing is re-selected. A color image forming apparatus characterized by setting. 7. The color image forming apparatus according to claim 6, wherein the specific resist pattern is input as a corresponding code number. 8. The color image forming apparatus according to claim 6, wherein the specific resist pattern is input by reading a mark.