JPH01235969A - Multicolor image forming device - Google Patents

Abstract

PURPOSE:To improve a processing speed by constituting the above device in such a manner that the device can be operated such a sequence by which multicolor toner images are transferred by each one on a transfer material at each one rotation of an image forming body so as to obtain the plural multicolor images. CONSTITUTION:This device forms multicolor toner images of the two same colors or different colors during one rotation of the image forming body 1 on the surface of the image forming body 1 by controlling the operation timing of an image exposing part 3 and respective developing devices 4-7 if the size of an original is below the specified size in case of obtaining many copies from the same original. The device has the function capable of controlling the operation timing of a transfer device 8, a separator 9, and 1st and 2nd paper feed rollers 11, 12 by the preset program. The copying speed is thereby automatically increased and the processing capacity is increased in case of executing copying to many sheets continuously by the original smaller than the specified size.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multicolor image forming apparatus, and is particularly characterized by sequence control of an apparatus that forms a multicolor toner image on an image forming member and transfers it to a transfer material. The present invention relates to a multicolor image forming apparatus having a multicolor image forming apparatus.

[Background of the invention]

The present inventors have developed a patent application for a multicolor image forming apparatus in Japanese Patent Application Laid-Open No. 60-75.
850, 60-76766.60-95456.60-
We have made proposals disclosed in various publications such as No. 95458.60-158475.

The multicolor image forming apparatus related to this proposal usually uses a system in which one single color image is exposed and developed for each rotation period of a drum-shaped or endless belt-shaped image forming member. , magenta, cyan, and black. In a device that obtains a multicolor image by combining monochrome images of four colors, magenta, cyan, and black, the image forming body rotates four times to superimpose the four color toner images on the image forming body, and then transfer these toner images all at once. A single color copy can be obtained by transferring the image onto a material.

[Problem that the invention seeks to solve]

Therefore, when attempting to obtain a large number of color copies of the same original using a multicolor image forming apparatus, it takes a very large amount of time, and the efficiency is significantly lower than that of a monochrome image forming apparatus.

To compensate for this, if the original size is sufficiently small compared to the length of the drum outer circumference of the image forming body, two or more toner images of the same color are continuously exposed during one rotation period of the image forming body. A method has also been considered in which a developing method is used to form two or more toner images on an image forming member in one image forming cycle, thereby obtaining a color copy.

However, in this method, the interval between the multicolor toner images formed on the drum circumferential surface becomes extremely narrow, so the toner image is normally transferred to the first transfer material, but it is transferred to the second and subsequent sheets. It becomes difficult to match the feeding timing of the transfer material.

In other words, the transfer material must be conveyed in synchronization with the toner image on the rotating image forming drum, and the toner image must be transferred onto the transfer material at the transfer section. The document must be conveyed to the standby position in advance with plenty of time, and since this operation overlaps with the conveyance of the preceding transfer material, it is impossible to take time to set the timing. Therefore, the document that can be copied is It is limited to a size that is extremely small compared to the outer circumference of the drum, making it impractical.

As a result of solving this problem and improving the present invention, it is possible to obtain two or more color copies in one image forming cycle on the premise that the feeding timing of the transfer material can be set. The object of the present invention is to provide a multicolor image forming apparatus that can increase processing speed.

[Failure to solve the problem]

The above object includes a rotatable image forming member, a latent image forming means for forming a latent image on the image forming member, a plurality of developing means for storing toner of different colors, and a transfer material for transferring the toner image from the image forming member to a transfer material. A multi-color printer comprising a transfer means for transferring the transfer material to the transfer means, a first feeding means for feeding the transfer material to a predetermined standby position, and a second feeding means for feeding the transfer material from the standby position to the transfer means. In the image forming apparatus, the control unit may control one of the image forming bodies after forming a plurality of multicolor toner images at different positions on the image forming body.
This is achieved by a multicolor image forming apparatus that is capable of operating in a sequence such that a plurality of multicolor images are obtained by transferring one multicolor toner image to a transfer material per rotation.

〔Example〕

Embodiments of the invention are shown in FIGS. 1-4.

The first part is a configuration diagram showing an outline of a multicolor image forming apparatus, in which 1 is a drum-shaped image forming body having a photoconductive photoreceptor surface layer such as Se and rotating in the direction of the arrow, and 2 is an image forming body 1. 3 is an image exposure unit with a built-in laser scanner as a latent image forming means, and 4 to 7 are developing means, in which toners of different colors such as yellow, magenta, cyan, and black are developed. A developing device is used as a developer and is configured to face the image forming body in a non-contact state and perform development by applying an AC bias, 8 is a transfer device as a transfer means, 9 is a separator, and 10 is a transfer device. This is a cleaning device for cleaning residual toner on the image forming body 1 after completion of the cleaning process, and the cleaning blade IOA is kept at a position apart from the surface of the image forming body 1 while a toner image is being formed on the image forming body 1. It will be done.

Reference numerals 11 and 12 denote a first paper feed roller as a first paper feed means and a second paper feed roller as a second paper feed means, and 13 is a paper feed cassette in which transfer materials are accumulated and stored. The transfer material carried out from the paper feed cassette 13 by the paper roller 11 is temporarily waited at the position of the second paper feed roller 12, and is moved to a second feed roller that rotates in synchronization with the rotation period of the multicolor toner image on the image forming body 1. The paper is fed to the transfer device 8 by the paper roller 12.

14 is a fixing device that fixes the multicolor toner image transferred to the transfer material, and 15 is a paper discharge tray that collects the transfer material discharged from the fixing device 14.

When the multicolor image forming apparatus attempts to obtain multiple copies from the same original, it recognizes the original placed on the original table fl11.
If the original size is less than the specified size, By controlling the operation timing of the image exposure section 3 and the developing devices 4 to 7, two multicolor toner images of the same color or different colors are formed on the surface of the image forming body 1 during one rotation of the image forming body 1, as shown in FIG. It has a function of controlling the operation timing of the transfer device 8, the separator 9, and the first and second paper feed rollers 11, 12 according to a preset program.

Hereinafter, an example of the operation and sequence of operation of each of the above-mentioned devices according to the image forming program of the present invention will be explained.

FIGS. 3 and 4 are time charts of each program with time elapsed on the horizontal axis, Y and M.

C and BK are abbreviations for yellow, magenta, cyan, and black color images, respectively, and IY, 2Y, etc. represent yellow image exposure for the first image, yellow image exposure for the second image, and the like.

The first program example shown in FIG.
Two images of the same color are sequentially exposed and developed on the surface of the image forming member L for each rotation, and the multicolor toner image obtained by four rotations of the image forming member L is divided into two parts and transferred to the first transfer material. For the second transfer material, paper is synchronously fed and transferred and separated during the second half of the fourth cycle, and for the second transfer material, paper is synchronously fed and transferred and separated during the first half of the sixth cycle. This is an example of performing separation.

By performing copying in this sequence, there is a distance greater than the length of two transfer materials between the end of the first transfer material being conveyed and the leading edge of the second transfer material. There will be more time intervals corresponding to .

According to the sequence, after the second paper feed roller 12 finishes feeding the first sheet of transfer material and the second paper feed roller 12 stops, the first paper feed roller 11 starts rotating and transfers the second sheet. Even if the transfer material is conveyed and the tip of the second transfer material is positioned at the position of the stopped second paper feed roller 12 and is then operated, sufficient synchronization is not achieved for the second transfer material. Since there is a time delay in waiting at the standby position, the second sheet of transfer material following the first sheet is also transferred in correct synchronization with the toner image on the image forming body. becomes.

In addition, in the above process, from the fifth rotation of the image forming body l, image formation on the next original or copying of the third and fourth sheets of the same original can be started in the same manner. The next two copies can be obtained without extending the processing time.

On the other hand, the second program example shown in FIG. 4 exposes and develops one or two images of different colors on the surface of the image forming body L every time the image forming body L rotates six times. The multicolor toner image is transferred and separated to the first transfer material in the latter half of the fourth rotation, and to the second transfer material in the first half of the sixth rotation. This is an example.

Therefore, in this example as well, the interval between the operating timings of the first paper feeding roller 11 and the second paper feeding roller 12 can be set to a time difference of more than one revolution of the image forming body 1, so that adjustment of the operating timing is sufficiently possible as in the previous example. It is.

In this case as well, it is possible to start the next image formation from the 5th rotation of the image forming body l by using the next original or the same original (two originals), so the process required to obtain the next two copies is Processing time remains the same as before.

Incidentally, in the present invention, two
The method is not limited to the method of forming and transferring an image of one sheet or more, but if the size of the original or transfer material is larger than the specified size, the above-mentioned program is automatically canceled upon detection of the original size. It is also possible to configure the image forming apparatus so that a normal image forming process mode is selected and images are formed one sheet at a time on the surface of the image forming body like a general multicolor image forming apparatus, and this is included in the present invention.

〔Effect of the invention〕

According to the present invention, when a large number of copies are to be made in succession from originals that are smaller than a specified size, it is possible to automatically increase the copying speed and increase the processing capacity. A multi-color image forming apparatus has been provided which is extremely useful for general office use where the image forming apparatus is frequently handled and has high working efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a multicolor image forming apparatus, FIG. 2 is a main part view, and FIGS. 3 and 4 are time charts showing the image forming process of the apparatus. l...Image forming body 2...Charger 3...Image exposure section 4.5.6.7...Developer 8...Transfer device 9...Separator 11...First Paper feed roller 12...second paper feed roller

Claims (1)

[Scope of Claims] A rotatable image forming member; a latent image forming means for forming a latent image on the image forming member; a plurality of developing means for storing toner of different colors; The apparatus includes a transfer means for transferring onto a transfer material, a first feeding means for feeding the transfer material to a predetermined standby position, and a second feeding means for feeding the transfer material from the standby position to the transfer means. In the multicolor image forming apparatus, the control section forms a plurality of multicolor toner images at different positions on the image forming body, and then transfers the multicolor toner images onto a transfer material one by one per rotation of the image forming body. A multicolor image forming apparatus is characterized in that it can operate in a sequence of transferring to obtain a plurality of multicolor images.