JPH10282815A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of reducing the transfer unevenness on a printing paper sheet of a toner image on a toner image carrier in an image forming device of an orthogonal transfer system. SOLUTION: In this image forming device of the orthogonal transfer system, the toner image 7c carried by the toner carrier 1 extended in the direction orthogonal to the transporting direction of the printing paper sheet 9 by plural rollers is transferred onto the printing paper sheet 9 in the direction orthogonal to the transporting direction of the printing paper sheet 9 by a transfer counter roller 8, and the toner image 7c transferred onto the printing paper sheet 9 is fixed. The device is provide with a transfer plate 10 on which the printing paper sheet 9 is placed, and the transfer bias power source 11 for applying the bias voltage to the transfer plate 10 on a forward path and the backward pass of the counter rollers 8. Then, by electrostatically attracting the toner image 7c to the printing paper sheet 9, the transfer unevenness of the toner image 7c can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orthogonal transfer type image forming apparatus for transferring a toner image onto a printing paper in a direction perpendicular to a conveying direction of the printing paper.

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with excellent resolution, such as laser printers, have become widespread. Among such toner-type image forming apparatuses, Japanese Patent Application No. 7-328600.
As proposed in Japanese Patent Application Laid-Open No. H11-163, an orthogonal transfer type image forming apparatus that rubs a toner image carrier in a direction perpendicular to the transport direction of a printing paper and transfers a toner image in small steps one step at a time, Very suitable for promoting product miniaturization.

FIG. 2 is a block diagram schematically showing a general image forming apparatus of the orthogonal transfer system, and FIG. 3 is a perspective view schematically showing a general image forming apparatus of the orthogonal transfer system. 2 and 3, 1 is a toner image carrier, 2a and 2b are toner image carrier rollers, 3 is a cleaning device, 4 is a static eliminator,
Reference numeral 5 denotes a charging device, 6 denotes an exposure device, 7 denotes a developing device, 8 denotes a transfer opposing roller, 9 denotes a printing sheet, 10 denotes a transfer plate, and symbol A denotes a rotation direction of the toner image carrier 1.

The operation, arrangement of each component, and the like of the image forming apparatus configured as described above will be described. The surface of the toner image carrier 1 composed of a photoreceptor belt is coated with a layer of an organic photoconductive material. A charger 5, a developing device 7, a cleaning device 3, a static eliminator 4 and the like are arranged around the toner image carrier 1. An upper portion of the toner image carrier 1 is exposed to laser light. The vessel 6 is arranged.

When the toner image carrier 1 rotates in a direction perpendicular to the direction in which the printing paper 9 is conveyed, the portion passing through the charger 5 is charged, and the portion irradiated with the laser beam 6a by the exposure An image is formed. When the developing roller 7b presses the toner 7a against the portion where the electrostatic latent image is formed,
The visible toner images 7c appear one after another on the toner image carrier 1. Next, when the transfer opposing roller 8 is moved in a direction orthogonal to the transport direction of the printing paper 9, the toner image 7 c is transferred to the printing paper 9. The operation of the transfer opposing roller 8 at this time moves so as to reciprocate inside the toner image carrier 1. Thus, an image can be formed on the printing paper 9 with the toner.

[0006]

In the conventional orthogonal transfer type image forming apparatus, the toner image 7c on the toner image carrier 1 is simply pressed against the printing paper 9 by the reciprocating operation of the transfer opposing roller 8, so that the toner image is not formed. When the toner image 7c is transferred to the printing paper 9, untransferred toner remains on the toner image carrier 1, or the toner once transferred to the printing paper 9 returns to the toner image carrier 1. There is a problem in that print quality is deteriorated due to occurrence of printing.

According to the present invention, when transferring a toner image to a printing paper, it is possible to prevent the remaining of the toner image on the toner image carrier and the return of the transferred toner from the printing paper to the toner image carrier, thereby preventing transfer unevenness. It is an object of the present invention to provide an orthogonal transfer type image forming apparatus that realizes high-quality image printing by reducing image quality.

[0008]

SUMMARY OF THE INVENTION In order to solve this problem, an image forming apparatus according to the present invention is directed to a toner carried on a toner image carrier stretched by a plurality of rollers in a direction perpendicular to a conveying direction of a printing paper. An image forming apparatus of an orthogonal transfer system, wherein an image is transferred to the printing paper in a direction orthogonal to a conveying direction of the printing paper by a transfer facing roller, and the toner image transferred to the printing paper is fixed, A transfer plate on which a print sheet is placed; and a transfer bias power supply for applying a transfer bias voltage to the transfer plate in forward and backward passes of the transfer opposing roller.

Thus, when transferring the toner image to the printing paper, the remaining of the toner image on the toner image carrier and the return of the transferred toner from the printing paper to the toner image carrier are prevented, and transfer unevenness is reduced. Thus, an image forming apparatus of the orthogonal transfer type that realizes high-quality image printing can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction perpendicular to a conveying direction of a printing paper is transferred and opposed. An orthogonal transfer type image forming apparatus in which the toner image transferred onto the printing paper is fixed by transferring the toner image onto the printing paper in a direction orthogonal to a conveyance direction of the printing paper by a roller, wherein the printing paper is placed on the printing paper. By providing a transfer plate to be used and a transfer bias power supply for applying a transfer bias voltage to the transfer plate in the forward path and the return path of the transfer opposing roller, the transfer unevenness can be reduced.

According to a second aspect of the present invention, the transfer bias voltage is set to +300 to +1200 V, and has an effect of improving transfer efficiency. The voltage is +3
When the voltage is lower than 00 V or higher than +1200 V, the transfer efficiency tends to decrease, and both are not preferable.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a configuration diagram of an orthogonal transfer type image forming apparatus according to an embodiment of the present invention. The toner image carrier 1 composed of a photoreceptor belt is rotated in a direction perpendicular to the conveying direction of the printing paper 9, and a portion charged by the charger 5 is irradiated with a laser beam 6 a by an exposure device 6 to form an electrostatic latent image. The toner 7a is rubbed by the developing device 7 on the formed portion where the electrostatic latent image is formed to form a toner image 7c.
At this time, since the toner image carrier 1 is negatively charged, the toner image 7c is also negatively charged. When the developing operation is completed, the toner image 7c formed on the toner image
In order to perform the transfer, the transfer opposing roller 8 is moved in a direction perpendicular to the conveying direction of the printing paper 9 to perform the transfer. After transfer,
When the printing paper 9 is conveyed by one process, the transfer opposing roller 8 is moved to the standby position (the toner image carrier roller 2a in the drawing).
Only when the transfer operation is completed, the transfer opposing roller 8 needs to return to the standby position. Therefore, after the transfer opposing roller 8 moves to the end of the printing paper 9 (the right end of the printing paper 9 in the drawing), it reciprocates inside the toner image carrier 1 and returns to the standby position. That is, the toner carrier 1 and the printing paper 9 come into contact with each other in the forward path and the backward path. When the transfer opposing roller 8 is started to move, the toner image 7c is negatively charged. Therefore, the transfer bias voltage is applied to the transfer plate 10 under the printing paper 9 by the transfer bias power supply 11 so that the transfer image is positively charged.
The toner image 7c is electrostatically attracted to the printing paper 9 to prevent the toner image 7c from remaining on the toner image carrier 1 without being transferred to the printing paper 9 on the outward path of the transfer opposing roller 8. I can do it. Also, in the return path of the transfer opposing roller 8, the transfer plate voltage is applied to the transfer plate 10 by the transfer bias power supply 11 and positively charged, so that the toner image 7 c once transferred to the printing paper 9 is transferred to the toner image carrier 1. Conversely, the transfer can be prevented.

When the transfer opposing roller 8 reciprocates and returns to the standby position, application of the transfer bias voltage to the transfer plate 10 is interrupted, and when the print paper 9 is transported, the print paper 9 is attracted to the transfer plate 10. To prevent Thereafter, the printing paper 9 is conveyed by the same width as the transfer effective width of the developing device 7, and the printing is completed by repeating the development and the transfer operation.

[0014]

As described above, according to the present invention, since the toner image is electrostatically attracted to the printing paper, the transfer unevenness of the toner image can be reduced, so that high quality image printing can be realized. The advantageous effect described above can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an image forming apparatus of an orthogonal transfer system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a general orthogonal transfer type image forming apparatus.

FIG. 3 is a perspective view schematically showing a general orthogonal transfer type image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toner image carrier 2a, 2b Toner image carrier roller 3 Cleaning device 4 Static eliminator 5 Charger 6 Exposure device 6a Laser beam 7 Developing device 7a Toner 7b Developing roller 7c Toner image 8 Transfer facing roller 9 Printing paper 10 Transfer plate 11 Transfer bias power supply

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Ogawa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Koji Mita 1006 Kazuma Kadoma, Kazuma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] A transfer roller for transferring a toner image carried on a toner image carrier stretched in a direction perpendicular to a transport direction of the printing paper by a plurality of rollers in a direction perpendicular to the transport direction of the print paper; An image forming apparatus of an orthogonal transfer system for transferring the toner image transferred to a print sheet and fixing the toner image transferred to the print sheet, comprising: a transfer plate on which the print sheet is placed; and a transfer opposing roller on the transfer plate. A transfer bias power supply for applying a transfer bias voltage on the forward path and the return path of
An image forming apparatus comprising: 2. The transfer bias voltage is between +300 and +12.
The image forming apparatus according to claim 1, wherein the voltage is 00V.