JP3493944B2 - Image forming device - Google Patents

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 print sheet in a direction orthogonal to the conveying direction of the print sheet.

[0002]

2. Description of the Related Art In recent years, as represented by a laser printer, a toner type image forming apparatus capable of forming a clear image with excellent resolution has become widespread. Among such toner type image forming apparatuses, Japanese Patent Application No. 7-328600
As proposed in Japanese Patent No. 3, the image forming apparatus of the orthogonal transfer system, in which the toner image carrier is rubbed in the direction orthogonal to the conveyance direction of the printing paper, to transfer the toner image in small steps, Very suitable for promoting miniaturization of products.

FIG. 2 is a block diagram showing the outline of a general orthogonal transfer type image forming apparatus, and FIG. 3 is a perspective view showing the outline of a general orthogonal transfer type image forming apparatus. 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 is a charging device, 6 is an exposing device, 7 is a developing device, 8 is a transfer facing roller, 9 is a printing paper, 10 is a transfer plate, and symbol A is the rotation direction of the toner image carrier 1.

With respect to the image forming apparatus having the above-described structure, the operation and the arrangement of each structure will be described. The surface of the toner image carrier 1 composed of a photoconductor belt is coated with a layer of an organic photoconductive material. Around the toner image carrier 1, a charger 5, a developing device 7, a cleaning device 3, a charge eliminator 4 and the like are arranged, and the upper portion of the toner image carrier 1 is exposed to irradiate laser light. The container 6 is arranged.

When the toner image carrier 1 is rotated in the direction orthogonal to the direction in which the print sheet 9 is conveyed, the portion passing through the charger 5 is charged, and the portion exposed to the laser beam 6a by the exposing device 6 is electrostatically latent. An image is formed. When the developing roller 7b presses the toner 7a on the portion where the electrostatic latent image is formed,
Toner images 7c that have become visible images appear one after another on the toner image carrier 1. Next, when the transfer counter roller 8 is moved in a direction orthogonal to the conveyance direction of the printing paper 9, the toner image 7c is transferred onto the printing paper 9. At this time, the operation of the transfer counter roller 8 moves so as to reciprocate inside the toner image carrier 1. As described above, an image can be formed on the printing paper 9 with toner.

[0006]

In the above-described conventional orthogonal transfer type image forming apparatus, the toner image 7c on the toner image carrier 1 is merely pressed against the printing paper 9 by the reciprocal movement of the transfer counter roller 8 to form the toner image. When the 7c is transferred to the printing paper 9, the 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, resulting in uneven transfer. However, there is a problem in that the print quality is deteriorated due to the occurrence of the problem.

The present invention prevents the residual toner image on the toner image bearing member and the return of the transferred toner from the printing sheet to the toner image bearing member when the toner image is transferred to the printing sheet, thus preventing transfer unevenness. It is an object of the present invention to provide an image forming apparatus of the orthogonal transfer system that realizes high-quality image printing by reducing the above.

[0008]

In order to solve this problem, an image forming apparatus of the present invention is a toner carried on a toner image carrier stretched by a plurality of rollers in a direction orthogonal to the conveying direction of a printing paper. An image forming apparatus of an orthogonal transfer system, wherein an image is transferred onto the printing paper by a transfer facing roller in a direction orthogonal to a conveying direction of the printing paper, and the toner image transferred onto the printing paper is fixed. possess a transfer plate printing paper is placed, and a transfer bias power source for applying a forward path and the transfer bias voltage in the backward path of said transfer opposed roller to the transfer plate, recovery and forward of said transfer opposed roller
The toner image carrier and the printing paper contact each other on the path
The transfer counter roller is reciprocated as well.
After printing, the printing paper can be conveyed .

Thus, when the toner image is transferred to the printing paper, the residual 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 the transfer unevenness is reduced. Thus, an image forming apparatus of the orthogonal transfer system which can realize high quality image printing can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is one in which a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction orthogonal to the conveying direction of a printing paper is transferred and opposed. An image forming apparatus of an orthogonal transfer system for transferring onto a print sheet in a direction orthogonal to a conveying direction of the print sheet by a roller and fixing the toner image transferred onto the print sheet, wherein the print sheet is placed on the image forming apparatus. And a transfer bias power source that applies a transfer bias voltage to the transfer plate in the forward and return paths of the transfer facing roller.
Then, the toner image is carried on the forward and backward paths of the transfer opposite roller.
The carrier and the printing paper come into contact with each other to perform transfer, and
Transfer the printing paper after the transfer roller is moved back and forth.
By allowing the transfer, it has an effect of reducing transfer unevenness.

According to a second aspect of the present invention, the transfer bias voltage is +300 to +1200 V, and has an effect of increasing transfer efficiency. The voltage is +3
If it is lower than 00V or higher than + 1200V, the transfer efficiency tends to be low, which is not preferable.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a block 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 photoconductor belt is rotated in a direction orthogonal to the conveying direction of the print sheet 9, and the portion charged by the charger 5 is irradiated with laser light 6a by the exposure device 6 to form an electrostatic latent image. The toner 7a is rubbed by the developing device 7 on the portion on which the electrostatic latent image has been 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 carrier 1 is printed on the printing paper 9
In order to perform the transfer, the transfer facing roller 8 is moved in the direction orthogonal to the conveyance direction of the print sheet 9 to perform the transfer. After transfer,
When the printing paper 9 is conveyed for one step, the transfer counter roller 8 is at the standby position (toner image carrier roller 2a in the figure).
Since the print sheet 9 can be conveyed only when it is in the right position), the transfer facing roller 8 needs to be returned to the standby position when the transfer operation is completed. Therefore, the transfer counter roller 8 moves to the end portion of the print sheet 9 (the right end of the print sheet 9 in the figure), and then reciprocates inside the toner image carrier 1 to return to the standby position. Therefore, the toner carrier 1 and the printing paper 9 come into contact with each other in the forward and backward paths. Therefore, when the transfer counter roller 8 is started to move, the toner image 7c is negatively charged, so that the transfer bias power source 11 applies a transfer bias voltage to the transfer plate 10 under the printing paper 9 to positively charge it.
By electrostatically adsorbing the toner image 7c on the printing paper 9, the toner image 7c is prevented from remaining on the toner image carrier 1 without being transferred to the printing paper 9 in the forward path of the transfer counter roller 8. You can Even on the return path of the transfer counter roller 8, the transfer bias power source 11 applies a transfer bias voltage to the transfer plate 10 to positively charge the transfer plate 10, so that the toner image 7c once transferred to the print sheet 9 is transferred to the toner image carrier 1. On the contrary, it is possible to prevent the transfer.

When the transfer opposing roller 8 reciprocates and returns to the standby position, the application of the transfer bias voltage to the transfer plate 10 is interrupted, and when the print paper 9 is conveyed, the print paper 9 is attracted to the transfer plate 10. Prevent doing. Thereafter, the printing paper 9 is conveyed by the same width as the effective transfer 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 adsorbed on the printing paper, the transfer unevenness of the toner image can be reduced, so that high-quality image printing can be realized. That is an advantageous effect.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing an outline of a general orthogonal transfer type image forming apparatus.

FIG. 3 is a perspective view showing an outline of a general orthogonal transfer type image forming apparatus.

[Explanation 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 light 7 Developer 7a toner 7b Developing roller 7c toner image 8 Transfer counter roller 9 printing paper 10 Transfer plate 11 Transfer bias power supply

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masashi Ogawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Yusuke Shiihara 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Koji Ueda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Yukinori Hara, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP 4-69254 (JP, A) JP 63-249880 (JP, A) JP 62-9361 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/16 B41J 3/18

Claims (2)

(57) [Claims] 1. A toner image carried on a toner image carrier stretched by a plurality of rollers in a direction orthogonal to the conveying direction of the print sheet, and a toner image carried by a transfer opposing roller in a direction orthogonal to the conveying direction of the print sheet. What is claimed is: 1. An orthogonal transfer type image forming apparatus for transferring onto a printing paper and fixing the toner image transferred onto the printing paper, comprising a transfer plate on which the printing paper is placed, and the transfer counter roller on the transfer plate. A transfer bias power source for applying a transfer bias voltage in the forward and backward paths of
Have a, the toner in the forward path and the backward path of said transfer opposed roller
While the image carrier and the printing paper contact each other to perform transfer,
Printing paper after the reciprocating movement of the transfer facing roller
An image forming apparatus capable of transporting a sheet . 2. The transfer bias voltage is +300 to +12.
The image forming apparatus according to claim 1, wherein the image forming apparatus is 00V.