JPH10198181A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of easily separating printing paper from the toner image carrier, and preventing a printing defect or a jamming from occurring, at the time of transferring the toner image on the toner image carrier to a printing paper sheet. SOLUTION: The image forming device of an orthogonal transfer system capable of transferring the toner image carried on the toner image carrier 1 by a transfer counter roller 8 on a printing paper sheet 7 in the direction orthogonal to the transporting direction of the printing paper sheet 7 and fixing the toner image 3c being transferred on the printing paper sheet 7, and the image forming device capable of facilitating separation of the printing separation of the paper sheet 7 from the toner image carrier, when transferring the toner image 3c on the toner image carrier 1, can be provided by making an outside diameter of the transfer counter 8 into 10 to 30mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses, such as laser printers, capable of forming clear images with excellent resolution have become widespread. Among such toner-type image forming apparatuses, as proposed in Japanese Patent Application No. 7-328600, the toner image carrier is moved in a direction perpendicular to the conveying direction of the printing paper, and the process is carried out step by step. An orthogonal transfer type image forming apparatus that transfers a toner image is very suitable for promoting miniaturization of a product due to its configuration.

FIG. 1 is a view schematically showing a general orthogonal transfer type image forming apparatus, and FIG. 2 is a view schematically showing a transfer section of the image forming apparatus shown in FIG. 1 and 2, 1 is a toner image carrier, 2 is a charger, 3 is a developer,
3a is a toner, 3b is a developing roller, 3c is a toner image, 4
Is a cleaning device, 5 is a static eliminator, 6 is an exposure device, 7 is a printing sheet, 8 is a transfer opposing roller, 9 is a support roller, 10 is a displacement roller, 11 is a transfer plate, 12 is a heat source, 13 is a reflection plate,
Reference numeral 14 denotes a reflection transport plate, and 15 denotes a fixing device.

[0004] The operation, arrangement, and the like of the image forming apparatus configured as described above will be described.

[0005] The surface of the toner image carrier 1 comprising a photosensitive belt is coated with a layer of an organic photoconductive material. The toner image carrier 1 is stretched by a plurality of rollers in a transfer direction Y (see FIG. 2) orthogonal to the print paper transport direction X of the print paper 7, and rotates in an arrow AR direction (see FIG. 1) during image formation. As a result, a toner image is formed on the surface of the toner image carrier 1. Around the toner image carrier 1, a charger 2, a developing device 3, a cleaning device 4, a static eliminator 5, an exposure device 6, and the like are arranged.

When the toner image carrier 1 rotates in the direction Y perpendicular to the transport direction X of the printing paper 7 as shown by the arrow AR in FIG. 1, the portion of the toner image carrier 1 that has passed the charger 2 is −600 V And the potential of the portion irradiated with the laser beam by the exposure device 6 based on the image signal becomes −100.
By rising to about V, an electrostatic latent image is formed. The toner 3a is applied to the developing roller 3 at the portion where the electrostatic latent image is formed.
When pressed by b, toner images 3c, which have become visible images, appear one after another on the toner image carrier 1.

As shown in FIG. 1, at the time of image formation, the toner image carrier 1 is supported by at least three rollers of a support roller 9, a displacement roller 10, and a transfer opposing roller 8, a direction Y orthogonal to the transport direction X of the printing paper 7. It is stretched.

A feature of such an orthogonal transfer type image forming apparatus is that, at the time of transfer, the rotation of the toner image carrier 1 and the conveyance of the printing paper 7 are temporarily stopped, and the toner The image carrier 1 is rubbed and displaced with the movement of the transfer opposing roller 8. At this time, the displacement roller 10 is displaced following the movement of the transfer opposing roller 8 in order to eliminate the slack of the toner image carrier 1.

Whenever the transfer for one process is completed, the transfer opposing roller 8 moves over the printing paper 7 and moves out of the area of the printing paper 7 so that the toner image carrier 1
Keep away from Then, the conveyance of the printing paper 7 is started, and the conveyance distance of the printing paper 7 is equal to the effective transfer width of the toner image carrier 1. The printing paper 7 is fixed by being sent to the fixing device 15 intermittently. The fixing device 15 is a heat source 12
The fixing method using the fixing device 15 is a method in which the reflection transport plate 14 is provided below the fixing device 15 to improve the thermal efficiency, thereby fixing the toner in a non-contact manner.

[0010]

However, in the above-described conventional image forming apparatus, there is no need to consider the outer diameter and material of the transfer opposing roller 8, and the transfer opposing roller 8
When the toner image on the toner image carrier 1 is transferred to the printing paper 7 by moving upward, the printing paper 7 is hard to be separated from the toner image carrier 1, and a printing failure or a jam may occur. Had a point.

In this image forming apparatus, when the toner image on the toner image carrier is transferred to the printing paper, it is required that the printing paper be easily peeled from the toner image carrier and printing defects and jams are less likely to occur. .

An object of the present invention is to provide an image forming apparatus in which the printing paper is easily peeled off from the toner image carrier when the toner image on the toner image carrier is transferred to the printing paper, and printing defects and jams are less likely to occur. Aim.

[0013]

SUMMARY OF THE INVENTION In order to solve this problem, an image forming apparatus according to the present invention prints a toner image carried on a toner image carrier in a direction perpendicular to a conveying direction of a printing paper by a transfer opposing roller. An orthogonal transfer type image forming apparatus for transferring a toner image transferred to a sheet and fixing the toner image transferred to a printing sheet, wherein the transfer opposed roller has an outer diameter of 10 to 30 mm.

Thus, an image forming apparatus in which the printing paper is easily peeled off from the toner image carrier when the toner image on the toner image carrier is transferred to the printing paper, and printing defects and jams are less likely to be obtained.

[0015]

According to the first aspect of the present invention, a toner image carried on a toner image carrier is transferred onto a printing paper in a direction perpendicular to a conveying direction of the printing paper by a transfer opposing roller. An image forming apparatus of an orthogonal transfer system for fixing a toner image transferred to a print sheet, wherein the transfer facing roller has an outer diameter of 10 to 30 mm,
The printing paper has an effect that the printing paper is easily peeled off from the toner image carrier, and there is no case where printing failure or jam occurs.

According to a second aspect of the present invention, in the first aspect, the transfer opposing roller is made of a conductive material. This has the effect of preventing the accumulation of static electricity on the inner surface of the body and the transfer facing roller.

According to a third aspect of the present invention, in the second aspect of the present invention, the transfer opposing roller is grounded, and the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller is reduced. It has the effect of being prevented.

According to a fourth aspect of the present invention, in the second aspect of the present invention, a bias is applied to the transfer opposing roller, and a static electricity is applied to the inner surface of the toner image carrier and the transfer opposing roller. It has the effect of preventing accumulation.

The invention described in claim 5 is the invention according to claim 3 or 4
In the invention described in (1), the transfer opposing roller is grounded or a bias is applied only at a specific position, thereby preventing the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller. Having.

The invention described in claim 6 is the third or fourth invention.
In the invention described in (1), the transfer opposing roller is always grounded or a bias is applied irrespective of movement or stop, and the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller is prevented. It has the action of:

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. (Embodiment 1) The configuration of an image forming apparatus according to Embodiment 1 of the present invention is the same as that of the image forming apparatus shown in FIGS. 1 and 2, and the description of its arrangement and operation is omitted. In this embodiment, a case where a laser is used as a typical example of the exposure unit 6 will be described. However, the exposure unit 6 may be an LED or an LCD instead of the laser.

The feature of this embodiment is that the outer diameter of the transfer opposing roller 8 is set to 10 to 30 mm. (Table 1)
The results of the transfer evaluation performed under different environments of normal temperature / normal humidity, high temperature / high humidity, and low temperature / low humidity while changing the outer diameter of the transfer facing roller 8 are shown.

[0023]

[Table 1]

The ○ symbol shown in Table 1 indicates that no printing defect or jam occurred when a printing test was performed on 2,000 sheets under each environment, and the × symbol indicates a printing defect or This indicates that a jam has occurred one or more times. As shown in (Table 1), it can be seen that there is a clear difference between the case where the outer diameter of the transfer facing roller 8 is 10 to 30 mm and the case where the outer diameter is 40 mm or more, regarding the printing failure and the occurrence of jam. The outer diameter of the transfer facing roller 8 is 10
In the case of ｍｍ30 mm, the releasability of the printing paper 7 from the toner image carrier was also good. Therefore, by setting the outer diameter of the transfer opposing roller 8 to 10 to 30 mm, the printing paper is easily separated from the toner image carrier,
An image forming apparatus with less occurrence of jams can be provided.

The outer diameter of the transfer opposing roller 8 is 10 mm.
It is very difficult to make the value less than the above in forming the bearing of the transfer opposing roller 8. When the outer diameter of the transfer opposing roller 8 approaches the outer diameter of the bearing, the bearing easily comes into contact with the printed image when the transfer opposing roller 8 is moved, which is a factor that disturbs the image.

In addition, static electricity may accumulate on the transfer opposing roller 8 and the inner surface of the toner image carrier 1 during repeated printing. The photo-organic semiconductor belt often used as the toner image carrier 1 often uses a PET (polyethylene terephthalate) sheet as a base material, and static electricity easily accumulates on the inner surface of the sheet. When the transfer opposing roller 8 moves to transfer the toner image onto the printing paper 7, contact and separation between the transfer opposing roller 8 and the inner surface of the toner image carrier 1 are repeated.
When the transfer opposing roller 8 is separated from (separated from) the inner surface of the toner image carrier 1, if static electricity is accumulated on the inner surface of the transfer opposing roller 8 and the inner surface of the toner image carrier 1, a discharge phenomenon occurs, and the printing paper The toner image 7 is hardly peeled off from the toner image carrier 1, and the toner image on the toner image carrier 1 may be disturbed, or the print disturbance on the printing paper 7 or transfer failure may occur. Therefore, by forming the transfer opposing roller 8 from a conductive material and grounding or applying a bias, static electricity accumulated on the transfer opposing roller 8 and the inner surface of the toner image carrier 1 can be released, and the printing paper 7 Can be easily separated from the toner image carrier 1 and printing defects and jams can be prevented.

As a method of applying a ground or a bias to the transfer opposing roller 8, a bearing (not shown) of the transfer opposing roller 8 is formed of a conductive material, and the transfer opposing roller drive for driving the transfer opposing roller 8 is performed. By arranging the electrodes on a holder (not shown), it is possible to easily apply grounding or bias. Further, a ground or a bias may be directly applied to the metal portion of the shaft end of the transfer opposing roller 8. The grounding or bias application to the transfer opposing roller 8 may be performed while the transfer opposing roller 8 is moving, or at a fixed location such as being located at the home position.

At this time, the transfer opposing roller drive holder may be always grounded, or may be always connected to the bias power supply. This connection to the ground or the bias power supply may be performed while the transfer opposing roller 8 is moving or when the transfer opposing roller 8 is located at the home position.

As described above, according to the present embodiment, by setting the outer diameter of the transfer opposing roller 8 to 10 to 30 mm, the printing paper is easily peeled from the toner image carrier, and the occurrence of printing defects and jams is reduced. Can be prevented. In addition, since the transfer opposing roller 8 is made of a conductive material and the transfer opposing roller 8 is grounded or a bias is applied, the accumulation of static electricity on the transfer opposing roller 8 and the inner surface of the toner image carrier 1 can be prevented. It can be easily peeled off from the image carrier 1 and also can prevent printing defects and jams.

[0030]

As described above, according to the image forming apparatus of the present invention, by setting the outer diameter of the transfer opposing roller to 10 to 30 mm, the printing paper is easily separated from the toner image carrier at the time of transfer. In addition, since the possibility of occurrence of printing defects and jams during transfer can be eliminated, an advantageous effect that printing defects and occurrence of jams can be prevented can be obtained.

Since the transfer opposing roller is made of a conductive material, the transfer opposing roller can be grounded to prevent the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller. An advantageous effect is obtained in that the releasability of the paper from the toner image carrier can be improved, and printing defects and occurrence of jam can be prevented.

Further, since the transfer opposing roller is grounded, the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller can be prevented, so that the printing paper can be separated from the toner image carrier during transfer. And the advantageous effects of preventing printing defects and occurrence of jams can be obtained.

Further, by applying a bias to the transfer opposing roller, the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller can be prevented, so that the printing paper is separated from the toner image carrier during transfer. This has the advantageous effect of improving printability and preventing the occurrence of printing defects and jams.

Further, since the transfer opposing roller is grounded or a bias is applied only at a specific position, the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller can be prevented. An advantageous effect is obtained in that the releasability of the paper from the toner image carrier can be improved, and printing defects and occurrence of jam can be prevented.

Further, since the transfer opposing roller is always grounded or a bias is applied regardless of whether the transfer opposing roller is moving or stopped, the accumulation of static electricity on the inner surface of the toner image carrier and the transfer opposing roller can be prevented. In this case, it is possible to improve the releasability of the printing paper from the toner image carrier and to prevent the occurrence of printing defects and jams.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a general orthogonal transfer type image forming apparatus.

FIG. 2 is a configuration diagram schematically illustrating a transfer unit of the image forming apparatus of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toner image carrier 2 Charging device 3 Developing device 3a Toner 3b Developing roller 3c Toner image 4 Cleaning device 5 Static eliminator 6 Exposure device 7 Printing paper 8 Transfer opposed roller 9 Support roller 10 Displacement roller 11 Transfer plate 12 Heat source 13 Reflecting plate 14 Reflective transport plate 15 Fixing unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasunori Sagara 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Shinichi Kizu 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Masashi Ogawa 1006 Odoma Kadoma, Kadoma City, Osaka Pref. Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] An orthogonal transfer system for transferring a toner image carried on a toner image carrier to a printing paper in a direction perpendicular to a conveying direction of the printing paper by a transfer opposing roller and fixing the toner image transferred to the printing paper. The image forming apparatus according to any one of claims 1 to 3, wherein the transfer opposed roller has an outer diameter of 10 to 30 mm. 2. The image forming apparatus according to claim 1, wherein said transfer opposing roller is made of a conductive material. 3. The image forming apparatus according to claim 2, wherein said transfer opposing roller is grounded. 4. The image forming apparatus according to claim 2, wherein a bias is applied to said transfer opposing roller. 5. The image forming apparatus according to claim 3, wherein the transfer opposing roller is grounded or biased only at a specific position. 6. The image forming apparatus according to claim 3, wherein the transfer opposing roller is always grounded or biased regardless of movement or stop.