JPS629361A - Serial type electrophotographic printer - Google Patents

Abstract

PURPOSE:To reduce necessary driving ability by providing a movable means which brings a beltlike recording body into contact with recording paper when a toner image is transferred and a power source switching means which switches a potential to be applied to the beltlike photosensitive body when the toner image is formed. CONSTITUTION:When the part of the beltlike photosensitive body 3 where the toner image is formed contacts the recording paper 1, the movable contact 8a of the power source switching means 7 is switched from a fixed contact 8b and connected to a fixed contact 8c. Consequently, the conductive base 4 of the beltlike photosensitive body 3 is applied with a potential for transfer and the toner image is transferred to the recording paper 1. Further, the movable contact 8 of the power source switching means 7 is connected to the fixed contact 8b again and the conductive base 4 is supplied with a potential for toner image formation. Thus, one-line transfer is completed and then a platen 2 rotates by a constant extent to feed the recording paper 1 by one line in a direction B, so that the beltlike photosensitive body 3 moves as shown by an arrow C. In this case, only beltlike photosensitive body is driven, so a conventional driving source having large driving ability is not necessary and a driving source having small driving ability is usable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer that applies electrophotographic technology, and particularly relates to a serial type electrophotographic printer that uses a belt-shaped photoreceptor.

[Conventional technology]

So-called electrophotographic printers that apply electrophotographic technology are well known, and high-priced electrophotographic printers are mainly line-type printers.

On the other hand, the mainstream of low-priced models are serial type printers.
There is one disclosed in Publication No. 86.

This serial type electrophotographic printer is equipped with a photoreceptor that rotates at a constant speed, and a recording means that includes a charger, an optical head, a developer, etc. arranged along the circumference of the photoreceptor drum, and is mounted on a carriage. While reciprocating in a direction perpendicular to the feeding direction of the recording paper, a toner image is formed on the photoreceptor and the toner image is transferred to the recording paper to obtain a desired recorded image on the recording paper. It is composed of

[Problem that the invention seeks to solve]

However, in the conventional serial type electrophotographic printer described above, mechanical inertia is extremely high because it is necessary to move a carriage carrying a recording means consisting of a photoreceptor, a charger, an optical head, a developer, etc. at high speed. However, in actual operation, there is a problem in that a drive source such as a motor with a large drive capacity is required to move the carriage.

Furthermore, because recording is performed by rotating the photoreceptor in only one direction, when the carriage moves back and forth, recording can only be performed in one direction, for example, when the carriage is moving in the forward direction. Another problem was that the effective time for recording was short, making it difficult to realize high-speed recording.

There are other conventional serial type electrophotographic printers that use a belt-like photoreceptor, but the belt-like photoreceptor is kept in constant contact with the recording paper, and the belt-like photoreceptor is moved even when toner images are transferred. Therefore, there was a problem in that it was difficult to obtain high-quality recorded images.

The present invention has been made to solve these problems, and is a serial type electronic device that does not require a drive source with large drive capacity, is capable of high-speed recording, and is capable of obtaining high-quality recorded images. The purpose is to realize a photo printer.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention disposes an endless belt-shaped photoreceptor composed of a conductive support and a photosensitive layer, facing a platen roller that supports recording paper, and A drive source for circulating the drum, a charging means, an optical head, and a developing device for forming the toner image; A movable means for bringing the photoreceptor into contact with the recording paper, and a power supply switching means for switching the potential applied to the conductive support of the belt-like photoreceptor during toner image formation and transfer.

[For production]

The present invention having the above configuration forms a toner image on the belt-like photoreceptor while circulating the belt-like photoreceptor while being separated from the recording paper, and moves the toner image to a position opposite to the recording paper. At the same time, an electrostatic latent image for forming an intermittent toner image is written on a portion of the belt-like photoreceptor other than the area where the toner image is formed, and then the movement of the belt-like photoreceptor is stopped, The belt-shaped photoreceptor is brought into contact with the recording paper, and the potential applied to the conductive support of the belt-shaped photoreceptor is switched to transfer the toner image onto the recording paper.

After the transfer, the belt-shaped photoreceptor is again moved away from the recording paper to form a toner image and write an electrostatic latent image, and at the same time, the recording paper is fed, and this process is repeated to create a recording image. Obtain image records.

Accordingly, since only the belt-shaped photoreceptor is moved, a drive source with a small driving capacity can be used, and a toner image is formed and an electrostatic latent image is written for the next toner image formation. Since the belt-shaped photoreceptor is separated from the recording paper during toner image formation, high-quality recording can be achieved without staining the recording paper.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a serial type electrophotographic printer according to the present invention, and FIG. 2 is a side view of FIG. 1.

In the figure, 1 is a recording paper, and 2 is a conductive platen roller. The recording paper 1 is supported in close contact with this platen roller 2, and the platen roller 2 rotates in the direction indicated by the arrow as shown in FIG. The recording paper 1 is fed in the direction of arrow B.

Reference numeral 3 denotes an endless belt-shaped photoreceptor, and the belt-shaped photoreceptor 3 is composed of a flexible conductive support 4 and a thin film-like photoreceptor layer 5 such as OPC provided on the surface thereof. Place the boot so that it faces the platen 2.
When the boot IJB a is rotated in a predetermined direction by a drive source (not shown), for example, a step motor, it moves cyclically in the direction of arrow C shown in FIG.

Reference numeral 7 denotes a power supply switching means connected to the conductive support 4 of the belt-shaped photoreceptor 3, which has a movable contact 8a and fixed contacts ab and ac. is switched to apply a potential to the conductive support 4 corresponding to the formation or transfer of the toner image.

Reference numeral 9 denotes charging means for uniformly charging the photosensitive material 5 of the belt-shaped photoreceptor 3, and a charging roll made of a semiconductive brush is used.A charging voltage is applied to the charging means 9. ing.

Reference numeral 10 denotes an optical head, and this optical head 10 includes a light source 11 such as an LED array in which a plurality of light emitting elements are arranged in a straight line, and images a light spot of this light source 11 on the thin film photosensitive material 5 of the belt-shaped photoreceptor 3. It is composed of a lens system 12 that serves as a lens.

Developing units 13a, 13b, and 13c store toners for different colors, and these developing units 13a
13c, the optical head 10, and the charging means 9 are provided along the belt-shaped photoreceptor 3 at a position opposite to the platen roller 2.

14 is an actuator, 15 is a pace connected to the actuator 14, and on this pace 15 is the aforementioned boo'
) A belt-shaped photoreceptor 3 is mounted together with 6a and 6b, and the actuator 14 moves the p base 15.
By moving in the direction of arrow E shown in FIG. 2, the belt-shaped photoreceptor 3 comes into contact with and separates from the recording paper 1 supported by the platen 2.

16 is a fixing device provided in the conveyance path of the recording paper 1.

Next, the effect will be explained.

First, in the case of monochrome recording, when forming a toner image, the belt-shaped photoreceptor 3 is separated from the recording paper 1, and the power supply switching means 7
The movable contact 8a is connected to the fixed contact 8b, and a potential for toner image formation is applied to the conductive support 4 of the belt-shaped photoreceptor 3.

In this state, when the cylindrical pulley 6a is driven by a drive source (not shown), the cylindrical photoreceptor 3 moves at a constant speed in the direction of arrow C. Along with this movement, the photosensitive layer 5 of the belt-shaped photosensitive member 3 is uniformly charged, and then an electrostatic latent image corresponding to the recorded image is written on the thin film photosensitive layer 5 by the optical head 10. .

This electrostatic latent image is transferred to the developing device 1 by the movement of the belt-shaped photoreceptor 3.
3a, and is developed with toner supplied from the developing device 13a to form a toner image.

The toner image formed on the belt-shaped photoreceptor 3 in this way is
By further moving the belt-shaped photoreceptor 3 in the direction of arrow C, it is sent to a position opposite to the recording paper 1 supported by the sifting platen roller 2, and then the movement of the belt-shaped photoreceptor 3 is stopped. .

The area in which one toner image is formed corresponds to the recording area within the width of the recording paper 1, and is, for example, the range t shown in FIG.

Further, while the toner image is being sent to a position opposite to the recording paper 1, an electrostatic latent image for forming the next toner image is written by the optical head 10 on other areas of the belt-like photoreceptor 3. be included.

Now, as described above, when the movement of the belt-shaped photoreceptor 3 is stopped, the actuator 11 moves the base 15 in the direction indicated by the arrow, whereby the portion of the belt-shaped photoreceptor 3 where the toner image is formed is moved. When the recording paper 1 is contacted, the movable contact 8a of the power supply switching means 7 switches from the fixed contact 8b to connect to the fixed contact 8C.

As a result, a potential for transfer is applied to the conductive support 4 of the belt-like photoreceptor 3 instead of the potential for forming the toner image. The toner image is transferred onto the recording paper 1, and after the transfer, the actuator 14 moves the υ base 15 in the direction of arrow E to move the belt-shaped photoreceptor 3 away from the recording paper 1, and the power switching means 7
The movable contact 8 is again connected to the fixed contact 8b, and a potential for toner image formation is applied to the conductive support 4.

In this way, when one line of transfer is completed, the platen 2 is rotated by a drive source (not shown) by a certain amount in the direction of the arrow B, the recording paper 1 is fed by one line in the direction of the arrow B, and then the belt-like photosensitive material is transferred again. The body 3 is moved in the direction of arrow C.

During this movement, the electrostatic latent image already written on the thin film photosensitive material 5 of the belt-shaped photoreceptor 3 is developed by the developing device 13a and sequentially turned into a toner image, and the area where the previous transfer was performed is It is charged again by the charging means 9, and then an electrostatic latent image is written by the optical head 10.

When the toner image is sent to a position facing the recording paper 1, the movement of the belt-shaped photoreceptor 3 is stopped and the toner image is transferred onto the recording paper 1 in the same manner as described above.

By repeating these steps, a recorded image is formed on the recording paper 1 by the transferred toner image, and this recorded image, or toner image, is moved in the direction of arrow B by the rotation of the platen roller 2. The recording paper 1 is sent to the fixing device 16 together with the recording paper 1, and is fixed on the recording paper 1 by the fixing device 16.

In the manner described above, serial monochromatic recorded images are obtained.

Next, the case of color recording will be explained. When recording in two colors, two developing units 13a and 13b are used.

In this case, first, a toner image of the first color is formed on the photosensitive layer 5 of the belt-shaped photoreceptor 3 using the toner of the developing device 13a in the same manner as in the case of monochrome recording, and this toner image is placed relative to the recording paper 1. While being sent to the opposite position, an electrostatic latent image for forming a second color toner image is written on the photosensitive layer 5.

Thereafter, the movement of the belt-shaped photoreceptor 3 is stopped, the belt-shaped photoreceptor 3 is brought into contact with the recording paper 1, and the toner image of the first color is transferred, and then the belt-shaped photoreceptor 3 is moved onto the recording paper 1. separate from

Here, the belt-shaped photoconductor 3 is moved again in the direction of arrow C, but at this time, the recording paper 1 is not sent in the direction of arrow B, and the portion onto which the first color toner image has been transferred is moved onto the belt-shaped photoconductor 3.
remain facing the

Then, the electrostatic latent image already written on the photosensitive layer 5 of the belt-shaped photoreceptor 3 is developed by the developing device 13b to form a second color toner image, and this second color toner image is transferred to the recording paper. At the same time, an electrostatic latent image is written to form an intermittent first color toner image, and then the belt-shaped photoreceptor 3 is brought into contact with the recording paper 1 to form the toner image of the first color. After the second color toner image is transferred to the row where the first color toner image has been transferred, the belt-shaped photoreceptor 3 is separated from the recording paper 1, and the recording paper 1 is fed in the direction of arrow B by one row.

By repeating the above steps and fixing the toner image on the recording paper 1 by the fixing device 16, a two-color recorded image is obtained.

In the case of three-color recording, three developing units 13a, 13b, 1
3c, by sequentially transferring the first color, second color, and third color toner images onto the same row of the recording paper 1 in the same process as described above, it is possible to obtain a three-color recorded image.

When performing color recording, in addition to the method described above, the developing area of each developing device 13a, 13b, 13c is divided in the width direction of the belt-shaped photoreceptor 30, and each developing device 13a, 13c is
After simultaneously forming toner images 13b and 13c and simultaneously transferring these toner images onto the recording paper 1, the recording paper 1 may be moved by one color. The toner images overlap on the recording paper 1 to obtain a color recorded image.

In the above-described embodiment, the actuator 14 is used as a movable means for bringing the belt-shaped photoreceptor 3 into contact with and separating from the recording paper 1, but it is also possible to use a means such as a cam.

〔Effect of the invention〕

As explained above, the present invention provides an endless belt-like photoreceptor composed of a conductive support and a thin film photosensitive material, which is provided to face a platen roller that closely supports recording paper, and which is applied to the conductive support. A power supply switching means is provided for switching the potential during toner image formation and transfer, and a charging means, an optical head, and a developing device are arranged at a position opposite to the platen roller, and the charging means, optical head, The toner image formed on the surface of the thin film photosensitive material of the belt-like photoreceptor by the developing device is sent to a position opposite to the recording paper by the movement of the belt-like photoreceptor, and then the belt-like photoreceptor is stopped. Since the toner image is transferred to the recording paper by moving the toner image, only the belt-shaped photoreceptor is moved.
Therefore, since the mechanical inertia is small, there is no need for a drive source with a large drive capacity as in the conventional case, and it is possible to use a drive source with a small drive capacity.

In addition, an electrostatic latent image for forming the next toner image can be written on the belt-shaped photoconductor during the formation of the toner image and while the toner image is being sent to a position opposite to the recording paper. , the effective time for recording is long υ, and high-speed recording can be realized.

Furthermore, since the belt-shaped photoreceptor is moved away from the recording paper when forming the toner image and feeding the recording paper, the recording paper may be contaminated during the formation of the toner image or the feeding of the recording paper. Therefore, it is possible to obtain high-quality recorded images.Moreover, since the potential of the conductive support of the belt-shaped photoreceptor is switched between toner image formation and transfer, the platen roller only needs to be grounded. Since there is no need to apply a potential, there are also advantages such as improved safety and reduced costs.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a serial type electrophotographic printer according to the present invention, and FIG. 2 is a side view of FIG. 1. 1: Recording paper 2 Nibraten roller 3: Belt-shaped photoreceptor 4: Conductive support 5: Thin film photosensitive material 6a, 6b: Pulley 7: Power supply switching means 9... Charging means 10: Optical head 13a to 13c: Developing device 14: Actuator 15: Base 16: Fuser

Claims (1)

[Scope of Claims] 1. An endless belt-shaped belt comprising a platen roller supporting recording paper, a conductive support and a photosensitive layer provided on the surface thereof, and arranged to face the platen roller. a photoreceptor, a drive source for circulating the belt-like photoreceptor, a charging means, an optical head, and a developing device for forming a toner image on the belt-like photoreceptor; movable means for separating the belt-like photoreceptor from the recording paper and bringing the belt-like photoreceptor into contact with the recording paper during toner image transfer; and a potential applied to the conductive support of the belt-like photoreceptor during toner image formation and toner image transfer. A serial type electrophotographic printer, characterized in that it is equipped with a power supply switching means for switching. 2. The serial type electrophotographic printer according to claim 1, wherein a plurality of developing units each containing toner of a different color are arranged along the belt-shaped photoreceptor.