JPS58127957A - Printer - Google Patents

Abstract

PURPOSE:To prevent the generation of filming images by providing an image generating part constituted of a latent image forming medium by which latent images are formed, and a latent image forming means which forms latent images on the latent image forming medium, and a means for varying an initial position where the latent images are formed. CONSTITUTION:A printer is provided with a photosensitive drum 1, a drum shaft 8 of the photosensitive drum, and a semiconductor laser 9 and a polyhedral mirror 10 which constitute an optical system 3 for forming electrostatic patterns on the drum 1. The laser 9 is operated to emit light according to the printing from a priority unit and the light thereof is scanned by the width AA' on the drum 1 by the mirror 10, whereby an electrostatic pattern is formed. At every prescribed period, the drum 1 is moved axially by a drum moving mechanism 11. Thus, in the case of printing forms, width is provided to rule printed parts and the generation of filming images is virtually reduced.

Description

Detailed Description of the Invention (A) Technical Field of the Invention The present invention relates to a printing device such as an electrophotographic recording device or an electrostatic recording device, and is particularly suitable for use in a printing device adopting a form overlay method. The present invention relates to a printing device equipped with all of the above image generating sections.

(B) Technical background Increased printing speed due to improved processing power of computers, office automation! In response to the diversification of printing required for I7 or image processing, electrophotographic printers have recently become rapidly popular as output devices in place of conventional impact type line printers.

(C) Prior art and problems Figure 1 shows a schematic diagram of the electrophotographic recording device Q. In the figure, the photosensitive drum unit is uniformly charged by an initial charger 2, and then image information is exposed by an optical system 3. In the exposed area, the surface potential of the photosensitive drum unit is lower than 9, and the image information from the light is converted into an electrostatic pattern.

This electrostatic pattern is developed into a visible image by supplying developer powder by a developing means.

Next, the visible image on the photosensitive drum 1 is transferred onto the recording paper 6 by the transfer means 5 .

After the transfer, the developer powder remaining on the photosensitive drum 1:C is removed by a cleaning brush 7.

By sequentially repeating the steps described above, printing of the electrophotographic recording device is performed.

However, the developer powder on the photosensitive drum l in the above-mentioned process is not completely removed, and a small amount of the developer powder remains attached to the photosensitive drum l before proceeding to the next process. In a printing device that performs such a printing method, for example, when printing forms such as lay, some of the lines of the line form are printed on the photosensitive drum 1.
The image of the horizontal line parallel to the direction of electrostatic pattern formation on the photosensitive drum l is repeatedly printed on its extension line. Therefore, printing is performed in a much shorter period on the photosensitive drum l than in other areas. A filming image of developing powder is formed. Even if no electrostatic pattern is formed on the photosensitive drum 1, as this filming image accumulates.

The portion of the filming image is developed with developing powder attached thereto by the developing means.

Therefore, the developer powder on the portion of the filming image on the photosensitive drum 1 is transferred to the recording paper 6 by the transfer means 6, resulting in a printed matter with poor print quality. In order to prevent this, a fleece mechanism was installed to clean the photosensitive drum 1t at predetermined intervals, but the filming image could not be removed sufficiently.

In addition, the fleece mechanism has the disadvantage that the apparatus for applying the gold film becomes large and expensive.Objective of the Invention In view of the above-mentioned disadvantages, an object of the present invention is to prevent the occurrence of filming images. The purpose is to provide a printing device that can.

According to the present invention, the structure and object of the invention is to provide a scratch-forming medium on which a latent image is formed, and a latent image forming means for forming a latent image on the latent image forming medium. 0 (P) Embodiment of the Invention This is achieved by providing an entire printing apparatus characterized by comprising: a part of the latent image forming medium; and a means for varying the initial latent image forming position in the main scanning direction on the latent image forming medium. EXAMPLE Next, the present invention will be explained in detail using drawings. FIG. 2 is a conceptual diagram showing an embodiment of a printing apparatus according to the present invention.

In the figure, 1 is a photosensitive drum, 8 is a drum axis of the photosensitive drum, and 9.10 is a semiconductor laser and a polygon mirror that constitute the optical system 3 for forming an electrostatic pattern on the photosensitive drum l shown in FIG. A semiconductor laser 9, which is a mirror, is caused to emit light in response to a printing command from a host device, and the light is scanned by a polygon mirror 10 over a photosensitive drum l by a width of 8' to form an electrostatic pattern.

Reference numeral 11 denotes a drum moving mechanism for moving the photosensitive drum 1t in the axial direction of the drum shaft 8.

With the configuration as described above, the photosensitive drum 1 is moved in one axis direction by the drum moving mechanism 10 at predetermined intervals. For example, as shown in FIG. 2, the photosensitive drum 1 is moved to the initial electrostatic pattern forming position AiB in the main scanning direction. Alternatively, when moving from position B to A, the distance between position A and 80 is divided into equal parts, and the distance is moved at predetermined intervals.

As a result, when printing a form, a width is created in the marked line printing area, so that filming images hardly occur. Next, another embodiment of the printing apparatus according to the present invention will be described.

FIG. 3 is a conceptual diagram showing another embodiment of the printing apparatus according to the present invention.

In the figure, l is a photosensitive drum, 9 is a semiconductor laser, and 10 is a photosensitive drum.
1 is a polygonal mirror; 12 is a semiconductor laser drive circuit for driving the semiconductor laser 9; and 13 is a print start position determination circuit for determining the print start position in the main scanning direction on the photosensitive drum 1, which is constituted by a counter. Reference numeral 14 represents a print position changeover switch that provides a preset value to the print start position determining circuit 13. Reference numeral 015 represents print data provided by the host device.

With the configuration described above, the initial electrostatic pattern forming position on the photosensitive drum l is changed by the operator switching the printing position changeover switch 141 at predetermined intervals. Move from A to B. As a result, on the photosensitive drum 1, a marked line printing area Kli is formed when printing a form, so that filming images hardly occur.

Also, book 1! In this example, a simple circuit configuration is required and a significant cost reduction can be expected.Also, by making the electrostatic pattern formation position on the photosensitive drum l variable, for example, the initial electrostatic pattern formation position can be changed to A. If the initial electrostatic pattern formation position moves to BK, the crease line printed portion formed in this case will be subjected to 1tVC cleaning with the existing cleaning brush. No filming image occurs at all.

In the above-mentioned embodiment, the printing position switching period is as follows:
Although the operator performs this at arbitrary intervals, the present invention is not limited thereto, for example.

l) When a predetermined number of drum rotations or number of printed sheets is reached.

2) When using a conventional fleece mechanism,
This is carried out every cleaning period of the fleece mechanism. 3) Move each sheet slightly from printing position YtA to B.

In this case, the recording paper 10 is also moved from A to B little by little. Various methods such as the above may be used.

(G) Detailed Description of the Invention As described above, according to the present invention, it is possible to realize a printing apparatus in which no filming image occurs on the photosensitive drum.

Further, since no filming image is generated, printed matter with good print quality can be obtained.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of an electrophotographic recording device, Figures 2 and 3
The figure is a conceptual diagram of an embodiment of a printing apparatus according to the present invention. In the figure, 1 is a photosensitive drum, 2 is a charger, 3 is an optical system, 4 is a current means, 5 is a transfer means, 6 is a recording paper, F is a cleaning brush, 8 is a drum shaft, 9 is a semiconductor laser, 1
o is a polygon mirror, 11 is a drum moving mechanism, 12 is a semiconductor laser drive circuit, 13 is a printing start position determining circuit, 14
is the print position changeover switch, and 16 is the print data.

Claims (1)

[Claims] An image generating section comprising a latent image forming medium on which a latent image is formed, a latent image forming means for forming a latent image on the latent image forming medium, and an initial latent image on the latent image forming medium in the main scanning direction. A printing device for copying is equipped with means for varying the image forming position.