JPH03252677A - Electrophotographic printer - Google Patents

Abstract

PURPOSE:To set the extent of a printing area at a specified position on a paper by detecting the movement of the position of a paper in a direction vertical to a suction direction at the time of sucking the paper and moving the photosensitive area of a photosensitive drum in accordance with the detected displacement. CONSTITUTION:A paper position sensor 3 detects the displacement of the positions of both ends in a paper width which is vertical to the suction direction of the sucked paper from a reference position, and the detected value is transmitted to a mechanical control unit 2. When the unit 2 which receives data on the displacement of the position of the paper from the reference position transmits the data on a printed image to an exposure control part 4, it takes the moving amount of the paper from the reference position as a correction value, and the exposure control part 4 corrects the moving amount to be on the photosensitive drum and controls a light source so as to expose the printed image. Thus, the deviation of a printing position in an absolute position from the end of the paper is prevented in the printed result.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrophotographic printer.

[Conventional technology]

Conventionally, this type of electrophotographic printer uses paper (cut paper).
It did not have a sensor to detect both ends of the paper width perpendicular to the suction direction when suctioning.

[Problem to be solved by the invention]

The conventional electrophotographic printer mentioned above does not have a sensor that detects the positions of both ends of the paper width perpendicular to the paper suction direction when paper is sucked in, so the paper is sucked while moving in the paper width direction from the reference position. In this case, there is a drawback that the print position is shifted at the absolute position near the edge of the paper in the print result.

[Means to solve the problem]

The electrophotographic printer of the present invention includes a traveling section that sucks in cut sheets one by one at the start of printing, a wide photosensitive drum that can print in an area larger than the width of the paper perpendicular to the sucking direction, and a An electrophotographic printer having an exposure device capable of exposing the entire width thereof has a sensor that detects both ends of the paper width when sucking paper, and the exposure range of the exposure device onto the photosensitive drum is determined by the sensor. It is characterized in that it changes according to both ends of the paper width detected by the paper width.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a functional block diagram showing one embodiment of the present invention. A mask control unit 1 that receives print data from a Centro interface (not shown) transmits print commands such as print image data and mechanism control commands to a mechanical control unit 2. The mechanical control unit 2 controls the exposure control section 4, the traveling section (not shown), and the EP section (not shown). It is composed of rollers, and absorbs paper according to instructions from the mechanical control unit 2.

A paper position sensor 3 detects the displacement of the positions of both ends of the paper width perpendicular to the suction direction of the sucked paper from a reference position, and transmits the value to the mechanical control units I-2. The mechanical control unit 2, which has received the data on the displacement of the paper position from the reference position, uses the amount of movement of the paper from the reference position as a correction value to be controlled when transmitting print image data to the exposure control unit 4. The exposure control section 4 controls the light source so as to correct the amount of movement of the photosensitive drum 2 and expose the print image.

The photosensitive drum that receives light from the light source by the exposure control unit 4 is
The toner is attached to the exposed area under control of the unit. The toner on the drum is transferred onto the sucked paper.

FIG. 2 is an explanatory diagram when the print area range is moved in accordance with the displacement of the paper position from the reference position at the time of paper feeding and its value in this embodiment.

When the paper 5 is sucked in according to the reference position (Fig. 2 (a)
)), the exposure range on the photosensitive drum is range A.

The printing result will be as shown in Figure 2(c), but if
If the paper 5 is sucked while being moved from the reference position as shown in FIG. 2(b), if exposure is performed at the range opening aligned with the reference position, the printing result will be as shown in FIG. 2(d). Therefore, when the paper 5 is sucked in as shown in FIG. 2(b), its displacement is detected by a sensor and the exposure range is changed to range C. If this is done, the printing result will be as shown in FIG. 2(c), and it is possible to prevent the printing result from being printed while being moved.

〔Effect of the invention〕

As explained above, when sucking paper, the present invention includes a sensor that detects the positions of both ends of the paper width in a direction perpendicular to the suction direction, and a print area width that indicates the print area range of the paper perpendicular to the suction direction. By having a photosensitive drum that is long enough to print with a wider width and an exposure device that can effectively utilize the photosensitive area of the photosensitive drum, it is possible to move the paper position in the direction perpendicular to the suction direction when sucking paper. This has the advantage of being able to detect and move the photosensitive area of the photosensitive drum according to the detected displacement to set the printing area range at a fixed position on the paper.

It is the opening of the country.

1... Mask control unit, 2... Mechanical control unit 1~. 3...Paper position sensor, 4...Exposure control unit.

Claims (1)

[Claims] A running unit that sucks in sheets one by one when printing starts, a wide photosensitive drum that can print on an area larger than the width of the paper perpendicular to the suction direction, and an exposure device that can expose the entire width of this photosensitive drum. An electrophotographic printer having a sensor that detects both ends of the paper width when sucking paper, and an exposure range of the exposure device onto the photosensitive drum at both ends of the paper width detected by the sensor. An electronic photo printer that is characterized by being able to change according to the user's needs.