JPH08194177A - Optical scanning device for electrophotographic printer - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to an optical scanning device of an electrophotographic printer, and an object of the present invention is to align a photoconductor with two or more laser beams in the prior art. SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for adjusting the distance between two or more beams at low cost and quickly by compensating for the drawbacks of an optical scanning device that forms a latent image. [Structure] A beam separating member 2, a lens 3, a modulating member 4, a lens 5, a beam interval adjusting member 6, a reflecting member 7, a lens 8, a rotary reflecting mirror 9, in order on the optical axis of a beam emitted from one writing light source 1. A lens 10 and a photoconductor 11 are provided. In addition, from the rotary reflecting mirror 9 to the optical path position determining member 12
The optical path position determining member 12 is installed in the vicinity of the photoconductor 11 such that the distance between the optical path position determining member 12 and the rotary reflecting mirror 9 is equal to the distance between the photoconductor 11 and the optical path position confirming member 13 that visualizes the output signal. Are connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device for an electrophotographic printer.

[0002]

2. Description of the Related Art In order to perform high-speed and high-definition printing with one laser beam emitted from one writing light source, (1) a rotary reflecting mirror must be rotated at high speed.

(2) The driving time per dot must be shortened.

240 dots / inch (d
For pi), the limit was 15,000 lines / minute.

Therefore, in order to achieve higher speed and higher definition,
There is a technique of printing using a plurality of laser beams. The technique using a plurality of laser beams can (3) suppress the rotation of the rotary reflecting mirror to a low level.

(4) The driving time per dot can be lengthened.

Due to the features described above, it is possible to achieve high speed and high definition. An optical scanning device that uses one laser beam emitted from one light source by dividing it into a plurality of beams is easier to adjust the passage position of the laser beam than an optical scanning device that uses a plurality of light sources. , Is used in optical scanning devices of electrophotographic printing devices for high-speed and high-definition applications.

An embodiment of a conventional optical scanning device using two beams will be described with reference to FIG. One laser beam emitted from one writing light source 1 is separated into two laser beams by using a beam separating member 2 such as a diffraction grating. The laser beam separated into two beams is focused by a lens 3 and enters a multi-channel modulation member 4. Each of the two laser beams incident on the modulation member 4 is modulated in accordance with an image signal from a control device (not shown). The two modulated laser beams are horizontally narrowed by the lens 5. The two laser beams narrowed in the lateral direction are adjusted by rotating a beam interval adjusting member 6 such as a Dove prism so that a predetermined laser beam interval can be obtained, and then the direction is changed by a reflecting member 7. . The two laser beams whose directions are changed enter the lens 8. After the two laser beams are narrowed down in the vertical direction by the lens 8, by the rotary reflecting mirror 9 having 12 faces and the lens 10, for example,
Uniform spot shapes (latent images) are formed in rows on the photoconductor 11. The latent image formed on the photoconductor 11 is, for example, 10
After being visualized by a toner (not shown) made of powder of μm, the toner is transferred to a printing paper (not shown) by a transfer device (not shown) to form an image.

In the conventional technique having such a configuration, horizontal line printing is performed for laser beam interval adjustment, and the horizontal line interval is measured using a magnifying glass on the printed sample of the horizontal line printing, and the beam is adjusted to a predetermined interval. It was necessary to rotate the space adjusting member 6.

[0010]

In the conventional optical scanning device, horizontal line printing is performed to adjust the distance between two laser beams, and the horizontal line interval is measured using a magnifying glass on a printed sample of the horizontal line printing, and a predetermined line width is measured. It was necessary to rotate the beam gap adjusting member 6 so that the gap becomes. Therefore, there is a problem that adjustment takes a lot of time. In addition, printing paper is required for the adjustment, which increases the adjustment cost.

The present invention has been made in view of the above points, and in an optical scanning device for writing a latent image on a photosensitive member by using two or more laser beams, it is possible to rapidly and inexpensively use two or more laser beams. An object of the present invention is to provide a laser beam interval adjusting mechanism.

[0012]

The above object is to install the optical path position determining member near the photoconductor so that the distance from the rotary reflecting mirror to the optical path position determining member is equal to the distance between the rotary reflecting mirror and the photoconductor. This is achieved by rotating the beam interval adjusting member so that a predetermined beam interval can be obtained while the output from the optical path position determining member is visualized by the optical path position confirming member.

[0013]

Since the above-mentioned means is provided, it is not necessary to perform printing in adjusting a plurality of laser beam intervals, not only the adjustment can be speeded up, but also printing paper is not required, and the cost can be greatly reduced.

[0014]

The present invention will be described below based on the illustrated embodiments. FIG. 1 shows an embodiment of the present invention. The same parts as those in the related art are denoted by the same reference numerals, and the description thereof will be omitted. In the embodiment shown in FIG. 1, the optical path position is set so that the distance (L1) from the rotary reflecting mirror 9 to the optical path position determining member 12 including, for example, a CCD sensor is equal to the distance (L2) between the rotary reflecting mirror 9 and the photoconductor 11. The determining member 12 was installed near the photoconductor 11. That is, L1 = L2. Further, an optical path position confirming member 13 such as a CRT having a dimensional scale is connected to the optical path position determining member 12.

When the laser beam spacing is adjusted, the two laser beams are incident on the optical path position determining member 12, so that the output video signal is visualized by the optical path position confirming member 13 to confirm the beam interval. Meanwhile, the beam interval adjusting member 6 is rotated. By doing so, the distance between the two laser beams can be adjusted without printing.

Needless to say, the optical path position determining member 12 may be installed at any position between the beam interval adjusting member 6 and the rotating mirror 9. Further, in this embodiment, the case where two laser beams are used has been described, but the same applies when three or more laser beams are used. It goes without saying that the optical path position determining member 12 may be set at a position equal to the focal length of the lens 10.

[0017]

As described above, according to the present invention, in an optical scanning device of an electrophotographic printing apparatus using two or more laser beams, the laser beam interval can be adjusted quickly and without using printing paper. Therefore, it is possible to obtain the optical scanning device of the electrophotographic printing apparatus, which can reduce the adjustment cost of the electrophotographic printing apparatus.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of an optical scanning device of an electrophotographic printing apparatus according to the present invention.

FIG. 2 is a schematic view showing a conventional technique of an optical scanning device of an electrophotographic printing apparatus.

[Explanation of symbols]

1 is a writing light source, 2 is a beam separating member, 3, 5, 8,
Reference numeral 10 is a lens, 4 is a modulation member, 6 is a beam spacing adjusting member, 7 is a reflecting member, 9 is a rotary reflecting mirror, 11 is a photoconductor, and 1
Reference numeral 2 is an optical path position determining member, and 13 is an optical path position confirming member.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunitomo Takahashi 1060 Takeda Hitachinaka City, Ibaraki Prefecture, Hitachi Koki Co., Ltd. (72) Inventor Yuuo Nakajima 1060 Takeda Hitachinaka City, Ibaraki Hitachi Koki Co., Ltd. (72) Inventor Muneaki Akai 1060 Takeda, Hitachinaka City, Hitachinaka City, Ibaraki Prefecture, Hitachi Koki Co., Ltd. (72) Inventor, Satoshi Aida, Hitachinaka City, Ibaraki Prefecture, 1060 Takeda, Hitachi Koki Co., Ltd. (72) Shigeo Nemoto, Hitachinaka City, Ibaraki Prefecture 1060 Takeda, Hitachi Koki Co., Ltd. (72) Inventor, Yasuyuki Shibayama 1060 Takeda, Hitachinaka, Ibaraki, Hitachi Koki Co., Ltd.

Claims (4)

[Claims] 1. An optical scanning device of an electrophotographic printing apparatus for forming a latent image on a photoconductor by scanning a plurality of light spots formed in a row by a rotary reflecting mirror, wherein An optical scanning device of an electrophotographic printer, wherein an optical path position determining member is provided at a position near the photoconductor equal to a distance between the rotary reflecting mirror and the photoconductor for adjustment. 2. The electrophotographic printing apparatus according to claim 1, wherein a beam emitted from one laser is split into a plurality of beams by using a beam splitting member, and light spots are formed in a row. Optical scanning device. 3. A beam interval adjusting member that is rotatable is provided between the beam separating member and the optical path position determining member, and the beam interval is adjusted by rotating the beam interval adjusting member. 1. An optical scanning device of the electrophotographic printing device according to 1. 4. The optical scanning device of an electrophotographic printing apparatus according to claim 1, wherein the optical path position determining member has position information output means.