JPS6378167A - Recorder - Google Patents

Abstract

PURPOSE:To always image-form an image on a spot diameter having a prescribed size of Gaussian distribution, and to reproduce a set-solid black without changing the power of a laser, by providing a light source on a moving means, and moving a part of a lens. CONSTITUTION:A laser beam 3 from a semiconductor laser 2 possible to be moved by the moving means 1, after being power-modulated, or ON/OFF- controlled by a control circuit 4 according to a picture signal, is emitted, and is converted to a parallel beam of light by a collimator lens 5. And it is converged toward a rotary polygon mirror 7 that is a laser deflector by a convergent lens system 6. The laser beam 3 arriving at the rotary polygon mirror 7 being rotated in one revolution with high accuracy by a motor 8 is deflected by the rotary polygon mirror 7. And an emitted laser beam having a certain angle is image-formed on the spot diameter having the prescribed size of Gaussian distribution in a main scanning and a sub-scanning directions by a second convergent lens system 9. By the above constitution, the laser beam 2 is stopped, and is made incident on a photosensitive body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording apparatus such as a copying machine or a printer using an electrophotographic method.

2. Description of the Related Art In recent years, copying machines using electrophotography and optical printers such as laser printers have become widespread due to the expansion of office automation.

An example of a conventional recording device will be described below with reference to the drawings. FIGS. 4 and 5 show a conventional recording apparatus. In FIG. 4, 41 is a semiconductor laser;
2 is a laser beam, 43 is a control circuit, 44 is a collimator lens, 45 is a converging lens system, 46 is a rotating polygon mirror, 47
is a motor, and 48 is a second converging lens system. Also,
In FIG. 5, 51 is a photosensitive member, 52 is a charger, 53 is a laser exposure device, 54 is a developing device, 55 is a transfer device, 56 is a photosensitive member cleaning device, and 57 is a static eliminator.

The operation of the recording apparatus configured as described above will be explained below.

First, a laser beam 2 from a semiconductor laser 1 mounted at a certain position is power-modulated or ON'-0FF controlled by a control circuit 3 according to an image signal, and then emitted and converted into parallel light by a collimator lens 4. converted. The light is then focused by a converging lens system 5 toward a rotating polygon mirror 6, which is a laser deflector. The motor 7 allows constant rotation with high precision. The laser beam emitted at a certain angle is then imaged in the main scanning direction and the sub-scanning direction by the second converging lens system 8. With the above configuration, the laser beam 1 is focused, and the photoreceptor 1
). Here, the developing process will be briefly explained. The photoreceptor 1) is rotated in the direction of the arrow, and a charge is applied to the surface by a charger 12 controlled by a charge control circuit, and an electrostatic latent image corresponding to the laser exposure pattern is formed by the laser exposure device 13 described above. form. The electrostatic latent image is turned into a toner image by the developing device 14, and transferred to the transfer device 1.
5 onto the transfer paper. After untransferred toner is scraped off from the photoconductor by a photoconductor cleaning device 16, the charge on the surface of the photoconductor is made uniform by a static eliminator 1). Further, the transferred transfer paper passes through a transfer path, is fixed by a fixing device, and then is discharged from the apparatus.

Problems to be Solved by the Invention However, with the above configuration, if the lens system is made of a material such as plastic, its shape will change depending on temperature and humidity because it has a larger coefficient of linear expansion than glass. do. Therefore, there is a problem that the focal length etc. change and the spot becomes blurred, making it impossible to obtain the necessary resolution.

In view of the above problems, the present invention provides a recording device that corrects changes caused by thermal expansion of plastic or the like by moving the position of the light source.

Means for Solving the Problems In order to solve the above problems, the recording apparatus of the present invention includes a light source on the moving means or moves a part of the lens.

Function: With the above-described configuration, the present invention can always form an image with a spot diameter having a Gaussian distribution of a certain size. Also, without changing the laser power,
It is possible to reproduce solid black.

Embodiment Hereinafter, a recording apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a recording apparatus according to a first embodiment of the present invention. In FIG. 1, l is a moving means, 2 is a semiconductor laser, 3 is a laser beam, 4 is a control circuit, 5 is a collimator lens, 6 is a converging lens system, 7 is a rotating polygon mirror, 8 is a motor, and 9 is a third lens. 2 is a converging lens system, and 10 is a photoreceptor. FIGS. 2 and 3 show simple means for moving semiconductor lasers and lenses.

The operation of the recording apparatus configured as described above will be explained below.

First, a laser beam 3 from a semiconductor laser 2 that is movable by a moving means 1 is power-modulated or ON-OFF controlled by a control circuit 4 according to an image signal, and then emitted and converted into parallel light by a collimator lens 5. Ru. The light is then focused by a converging lens system 6 toward a rotating polygon mirror 7 that is a laser deflector. motor 8
The laser beam 3 reaching the rotating polygon mirror 7, which is rotated at a constant rate with high precision, is deflected by the rotating polygon mirror 7. The laser beam emitted at a certain angle is then imaged by the second converging lens system 9 into a spot diameter having a Gaussian distribution of a certain size in the main scanning direction and the sub-scanning direction. With the above configuration, the laser beam 2 is focused and enters the photoreceptor 10. Here, the process conditions are the same as in the conventional example. In such a recording device,
If the converging lens 6.9 is made of plastic or the like, its shape changes depending on temperature and the like. Therefore, in FIG. 2, 21 is a semiconductor laser, and 22 is a jig for fixing the semiconductor laser. 23 is a shape memory alloy that moves the semiconductor laser 22 back and forth by expanding and contracting depending on the temperature. In the transportation means configured in this way, a shape memory alloy that expands and contracts back and forth is used to compensate for changes in the shape of the lens due to temperature changes.
By changing the distance between the semiconductor laser and the collimator lens, it is possible to form an image with a spot diameter that always has a Gaussian distribution of a certain size.

Further, in FIG. 3, 31 is a part of the lens system;
2 is a lens fixing jig, and 33 is a shape memory alloy. A similar effect can be obtained by moving the lens in this way. A similar effect can also be obtained by using an inverse piezo element that converts electrical energy into mechanical energy.

In the case of an inverted piezo element, the semiconductor laser and lens can be moved using a control circuit or the like to prevent the spot from becoming dull, without changing the laser power.
A solid ring can be reproduced. Here, when moving the lens or semiconductor laser, a highly accurate end face of the jig is required to prevent it from tilting, and the jig must be moved along the end face.

Effects of the Invention As described above, according to the present invention, it is possible to always form an image with a spot diameter having a Gaussian distribution of a certain size. On the other hand, by moving the semiconductor laser and lens so as not to dull the spot, a solid ring can be reproduced without changing the laser power.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a recording device according to an embodiment of the present invention, and FIG.
3 are partially detailed views of FIG. 1, and FIGS. 4 and 5 are configuration diagrams of a conventional embodiment. 1... Moving means, 2... Semiconductor laser, 3... Laser light, 4... Control circuit, 7 Rotating polygon mirror, 6.9. ... Convergent lens system, lO ... Photoreceptor, 23 ... Shape memory alloy. /-- Kazuma's first method? - Hand a stop lead - 3 - Ray part 4 - 0 control recirculation 5 - Collimator lens 8 - ±-ter 9 - Second converging cis thread 10 - Acrobody 21 - Eleventh stop Laser 3 - Lens No. 3 Figure 32 - Luns round fixture 33 - Shape 4 Tortoise dinner 4I - Hand injury book Laser 42 - Laser light 43 - 1 FI control circuit 4 - Collimator lens 45 - Coming lens system 48 -Second pickup vehicle, 51-sensor body 52-charger 53-loser dew device 54-・Ui1! L # 55-k Photo 6 A-Bokuguang Stop Greening Device 57-Kui Denki Fig. 5

Claims (4)

[Claims] (1) a moving means; a laser provided on the moving means; a modulating means for modulating the power of the laser beam; a scanning means for scanning the laser beam; a lens system that forms an image with a certain diameter spot in the scanning direction and the sub-scanning direction; an electrophotographic photoreceptor that forms an image corresponding to a light pattern formed from light energy; 1. A recording device comprising: charging means for applying a potential; and a control circuit for modulating the power and charging amount of the laser beam. (2) The recording device according to claim (1), wherein a part of the moving means is made of a shape memory alloy whose shape changes depending on temperature. (3) The recording device according to claim (1), wherein a part of the moving means is constituted by an inverse piezo element that converts electrical energy into mechanical energy. (4) The recording apparatus according to claim (1), wherein the moving means moves not a laser but a part of a lens system or a folding mirror.