JPS6156318A - Laser printer - Google Patents

Abstract

PURPOSE:To realize thinning of an optical body for determining the size of the whole printer, and to make a laser printer small in size by constituting the laser printer so that one side in roughly rectangular shape of a condensing means is equal to the scanning width of a deflecting means, and the other side has a width required for making the emitted light of the deflecting means transmit. CONSTITUTION:A laser light modulated and emitted in accordance with image information from a semiconductor laser 1 is converted to parallel rays by a collimator lens 2, and deflected so as to scan an image width by a polygon mirror 3. The light emitted from the mirror 3 is condensed by an Ftheta lens 17 and corrected so as to form a focus on the surface of a photosensitive body, a latent image is formed on a trasfer paper by a process of an electrophotographing system. Also, by setting a width of the Ftheta lens 17 to a width required for making a light transmit in the direction vertical to the scanning direction, a width of an optical body 6 can be reduced, and the laser printer can be made small in size by lowering the height.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laser printer that can be miniaturized.

Conventional configurations and their problems In recent years, demand for laser printers has increased as word processors and other information devices have been introduced to small businesses, and as a result, demands for smaller size and lower prices have emerged. . In a laser printer, the laser optical system occupies a large volume, and in particular, there is a demand for miniaturization of Fθ lenses and polygons.

A conventional optical device will be described below with reference to the drawings. FIG. 1 is a front view of a conventional optical device.
2 is a semiconductor laser, 2 is a collimator lens, 3 is a polygon mirror, 4 is a motor, 5 is an Fθ lens, and 6 is an optical main body.

FIG. 2 is a side view of a conventional optical device.

Fig. 3 shows a laser printer equipped with a conventional optical device, where 6 is the optical body, 7 is a mirror, 8 is a photoreceptor, 9 is a charger, 1o is a developing device, 11 is a paper cassette, and 12 is a feeder. In the paper unit, 13 is a transfer device, 14 is a cleaner, 15 is a fixing device, and 16 is a paper discharge tray.

The operation of the laser printer configured as above will be described below. A laser beam modulated according to image information and emitted from a semiconductor laser 1 is collimated by a collimator lens 2 and deflected by a polygon mirror 3 so as to scan the image width. The light emitted from the polygon mirror 3 is condensed by the Fθ lens 5 and is directed onto the photoreceptor 8.
The image is corrected to focus on a plane. A latent image is formed by the laser light incident on the photoreceptor 8, and an image is formed on the transfer paper through a series of electrophotographic processes.

However, in the above configuration, since the width of the optical body 6 is determined by the Fθ lens 5, the third
As seen in the figure, this method had the disadvantage of increasing the size of the device.

OBJECT OF THE INVENTION An object of the present invention is to provide a laser printer that can be miniaturized.

Structure of the Invention The laser printer of the present invention includes a laser light source, a deflection means for deflecting light emitted from the laser light source to scan an image width, and a substantially rectangular pulp for condensing the emitted light from the deflection means. means, wherein one side of the substantially rectangular shape of the condensing means is made equal to the scanning width of the deflecting means, and the other side is configured to have a width necessary to transmit the emitted light of the deflecting means.
This made it possible to make the optical body, which determined the overall dimensions of the laser printer, thinner.
This makes it possible to downsize the laser printer.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 4, 6, and 6, parts corresponding to the conventional apparatus shown in FIGS. 1 to 3 are given the same reference numerals, respectively. The difference is that the converging F.theta. lens 17 is narrow in width in a direction perpendicular to the scanning direction, and is a substantially rectangular F.theta. lens as shown in a perspective view in FIG.

In the laser printer of this embodiment configured as described above, the width of the optical body 6 can be reduced by setting the width of the Fθ lens 17 to the width necessary to transmit the light beam in a direction perpendicular to the scanning direction. As shown in Fig. 6, the height has been lowered to reduce the size.

In the above embodiment, an image is formed using an electrophotographic method, but the present invention can be applied to any printer using a laser, such as an electrofax method or a thermal transfer method. Furthermore, it goes without saying that the optical body can be placed in other positions as well as in this embodiment.

Effects of the Invention As is clear from the above explanation, the present invention provides a comb in which one side of the substantially rectangular shape of the condensing means is equal to the scanning width of the deflecting means,
The other side has the effect of being transparent to the light emitted from the deflection means. Here, if the optical main body is arranged next to the fixing device or the developing device and is deflected by a mirror so as to expose the photoreceptor, an even smaller laser printer can be obtained.

[Brief explanation of drawings]

FIG. 1 is a front view of an optical device of a conventional laser printer, FIG. 2 is a side view of the same, FIG. 3 is a configuration diagram of a conventional laser printer, and FIG. 4 is an optical device of a laser printer according to an embodiment of the present invention. FIG. 6 is a front view of the device, FIG. 6 is a side view of the same, FIG. 6 is a configuration diagram of the above embodiment, and FIG. 7 is a perspective view of a light condensing means. 1... Semiconductor laser, 2... Collimator lens, 3... Polygon mirror, 4...
...Motor, 6...-Optical body, completed...
Mirror, 8...photoreceptor, 17...lens. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 4 Cow Figure 5 17

Claims (2)

[Claims] (1) comprising a laser light source, a deflection means for deflecting the light emitted from the laser light source to scan an image width, and a substantially rectangular condensing means for condensing the light emitted from the deflection means,
A laser printer characterized in that one side of the substantially rectangular shape of the condensing means is set equal to the scanning width of the deflecting means, and the other side is set to a width necessary to transmit the emitted light of the deflecting means. (2) A laser printer according to claim 1, characterized in that the laser light source, deflection means, and condensing means are integrally constructed.