JPS6128920A - Optical scanner - Google Patents

Abstract

PURPOSE:To arrange the axis of rotation of a polygon mirror in such a direction that its rotation is stable by providing a scanning direction converting means in an optical path of projection light from the polygon mirror. CONSTITUTION:The scanning direction converting means 13 is arranged between the polygon mirror 4 and an ftheta lens 5. A light beam generated by a signal light beam generating means 14 is reflected by the polygon mirror 4 and scanned horizontally, and then passed through the scanning direction converting means 13, and consequently its scanning direction is changed by an angle theta from the horizontal and the light passes through the ftheta lens 5. Further, the optical path is returned by a mirror 11 arranged at the angle theta to the horizontal to scan on the irradiated surface 21 of a photosensitive body belt 2 as shown by an arrow. Similarly, the reflection scanning direction of the polygon mirror which rotates stably when its axis of rotation is perpendicular can be converted by 90 deg., and this scanner is therefore applicable to an image display device on which an image is displayed in the left-right direction.

Description

Detailed Description of the Invention 41 Object of the Invention [Field of Industrial Application] The present invention relates to an image forming apparatus, for example, electrical image information that is calculated or read out from an electronic computer or an image reading device, or a magnetic tape. The present invention relates to a device that reproduces image information stored and recorded on microfilm as a visible image, or a printing device that prints out an image, and particularly relates to the improvement of an optical scanner for organically utilizing these devices.

[Conventional technology]

FIG. 5 is a longitudinal sectional side view showing a schematic structure of an example of this type of image display device.

1 is a frame, 2 is an endless belt-shaped photoreceptor having a conductive substrate and a photoconductive layer, and is suspended between pulleys P1 and 22 driven in the direction of the arrow by a drive source (not shown). 3 is a charger, 4 is a laser beam scanner, 5 is a lens, 6 is a developer, 7 is a static elimination lamp, and 8 is a cleaner.

A light beam modulated by an electric signal and emitted from a light beam generator (not shown) (for example, a semiconductor laser modulated by an electric signal) is reflected by the scanner 4 and scans the surface of the photoreceptor 2 in the width direction. Thus, the toner image formed in the developing device 6 by the well-known Carlson method is displayed on a window provided with a transparent member 9 such as glass by rotation of the photoreceptor belt 2. IO is a display illumination lamp.

The one shown in FIG. 6 is another example of an electrophotographic image display device similar to the above, and this example does not particularly require charging means or cleaning means, and uses conductive magnetic toner at the same time as exposure. This is a method in which development is performed in step 6. 11 is a light beam folding mirror (Japanese Patent Application Laid-Open No. 1982-
(See Publication No. 98748).

Image display devices such as those shown in FIGS. 1 and 2,
In conventionally known copying machines, laser beam printers (LBPs), and electrostatic recording devices, the developing device 6 normally carries toner on a horizontally held developing sleeve. Toner is applied onto a photoreceptor or other image carrier by rotation or by rotation of a magnet roll within the sleeve.

However, as shown in the perspective view of FIG. 7 and the side view of FIG. It is also possible to move it to As the image forming method using toner used in this display device, the method shown in FIG. 5 or FIG. 6 and others can be used.

Since the image display device shown in FIGS. 7 and 8 is tilted with respect to the horizontal, it has the advantage that the image is easy to see and does not cause fatigue. In addition to this good visibility, there are the following advantages.

That is, for example, if the display surface 9 of the image display device has the size of A3 and is arranged so that the short side of the display surface is in the depth direction and the long side is in the left and right direction, it is usually seen more often. It corresponds well to the format of the document. In other words, most A3 size documents have text or drawings written on the long side of the document, and A4 size documents have text or drawings written on the short side of the document. If the display device configuration is adopted, A4
Two pages of size documents can be displayed simultaneously, and A3 size documents can be displayed in the most familiar form. Furthermore, since hard copies obtained by conventional LIBF and the like often have the same document format as above, it is possible to obtain documents that are well matched to these interfaces. This shows that the matching to the writing electrical signal used is good.

[Problem that the invention seeks to solve]

However, in the above-described apparatus, as shown in FIG. 8, the polygon mirror 4 that rotates at high speed has a configuration in which its axis of rotation is inclined with respect to the vertical.

In order for the polygon mirror to rotate uniformly and at high speed, it is desirable that its rotation axis be as vertical as possible.

Therefore, it is an object of the present invention to make it possible to always arrange the rotation axis of a polygon mirror in a direction in which its rotation is stable.

Summary: Structure of the Invention [Means for Solving Problems] The present invention provides an optical scanning system in which a modulated light beam is exposed and scanned onto a beam irradiated object by a rotating polygon mirror. An optical scanner is characterized in that a scanning direction converting means is provided in an optical path.

[Effect]

When the modulated light beam is scanned for exposure onto the irradiated object by the rotating polygon mirror via the fO lens, the scanning direction after exiting the polygon mirror is changed, so the rotation of the polygon mirror is independent of the inclination of the image display surface. The shaft can be held in a stable vertical direction.

〔Example〕

The present invention will be explained below with reference to the embodiments shown in FIGS. 1 to 4.

In FIG. 1, reference numeral 13 denotes scanning direction converting means of the present invention, which is arranged between the polygon mirror 4 and the fθ lens 5. 14 is a semiconductor laser.

FIGS. 2 and 3 show an image rotator using a prism as an example of a scanning direction converting means. Figure 2 (
(a) is a front view, (b) is a top view, and (C) is a side view. For example, as shown in (e), it is approximately 45 degrees to the bottom surface.
The image light 17 incident at an angle of 17 passes through the prism l 3 r and changes its direction at an angle of approximately 80° with respect to the image light upon exit (output light 18), which is (a).
This is because, as shown in b), the images are reversed in the vertical direction of the prism, but the direction of the images does not change in the horizontal direction.

As shown in FIGS. 3(a) and 3(b), if a light beam scanned by a polygon mirror as image light is also scanned at an angle of 45° with respect to the bottom surface, the scanning direction will similarly change by 80°.

Furthermore, if scanning is performed at an angle of θ0 with respect to the bottom surface, the scanning direction changes by 2θ0 at the time of emission. However, in the case of image light, the outgoing state is a mirror image of the incoming state.

FIG. 1 shows the horizontal scanning direction of the beam by the polygon mirror converted to the θ direction with respect to the horizontal.

FIG. 4 shows an example in which the scanning optical system shown in FIG. 1 is applied to an image display device as shown in FIG. In the figure, the optical path is folded back using a mirror 11 in order to obtain an appropriate optical path length.

The rotation axis direction of the polygon mirror 4 is vertical, and the scanning direction is the irradiated surface 2. The figure shows a state in which the means 13 converts the angle of inclination to match the inclination angle θ (FIG. 8).

A light beam generated from a signal light beam generation source (for example, a modulated semiconductor laser) (not shown) passes through a polygon mirror 4.
0 which is reflected and scanned in the horizontal direction, then passes through the scanning direction converting means 13 to convert the scanning direction at an angle θ with respect to the horizontal, and passes through the fO lens 5. Further, the optical path is turned back by a mirror], 1, which is also arranged at an angle of 0 with respect to the horizontal, and the irradiated surface 21 of the photoreceptor belt 2 is scanned in the direction of the arrow.

Similarly to the above, it is also possible to convert the reflection scanning direction by 80 degrees using a polygon mirror whose rotation axis stably rotates in the vertical direction. Therefore, for example, if the display surface is vertical,
The present invention can also be applied to an image display device in which images are displayed horizontally.

FIG. 9 is an explanatory diagram of a toner developing device inclined with respect to the horizontal in the apparatus shown in FIG. 8, and the toner on the developing sleeve is uniformly supplied onto the sleeve. This is an example of a configuration for obtaining an image. Here, the one described in Japanese Patent Application No. 134173/1988 will be described.

Since the irradiated surface 21 of the photoreceptor is inclined as shown in FIG. 4, the developing device 6 is also inclined. Therefore, the developing sleeve 15 immersed in the toner in the toner developing device is also inclined at an angle θ1, and the blade 16 disposed close to the sleeve 15 is also inclined at an angle θ2 with respect to the sleeve 15. The sleeve 15 is fixed and a magnet roll inside it is rotated, or the magnet roll is fixed and the sleeve 15 is rotated to smoothly develop with magnetic toner.The principle of operation is based on the above patent application. 58
Since it is described in No.-134173, details will be omitted.

C. Effects of the Invention According to the present invention, an optical scanner that is compatible with an image display device that has a tilted display section, has good visibility, and is compatible with a document format, for example, can be used with the rotation axis of a polygon mirror that rotates at high speed. This effect can be obtained by holding it in the most stable vertical direction.

[Brief explanation of drawings]

Figures 1 to 3 illustrate the present invention; Figure 1 is an external perspective view, Figures 2 and 3 are explanatory diagrams of the scanning direction conversion element, and Figure 4 is an image to which the present invention is applied. An explanatory diagram of the display device, Figure 5, Figure 6 is a schematic diagram of a known image display bag device, Figures 7 and 8 are schematic diagrams of an image display device with an inclined display surface, and Figure 9 is a developing sleeve. A perspective view of. 4 is a polygon mirror, 5 is an fθ lens, 13 is a scanning direction conversion element, and 21 is an inclined object to be irradiated. Figure 7. l Figure 9

Claims (1)

[Claims] (1) An optical scanning system in which a modulated light beam is exposed and scanned on a beam irradiated object by a rotating polygon mirror, characterized in that a scanning direction conversion means is provided in the optical path after exiting from the polygon mirror. optical scanner.