JPS62295085A - Color image output device - Google Patents

Abstract

PURPOSE:To reduce the size, cost and power consumption, to expand the life of a device and to uniform picture quality by reflecting laser beams modulated in accordance with plural color image signals by a single deflecting mirror means and scanning corresponding photosensitive bodies. CONSTITUTION:When laser beams 3a, 3b, 4a, 4b (having P wave polarizing faces for polarizing beam splitters PBS 5a, 5b) modulated in accordance with BL, Y, M and C color signals are projected from laser light sources 1a, 1b, 2a, 2b and the laser beams 3a, 3b are transmitted through the PBSs 5a, 5b. The laser beams 4a, 4b are reflected by reflection mirrors 7a, 7b and phase- shifted by 1/2 wavelength plates 6a, 6b so as to be turned to S waves, and the S waves are made incident upon the PBSs 5a, 5b. Thereby, the laser beams 4a, 4b are reached to a scanner mirror 8 together with the laser beams 3a, 3b and the scanning in the main scanning direction can be executed by the reciprocating motion of the scanner mirror 8 at a prescribed angle.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention reflects laser beams modulated in accordance with a plurality of color image signals by a single deflection mirror means. The present invention relates to a color image output device that scans a corresponding photoreceptor.

[Conventional technology]

Conventional color image output devices include, for example, a color device equipped with a rotating polygon mirror that modulates laser light output from a laser light source according to a color image signal, and scans and exposes a photoreceptor with the modulated laser light. There is an image output device.

Laser light sources, modulation means, rotating polygon mirrors, photoreceptors, etc. are provided in sets corresponding to the number of colors, and the electrostatic latent image formed on the photoreceptor by the above-mentioned exposure is developed with corresponding color toner. Thereafter, a full color image can be reproduced by superimposing and transferring a plurality of color toner images. Of course, instead of a full color image,
Copying of multicolor images can also be performed.

[Problem that the invention seeks to solve]

However, conventional color electronic copying machines are provided with rotating polygon mirrors whose number of cents corresponds to the number of colors;
Because it rotates at high speed, costs are reduced and power consumption is reduced.
There is a limit to the longevity of the mirror, and if each mirror surface has a tilted surface or a difference in reflectance, there is a disadvantage that the image quality becomes uneven.

[Means for solving problems]

The present invention has been made in view of the above, and in order to achieve miniaturization, cost reduction, low power consumption, long life, and uniform image quality, the present invention uses laser light that is modulated according to a plurality of color image signals. The object of the present invention is to provide a color image output device that scans a corresponding photoreceptor by reflecting the image using a single deflection mirror means.

Hereinafter, the color image output device of the present invention will be explained in detail.

〔Example〕

1 to 3 show a first embodiment of the present invention. First, the scanner part 11 will be explained with reference to FIGS. 1 and 2. This scanner part 11 is provided with laser light sources 1a, lb, 2a, and 2b on a base IIA. These laser light sources 1a, lb, 2a, 2b are, for example, black (
Laser light 3 is rotated three times according to color signals of BL), yellow (Y), magenta (M) and cyan (C).
a, 3b, 4a, and 4b (regardless of whether it is one that emits only modulated laser light or one that uses an external modulation method that includes an external modulator).

Polarizing beam splitters (hereinafter referred to as rPBsJ) 5a:, 5b are provided on the optical axes of the laser beams 3a, 3b, and the laser beams 4a, 4b are connected to PBSs 5a, 5b on the optical axes of the laser beams 4a, 4b. Incoming cell reflection mirrors 7a and 7b are provided. 172 wavelength plates 6a, 6b are provided between the reflecting mirrors 7a, 7b and the PBSs 5a, 5b, and the laser beams 3a emitted from the PBSs 5a, 5b
, 3b, 4a, and 4b, there is provided a double-sided reflective scanner mirror 8 supported by a scanner main body 9 so as to rotate by a predetermined angle. Scanner mirror 8
Laser beams 3a, 3b, 4a, 4b reflected by
On the optical axis of the scanner lens (f arc sinθ
lenses) 10a and 10b are provided.

FIG. 3 shows a color image output device including this scanner part 11. A PBS 12a is located on the optical axis of the laser beams 3a and 4a emitted from the scanner part 11, and a PBS 12a is located on the optical axis of the laser beams 3b and 4b. is provided with a PBS 12b. Reflection mirror 1 is placed on the transmission optical axis of PBS12a and 12b.
3a and 13b are provided, and reflection mirrors 14a and 14b are provided on the reflection optical axis thereof. Reflection mirror 13a
, 13b, 14a, and 14b, photosensitive drums 15, 16, 17, and 18 are provided on the reflection optical axes.

The photosensitive drums 15, 16, 17, and 18 are developed with black, yellow, magenta, and cyan developing toners,
Each toner image is transferred to a recording paper conveyed through the transfer path 30 (obvious parts such as a fixing section are omitted).

In the above configuration, the laser light sources 1a, lb, 2a,
Laser beams 3a, 3b, 4a, 4b modulated according to color signals of BL, , Y, M, C from 2b (polarization plane is P
When the laser beams 3a and 3b are transmitted through the PBSs 5a and 5b, and the laser beams 4a and 4b are reflected by the reflecting mirror 7a and 7b, they are 1/2 wavelength The waves are phase-shifted by the plates 6a and 6b to become S waves and enter the PBSs 5a and 5b. Therefore, the laser beams 4a and 4b are
At the same time, the light reaches the scanner mirror 8, and scanning in the main scanning direction is performed by reciprocating the scanner mirror 8 at a predetermined angle.

Of the laser beams 3a, 3b, 4a, 4b reflected by both surfaces of the scanner mirror 8, the laser beams 3a, 3b
is the reflection mirror 13a after passing through the PBSs 12a and 12b.
, 13b and illuminates the photosensitive drum 15.18, forming an electrostatic latent image thereon in accordance with the black and yellow color signals. In addition, the laser beams 4a and 4b are connected to the PBS1
After being reflected by 2a and 12b, the reflection mirror 14a
, 14b and illuminates the photosensitive drums 16, 17, forming electrostatic latent images thereon in accordance with magenta and cyan color signals. After this, black, yellow, magenta,
The electrostatic latent image on the photosensitive drums 15, 16, 17, and 18 is developed with cyan toner and transferred onto the recording paper conveyed through the conveyance path 30, reproducing a full-color image in which black printed areas are recorded with black toner. be done.

Here, the screen scanner mirror 8 may be replaced with two single-sided scanner mirrors, and instead of full color, multicolor recording of two or three colors may be performed. In the case of two colors, if the laser light sources 2a and 2b are omitted, PBS
5a, 5b, 1/2 wavelength plates 6a, 6b, etc. are naturally unnecessary, and if the laser beams itb and 2b are omitted, the scanner mirror 8 can be replaced with a single-sided mirror.

4 and 5 show a second embodiment of the present invention, in which the optical axes of laser beams 3a and 4b and 3b and 4b emitted from the PBSs 5a and 5b of the scanner part 11 are shifted, As a result, PBS12a, 1 shown in FIG.
2b can be omitted and replaced with reflective mirrors 19a and 19b. That is, the laser beams 3a and 3b directly enter the reflecting mirrors 13a and 13b, and the laser beams 4a and 4b directly enter the reflecting mirrors 19a and 19b. Other operations are the same as those in the first embodiment, so explanations will be omitted.

FIG. 6 shows a third embodiment of the present invention, in which the PBSs 5a, 5b and 172 wavelength plates 6a, 6b of the first embodiment are omitted and replaced with reflecting mirrors 20a, 20b. Other explanations will be omitted as they are self-explanatory.

In addition, in the first and second embodiments, the 172 wavelength plate 6
a and 6b may be placed on the light source side of the reflecting mirrors 7a and 7b. Furthermore, in each embodiment, the scanning lenses 10a, 10
Since b has the far arc sin θ characteristic, the moving speed of the laser light on the photosensitive drums 15 to 18 is kept constant. On the other hand, on the photosensitive drum 15.16.17.18,
Although the scanning direction of the laser beam is reversed, this problem can be solved by arranging the image data in the opposite direction or by shifting the writing timing in reciprocating scanning by half a cycle. Furthermore, the aforementioned scanning lenses 10a and 10b are two in number.
In the case of color, only one lens is needed, so there is no shift in the scanning position of the photosensitive drum due to individual differences in lenses (thereby, color shifts due to differences in image height can be prevented.
Since the unidirectional rotational scanning by the rotating polygon mirror is replaced by the reciprocating scanning by the single mirror, the writing speed is doubled because images are written on both the forward and backward passes.

〔Effect of the invention〕

As explained above, according to the color image output device of the present invention, laser beams modulated according to a plurality of color image signals are reflected by a single deflection mirror means to scan the corresponding photoreceptor. Therefore, it is possible to achieve miniaturization, cost reduction, lower power consumption, longer life, and uniform image quality. A part of the scanner can be made 1/4 smaller in size, and the power consumption is about 1/1000 compared to when four rotating polygon mirrors are used. There are no moving parts, so it has a long life and is easy to use.
Since scanning is performed using the mirror surface of a rotating polygon mirror, it is possible to prevent errors in scanning position due to surface tilt and unevenness of images due to differences in reflectance between each surface, which is the case with rotating polygon mirrors. Since precision machining is not required, costs can be reduced by reducing the number of each component.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention.
The figure is a plan view of a part of the scanner, FIG. 2 is a side view of the scanner, and FIG. 3 is an explanatory diagram of the entire scanner. 4 and 5 show a second embodiment of the present invention, FIG. 4 is a side view of a part of the scanner, and FIG. 5 is an explanatory diagram of the entire scanner. FIG. 6 is a side view of a part of a scanner showing a third embodiment of the present invention. Explanation of symbols la, lb, 2a, 2 b---Laser light source 3
a, 3b, 4a, 4 b--laser light 5a, 5b--
---Polarizing beam splitter 6a, 6b----4
/2 wavelength plate 7a, 7b------Reflection mirror 8------Scanner mirror 9------Scanner body 10a, 10b------Scanner lens 11-- --- Scanner part 12 a, 12 b --- Unipolarization beam splinter 13 a, 13 b, 14 a, 14 b ---
--Reflection mirror 15.16.17.18 --- Photosensitive drum Patent applicant Fuji Xerox Co., Ltd. Representative Patent attorney Taira 1) Tadao Figure 1 b Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A plurality of laser beams each modulated according to a plurality of color image signals are irradiated and exposed to the corresponding photoreceptors, and a color image is reproduced based on the electrostatic latent image formed by this exposure. In a color image output device, a single deflection mirror means for receiving the plurality of laser beams and reflecting the plurality of laser scanning beams in a predetermined direction; and a plurality of laser beams reflected by the single deflection mirror means. A color image output device comprising a light guiding means for guiding scanning light to the corresponding photoreceptor without mutual interference. (2) The single deflection mirror means is constituted by a plate-shaped mirror having reflective surfaces on both sides, and the plurality of laser beams are incident from opposite directions and reflected in other opposite directions by the both surfaces. A color image output device according to scope 1. (3) The color image output device according to claim 1, wherein the single deflection mirror means makes the plurality of laser beams incident on a common deflection mirror surface and reflects them in the same direction.