JP2003276236A - Color imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speed up imaging during an imaging time in one black color by a constitution of one laser and one polygon of a color imaging apparatus. <P>SOLUTION: In one polygon, a miller index is set to be 6 faces, three miller faces are set for black, and one face is set for each of the other colors. Speeding up by three times is thus enabled at the imaging time in one black color. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming technique, and in particular, it is applied to a technique for printing a plurality of colors on a paper medium or the like through a photoconductor such as a color image forming apparatus or a laser beam copying machine. And about effective technology.

[0002]

2. Description of the Related Art As a conventional reference technique, a tandem type color image forming apparatus having a plurality of scanning optical system units is known. In this color image forming apparatus, a plurality of scanning optical system units having a configuration in which a plurality of polygon mirrors are arranged on the emission optical paths of a plurality of semiconductor lasers and a plurality of lenses and reflection mirrors are respectively arranged on the reflection optical paths are provided. A plurality of photosensitive drums are arranged on the outgoing optical paths of the plurality of sets of scanning optical system units. Then, the information of each color of yellow, magenta, cyan, and black is written as an electrostatic latent image on the plurality of photoconductor drums by the laser beam emitted from each scanning optical system unit. Then, the visible image obtained by developing the electrostatic latent image corresponding to each primary color on each photoconductor drum is transferred onto the paper by superimposing each color, and the image on the paper is fixed by the fixing device. It is fixed by and becomes a color print.

As another conventional technique, Japanese Unexamined Patent Publication No. H11-11
-218991 and Japanese Patent Laid-Open No. 2000-2846 disclose a low-cost color image forming apparatus that writes electrostatic latent images on a plurality of photosensitive drums by one semiconductor laser and one polygon mirror. Has been done.

In this disclosed technique, one semiconductor laser is used to write electrostatic latent images on a plurality of photosensitive drums, so that the reflecting surface of one polygon mirror has several reflection angles. There is. Since the type of the reflection angle of each reflection surface corresponds to the number of photoconductor drums, there are yellow (Y), magenta (M), cyan (C), and black (Bk) used in general color image formation. When writing four colors as an electrostatic latent image, the number of reflecting surfaces of the polygon mirror is required to be four. Normally, the number of reflecting surfaces of the polygon mirror is set to four or a multiple of four, and latent images of respective colors are sequentially formed. It is done.

[0005]

However, in the four-sided polygon mirror having the above-mentioned structure, since it is assumed that a color image is formed in which four colors of latent images are formed, efficient latent image formation can be performed in a color image. , Bk for developing only one color, in the case of a four-sided polygon mirror, the latent image forming efficiency is reduced to 1/4 because the latent image is formed on only one of the four surfaces. Even if only latent images are formed, it takes the same time as that for four colors. This reduction in latent image forming efficiency is the same even when the polygon mirror is configured to have a multiple surface of 4.

In other words, if the application is mainly for Bk1 color image formation and occasionally for color image formation, B
To cope with the increase in the image forming speed for k1 color,
There has been a technical problem such as a cost increase and an increase in the size of the apparatus because it is necessary to provide means for complicating the control by changing the rotation speed of the polygon mirror and unnecessarily increasing the number of mirror surfaces.

The present invention has been made to solve such a problem, and its technical problem is to keep the number of revolutions of a polygon mirror constant and prevent inefficient multifaceted mirror surfaces. An object of the present invention is to provide a color image forming apparatus which can be downsized and improved in reliability.

[0008]

According to the present invention, in a tandem type color image forming apparatus having four developing units, the number of mirror surfaces is a multiple of 6 so that every two surfaces have the same angle. The three mirror surfaces with different angles are placed between the mirror surface and the mirror surface configured so that every other surface has the same angle, and the mirror surface is a multiple of 6 and the four mirror surfaces with different angles are provided. To place.

Irradiating data for one color corresponding to a polygon mirror and one mirror surface angle of the polygon mirror 1
A color image forming apparatus having one laser unit having two laser diodes is obtained.

According to the present invention, in the color image forming apparatus, the image laser beam of a specific color emitted from the laser diode is emitted to the surface of the polygon mirror inclined by a predetermined degree and deflected. It is possible to obtain a color image forming apparatus provided with three types of folding mirrors for changing the optical paths for scanning on the photosensitive drums for the dedicated colors of the respective types, respectively.

Further, according to the present invention, in the color image forming apparatus, between a mirror surface configured to have the same angle every two surfaces and a mirror surface configured to have the same angle every two surfaces. Arrange 3 types of mirror surfaces with different angles, and arrange 4 types of mirror surfaces with different angles on the mirror surface of multiples of 6.

Color data correspondence of each mirror surface angle is represented by Bk,
By arranging in order of Y, Bk, C, Bk, M, etc. on the mirror surface of a multiple of 6, it is possible to form a latent image of only four colors and one Bk color.

For example, one rotation of a polygon mirror having six mirror surfaces makes it possible to form a latent image of 3 lines of Bk, 1 line of each color of Y, C, and M, while forming a latent image of 2 faces of Bk. By stopping the process, it is possible to unify the latent image formation with one line for each of the four colors. When a latent image of one color of Bk is formed, Bk
Since the latent image is formed by using the corresponding three mirror surfaces, the latent image can be formed three times as much as the color image, and the image forming speed of the apparatus can be tripled without changing the rotation control of the polygon mirror. be able to.

Further, according to the present invention, it is possible to obtain a color image forming apparatus which is most suitable for the purpose of forming a color image from time to time, centering on the Bk1 color image formation.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side sectional view showing a basic structure of a color image forming apparatus according to an embodiment of the present invention. This color laser printer is also a tandem type printer having four developing units for printing four colors of yellow (Y), magenta (M), cyan (C), and black (Bk). Drum cleaner 15
Photosensitive drums 11 (Y), 11 (M), 11 to which (Y), 15 (M), 15 (C), 15 (Bk) are attached
(C), a developing device including 11 (Bk), a mirror surface configured to have the same angle every two surfaces by making the number of mirror surfaces a multiple of 6 (usually six surfaces), and the same every other surface. Three kinds of mirror surfaces with different angles are arranged between the mirror surfaces configured to have an angle, and four kinds with different angles (Y degree, M degree, C degree, Bk degree) are provided on the mirror surface that is a multiple of 6. A laser unit 1 having a polygon mirror (not shown) tilted at an angle and a laser diode for irradiating a laser beam for a four-color image, and a laser beam emitted from the laser unit 1 for the photosensitive drums 11 (Y), 11 (M), respectively. 11 (C), 11
First folding mirrors 5 (Y), 5 (M), 5 (C), 5 for folding back on (Bk) to form an electrostatic image
(Bk) and the second folding mirror 6 (Y), 6
(M), 6 (C), 6 (Bk) and the third folding mirrors 7 (Y), 7 (M), 7 (C), 7 (Bk), and the photosensitive drum 11 ( Y), 11
Developing units 10 (Y), 10 (M), 10 for forming toner images on (M), 11 (C), 11 (Bk)
(C) and 10 (Bk).

In this color laser printer, the drive roller 18, the first driven roller 19, and the second driven roller 2 for feeding and conveying the paper 23 from the paper feeding unit.
0, a third driven roller 21, a paper feed roller 24, and a transport roller 25, and a photosensitive drum 11 (Y), 11 (M), 11 for transporting the paper 23.
(C) and 11 (Bk), the transfer belt 16 is provided with a transfer belt cleaner 22 for sequentially superposing the monochromatic toner images on the paper 23 to form one toner image, and the transfer belt 16 is transferred. A fixing unit 26 that fixes the toner image on the sheet 23 by heat and pressure, a discharge unit that discharges the fixed sheet 23 to the outside of the apparatus, a discharge tray that stacks the discharged sheet 23, and the like. To be done.

Of these, the photosensitive drums 11 (Y), 11
Main chargers 14 (Y), 14 (M), 14 (C), 14 are provided near (M), 11 (C), 11 (Bk).
(Bk) is provided, and transfer devices 17 (Y), 17 (M), 17 (C), 17 (B
k) is provided, and the photosensitive drums 11 (Y), 11 are provided.
(M), 11 (C), 11 (Bk) are the developing roller 12
(Y), 12 (M), 12 (C), 12 (Bk) are contacted and toner supply rollers 13 (Y), 13 (M), 13
(C), 13 (Bk) and developing rollers 12 (Y), 12
(M), 12 (C), and 12 (BK) are interlocked to rotate.

That is, in this color laser printer,
In one laser diode, the number of mirror surfaces is set to be a multiple of 6 so that every other mirror surface has the same angle, and every two mirror surfaces has the same angle. Place 3 different types of mirror surfaces, 6
It is configured by one laser unit 1 which irradiates data for one color corresponding to one surface angle of a polygon mirror in which four different mirror angles are tilted on multiple mirror surfaces.

FIG. 2 is a perspective view showing a simplified configuration of the main parts of this color laser printer. Here, the number of mirror surfaces is a multiple of 6 (usually 6 surfaces) between mirror surfaces configured to have the same angle every other surface, and between mirror surfaces configured to have the same angle every two surfaces. In the polygon mirror 2 in which three types of mirror surfaces with different angles are arranged in the polygon mirror 2 which are inclined to four types (Y degree, M degree, C degree, Bk degree) with different angles on the mirror surface of a multiple of 6, the laser diode ( LD)
The image laser beams of four colors emitted from 3 are controlled so as to be emitted respectively to the surfaces of the polygon mirror 2 which are inclined by a predetermined degree, and are deflected by these surfaces, and the lenses 4 (Y),
After passing through 4 (M), 4 (C), 4 (Bk), the first folding mirrors 5 (Y), 5 (M), 5 (C), 5 (B
k) and the second folding mirror 6 (Y), 6 (M), 6
(C), 6 (Bk) and the third folding mirror 7 (Y),
7 (M), 7 (C), and 7 (Bk) change the optical paths, and then the photosensitive drums 11 (Y), 11 for dedicated colors are used.
It shows a state of scanning along (M), 11 (C), and 11 (Bk) along the arrow direction.

In other words, the image laser beam of the specific color emitted from the laser diode 3 is applied to the surface of the polygon mirror 2 which is inclined by a predetermined degree and deflected. (Y), 11 (M), 11
(C), 11 (Bk) In the three types of folding mirrors that change the optical path for scanning, the first folding mirrors 5 (Y), 5 (M), 5 (C), and 5 (Bk) deflect the light. The reflected beam is reflected and the second folding mirror 6 (Y),
6 (M), 6 (C), 6 (Bk) re-reflects the reflected beam, and the third folding mirrors 7 (Y), 7
In (M), 7 (C), and 7 (Bk), the beams re-reflected are used for the dedicated color photosensitive drums 11 (Y), 11 (M), 11
Scan on (C) and 11 (Bk).

A color image forming method according to an embodiment of the present invention will be described below. This is an example of a technique using a six-sided polygon mirror having different numbers of faces for four colors.

For example, when irradiating a yellow (Y) image laser beam, the surface of the polygon mirror 2 is Y every 6 sheets.
Since it is a tilted surface, the laser diode 3 transfers the yellow (Y) image data to the lens 4 as shown in FIG.
It is controlled to irradiate every 6th surface of the polygon mirror 2 through (Y), and the irradiated laser beam is controlled by the Y-degree inclined surface of the polygon mirror 2 rotating in the direction shown in the figure. Deflection and first folding mirror 5
(Y), the second folding mirror 6 (Y), and the third folding mirror 7 (Y) change their optical paths, and the photosensitive drum 11 (Y) is scanned in the direction of the arrow to sequentially form electrostatic images. Form. The formed electrostatic image is the developing roller 12
The yellow toner is attached by (Y) to form a yellow toner image.

The yellow toner image on the photosensitive drum 11 (Y) is first fed from the paper feed unit by the paper feed roller 24, and the position of the paper 23 and the position of the toner image are controlled by the conveyance roller 25. The image is transferred onto the sheet 23 conveyed by the transfer belt 16 rotating in the direction of by the transfer belt 17 (Y) provided below the transfer belt 16.

Next, as shown in FIG. 3B, image data of magenta (M) from the laser diode 3 is formed on the lens on the M-degree inclined surface adjacent to the Bk-degree inclined surface adjacent to the polygon mirror Y-degree inclined surface. When irradiated through 4 (M), the irradiated laser beam is deflected by the M-degree inclined surface of the polygon mirror 2 rotating in the direction shown, and the first folding mirror 5 (M) and the second folding mirror 5 (M) The optical path is changed by the mirror 6 (M) and the third folding mirror 7 (M), and the photosensitive drum 11 (M) is scanned in the arrow direction to sequentially form an electrostatic image.

As in the case described above, the polygon mirror 2 has M-degree inclined surfaces every 6 sheets, so that the laser diode 3
Irradiates magenta (M) image data every six mirrors to sequentially form an electrostatic image on the photosensitive drum 11 (M). Magenta toner is attached to the formed electrostatic image by the developing roller 12 (M) to form a magenta toner image.

The writing timing of the laser diode 3 is controlled so that the magenta toner image on the photosensitive drum 11 (M) is superposed on the yellow toner image on the transfer belt 16 on the transfer belt 16. It is superposed on the yellow toner screen on the paper 23 which has been transferred to.

Further, as shown in FIG. 3C, the image data of cyan (C) is transferred from the laser diode 3 to the lens 4 on the C-degree inclined surface adjacent to the Bk-degree inclined surface adjacent to the M-degree inclined surface.
When irradiated through (C), a cyan toner image is formed on the photosensitive drum 11 (C), and the cyan toner image is superimposed on the yellow image and the magenta toner image on the paper 23 conveyed to the transfer belt 16. .

Subsequently, as shown in FIG. 3D, image data of black (Bk) from the laser diode 3 is transferred from the laser diode 3 to the lens 4 (on the Bk-degree inclined surface adjacent to each of the polygon mirror Y, M, and C-degree inclined surfaces. When irradiated through Bk), the irradiated laser beam is deflected by the Bk-degree inclined surface of the polygon mirror 2 rotating in the direction shown, and the first folding mirror 5 (Bk) and the second folding mirror 6 (B
k) and the third folding mirror 7 (Bk) change its optical path, and the photosensitive drum 11 (Bk) is scanned in the direction of the arrow to sequentially form an electrostatic image.

In the case of this black, the surface of the polygon mirror 2 is inclined every Bk degrees, so that the laser diode 3 irradiates black (Bk) image data every two mirrors three times as much as other colors. This is possible, but this time, in order to match with the latent image creation speed of other colors, image data is irradiated to one surface of the Bk-degree inclined surface, and the remaining two surfaces are not irradiated (at the time of normal 6 surfaces). Then, electrostatic images are sequentially formed on the photosensitive drum 11 (Bk). The formed electrostatic image is the developing roller 1.
Black toner is attached by 2 (Bk) to form a black toner image.

When writing the image data of four colors by the laser diode 3 when writing the image data of four colors, one predetermined inclined surface of the polygon mirror 2 is adjusted according to the timing of the BD signal obtained by the reference clock. Data of a specific color with yellow (Y) data →
Stop (original Bk) → magenta (M) data → stop (original Bk) → cyan (C) data → black (Bk) data → yellow (Y) data → stop (original Bk) → magenta (M) data → ... The inclined surface of the selected color is irradiated by controlling the condition in sequence.

The paper 23 on which the four colors are superimposed is fixed by heat and pressure applied by the fixing unit 26. The fixed paper 23 is discharged to the outside of the apparatus and stacked on the paper discharge tray.

A black monochromatic image forming method according to an embodiment, which is a feature of the present invention, will be described below.

As shown in FIG. 3D, image data of black (Bk) from the laser diode 3 is transferred to the lens 4 (Bk) from the laser diode 3 on the Bk-degree inclined surface adjacent to each of the polygon mirror Y, M, and C-degree inclined surfaces. When the laser beam is radiated through, the radiated laser beam is deflected by the Bk-degree inclined surface of the polygon mirror 2 rotating in the illustrated direction, and the first folding mirror 5 (Bk) and the second folding mirror 6 (Bk ), And the third folding mirror 7 (Bk) changes its optical path, and the photosensitive drum 11 (Bk) is scanned in the direction of the arrow to sequentially form an electrostatic image.

In the case of this black, the surface of the polygon mirror 2 is a Bk-degree inclined surface every two sheets, so that the laser diode 3 irradiates black (Bk) image data every two mirrors three times as much as other colors. Therefore, the laser diode 3 controls so that the image data of black (Bk) is sequentially irradiated to all the inclined surfaces of Bk degree, and the photosensitive drum 11 (B
k) sequentially form an electrostatic image on top.

The formed electrostatic image is applied to the developing roller 12 (B
The black toner is attached by k) to form a black toner image.

When writing image data of one color by the laser diode 3 when writing such image data of black monochromatic color, according to the timing of the BD signal obtained by the reference clock, with respect to one predetermined inclined surface of the polygon mirror 2. Stop the data of a specific color (Y originally)
→ black (Bk) data → stop (original M) → black (Bk) data → stop (original C) → black (Bk) data → stop (original Y) → black (Bk) data → stop (original M) → ... That is, the black and white inclined surfaces are irradiated by sequentially controlling them.

Paper 23 on which one black color image is formed
Is fixed by applying heat and pressure by the fixing unit 26. The fixed paper 23 is discharged to the outside of the device,
Stacked in the output tray.

That is, the latent image forming speed is three times as high as that in the color image forming. It is possible to increase the image forming speed for one black color of the apparatus.

[0040]

According to the present invention, the Bk1 color image formation is mainly used and the color image formation is sometimes performed.
When an image of one black color is formed, the speed can be increased and an optimum color image forming apparatus can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a basic configuration of a color laser printer according to an embodiment of the present invention.

2 is a perspective view showing a simplified configuration of a main part of the color laser printer shown in FIG.

FIG. 3 is a perspective view showing a detailed state of a laser unit included in the main part shown in FIG. 2, and relates to a case of irradiating an inclined surface of each color.

[Explanation of symbols]

1 Laser Unit 2 Polygon Mirror 3 Laser Diode (LD) 4 (Y), 4 (M), 4 (C), 4 (Bk) Lens 5 (Y), 5 (M), 5 (C), 5 (Bk) ) First folding mirror 6 (Y), 6 (M), 6 (C), 6 (Bk) Second folding mirror 7 (Y), 7 (M), 7 (C), 7 (Bk) Three folding mirrors 10 (Y), 10 (M), 10 (C), 10 (Bk)
Developing units 11 (Y), 11 (M), 11 (C), 11 (Bk)
Photosensitive drums 12 (Y), 12 (M), 12 (C), 12 (Bk)
Developing rollers 13 (Y), 13 (M), 13 (C), 13 (Bk)
Toner supply rollers 14 (Y), 14 (M), 14 (C), 14 (Bk)
Main charger 15 (Y), 15 (M), 15 (C), 15 (Bk)
Photosensitive drum cleaner 16 Transfer belts 17 (Y), 17 (M), 17 (C), 17 (Bk)
Transfer device 18 Drive roller 19 First driven roller 20 Second driven roller 21 Third driven roller 22 Transfer belt cleaner 23 Paper 24 Paper feeding roller 25 Conveying roller 26 Fixing unit

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/04 111 H04N 1/036 Z 5C072 H04N 1/036 B41J 3/00 D 1/113 H04N 1/04 104A (72 ) Inventor Nobuo Nakazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masafumi Fukuda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Akashi Wasei 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Co., Ltd. (reference) 2C362 AA03 AA10 BA05 BA50 BA51 BA53 CA18 CA39 CB64 2H045 AA04 BA26 BA34 CA63 DA02 2H076 AB05 AB08 AB12 AB18 AB22 EA01 2H300 EA11 EB04 EB04 ED11 ED13 EF02 EF06 EF13 EG03 EH16 EH36 EJ09 EJ48 EK03 EL07 FF02 FF08 GG02 GG31 HH19 HH32 HH40 QQ10 QQ32 RR17 RR50 5C051 AA02 CA07 DB24 DB30 DC07 EA01 5C072 AA03 DA06 DA02 DA04 DA02 DA04 DA02 DA04 DA04 DA04

Claims (4)

[Claims] 1. In a tandem color image forming apparatus having four developing units, the number of mirror surfaces is a multiple of 6 and the mirror surface has the same angle every two surfaces, and the mirror surface has the same angle every two surfaces. A total of 4 mirror surfaces are arranged between the mirror surfaces, each of which has three different angles from the aforementioned mirror surface.
One laser unit having a polygon mirror having mirror surfaces inclined at various angles and one semiconductor laser for irradiating data for one color corresponding to the mirror surfaces inclined at four angles of the polygon mirror are provided. A color image forming apparatus characterized by being provided. 2. The color image forming apparatus according to claim 1, wherein when forming a color image, the semiconductor laser irradiates or stops irradiation of black data on mirror surfaces having the same angle every two surfaces of the polygon mirror. Do it periodically
A color image forming apparatus characterized in that color data other than black is applied to three mirror surfaces having different angles from the mirror surfaces between the mirror surfaces having the same angle every two surfaces. 3. The color image forming apparatus according to claim 1, wherein when forming a black monochromatic image, the semiconductor laser irradiates black data on mirror surfaces having the same angle every two surfaces of the polygon mirror. A color image forming apparatus, characterized in that, between two mirror surfaces having the same angle every two surfaces, irradiation of color data is stopped on three mirror surfaces having different angles from the mirror surfaces. 4. The color image forming apparatus according to claim 3, wherein the semiconductor laser is the polygon mirror.
A color image forming apparatus, characterized in that mirror data having the same angle every other surface is irradiated with black data to accelerate an image forming speed of the developing unit.