JPH0361965A - Color image forming method - Google Patents

Abstract

PURPOSE:To eliminate the need of an useless toner image forming stage and to shorten a time for forming a color image by carrying out only a color toner image forming stage corresponding to a color flag set and used out of the color toner image forming stages. CONSTITUTION:For instance, the image data of yellow, magenta, cyan and black is transferred to a printer controller 50 from a host computer 60. The printer controller 50 transfers each flag to a main body control system 55 from a frame memory used. The flag of color used is set to the main body control system 55. Then, only the color toner image forming stage corresponding to the flag of the color used is set and carried out among the color toner image forming stages. Thus, an useless toner image forming stage is not carried out, so that a time for forming a color image is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a color image forming method in which a color toner image is formed by sequentially forming toner images of a plurality of colors on a photoreceptor.

[Background of the Invention] Conventionally, color printers have been proposed that sequentially form toner images of a plurality of colors on a photoreceptor to form a color toner image. FIG. 4 shows an example.

In the figure, 1 is a photoreceptor having a photoconductive layer provided on a conductive substrate. Further, 21 is a corona charger, 26 is an image exposure device, L is image exposure irradiated from the image exposure device 26, and AS
31 is a fixing device, 32 is a pre-transfer exposure lamp, 33 is a transfer electrode, 34 is a separation electrode, P is a transfer paper, and 35 is a cleaning device. This is a static elimination electrode for use.

Further, 36 is a cleaning Ha, which includes a cleaning blade 36a1, a bias roller 36b, and a cleaning roller 36c.

The surface of the photoreceptor 1 is uniformly charged by a corona charger 21. Next, image exposure according to the yellow image data is applied from the image exposure device 26 onto the photoreceptor 1.
A latent image is formed thereon. This latent image is developed by a developing device A having yellow toner. As a result, a yellow toner image is formed on the photoreceptor 1.

Further, the surface of the photoreceptor 1 on which the yellow toner image is formed is uniformly charged by the corona charger 21 . continue,
Image exposure according to magenta image data is emitted onto the photoreceptor 1 from the image exposure device 26, and a latent image is formed on the photoreceptor 1. This latent image is developed by a developing device B having magenta toner. As a result, a yellow toner image and a magenta toner image are formed on the photoreceptor 1 in an overlapping manner.

Thereafter, a cyan toner image and a black toner image are sequentially formed on the photoreceptor 1 in the same manner. As a result, the photoreceptor 1
A color toner image is formed thereon.

The color toner image thus formed is neutralized by the exposure lamp 32 to facilitate transfer, and then transferred to the transfer paper P by the transfer electrode 33. And transfer paper P
is separated from the photoreceptor 1 by the electrode 34 and fixed by the fixing device 31. At this time, the photoreceptor l is cleaned by the static elimination electrode 35 and the cleaning device 3G.

Note that such printer main body operation is performed by the main body control system 55.
Communication with the host computer 60 and transfer of image data are controlled by the printer controller 50.

Further, FIG. 5 shows the image exposure device 26 and the photoreceptor 1. As shown in FIG.

In the figure, 41 is a frame memory, and in this frame memory 41, yellow magenta, cyan, and black image data Y, M, C, and () are transferred from the host computer 60 and written for one screen each. ing.

In this case, the recording format is, for example, a packed pixel format (see Figure 6A) in which m image data Y, M, C, and K are stored together for each pixel.
Alternatively, there is a planar pixel format (see B in the same figure) in which image data Y, M, C, and K are stored in separate areas.

As described above, when the yellow toner image is being formed, the yellow image data Y is stored in the frame memory 41.
are sequentially read out and supplied to the laser drive circuit 42, and the semiconductor laser 37 is driven based on the yellow image data Y. The image exposure output from the semiconductor laser 37 is transmitted to a rotating polygon mirror 38 for deflection and f-θ for imaging.
Photoreceptor 1 uniformly charged in advance via lens 39
is irradiated. As a result, a latent image corresponding to the yellow image data Y is formed on the photoreceptor 1, and this is developed by the developing device tA to form a yellow toner image.

Furthermore, during the process of forming a magenta toner image, magenta image data M is sequentially read out from the frame memory 41 and supplied to the laser drive circuit 42, and the semiconductor laser 37 is driven based on the magenta image data M. . The image exposure output from the semiconductor laser 37 is transmitted to a rotating polygon mirror 38 for deflection and an f-theta lens 3 for imaging.
The photoreceptor l, which has been uniformly charged in advance, is irradiated via the photoreceptor 9. As a result, a latent image corresponding to the magenta image data M is formed on the photoreceptor 1, and this latent image is developed by the developing device B to form a magenta toner image.

Thereafter, the same operation is performed in the cyan toner image forming step and the black toner image forming step, and latent images corresponding to the cyan image data C and the black image data K are formed on the photoreceptor 1, respectively. , these are developing devices C and D
A cyan toner image and a black toner image are formed.

[Problems to be Solved by the Invention] By the way, according to the device that forms a color image in this way, even if there is no image data of a predetermined color in the frame memory 41, the toner image forming step of that color can be performed. .

Therefore, there is an inconvenience that it takes a long time to form a color image.

Therefore, in the present invention, it is possible to shorten the time for forming a color image by eliminating unnecessary steps.

[Means for Solving the Problems] The present invention provides toner image formation in which a photoreceptor is uniformly charged and then imagewise exposed according to image data to form a latent image, and this latent image is developed with color toner. This is a color image forming method in which the steps are repeated for each of a plurality of colors to form a color toner image on the photoreceptor.

It is provided with a memory for storing image data of each color, and a means for setting a used color flag during the writing of the above-mentioned image data of each color in this memory, and is inscribed in the used color flag set during the toner image forming process of each color. Only the step of forming a toner image of the corresponding color is performed.

[Function] In the above-described configuration, only the toner image forming process for the color for which image data exists is performed, so no wasted toner image forming process is performed, and the time for color image formation can be shortened. Become.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In this example, yellow magenta, cyan, and black image data Y, MSC, and K are transferred from the computer 60 to the printer controller 50, for example. The printer controller 50 sends flags YFLG and M to the main body control system 55 depending on the frame memory used.
Transfer FLG, CFLG and KFLG (see Figure 1). The main body control system δ5 has color flags (mode color flags) MDCLYS MDCLM, MDC
LC and MDCLK are set. FIG. 2 is a flowchart when the use color flag is set in the main body control system 55 in this manner.

In the same figure, in step 71, it is determined whether or not the flag YFLG is supplied, and when it is supplied,
In step 72, the used color flag MDCLY is set, and then the process proceeds to step 73.

Even when the flag YFLG is not supplied in step 71, the process proceeds to step 73. In this step 73, it is determined whether or not the flag MFLG is supplied, and when it is supplied, in step 74, the used color flag MDC is determined.
After LM is set, the process proceeds to step 75.

In step 73, even when the flag MFLG is not supplied, the process proceeds to step 75. In this step 75, it is determined whether or not the flag CFLG is supplied, and if it is supplied, in step 76, the used color flag MDC is determined.
After LC is set, it is supplied to step 77.

In step 75, even if the flag CFLG is not supplied, the process proceeds to step 77. In this step 77, it is determined whether or not the flag KFLG is supplied, and if so, in step 78, the used color flag MDC is determined.
The process ends after LK is set.

In step 77, the process also ends when the flag KFLG is not supplied.

In addition, the use color flags MDCLY, MDCLM, MDCLC and MD set in the main body control system 55 in this way
Based on CLK, the color toner image forming process in the printer is controlled according to the flowchart shown in FIG.

In the same figure, in step 81, the used color flag MDCL
It is determined whether or not Y is set, and if it is set, the write color flag C0LO is set in step 82.
After RY is set, a writing process for forming a yellow toner image is performed in step 83, and further, in step 84, the writing color flag C0LORY is reset, and then the process proceeds to step 85.

Even if it is not set in step 81, the process proceeds to step 85. In this step 85, the used color flag MDC
It is determined whether or not LM is set, and if it is set, the write color flag COL is set in step 86.
After the ORM is set, a write process for forming a magenta toner image is performed in step 87, and after the write color flag COLORM is reset in step 188, the process proceeds to step 89.

Even if it is not set in step 8δ, the process proceeds to step 89. In this step 89, the used color flag MDC
It is determined whether or not LC is set, and if it is set, the writing color flag C0L is set in step 90.
After ORC is set, a writing process for forming a cyan toner image is performed in step 91, and further, in step 92, the writing color flag C0LORC is reset, and then the process proceeds to step 93.

Even if it is not set in step 89, the process proceeds to step 93. In this step 93, the use flag MDC
It is determined whether or not LK is set, and if it is set, the writing color flag C0 is set in the Stella 5b 94.
After LORK is set, a writing process for forming a black toner image is performed in step 95, and further, in step 96, the writing color flag C0LORK is reset, and then the process proceeds to step 97.

Even if it is not set in step 93, the process proceeds to step 97. In step 97, it is determined whether or not color toner images are to be formed continuously. If not, the process ends, and if it is to be formed, the process returns to step 81.

As described above, according to this example, the use color flag corresponding to a color for which there is no image data is not set in the main body control system 55, and the toner image forming process for that color is not performed.
Time can be used effectively, and the time required to form a color image can be shortened.

1. In the above-mentioned embodiments, a case is shown in which there is a step of forming a black toner image, but the present invention can be similarly applied to a case in which only a step of forming a yellow, magenta, and cyan toner image is provided.

Furthermore, in the above embodiment, the image data Y, MSC, and K are transferred from the host computer 60 and written into the frame memory 41, but the image data is supplied from the Ike's device and written into the frame memory 41. Even if there is, the same effect can be obtained by setting the used color flag depending on the presence or absence of image data and arranging the operation in the same way.

[Effects of the Invention] As explained above, according to the present invention, only the toner image forming step of the color for which image data exists is performed.
A wasteful toner image forming process is not performed, and the time for color image formation can be shortened.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining one embodiment of the present invention, FIG. 4 is a configuration diagram of a color printer, FIG. 5 is a configuration diagram of an image exposure device, and FIG. 6 is a recording of frame memory. FIG. 3 is a diagram showing a format. 1...Photoreceptor 21...Corona charger 26...Image exposure device 31...Fixer 32...Pre-transfer exposure lamp 33...Transfer electrode 34...Separated i4 pole 35...・Cleaning static elimination electrode 36...Cleaning device 37...◆Semiconductor laser 3 days...Rotating polygon mirror 39・--f-θ lens 41・◆◆Frame memory 42...Laser drive circuit δO・◆・Printer controller 55...Main control system 60...◆Host computers A to D...Developing device P...Transfer paper L...Configuration diagram of image exposure color printer Fig. 1 Color flag used cent 2 Figure 5 Recording format Figure 6

Claims (1)

[Claims] (1) The toner image forming process of uniformly charging the photoreceptor, exposing it to image data according to the image data to form a latent image, and developing this latent image with color toner is repeated for each of multiple colors. A color image forming method in which a color toner image is formed on the photoreceptor by means of a memory for storing image data of each color, and means for setting a used color flag when writing image data of each color to the memory. A color image forming method, comprising performing only the toner image forming step of the color corresponding to the set use color flag among the toner image forming steps of each color.