JPH04326372A - Color image electrophotographic device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image electrophotographic apparatus, and more particularly to image data development and printing control for a color printer.

0002

2. Description of the Related Art Electrophotographic devices, typified by copying machines, are widely used. Further, by applying this electrophotographic technology, optical printers that use a laser scanning optical system, an LCD optical system, or the like as an exposure means in a printing process execution means are rapidly becoming popular.

On the other hand, color image electrophotographic devices also apply the technology of copying machines and optical printers, and use yellow (Y) toner, magenta (M) toner, and cyan (C) toner in the developing means in the printing process execution means. Color copying machines and color printers are beginning to become popular, using developing systems of black (K) toner and black (K) toner (K toner may not be used in some cases).

[0004] The difference between a copying machine and a printer lies in the information source to be printed. That is, in the case of a copying machine, the information source to be printed is a document, and in the case of a printer, the information source to be printed is print data created by a personal computer, workstation, or word processor. Looking at it from a different perspective, the difference between copiers and printers also lies in the way they are used. Copiers are in stand-alone form and printers are in remote control form.

[0005]

[Problems to be Solved by the Invention] Impact printers, which are generally called printers, develop print data into image data and execute actual printing in parallel.
If development into image data is delayed, actual printing is interrupted. However, an optical printer that applies electrophotographic technology cannot interrupt the actual printing process once it starts the printing process and starts actual printing. Therefore, in the optical printer, the printing process by the printing process execution means is started after completing a development process in which print data corresponding to one page is developed into image data. For this reason, optical printers are also called page printers. Once an optical printer starts the printing process, the time it takes to finish printing is very short compared to general printers, but the problem is that the overall printing time does not feel short due to the time required for the development process. Ta. Therefore, by preparing memory for several pages of image data and processing the development process of the next page of the target page in parallel while the printing process of the target page is being executed, the overall printing time can be shortened. However, in this case, a new problem arises in that it requires a large memory capacity and becomes expensive.

On the other hand, in color copying machines and color printers, it is important to perform control so that the positions of the toner images created by each developing system are accurately aligned. That is, information for each toner color from an information source to be printed must be input according to timing determined in the printing process for each toner color. Since the color copying machine is a stand-alone type and the information source is a document, the input timing of information for each toner color can be controlled by the color copying machine itself. However, since color printers are remote controlled and the information source is print data, the process of developing print data for each toner color into image data for each toner color is completed in advance. Each printing process must be started. Therefore, in the case of color printers, as in the case of optical printers mentioned above, the problem of longer overall printing time and
Creating one page of color images requires a total of more than three pages of memory for image data for each toner color.
The problem arises that the memory capacity becomes large and the price becomes high.

An object of the present invention is to provide a color image electrophotographic apparatus for a color printer that employs a control method suitable for color image creation.

[0008]

[Means for Solving the Problems] The present invention provides a development control means for developing color information into image data for each toner color, and printing and recording for each toner color in accordance with image data for each toner color. In a color image electrophotographic apparatus including a printing means for printing on a medium, the development control means develops image data of the next target toner color while the printing unit is printing the target toner color. Furthermore, the image data development status of the next target toner color is notified to the printing means, and the printing unit manages and controls the optimum printing time of the next target toner color while judging the development status. It is characterized by

[0009]

[Operation] While the printing process of the target toner color is being executed, the development process of the image data of the toner color next to the target toner color is performed in parallel, so that the overall printing time can be shortened. In addition, to create a color image for one page, it is sufficient to prepare memory for two pages for image data for each toner color, so it is possible to provide an inexpensive color image electrophotographic device without increasing the memory capacity. .

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of a multiple development type color printer according to the present invention, FIG. 2 is a block diagram of the main parts, and FIGS. 3 and 4 are operation timing charts of the main parts.

First, the overall configuration of a color printer is shown in FIG.
This is explained by:

The color printer 1 receives print data from a host 2 such as a personal computer, workstation, or word processor, and prints image data for each toner color (Y-based toner, M-based toner, C-based toner, K toner). It is comprised of a development control section 100 that develops the image data, and a printing section 200 that prints the image data on a recording medium.

The deployment control unit 100 includes a CPU 101 and a ROM 1 that stores a control program for the CPU 101.
02 and a RAM 103 as a work memory required during execution of the control program. Print data from the host 2 is stored in the print data storage memory 104. The print data is composed of various data such as coded character data, vectorized graphic data, and bitized pixel data. This print data is processed by the CPU according to the type of each data.
101, ROM 102, and RAM 103, the data is developed on bitmap memory 105 as image data for each toner color. The image data for each toner color is transferred to the input/output interface 206 of the printing unit 200 via the input/output interface 106 according to image data transfer control timing, which will be described later.

Next, the printing section 200 will be explained.

[0015] The printing unit 200 includes a CPU 201 and a CPU 201.
ROM202 that stores the control program of U201
The core of the control program is a RAM 203, which serves as a work memory required during the execution of the control program. In addition, the input/output interface 10 of the deployment control unit 100
The control signal group from 6 to the image data synchronization control unit 204 and C
It is provided with an input/output interface 206 for transmitting information to the PU 201, and further provided with a mechanism control unit 205 that controls the timing of a group of printing process execution mechanisms that execute the printing process and perform actual printing.

Next, the operation of the mechanism group that executes the printing process and performs actual printing will be explained. The photoreceptor 211 is a static eliminator 2
12 neutralizes the electric charge on the surface, and then a charger 213 uniformly charges the surface. Exposure beam 2 controlled by yellow (Y) image data during the first rotation
14, a latent image is formed, and yellow (
Y) Activate the developing device 215 to form a yellow (Y) toner image. Next, in the second rotation, a latent image is formed by the exposure beam 214 controlled by the image data for magenta (M), and a magenta (M) developer 216 is applied to the latent image.
to form a magenta (M) toner image. Next, in the third rotation, a latent image is formed using the exposure beam 214 controlled by the image data for cyan (C), and the cyan (C) developing device 217 is caused to act on the latent image to form a cyan (C) image.
C) Form a toner image, and finally, black (K) in the fourth rotation.
A latent image is formed by the exposure beam 214 controlled by the image data for the image, and a black (K) developer 218 is applied to the latent image.
to form a black (K) toner image.

Through the process described above, toner images of four colors are developed multiple times on the photoreceptor 211. Next, the recording medium is conveyed via the medium conveyance path 219 in synchronization with the position of the four-color toner image. When the recording medium is in contact with the photoreceptor 211, the transfer device 220 applies transfer charges to transfer the four-color toner image onto the recording medium. After that, the fixing device
A color image print is completed by fixing the color toner image onto a recording medium. Note that the residual toner on the photoreceptor 211 after the four-color toner image has been transferred to the recording medium is removed by the cleaner 221, which has been inactive up to this point.

Next, the image data transfer control timing will be explained with reference to FIGS. 2 and 3.

First, the CPU 101 sends a print data generation enable signal 25 when the development of the Y image data is completed.
2 and simultaneously generate a print request signal 251,
A print request is made to the CPU 201.

Next, the CPU 201 rotates the photoreceptor 211 so that the reference position of the photoreceptor 211 is aligned with the reference position sensor 2.
22 and waits for the input of the reference position signal 223 which is generated when passing the point 22. The reference position signal 223 is also input to the image data synchronization control section 204. First reference position signal 22
3 is input, the CPU 201 inputs the vertical synchronization generation permission signal 224 to the image data synchronization control unit 204 after confirming that the print request signal 251 and the print data generation enable signal 252 have been issued. Image data synchronization control section 2
The printing area signal counting circuit 226 of 04 receives the reference position signal 2.
After a certain period of time (Tm) from the occurrence of 23, a print area signal 225 with a time width corresponding to the distance according to the conveyance direction of the recording medium is generated.
occurs. Tm is accurately counted using, as a clock source, a horizontal position signal 232 output from a horizontal position sensor 231 when horizontal position reference light deflected by a rotating polygon mirror 230, which will be described later, is detected. The print area signal 225 and the vertical synchronization generation permission signal 224 are ANDed by an AND circuit 227 and issued as the first vertical synchronization signal 253.

The bitmap memory 105 to which the first vertical synchronization signal 253 is input synchronizes the timing and sequentially transfers the Y image data to the exposure control section 233 in accordance with the image data signal 254. The exposure control section 233 converts the image data signal 254 from an electrical signal to an optical signal, and outputs the exposure beam 214. The exposure beam 214 is deflected by a rotating polygon mirror 230 that is stably rotating at high speed, and exposes the photoreceptor 211 in the axial direction to create a latent image.

Meanwhile, at the same time, the first vertical synchronizing signal 25
3 is input, the CPU 101 stops the print data generation enable signal 252, develops the next M image data, and generates the print data generation enable signal 252 again when the development is completed.

The CPU 201 generates the vertical synchronization generation permission signal 224 according to the procedure described above. The bitmap memory 105 to which the second vertical synchronization signal 253 generated thereby is input synchronizes the timing and sequentially transfers the M image data to the exposure control unit 233 using the image data signal 254. In other words, the exposure beam 214 controlled by the Y image data and the M image data creates a latent image by exposing the photoreceptor 211 without positional deviation.

Through the same procedure, the image data for C and the image data for K are sequentially transferred to the exposure control unit 233 using the image data signal 254, and the exposure beam 214 based on all the image data is shifted on the photoreceptor 211. Create a latent image.

Incidentally, when the fourth vertical synchronization signal 253 is input, the CPU 101 stops the print request signal 251. The CPU 201 confirms that the print request signal 251 has stopped.
stops the vertical synchronization generation permission signal 224 and ends the series of operation processes.

Next, a case where it takes a long time to develop image data will be explained with reference to FIG.

The CPU 101 to which the first vertical synchronization signal 253 is input stops the print data generation enable signal 252 and develops the next M image data, but if the development time (Tdp) is long, , to which the second reference position signal 223 is input, the CPU 201 confirms that the print data generation enable signal 252 has not been issued, and stops the vertical synchronization generation enable signal 224. As a result, the generation of the vertical synchronizing signal 253 from the AND circuit 227 is prohibited. Then, the CPU 101 continues to develop the M image data, and when the development is completed, generates the print data generation enable signal 252 again. CPU2 to which the third reference position signal 223 is input
01 confirms that the print request signal 251 and the print data generation enable signal 252 have been issued, and then inputs the vertical synchronization generation permission signal 224 to the image data synchronization control unit 204 again. The bitmap memory 105 to which the second vertical synchronization signal 253 generated thereby is input synchronizes the timing and sequentially transfers the M image data to the exposure control unit 233 using the image data signal 254. Through the same procedure, C image data with a short Tpd and K image data with a long Tpd are sequentially transferred to the exposure control unit 233 by the image data signal 254.
Exposure beam 21 controlled by all image data
4 creates a latent image on the photoreceptor 211 without any displacement.

According to this embodiment, the printing process for each toner color is not started after the process of developing print data for each toner color into image data for each toner color is completed in advance. While the printing process for the target toner color is being executed, it is possible to perform the development process that develops the print data for the next toner color into image data in parallel, reducing the overall printing time. . In addition, to create a color image for one page, it is sufficient to prepare bitmap memory for two pages in total for image data for each toner color, so it is possible to provide an inexpensive color printer without increasing the memory capacity. .

[0029]

[Effects of the Invention] According to the present invention, while the printing process of the target toner color is being executed, the process of developing the target toner color into the image data of the next toner color can be performed in parallel, so that the overall Printing time can be shortened. In addition, to create a color image for one page, it is sufficient to prepare memory for two pages in total for image data for each toner color, thus providing an inexpensive color image electrophotographic device without increasing memory capacity. can.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of main parts of an embodiment of the present invention.

FIG. 3 is a timing chart of one embodiment of the present invention.

FIG. 4 is a timing chart of one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Color printer, 2...Host, 100...Development control unit, 101,201...CPU, 102,202...ROM,
103, 203... RAM, 104... Print data storage memory, 105... Bitmap memory, 106... Input/output interface, 200... Printing section, 204... Image data synchronization control section, 205... Mechanism control section, 206... Input/output interface , 211...Photoreceptor, 212...Static eliminator, 213
...Charger, 214...Exposure beam, 215...Yellow developer, 216...Magenta developer, 217...Cyan developer,
218...Black developing device, 219...Medium transport path, 220...Transfer device, 221...Cleaning device, 222...Reference position sensor, 223
...Reference position signal, 224...Vertical synchronization generation permission signal, 22
5... Print area signal, 226... Print area signal counting circuit, 2
27...AND circuit, 230...rotating polygon mirror, 231...horizontal position sensor, 232...horizontal position signal, 233...exposure control section, 251...print request signal, 252...print data generation enable signal, 253...vertical synchronization signal, 254 ...image data signal.

Claims (2)

[Claims] 1. A development control means for developing color information into image data for each toner color, and a mark for printing each toner color on a recording medium according to the image data for each toner color. In the color image electrophotographic apparatus, the color image electrophotographic apparatus is characterized in that, when the printing means is printing the target toner color, the development control means performs image data development of the next target toner color. A color image electrophotographic device. 2. A development control means for developing color information into image data for each toner color, and a mark for printing each toner color on a recording medium according to the image data for each toner color. In the color image electrophotographic apparatus, the development control means develops image data of the next target toner color when the printing unit is printing the target toner color, and further develops the image data of the next target toner color. The image data development status of the target toner color is notified to the printing means, and the printing unit manages and controls the optimum printing time of the next target toner color while determining the development status. Electrophotographic equipment.