JPS63166550A - Image forming device - Google Patents

Abstract

PURPOSE:To contrive higher image quality, by discriminating whether received data is a character code or image data, and storing the result of discrimination. CONSTITUTION:When received data is a character code, the character code is developed into a bit map, then a bit in a flag memory 4F corresponding to the position of the character is set to '1', and the code is stored into each of page memories 4Y, 4M, 4C for yellow (Y), magenta (M), cyan (C). When the received data is not a character code, the code is directly stored into each of the page memories 4Y, 4M, 4C. For example, in the case of a filtering process, the flag memory 4F is referenced, and only the bits corresponding to image data are smoothened, whereby a character part is reproduced in a sharp form, while a pattern part is reproduced in a smoothened form, and image quality is enhanced.

Description

[Detailed description of the invention] Ibarara disaster The present invention relates to an image forming apparatus.

In general, various image forming devices (hereinafter referred to as "printers") such as printing devices using electrophotographic processes such as laser printers, thermal printers, and inkjet printers are printers and intermediates that can form color images. There are printers that can express different tones.

In such a printer, if the same processing is applied to a character part and a picture part, there will be problems such as the text part becoming blurred due to filtering processing, or the smoothness of the picture part being lost. .

This invention was made in view of the above points, and aims to improve image quality.

Mr. Yutaka: In order to achieve the above object, the present invention is provided with a function of determining whether received data is character code or image data, and storing the result of this determination.

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

FIG. 1 is a block diagram showing an example of a printer embodying the present invention.

The host 1 is, for example, a personal computer.

Various information processing devices or image reading devices such as word processors, data processors, image editing processing devices, and workstations, which use character codes (
character code) or bit data (image data) to the printer (image forming device) 2.

The data transferred from the host 1 to the printer 2 is appended with data indicating each color attribute of red (R), green (G), and blue (B). Note that data indicating the color attributes of yellow (Y), magenta (M), and cyan (C) may be used instead of red (R), green (G), and blue (B).

The controller 3 receives the image data sent from the host 1 via the input interface, develops the character code into a bit map, and also converts the image data into red (R), green (G), and blue. (B)
The data is converted to yellow (Y), magenta (M), and cyan (C) data through color correction processing, and yellow (
Y).

Each magenta (M) and cyan (C) data is written to the page memory (frame memory) 4 where the data is located.

As shown in FIG.
), page memory 4Y has a capacity for one page to store data for magenta (M), page memory 4M has a capacity for one page to store data for magenta (M), and page memory 4M has a capacity for one page to store data for magenta (C). The page memory 4c has a capacity for one page to store data for black (K), and the page memory 4c has a capacity for one page to store data for black (K).
As a gradation unit, each page memory 4 y e 4 ia v 4 c −
Each has n pieces of 4pc. At the same time, the image data as received data from host 1 has a character code (
A flag (F) memory 4F, which is a memory having a capacity for one page, is provided to store a determination result as to whether the data is a character code) or image data (bit data). Note that the page memory 4 for black (K) does not need to be provided.

The arithmetic processor 5 takes in the data written in the page memory 4 and performs various filtering processes such as edge emphasis and smoothing, enlargement/reduction processing, 9-rotation processing, UCR (undercolor removal) processing, and dither processing (two-way processing). The processed data is then written to the page memory 4 again.

The engine controller 6 reads data from each page memory 4y, 4M, 4C, and 4K of the page memory 4, creates a signal at a timing that matches the printer engine 7, and sends the signal to the printer engine 7 via the output interface.

The printer engine 7 is a printer engine such as a laser printer, a thermal printer, or an inkjet printer.

FIG. 3 is a schematic configuration diagram showing an example of the printer engine 7. As shown in FIG.

This printer engine 7 rotates a drum-shaped photoreceptor 11 in the direction of the arrow, and first uniformly charges the surface with an electrostatic charger 12, and then emits a laser beam from a laser diode 13 according to the color image to be printed. turn on light/
The off-modulated laser beam is irradiated onto the photoreceptor 11 via the mirror 14 to form an electrostatic latent image corresponding to the color image to be printed. The modulation of this laser diode 13 is performed in page memories 4y, 4M, and 4C for yellow (Y), magenta (M), cyan (C), and black (K).

This is performed sequentially for each color using data generated based on data stored in 4K.

And yellow toner developer 15. Magenta toner developer 16. A developer corresponding to the color to be printed is selected from among the developer 17 for cyan toner and the developer 18 for black toner, and the electrostatic latent image corresponding to the image of the color to be printed is formed on the photoreceptor 11. A coloring material (toner) is attached and visualized.

On the other hand, the uppermost paper 20 held in the paper feed cassette 19 is fed by the paper feed roller 21 and sent to the transfer position at a predetermined timing, and a high voltage is applied to the transfer charger 22 at a predetermined timing. The toner image on the photoreceptor 11 is transferred to the paper 20.

Thereafter, the charge remaining on the photoreceptor 11 is eliminated by a quenching lamp 23, and the toner remaining on the photoreceptor 11 is removed by a cleaning brush 24 and collected in a wandering toner bottle 25, and the toner is removed from the photoreceptor 11. The body 11 is placed in an initial state for the image forming process. Also, the paper 20 is returned to a predetermined position for the next color printing, but the paper 20
may be rotated for the next color print.

Then, in the same manner as described above, the laser diode 13 is modulated on/off in accordance with the next color image to be printed, and the toner image of that color is transferred onto the paper 20.

By repeating this action, cyan.

After a color toner image is formed on the paper 20 using magenta, yellow, and black color materials, the paper 20 is sent to a fixing unit 27, subjected to fixing processing, and then discharged to a paper discharge stacker 28.

Next, the operation of this embodiment configured as described above will be explained with reference to FIG. 4 and subsequent figures.

First, the flow of processing in the image processing section of this printer 2 will be explained with reference to FIG.

The red (R), green (G), and blue (B) data input from the host 1 side to the input interface CI/F are enlarged/reduced 9 times as necessary (these processes are performed using color correction). After applying (may be after treatment, etc.),
After this treatment, red (R), green (G), blue (
Color correction processing is performed on each data in B) to produce yellow (Y).

Convert to magenta (M) and cyan (C) data.

After that, yellow (Y) obtained by this color correction,
U based on magenta (M) and cyan (C) data
Yellow (Y) after CR treatment.

Convert to magenta (M), cyan (C), and black (K) data, and then convert this yellow (Y) and magenta (M)
, cyan (C), and black (K) data are subjected to filtering processing such as edge enhancement and smoothing, and then further binarized processing such as dithering processing is performed, and the data is sent via the engine interface (I/, F). and sends it to the printer engine 7.

Next, the fifth section describes the process when receiving data from host 1.
This will be explained with reference to the figures.

First, after setting all bits of the flag memory 4F of the page memory 4 to 0', it is determined whether or not the received data has ended.

If the received data is not finished, it is determined whether the received data is a character code.

At this time, if the received data is a character code, after developing the character code into a bit map, the bit of the flag memory 4F where the character is located is set to 1.
゛, and then yellow (Y), magenta (M),
It is stored in each page memory 4Y, 4M, and 4C for cyan (C).

Also, if the received data is not a character code, that is, if it is bit data (image data) as halftone data, it will be converted into yellow (Y) or magenta (M) as is.
, and stored in each page memory 4y, 4M, and 4C for cyan (C).

In this way, it is determined whether the image data as received data is a character code (character code) or image data (bit data), and the bits corresponding to one page are stored in the flag memory 4F. A flag corresponding to the determination result as to whether it is a character or an image, that is, a flag that becomes 1' in the case of a character code, is set.

Therefore, when processing the data stored in the page memory 4, for example, when performing filtering processing, the flag memory 4F is referred to and bits corresponding to character codes are processed as image data without smoothing processing. You can easily apply smoothing processing to only the bits, or change the contents even when applying smoothing processing, so that single character parts can be reproduced clearly and picture parts can be reproduced smoothly. This will improve the image quality.

Also, when performing UCR processing, the amount of black (K) can be changed depending on whether the image is a character or not.

That is, in the UCR process, as shown in FIG. 6, the amount of yellow (Y), amount of magenta (M), and amount of cyan (C) of the corresponding bit are stored in register A, respectively.

Set the contents of B and C as (A), (B), and (C),
The contents of these registers A, B, and C (A).

The minimum value in (B) and (C) is set as the content (D) of register D.

Thereafter, it is determined whether the relevant bit of the flag memory 4F is '1° or not, that is, whether it is a character or not.

Here, if the relevant bit is °1', that is, a character, the predetermined constant is i (%), and after setting r (D)Xi/100J as the amount of black (K), As the amount “(A)-(D)xi/100J
r (B) − (D)X as the amount of magenta (M)
i/100J, cyan (C) (7) r (
C) - (D) Set Xi/100J 0 For example, when the constant i is set to 100 (%), the amount of black (K) will be the amount of magenta (M) before processing, as shown in Figure 7. , the amount of yellow (Y) and the amount of cyan (C) are the amount obtained by subtracting the amount of black (K) from the amount of self before processing, and the amount of magenta (CM) becomes 0.

On the other hand, if the relevant bit is 1°, that is, it is not a character, that is, the relevant bit is O゛, then the amount of black (K) is r (D
)Xj/100", set the amount of yellow (Y) as r (A) - (D)
, as the amount of cyan (C) r (C)-CD)Xj/1
Set 00J 0 For example, when the constant j is set to 50 (%), the amount of black (K) and the amount of magenta (M) will be the amount of magenta (M) before processing, as shown in Figure 8. The amount of yellow (Y) and the amount of cyan (C) are the amount obtained by subtracting 172 of the amount of magenta (M) before processing from the amount of self before processing.

In this way, increase the amount of black (K) in one character area to use more black toner, and reduce the amount of black (K) in the image area (halftone area) to use black toner. By reducing the amount.

It is possible to improve the black reproducibility of the text portion without impairing the image quality of the halftone portion.

As described above, according to the present invention, image quality is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the configuration of the page memory, FIG. 3 is a schematic configuration diagram showing an example of the printer engine, and FIG. FIG. 5 is an explanatory diagram illustrating the flow of the image processing, and FIG. 5 is a flow diagram illustrating an example of the data reception processing. FIGS. 6 to 8 are a flowchart showing an example of the UCR processing and an explanatory diagram providing a specific explanation thereof. 1...Host 2...Image forming device 3°°
° Controller 4... Page memory 5... Arithmetic processor 6... Engine controller 7... Printer engine Figure 1 Figure 2 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. In an image forming apparatus capable of receiving both character code and image data as image data, determining means for determining whether received data is character code or image data, and the determining means 1. An image forming apparatus comprising: storage means for storing determination results. 2. The image forming apparatus according to claim 1, further comprising means for changing the usage rate of black toner between text areas and non-text areas.