JPH09116742A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve processing efficiency by adopting the hardware for memory clearing processing to store an area identification code and executing the clearing so as to reduce the load on a CPU for image processing and so as to execute another processing even when the memory clearing is being executed. SOLUTION: An area generating section 308 is provided with a memory 508 that stores an area identification code, a write address generating section 502, that generates an address to write a default area identification code to all areas of the memory 508, and an area identification code generating section 505 to generate a default area identification code. Then the area identification code generated by the area identification code generating section 505 is written in the address of the memory 508 generated by the write address generating section 502.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copying machine,
The present invention relates to an image forming apparatus provided with a so-called editor display for displaying a read image on a full-color digital copying machine and instructing processing such as editing.

[0002]

2. Description of the Related Art After inputting an image input from a scanner or the like into an editor having an image display function, the image is thinned out and displayed, and a desired image editing operation is performed on the display screen to obtain a final image. Digital color copiers (hereinafter referred to as copiers) have been developed that have an area editing function for obtaining realistic copy images.

In the above copying machine, a designated area can be identified by mounting a memory for storing the image data of the maximum size of the original image.
This will be specifically described with reference to FIG. 7. For example, the maximum size of the original image is A3 (297 mm x 420 mm),
If the resolution is 400 dpi, the area resolution of 400
In order to be able to identify up to 16 types in dpi, as shown in FIG. 7, 4680 × 6620 × 4 = 124
A memory size of Mbit is required. In this case, 16
Eight (128 Mb) when using the Mbit memory IC
It) memory IC is required.

Further, the control of the above memory will be described with reference to FIG. In the figure, 801 is a CPU that executes control of image processing, 802 is an area control unit that writes an area identification code in a memory 803 based on a designated address from the CPU 801, and 803 is an area identification code for identifying a designated area. It is a stored memory.

In the above configuration, first, when the power is turned on, the default area identification code (here, 0) is written in all areas of the memory 803 to initialize it. That is, the default area identification code “0” is output from the CPU 801 which controls the image processing.
Is written in the memory 803 through the area control unit 802. Here, the area identification code is 4 bi per dot.
Since t (16 types), 4 dots are written at one time. That is, if the data width is 16 bits, it will be written 8 million times.

In the case of whole surface processing (not area processing),
The area control unit 802 reads the area identification code written in the memory 803 in synchronization with the image data and outputs it as an area signal. That is, a timing signal (sub-scanning synchronization signal and main-scanning synchronization signal / pixel synchronization signal) for synchronizing with the image data is input to the area control unit 802, and the memory 803 is based on this timing signal.
The area identification code written in is read and the area signal is output so as to be synchronized with the image data.

Therefore, the area identification code "0" is always output during the entire surface processing. Further, the data written in the memory 803 is constantly refreshed so as not to be erased.

Next, the case of area processing will be described with reference to FIG. When area 1 is designated as shown in FIG. 9A, the CPU 801 obtains the address of the boundary of the area 1 in the sub-scanning direction, and the address obtained by the above operation of the memory 803 through the area control unit 802, that is, the figure The area identification code "1" is written in the solid line portion of 9 (b).

Further, in the above, at the time of reading, the area control section 802 reads the area identification code written in the memory 803 in synchronization with the image data and outputs the area signal. Here, the area signal is "0" until the read area identification code changes from "0" to "1", "1" is output until the next "1" when "1" is read, and then "0". Is output. Therefore, FIG.
“0” is output outside the designated area of (a), and “1” is output in area 1.

Next, when the whole surface processing is designated, the area identification code "0" is stored in the memory 803 in the same manner as when the power is turned on.
Write. On the other hand, when the area processing different from the above is designated, first, the area identification code “0” is written in the memory 803 as in the above. Then, the procedure similar to the above-described area processing is executed for the newly designated area.

By the way, as a means for displaying an input image from the image input means on a CRT, for example, Japanese Patent Laid-Open No. 63-
It is disclosed in "Image Display Device" of Japanese Patent No. 258163. This device uses the read image data (400 dp
i) uses the fixed threshold method for the text area and 4 for the photo area.
Binarize the pixel block of × 4 using the dither method,
The binarized image data is thinned out to 100 dpi and displayed.

Further, in this case, the thinning method is used for thinning out the character area in 1-bit units and thinning out in the 4 × 4 block units for the photo area with 4 × 4 bits as one block. That is, when thinning out to 100dpi, 4 ×
Four bits are set as one block, one pixel at a predetermined position among 16 pixels in the one block is set as a target pixel, and the target pixel is output as a representative value of the corresponding block.

[0013]

However, the conventional device as described above has the following problems.

First, when power is turned on, when the entire surface processing is designated from the area processing, or when another area processing is designated from the area processing, the CPU sets a default area identification code "0" to the area control unit. Is writing to memory through. That is, since the memory is cleared by software, the processing time is long and the CPU cannot execute other image processing while the memory is being cleared.

Secondly, when the power is turned on and when the area processing is switched to the surface processing, the CPU writes a default area identification code "0" to the memory through the area control unit and reads it from the memory in synchronization with the image data. An area signal is output through the area controller. That is,
When the processing is switched to the whole surface processing, the CPU executes the memory clear, so that a waiting state occurs during this period and the processing efficiency decreases.

Thirdly, when the whole surface processing is switched to the area processing in the above, it is necessary to write the default area identification code "0" in the memory and then the identification code of the designated area. It becomes a waiting state while is cleared.

Fourth, the default area identification code "0" is written in the memory when the power is turned on and the entire surface is processed. Then, when the entire surface is processed, the memory is read from the memory in synchronization with the image data and the area signal is output through the area control unit, so that the memory is always in the operating state, resulting in unnecessary power consumption.

Fifth, in Japanese Patent Laid-Open No. 63-258163, the character portion of the read image (here, 400 dpi) is processed using the fixed threshold method. For example, when thinning out to 100 dpi, 4 × 4 bits are set as one block, and only one pixel at a predetermined position of 16 pixels in this one block is focused, and this focused pixel is output as a representative value of this block. That is, since the remaining 15 pixels are ignored, thin lines are cut off and small characters are difficult to see.

The present invention has been made in view of the above, and reduces the load of the CPU for image processing by implementing the clear processing of the memory for storing the identification code of the area by hardware. At the same time, it is possible to execute other processing even while the memory clear is being executed.
A first object is to improve processing efficiency.

In addition, the power consumption can be reduced by stopping the operation of the memory when processing the entire surface.
The purpose of.

A third object of the present invention is to obtain a display quality in which thin lines are not broken and a small character is easy to see when displaying by performing thinning processing.

[0022]

In order to achieve the above object, in an image forming apparatus according to a first aspect of the present invention, a document reading is performed that optically reads a document and outputs image data corresponding to the document image. Means, area generating means for outputting an area signal for instructing area processing for the image data from the document reading means, and image processing means for executing image processing based on the area signal output from the area generating means. In the image forming apparatus having the above, the area generation means is an area storage means for storing an area identification code, and a write address for generating an address for writing a default area identification code in the entire area of the area storage means. The write address generation means includes a generation means and an area identification code generation means for generating a default area identification code. To the address of the area storing means further generated, in which writing area identification code generated by the area identification code generating means.

That is, by providing a means for writing the default area identification code in the entire area of the area storage means, it is possible to perform the memory clear by the dedicated hardware without using software, and the load on the CPU is reduced accordingly. In addition, the writing time is shortened.

Further, in the image forming apparatus according to the second aspect, the area generation means does not output the area identification code from the area storage means when the entire surface is processed, and the area identification code generation means From the default area identification code.

That is, by providing an output means for outputting a default area signal and using this output means at the time of processing the entire surface, the waiting time while the memory clear is executed is eliminated.

Further, in the image forming apparatus according to the third aspect, the area generation means does not output the area identification code from the area storage means when the area processing is changed to the entire surface processing, The output means outputs the default area identification code from the area identification code generating means, and also writes the default area identification code from the area identification code generating means into the area storage means.

That is, by writing the default area identification code in the area storage means, the waiting time while the memory clear is executed is eliminated.

Further, in the image forming apparatus according to the fourth aspect, the area generation means does not output the area identification code from the area storage means in the case of the whole surface processing, and the area identification means is operated by the output means. The default area identification code is output from the code generation means and the operation of the area storage means is stopped.

That is, in the case of the entire surface processing, the output means prepared separately outputs the default area identification code from the area identification code generating means, and the operation of the area storing means is stopped (also stopped during standby). ， Reduces power consumption.

Further, in the image forming apparatus according to the fifth aspect, the document reading means for optically reading the document and outputting the image data corresponding to the document image, and the image data from the document reading means are thinned out. In an image forming apparatus having a display unit for displaying, of the image data output by the document reading unit, an image identification unit for identifying whether it is a character region or a photo region, and an identification result of the image identification unit. ，
A thinning-out processing unit that executes thinning-out processing by changing the filter coefficients of the character area and the photograph area is provided.

That is, by identifying whether it is a character area or a photograph area, changing the filter coefficient of the character area and the photograph area, executing the thinning-out process and displaying it on the display means, an easy-to-see display without thin line breaks. An image is obtained.

In the image forming apparatus according to the sixth aspect, the filter coefficient is set so that the character area is through and the photograph area is smooth.

That is, it is discriminated whether it is a character area or a photograph area, and among the filter coefficients of the character area and the photograph area, setting is made so that the character area is through and the photograph area is smooth, so that the thin line breaks. It is possible to obtain a display image that is easy to see and is free from

Further, in the image forming apparatus according to the seventh aspect, the thinning processing means thins the image data into 1 / n (n is an integer) in both main scanning and sub-scanning and n × n blocks. The maximum value of these is output to the display means as a representative value in the block.

That is, both the main scanning and the sub scanning of the image data are thinned to 1 / n (n is an integer), and the maximum value in the n × n block is output to the display means as a representative value in the block, An easy-to-read display image without fine line breaks is obtained, and the photographic area is displayed in a state where gradation is maintained by taking the maximum value after smoothing.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image forming apparatus according to the present invention will be described below with reference to the accompanying drawings.

First Embodiment (Structure of Copying Machine) FIG. 1 is an explanatory diagram showing the structure of a digital full-color copying machine suitable for applying the present invention.
Further, FIG. 2 is an explanatory diagram showing a detailed configuration of an image forming unit and an intermediate transfer belt portion.

This digital full-color copying machine is roughly composed of a color image reading device 100 as a document reading means.
(Hereinafter referred to as a color scanner), a color image recording device 110 (hereinafter referred to as a color printer), a paper feeding device 170 for increasing the amount of paper fed, and a color scanner 10.
A display device (hereinafter referred to as a display editor) 180 as a display unit for displaying an image read by 0
It is configured to be installed.

The color scanner 100 includes a halogen lamp 101 for illuminating the original P, a first mirror 102, a second mirror 103, a third mirror 104 for guiding the reflected light of the original P, an imaging lens 105, The imaging lens 105
A color sensor function of converting the light imaged by the image sensor into an image signal, that is, a three-line CCD (electric charge) capable of simultaneously reading three colors as color separation means for blue (B), green (G), and red (R). (Coupling element) 106 and the like.

The color printer 110 is roughly composed of an optical writing unit 111, an image forming section 112, and a paper feeding section 113.
And a fixing / paper discharging unit 114 and the like. The optical writing unit 111 is a laser 11 using a semiconductor laser.
5, a laser drive control plate (not shown), a polygon mirror 116, a polygon motor 117 for rotating the polygon mirror 116, an f / θ lens 118, a reflection mirror 119, and the like. Is.

The image forming unit 112 is provided with the following functions centering on the photosensitive drum 120 that forms an electrostatic latent image. 121 is a charger for uniformly charging the photosensitive drum 120, 122 is a potential sensor for detecting the surface potential of the photosensitive drum 120, 123 is a Bk developing device for black toner, and 124 is C for cyan toner. Developing unit, 1
Reference numeral 25 is an M developing device for magenta toner, 126 is a Y developing device for yellow toner, 127 is a photoconductor cleaning unit for removing and collecting residual toner on the photoconductor drum 120, and a pre-cleaning static eliminator is provided. There is.

Numeral 128 is a charge eliminating lamp for erasing the residual potential of the photosensitive drum 120, and numeral 129 is a developing density pattern detector.

Reference numeral 130 denotes an intermediate transfer belt unit, which includes a driving roller 131 and a belt transfer bias roller 1
32, and a driven roller 133.
The belt drive motor 134 can be driven.

The intermediate transfer belt unit 130 is provided with a belt cleaning unit 135, and the belt cleaning unit 135 includes the brush roller 1
36, a rubber blade 137, and a contact / separation mechanism 138 from the intermediate transfer belt unit 130.

Further, as shown in FIG. 2, each of the developing devices 123 to 126 is rotated by bringing a brush of developer for developing an electrostatic latent image on the photosensitive drum 120 into contact with the surface of the photosensitive drum 120. Bk developing sleeve 139, C developing sleeve 140, M developing sleeve 141, Y developing sleeve 142
And developing paddles 143 to 146 that stir to scoop up and stir the developer, and toner concentration detection sensors 147 to 150 of the developer.

The paper feed unit 113 is provided with a paper feed cassette 151, a paper feed cassette 152, and a manual paper feed tray 153 for feeding special paper such as OHP film one by one.
And is equipped with. Further, 154 is a paper feed cassette 15
A sheet feeding roller 155 for feeding the first recording sheet is a registration roller that conveys the recording sheet in synchronism with the image on the intermediate transfer belt unit 130.

Further, 156 is a paper transfer unit, and this paper transfer unit 156 is a paper transfer bias roller 15
7, a roller cleaning blade 158, a contact / separation mechanism 159 from the belt, and the like. Also, 1
Reference numeral 60 denotes a conveyor belt for conveying the recording paper after transfer.

The fixing / paper discharging unit 114 includes a fixing unit 163 including a fixing roller 161 having a fixing heater built therein and a pressure roller 162 facing the fixing roller 161 and biased with a predetermined pressure. The sheet discharge roller 164 and the sheet discharge tray 165 are included. Also, the paper feeding device 1
The reference numeral 70 includes sheet feeding cassettes 171 and 172.

Further, the display editor 180 is
In the present embodiment, a touch panel type CRT or LCD mounted on the upper right side of the color scanner 100 for displaying and editing image data read by the color scanner 100 is used to provide an image display function and an image editing function. I have it.

(Operation of Copying Machine) Next, the operation of the above configuration will be described. The color scanner 100 receives a scanner start signal in timing with the operation of the color printer 110, scans the document in the direction of the left arrow, and obtains image data of one color for each scan. The halogen lamp 101 illuminates the image of the original P, and the reflected light is emitted from the first mirror 10.
An image is formed on a 3-line CCD 106 by an image forming lens 105 via a second mirror 103, a second mirror 103, and a third mirror 104. This operation is repeatedly performed a total of four times to sequentially obtain four-color image data.

Then, the color image information of the original P is read for each color separation of blue, green and red, and converted into an electric image signal. Next, color conversion processing is performed by a color correction unit (see FIG. 3) that performs image processing, and black (hereinafter referred to as Bk), cyan (hereinafter referred to as C), magenta (hereinafter referred to as M), yellow (hereinafter referred to as Y) color image data is obtained.

This color image data is Bk, C, M, Y by the color printer 110 for each color.
Is visualized as a final color copy. The details will be described below. The optical writing unit 111 converts the color image data from the color scanner 100 into an optical signal and performs optical writing corresponding to the original image, and the photoconductor drum 12
An electrostatic latent image is formed on 0.

Now, in the standby state, the four developing devices 123
Although all of Nos. To 126 are in the state of cutting off the developing sleeves 139 to 142 (development inoperative), the order of the developing operation (color image forming order) is as follows in the example of Bk, C, M and Y. explain. The developing order is not limited to this.

When the copying operation is started, the color scanner 100 starts reading Bk image data at a predetermined timing, and optical writing by a laser beam and latent image formation are started based on the image data. Hereinafter, the electrostatic latent image based on this Bk image data is referred to as a Bk latent image. Note that C, M, and Y are treated in the same manner.

In order to enable development from the tip of the Bk latent image, the Bk developing sleeve 139 is rotated to raise the developer before the latent image tip reaches the developing position of the Bk developing device 123. , Bk latent image is developed with Bk toner.

After that, the developing operation of the Bk latent image area is continued, but when the trailing edge of the latent image passes the Bk developing position, the developer of the Bk developing sleeve 139 is quickly cut off, and the developing operation is stopped. Put in a state. This is completed at least before the leading edge of the C latent image by the next C image data arrives. It should be noted that this cutting is performed by switching the rotation direction of the Bk developing sleeve 139 to the opposite direction to that during the developing operation.

The Bk toner image formed on the photosensitive drum 120 is transferred onto the surface of the intermediate transfer belt unit 130 which is driven at a high speed such as the photosensitive drum 120. Hereinafter, this is performed by applying a predetermined bias voltage to the transfer bias roller 132 while the intermediate transfer belt unit 130 is in contact with the photosensitive drum 120.

In the intermediate transfer belt unit 130, Bk, C, M, which are sequentially formed on the photosensitive drum 120,
The toner images of Y are sequentially aligned on the same surface to form a belt transfer image of four colors, and then are collectively transferred to a recording paper. The operation of the intermediate transfer belt unit 130 will be described later.

By the way, on the photosensitive drum 120 side, B
After the k step, the C step is started, but the C image data reading by the color scanner 100 is started at a predetermined timing, and the C latent image formation is executed by the laser light writing by the image data. The C developing device 124 starts the rotation of the C developing sleeve 140 after the trailing end of the Bk latent image to the developing position has passed and before the leading end of the C latent image reaches the developing position. The ears are raised and the C latent image is developed with C toner.

After that, the development of the C latent image area is continued, and when the trailing edge of the latent image passes, the C latent image is developed in the same manner as the Bk developing device 123.
The cutting of the developing sleeve 140 is performed. This is also completed before the leading end of the next M latent image arrives. Further, in the steps M and Y, the operations of reading, latent image formation and development of the respective image data are performed in the same manner as the steps Bk and C, and thus the description of these operations is omitted.

The intermediate transfer belt unit 130 is rotationally driven by a belt drive motor 134. Further, the bias roller 157 of the paper transfer unit 156 is usually separated from the surface of the intermediate transfer belt unit 130, but the four-color superposed images transferred and formed on the surface of the intermediate transfer belt unit 130 are collectively transferred onto the recording paper. At this time, the contact / separation mechanism 159 presses at a timing, and a predetermined bias voltage is applied to the bias roller 157 to perform the transfer process on the recording paper.

The recording paper is fed from, for example, a paper feed cassette 151 by a paper feed roller 154, and is registered by an intermediate transfer belt unit 130 by a registration roller 155.
The leading edge of the four-color superimposed image on the surface is fed at the timing when it reaches the paper transfer position.

Next, the operation of the intermediate transfer belt unit 130 will be described in detail. Intermediate transfer belt unit 130
There are the following three operation methods as the operation method after the belt transfer of the Bk toner image of the first color is completed to the rear end. In order to speed up the copy process according to one of these methods or according to the copy size, selection / operation is executed by an efficient combination. Hereinafter, each method will be described.

(1) Constant speed forward movement method Even after the Bk toner image is transferred onto the belt, the forward movement is continued at a constant speed. When the front end position of the Bk image on the surface of the intermediate transfer belt unit 130 reaches the belt transfer position of the contact portion with the photosensitive drum 120 again, the photosensitive drum 12
On the 0 side, an image is formed with a timing so that the front end of the next C toner image exactly matches the position.

As a result, the C image is accurately aligned with the Bk image and is transferred onto the intermediate transfer belt unit 130 by belt transfer. After that, by the same operation, M,
Proceeding to the Y image process, a belt transfer image of four colors is obtained.
Subsequent to the Y toner image belt transfer process for the fourth color, the four color superimposed toner images on the belt surface are collectively transferred onto the recording paper while moving forward.

(2) Skip Forward Method After the belt transfer of the Bk toner image is completed, the intermediate transfer belt unit 130 is separated from the surface of the photoconductor drum 120, and the intermediate transfer belt unit 130 is skipped at a high speed in the forward direction and moved by a predetermined amount. Then return to the original forward speed. After that, the intermediate transfer belt unit 130 is again attached to the photosensitive drum 120.
Contact.

Then, when the front end position of the Bk image on the surface of the intermediate transfer belt unit 130 reaches the belt transfer position again, the front end part of the next C toner image on the photosensitive drum 120 side is exactly aligned with that position. An image is formed with a timing.

As a result, the C image is accurately aligned with the Bk image, and the four colors are superimposed and transferred on the belt. Thereafter, the same operation is performed to proceed to the M and Y image process, and a belt transfer image of four colors is obtained. Following the transfer process of the Y toner image belt for the fourth color, the 4
The color-superimposed toner image is transferred to the recording paper all at once.

(3) Reciprocating (quick return) method When the belt transfer of the Bk toner image is completed, the intermediate transfer belt unit 130 is separated from the surface of the photosensitive drum 120. Then, the forward movement is stopped and at the same time, a high speed return is made in the opposite direction. In this return, the front end position of the Bk image on the surface of the intermediate transfer belt unit 130 passes the position corresponding to the belt transfer in the opposite direction, and further, after moving for a preset distance, it is stopped and put in a standby state.

Next, when the front end portion of the C toner image on the photosensitive drum 120 side reaches a predetermined position before the belt transfer position, the intermediate transfer belt unit 130 is restarted in the forward direction. Further, the intermediate transfer belt unit 130 is brought into contact with the surface of the photosensitive drum 120 again.

In this case as well, the C image is transferred under the condition that it is accurately overlapped with the Bk image on the surface of the intermediate transfer belt unit 130. Thereafter, the same operation is performed to proceed to the M and Y image process, and a belt transfer image of four colors is obtained. Subsequent to the transfer process of the Y-color toner image belt for the fourth color, the four-color overlaid toner image on the surface of the intermediate transfer belt unit 130 is collectively transferred onto the recording paper by moving forward at the same speed without returning.

The recording paper on which the four-color superposed toner images are collectively transferred from the surface of the intermediate transfer belt unit 130 by the above method is carried into the fixing unit 136 by the conveyor belt 160. In the fixing unit 136, the toner image on the recording paper is melted and fixed by the fixing roller 161 controlled to a predetermined temperature and the pressure roller 162 biased with a predetermined pressure.
After that, the recording paper is ejected to the paper ejection tray 165 by the paper ejection roller 164, whereby a final full-color copy is obtained.

On the other hand, the photosensitive drum 120 after the belt transfer
The surface is cleaned by the photoconductor cleaning unit 127, and the residual charge is erased by the static elimination lamp 128 to prepare for the next copying process. In addition, the intermediate transfer belt unit 130 after the toner image is transferred onto the recording paper, the belt cleaning unit 135 is pressed again by the contact / separation mechanism 138, and the surface thereof is cleaned.

At the time of repeat copying, the color scanner 10
0 operation and image formation on the photosensitive drum 120 are 1
Subsequent to the Y (fourth color) image process of the first sheet, the second Bk (first color) image process is performed at a predetermined timing. Further, in the intermediate transfer belt unit 130, following the batch transfer process of the first four-color superimposed image onto the recording paper, the surface of the second Bk toner image is cleaned by the belt cleaning unit 135. To be transcribed. After that, the same operation as the first sheet is executed.

In the above description, the copy mode for obtaining four full colors has been described as an example.
In the two-color copy mode, the same operation as described above is performed for the designated color and the number of times. In the case of the single-color copy mode, only the developing device for the target color is set to the developing operation (developer spike) state until the predetermined number of sheets is completed.

Further, the intermediate transfer belt unit 130 is
While being in contact with the surface of the photosensitive drum 120, it is driven at a constant speed in the forward direction. Then, the belt cleaning unit 135 also executes the single-color copying operation while keeping contact with the intermediate transfer belt unit 130.

Next, the basic operation of the display editor 180 will be described. First, when the reading start switch (not shown) is pressed, the color scanner 100
Exposes and scans the original P set on the original table, and obtains image data R, G, B of electric signals corresponding to the original image by the 3-line CCD 106 as described above.

The R, G, and G image data are sent to an image processing unit, which will be described later, and subjected to predetermined processing. That is, the image processing unit performs γ conversion → filtering → thinning processing on the image data, and outputs the image data to the display editor 180. The details of the series of image processing will be described later.

Here, the image data is thinned out because the read image density is a high resolution of, for example, 400 dpi. Therefore, if the density is kept as it is, the memory capacity becomes enormous and the memory cost increases. So
This is performed to reduce the memory capacity by the thinned image.

Therefore, in order to reduce the memory capacity, after thinning out the image data, the display editor 180
And is stored in the memory in the display editor 180. The display editor 180 displays the received image data.

Next, the area of the image displayed on the display editor 180 is touched by a coordinate display means (not shown) such as a generally used touch pen. Since the display portion is a touch panel, the touched portion is recognized as the designated area.

Therefore, the content to be changed, for example, the operation corresponding to the case of converting to red by color conversion is performed, and the instruction is confirmed. Also, these operations are displayed on the screen by a menu or the like.

After that, when the instruction operation is completed and the copy start switch is pressed, the above-mentioned instruction content is notified to the image processing section, and the parameter according to the instruction content is set. When the parameter setting is completed, the image reading of the color scanner 100 is started based on the above-described process, and a series of copying operations are performed.

(Structure of Image Processing Unit) FIG. 3 is a block diagram showing the structure of the image processing unit according to the present embodiment. The image processing unit 300 as the image processing means has the following 301 to 30.
It is composed of 9 functional elements.

That is, in the figure, 301 is a γ correction unit for executing γ correction processing for density conversion of input R, G, B image data, and 302 is a character area in m × m bit units from the image data. An image separating unit 302 as an image identifying unit for determining whether it is a photographic region, and whether it is chromatic or achromatic as necessary, and 303 is an image separating unit 302.
Is a filter that switches the parameter based on the output signal of 1 to execute the filtering process of the image data.

Further, 304 is a color correction unit for executing color correction / color conversion processing, 305 is an editing processing unit for executing editing processing based on a specified editing instruction, and 306 is a through processing or photographic processing in case of character processing. In the case of, a gradation processing unit that executes gradation processing, 307 is a printer γ correction unit that executes density correction according to the output characteristics of the color printer 110, and 308 is an area as an area generation unit that generates an area for color conversion. A generation unit 309 performs a thinning process on the image data to a predetermined pixel density, and a thinning processing unit 310 serves as a thinning processing unit that gives the thinned image data to the display editor 180. A control unit 310 controls each block of the image processing unit 300. It is a CPU.

(Operation of Image Processing Unit) Next, the operation of the image processing unit configured as described above will be described. Image data R corresponding to the original P from the color scanner 100,
G and B (8 bits for each color) are simultaneously sent to the image processing unit 300. The image processing unit 300 applies a predetermined correction to the input image data and outputs it to the color printer 110 or the display editor 180.

The γ correction unit 301 of the image processing unit 300 converts the image data R, G, B (linear reflectance) from the color scanner 100 into density linear. The converted data is input to the filter 303 and the image separation unit 302. The image separation unit 302 determines from the input data in m × m bit units (for example, 4-bit units) whether it is a character region or a photo region, and outputs the result to the filter 303. The output data in this case is represented by 2-bit data, and bit 0 is 0: character, 1: photo, bit 1 is 0: chromatic, 1: achromatic.

The filter 303 executes a filtering process of image data. That is, the parameters are switched according to the output signal from the image separation unit 302. In other words, through (outputting the input data as it is without processing it)
And edge enhancement / smoothing are processed in parallel, and the parameter is switched to the through or edge enhancement processing parameter for the character area and the smoothing processing parameter for the photo area. Then, the image data corrected by the filter 303 is processed by the color correction unit 30.
4 and the decimation processing unit 309.

The color correction unit 304 executes color correction / color conversion. That is, the image data read by the color scanner 100 is R, G. B, but color printer 1
Since the output of 10 is printed out with Bk, C, M, and Y toners and inks, the R, G, and B data are converted into Bk, C, M, and Y based on the following expression 1.

[0091]

(Equation 1)

Here, the coefficients r, g, b and the constant d are
It is automatically switched depending on the hue division plane of R, G, B data. Further, when converting an arbitrary color or area into a desired color, the coefficients and constants are switched to predetermined values.
Here, the area is switched by the area signal from the area generation unit 308.

The output data from the color correction unit 304 is input to the editing processing unit 305, the editing process is executed based on the editing instruction, and the data is sent to the gradation processing unit 306 in the next stage.
The gradation processing unit 306 outputs through in the case of character processing, that is, outputs the input data as it is.

On the other hand, in the case of the photographic processing, the gradation processing for expressing gradation in block units that is usually performed is executed.
After that, the data after this processing is processed by the printer γ correction unit 30
7

The printer γ correction unit 307 corrects the image data so that the character area is reproduced clearly so that the low density portion is white and the middle to high density portions are dark. In addition, the photographic area is corrected so that it can be smoothly viewed from the low density area to the middle and high density areas. Then, by outputting the corrected image data to the color printer 110, the color printer 110 forms an image.

Here, the area generation unit 308 outputs the area signals (0 to 15) to the filter 303 regardless of the presence or absence of area processing. That is, the area signal "0" is output in synchronization with the image data output from the color scanner 100 during the entire surface processing. Further, during the area processing, area signals (1 to 15) for recognizing the area based on the timing of the designated area are output to the filter 303. Note that the filter 303 to the printer γ correction unit 30
Up to 7, processing is executed by switching each parameter based on the area signal and the image separation signal.

Next, the case of outputting an image to the editor display 180 will be described. Color scanner 1
The image data output from No. 00 is converted by the γ correction unit 301 into image data B, G, R (reflectance linear) into density linear. Then, the filter 303 performs filtering. In this case, according to the character / photograph signal from the image separation unit 302, a through result for a character and a smoothing result for a photograph are output to the thinning processing unit 309.

On the other hand, the thinning-out processing unit 309 uses the filter 3
The image data R, G, and B having a pixel density of 400 dpi sent via 03 are thinned to a pixel density of 100 dpi, as shown in FIG.
Output to the editor 180.

FIG. 4 is an explanatory diagram showing an example of thinning processing according to this embodiment. Here, the pixel density is from 400 dpi to 1
In order to thin out to 00 dpi, 4 × 4 bits are set as one block unit (a11, a12, ...), and the maximum value in the block is output as a representative value of the block to generate a thinned image.

(Structure of Area Generating Unit 308) FIG. 5 is a block diagram showing the detailed structure of the area generating unit 308.
In the figure, reference numeral 501 denotes a read address to which a sub-scanning synchronizing signal, a main scanning synchronizing signal, and a pixel clock signal are input, and which generates an address for reading an area identification code written in a memory 508 described later in synchronization with an image. The generation unit 502 is a write address generation unit as a write address generation unit that generates an address for writing the default area identification code “0” in all areas of the memory 508 described later.

Further, 503 is a read address generation unit 50.
1 and the write address generator 502. A selector that outputs an address selected from the respective addresses output from the CPU 310. The address from the CPU 310 is
This is selected when writing or reading the area identification code directly from the CPU 310 to the memory 508.

Reference numeral 504 is a selector for switching the connection between the data bus of the CPU 310 and the selector 806 or the data bus of the memory 508 described later, and 505 is an area identification code as an area identification code generating means for generating an area identification code "0". The generation unit, 506 is the CPU 31
This is a select for switching between the data of 0 and the data from the area identification code generator 505.

Reference numeral 507 denotes an output unit which outputs 16 bits of data (area signals for 4 pixels) from the lower 4 bits in synchronization with the pixel clock signal. Reference numeral 508 is a memory in which the area identification code of the area is written.

(Operation of Area Generating Unit 308) Next, the operation of the area generating unit 308 configured as above according to the first embodiment will be described.

First, when the power is turned on, the default area identification code "0" is written in the memory 508. in this case,
The selector 503 selects the address generated by the write address generation unit 502, and the selector 506 selects the area identification code “0” generated by the area identification code generation unit 505.

That is, for the address of the memory 508 generated by the write address generation unit 502, the area identification code "0" generated by the area identification code generation unit 505.
Is written.

At the time of area processing, the area identification code is stored in the memory 508 from the CPU 310 according to the designated area.
Write to. In this case, the selector 503 is the CPU 310.
From the CPU 31.
The data bus of 0 is connected to the selector 506, and the data bus of the CPU 310 is selected by the selector 506.

When the area signal is output in synchronization with the image, the write address generator 501 in the selector 503.
The address generated in step 1 is selected, and the area identification code in units of 16 bits is read from the memory 508 in accordance with this address. Further, the output unit 507 outputs an area signal synchronized with the pixel clock signal by 4 bits. At this time, the selector 504 is cut off, and the output of the selector 506 is also cut off.

Returning to the whole surface processing, the default area identification code "0" is written in the memory 508 by the same operation as when the power is turned on. When the area signal is output in synchronization with the image data, the area signal is output by performing the same operation as in the area processing.

[Second Embodiment] (Structure of Second Embodiment) The device structure relating to the second embodiment is the same as that of FIGS. 1 to 3 described in the first embodiment. The structure shown in FIG. 6 is used. That is, FIG. 6 is a block diagram showing a detailed configuration of the area generation unit 308 according to the second embodiment, and is different from the area identification code generation unit 5 in FIG.
The generated signal 05 is also given to the output unit 507 as an output means. Therefore, since the other functional elements are the same as those in FIG. 5, the same symbols are given and the description of the same portions is omitted.

That is, the output unit 507 has the memory 508.
The area identification code data and the area identification code generation unit 505 "0" are switched and 16 bits of data (an area signal of 4 pixels) are output from the lower 4 bits in synchronization with the pixel clock signal. ing.

(Operation of Second Embodiment) Next, the operation of the second embodiment will be described. When the area signal is output during the entire surface processing, the output unit 508 is the area identification code generation unit 50.
The area identification code “0” from 5 is selected and output in synchronization with the pixel clock signal.

On the other hand, as in the first embodiment, with respect to the address of the memory 508 generated by the write address generation unit 502,
By writing the area identification code “0” generated by the area identification code generation unit 505, the default area identification code “0” is written in the memory 508.

[Third Embodiment] (Structure of Third Embodiment) The device structure according to the third embodiment is the same as that of FIGS. 1 to 3 described in the first embodiment. 2 has the configuration shown in FIG.

(Operation of Third Embodiment) When processing the entire surface, when outputting the area signal in synchronization with the image as in the second embodiment, the output unit 507 outputs the area identification code "A" from the area identification code generation unit 505. 0 "is selected and output in synchronization with the pixel clock signal.

When the area processing is designated, the default area identification code "0" is written in the memory 508 as in the case of turning on the power in the first embodiment. Then, the CPU 310 writes an area identification code in the memory 508 in accordance with the designated area. On the other hand, the operation of the memory 508 is stopped during the standby and during the entire surface processing.

[0117]

As described above, according to the image forming apparatus (Claim 1) of the present invention, a dedicated means for writing the default area identification code in the entire area of the area storage means is provided, and software is used. Instead, since the memory is cleared by the dedicated hardware, the load on the CPU is reduced by that amount, the writing time is shortened, and the processing efficiency can be improved.

Further, according to the image forming apparatus (Claim 2) of the present invention, the output means for outputting the default area signal is provided, and the output means is used during the entire surface processing,
The waiting time while the memory clear is executed can be eliminated, and the processing efficiency can be improved.

According to the image forming apparatus (Claim 3) of the present invention, since the default area identification code is written in the area storage means, the waiting time during the memory clear is eliminated. The processing efficiency can be improved.

Further, according to the image forming apparatus (Claim 4) of the present invention, in the case of the whole surface processing, the output area prepared separately outputs the default area identification code from the area identification code generating means, Since the operation of the area storage means is stopped (also stopped during standby), power consumption can be reduced.

According to the image forming apparatus (Claim 5) of the present invention, it is discriminated whether it is a character area or a photograph area,
Since the thinning processing is executed by changing the filter coefficients of the character area and the photograph area and the thinning processing is performed, the display image without thin line breaks can be obtained.

Further, according to the image forming apparatus of the present invention (claim 6), it is discriminated whether it is a character area or a photograph area,
Of the filter coefficients of the character area and the photograph area, the character area is set to be through and the photograph area is set to be smooth, so that an easy-to-see display image without thin line breaks can be obtained.

Further, according to the image forming apparatus (Claim 7) of the present invention, the main scanning and the sub scanning of the image data are 1 / n.
(N is an integer), and the maximum value in the n × n block is output to the display means as a representative value in the block.
An easy-to-see display image without fine line breaks can be obtained. Especially, by taking the maximum value after smoothing the photographic area, it is possible to display satisfactorily while maintaining gradation.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a digital full-color copying machine suitable for applying the present invention.

FIG. 2 is an explanatory diagram showing a detailed configuration of an image forming unit and an intermediate transfer belt portion in FIG.

FIG. 3 is a block diagram showing a configuration of an image processing unit according to the present embodiment.

FIG. 4 is an explanatory diagram showing an example of thinning processing according to the present embodiment.

FIG. 5 is a block diagram illustrating a detailed configuration of an area generation unit according to the first embodiment.

FIG. 6 is a block diagram showing a detailed configuration of an area generation unit according to Examples 2 and 3.

FIG. 7 is an explanatory diagram showing the maximum document size and memory size in the related art.

FIG. 8 is a block diagram showing a configuration of a conventional memory control portion.

FIG. 9 is an explanatory diagram showing an example of conventional area processing processing.

[Explanation of symbols]

100 color scanner 110 color printer 180 display editor 300 image processing unit 302 image separation unit 303 filter 308 area generation unit 309 thinning processing unit 310 CPU 501 read address generation unit 502 write address generation unit 505 area identification code generation unit 507 output unit 508 memory

Claims (7)

[Claims] 1. An original reading unit that optically reads an original and outputs image data corresponding to an original image, and an area generation unit that outputs an area signal instructing area processing for the image data from the original reading unit. In an image forming apparatus having image processing means for performing image processing based on the area signal output from the area generation means, the area generation means includes area storage means for storing an identification code of the area, The write address comprises: a write address generating means for generating an address for writing a default area identification code in all areas of the area storing means; and an area identification code generating means for generating the default area identification code. For the address of the area storage means generated by the generation means, the area identification code generator An image forming apparatus characterized by writing an area identification code generated in a step. 2. The area generating means does not output the area identification code from the area storing means, but outputs the default area identification code from the area identifying code generating means, when the entire surface is processed. The image forming apparatus according to claim 1, further comprising: 3. The area generating means does not output the area identification code from the area storing means when the area processing is changed to the whole surface processing, and the output means outputs a default value from the area identifying code generating means. 3. The image forming apparatus according to claim 2, wherein the area identification code is output and the default area identification code is written in the area storage means from the area identification code generation means. 4. The area generation means does not output the area identification code from the area storage means in the case of whole surface processing, but outputs the default area identification code from the area identification code generation means by the output means. At the same time, the operation of the area storage means is stopped, and the image forming apparatus according to claim 2. 5. An image forming apparatus comprising: a document reading unit that optically reads a document and outputs image data corresponding to the document image; and a display unit that thins out and displays the image data from the document reading unit. In the image data output by the document reading unit, an image identification unit that identifies whether it is a character region or a photo region, and in the identification result of the image identification unit, the filter coefficients for the character region and the photo region are changed. An image forming apparatus comprising: a thinning processing unit that executes a thinning process. 6. The image forming apparatus according to claim 5, wherein the filter coefficient is set so that the character area is through and the photograph area is smooth. 7. The thinning processing unit thins out the image data to 1 / n (n is an integer) in both main scanning and sub-scanning, and n
The image forming apparatus according to claim 5, wherein the maximum value in the block of × n is output to the display unit as a representative value in the block.