JP2003122063A - Image forming device and control method therefor - Google Patents

Image forming device and control method therefor

Info

Publication number
JP2003122063A
JP2003122063A JP2001320513A JP2001320513A JP2003122063A JP 2003122063 A JP2003122063 A JP 2003122063A JP 2001320513 A JP2001320513 A JP 2001320513A JP 2001320513 A JP2001320513 A JP 2001320513A JP 2003122063 A JP2003122063 A JP 2003122063A
Authority
JP
Japan
Prior art keywords
density
image
mode
image forming
threshold value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2001320513A
Other languages
Japanese (ja)
Inventor
Takashi Fujimori
Hideyuki Ikegami
Shokyo Ko
Eiichi Motoyama
Mitsuhiko Sato
Hidenori Sunada
Satoru Yamamoto
光彦 佐藤
悟 山本
栄一 本山
英之 池上
秀則 砂田
貴司 藤森
松強 黄
Original Assignee
Canon Inc
キヤノン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc, キヤノン株式会社 filed Critical Canon Inc
Priority to JP2001320513A priority Critical patent/JP2003122063A/en
Publication of JP2003122063A publication Critical patent/JP2003122063A/en
Application status is Withdrawn legal-status Critical

Links

Abstract

(57) [Problem] To provide a digital image forming apparatus with a well-balanced function that automatically saves toner while minimizing print quality without individually setting a toner saving amount by a user. Enables printing. A document is read by a document reading unit, converted into digital image information, and the sum of the densities of respective pixels in the entire image is counted by a density counter to detect the image density of the document. When the average density of the detected digital image information exceeds the set threshold value in the test copy mode having a density lower than the normal image forming density, the image density automatic reduction processing means 7 automatically sets the image. The density conversion for reducing the formation density is performed, and the printing unit 3 prints the original image.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
An image forming apparatus that uses toner,
The print quality is changed according to the image print quality switching mode to be set.
The present invention relates to an image forming apparatus to be converted and a control method thereof.
is there. [0002] In a copying apparatus using toner as a developer,
Before copying, copy conditions and finishing
In some cases, a trial copy is performed to check the pasting state.
This means that the user does not always need to
If you are not asking for a similar level
This is to save toner. As a technique for saving the toner, there is an example.
For example, as seen in JP-A-7-160150,
Change the transfer and development conditions to save toner consumption
It has been proposed to. [0004] However, the above-mentioned problems
In such a conventional method of saving toner in a copying machine, one method is as follows.
To reduce toner usage over the entire image area.
Text documents with low toner consumption or thin lines
And light color images use the minimum amount of toner required.
In some cases, blurring or omission may occur. However, if only the outlines of characters and lines can be recognized,
Such an image is sufficient if it is sufficient.
However, graphics and photos centered on halftone images
In the case of true, the color of the low density part is lost,
-The purpose of the trial copy of confirming the finished
Absent. In such a case, the amount of toner used
Reduce blurring and dropout by reducing the degree of degradation
Is possible, but with high-density images like posters
Means that the toner saving effect is insufficient. For this reason,
In the case of a manuscript, the user
Must select and execute the toner saving mode for each sheet
Was. The present invention has been made in view of the above problems.
The purpose of the test copy is to
Automatically without user setting toner savings
Saves toner while ensuring minimum print quality
Image forming equipment capable of performing well-balanced printing
And a control method therefor. [0008] An image forming apparatus according to the present invention.
The device and its control method are configured as follows.
You. (1) Document reading means for reading a document,
Detecting means for detecting the image density of the read original;
Setting means for setting the threshold value for decreasing the concentration
And the first mode for performing image formation with the normal image density setting
Mode and the second mode in which the image density is lower than in the first mode.
Instruction means for switching between the first mode and the second mode
The image density detected by the detection means during operation in
Image formation density automatically when exceeding the specified threshold
Processing means for performing density conversion processing so as to reduce
I got it. (2) In the above (1), the original reading means
Scans the original placed on the platen
And the detection means calculates the sum of the densities of the pixels in the entire image.
Counting means for obtaining the second mode.
The digital image information obtained by the original reading means.
The count that stores the sum of the densities of each pixel in all the images of the report
Average of digital image information obtained from means count value
Automatically images when the density exceeds the set threshold
Density conversion for lowering the formed density was performed. (3) Document reading means for reading a document,
A character area or an image
Identification means for identifying an image area; and
Detecting means for detecting an image density; and an image for each of the divided areas.
Setting procedure for setting the threshold value for lowering the image forming density
And the first mode for forming an image with a normal image density setting.
Mode and a second mode in which the image density is lower than in the first mode.
Instruction means for switching between the first mode and the second mode.
The image density detected by the detection means during operation in
When the set threshold is exceeded, the image
The density conversion processing is performed on each of the divided areas so as to reduce the degree.
And a processing means for performing a (4) In the above (3), the document reading means
Scans the original placed on the platen
And the detection means calculates the density of each pixel in each divided area.
Counting means for obtaining the sum, wherein the processing means
The digital image obtained by the original reading means in the mode.
Storing the sum of the densities of the pixels in each divided area of the image information
Digital image information obtained from the count value of the counting means
Automatically when the average concentration of the report exceeds the set threshold
Density conversion to lower image formation density
Was. (5) Any one of the above (1) to (4)
To change the threshold value to two or more values.
An indicator is provided. (6) Any one of the above (1) to (4)
When forming an image on a multicolor original,
The threshold and the processing means are stored for each color.
Was. (7) In (6) above, each color is stored.
The threshold value is changed to two or more values for each color independently.
There is provided an instruction means for causing the instruction to be made. (8) Reading an original on an original platen to form an image
A method for controlling an image forming apparatus for performing
Detects the image density of the original and adjusts the image
Set a threshold for lowering the formation concentration
First, the first mode for forming an image with the normal image density setting
Mode and the second mode in which the image density is lower than in the first mode.
And the detection during the operation in the second mode.
Automatically when the image density exceeds the set threshold value.
The image forming density was dynamically reduced. (9) In the above (8), the original is read
Is converted to digital image information, and each pixel in the entire image
The sum of the densities is counted to detect the image density of the original,
In the second mode, the flattening of the detected digital image information is performed.
Automatically images when the average density exceeds the set threshold
Density conversion for lowering the formed density was performed. (10) Reading an original on an original platen and reading an image
A method for controlling an image forming apparatus for forming, the method comprising:
Text area or image area for the divided area in the original document image
And check the image density of the scanned document.
And output an image for each of the divided areas according to an instruction on the operation unit.
Set a threshold for lowering the formation concentration
First, the first mode for forming an image with the normal image density setting
Mode and the second mode in which the image density is lower than in the first mode.
And the detection during the operation in the second mode.
Automatically when the image density exceeds the set threshold value.
Density conversion for dynamically lowering image formation density
It was done in the unit of area. (11) In the above (10), the original is read.
And convert it to digital image information.
Detects the image density of the original by counting the sum of the pixel densities
In the second mode, the detected digital image information
Automatically when the average concentration of the report exceeds the set threshold
Density conversion to lower the image formation density
Was. (12) Any one of the above (8) to (11)
In the method, the threshold value is changed to two or more values.
I'm sorry. (13) Any of the above (8) to (11)
When forming an image on a multi-color original,
The threshold value setting and the density conversion are performed for each color.
I'm sorry. (14) In the above (13), for each color
Change the threshold value to two or more values for each color independently.
I changed it. Embodiments of the present invention will be described below with reference to the drawings.
Will be described. [Embodiment 1] In this embodiment, an electrophotographic system
Digital black-and-white copying machine
An example will be described. FIG. 1 shows the functions of the digital copying machine according to the present invention.
FIG. 3 is a block diagram showing a configuration. In the figure, 1 is a manuscript
An original that reads an original on the table and converts it into digital image information
Document reading means 2 is read by document reading means 1
Image processing for performing predetermined image processing on digital image information
Image processing here is shading, background removal
Print original image information on recording paper, such as
Refers to the overall image processing required for printing. Reference numeral 3 denotes an image processing required by the image processing means 2.
Receiving the digital image information after the
The printing means (print engine) to execute
ON / OFF of laser, output of high voltage, recording in stage 3
Performs all printing operations necessary for printing, such as material transport. 4
Displays the overall operation status of the copier and allows the user to
Operation unit for making various settings for the copier
Has a display panel for displaying the overall operation status of the copier.
ing. 5 is image processed by the image processing means 2
Density counter (density)
Detecting means) and 6 are based on the operation contents designated by the operation unit 4.
And outputs an automatic image density reduction request to the image processing means 2.
Means 7 for instructing automatic image density lowering;
The image sent from the image processing means 2 according to the count value
Image density automatically lowers
This is a dynamic reduction processing means. FIG. 2 shows a digital copying machine according to this embodiment.
It is sectional drawing which shows a general whole structure. In the figure, 100 is
The automatic document feeder (DF) 180
Is installed. 101 is a platen as a document placing table
And 102, a scanner, and a document illumination lamp 103.
And a scanning mirror 104 and the like. And unfair
Scanner 102 reciprocates in a predetermined direction by the motor shown.
As a result, the reflected light from the original is
4 through 106, through the lens 107,
An image is formed on the CCD sensor in the sensor unit 108. Reference numeral 109 denotes a laser, a polygon scanner, or the like.
The exposure control unit is configured and the image sensor unit 108
It is converted into an electric signal and subjected to predetermined image processing described later.
The laser beam 119 modulated based on the image signal
Irradiate the body drum 111. Around photoconductor drum 111
Include a primary charger 112, a developing device 113, and a transfer charger 1
16, the pre-exposure lamp 114 and the cleaning device 115
The image forming unit 110 is configured to be provided. In the image forming section 110, the photosensitive drum
The ram 111 is driven by a motor (not shown) in the direction of the arrow shown in the figure.
At the desired potential by the primary charger 112.
After being charged, the laser light 119 from the exposure control unit 109
Is irradiated to form an electrostatic latent image. This photosensitive drum
The electrostatic latent image formed on 111 is
It is developed and visualized as a toner image. On the other hand, the right cassette deck 121 and the left cassette
Todeck 122, upper cassette 123 or lower cassette
From the pickup roller 125, 126, 1
The recording paper fed by the feed rollers 27 and 128
Sent into the main body by 29, 130, 131, 132,
The sheet is fed to the transfer belt by the registration roller 133 and
The visualized toner image is transferred by the transfer charger 116
Is done. After the transfer, the photosensitive drum 111 is
The residual toner is cleaned by the device 115 and the pre-exposure lamp 1
14 erases the residual charge. The recording paper on which the toner image has been transferred is separated.
Separated from the photosensitive drum 111 by the charger 117
And is sent to the fixing device 135 by the transfer belt 134.
You. Then, the toner is pressed and heated by the fixing device 135.
Is fixed, and then the main body 100 is
It is discharged outside. The main body 100 records, for example, 4000 sheets.
A deck 150 capable of storing paper is provided. This de
The lifter 151 of the hook 150 is
2 according to the amount of recording paper so that the recording paper always touches
Ascends and the recording paper is fed into the main unit by the paper feed roller 153.
It is. In addition, a multi-hand printer that can accommodate 100 sheets of recording paper
154 is also equipped. In FIG. 2, reference numeral 137 denotes a paper discharge flapper.
Switching between the transport path 138 side and the discharge path 143 side
You. 140 is a lower conveyance path, which is fed from the paper discharge roller 136.
The fed recording paper is turned over and re-supplied via the reversing path 139.
It leads to the paper path 141. Feed paper from the left cassette deck 122
The recording paper fed by the roller 130 is also in the refeed path 1
It is led to 41. Reference numeral 142 denotes a recording sheet for the image forming unit 110.
A re-feed roller for re-feeding. 144 is disposed near the paper discharge flapper 137
Then, the discharge path 143 is formed by the discharge flapper 137.
Paper discharge roller that discharges the recording paper switched to the outside to the outside of the machine
It is. During double-sided recording (double-sided copying), the discharge flapper 1
37, the copied recording paper is transported to the transport path 13.
8, re-feeding via reverse path 139 and lower transport path 140
Lead to path 141. At this time, the reversing rollers 145
All the trailing edge of the recording paper comes out of the transport path 138, and
To the position where the recording paper is bitten by the reversing roller 145.
The reversing roller 145 is reversed by pulling in the reversing path 139.
To the transport path 140. The recording paper is inverted from the main body 100 and discharged.
When the paper is ejected, the discharge flapper 137 is raised and
The trailing edge of the recording paper is transported by the roller 145 to the transport path 138.
Into the reversal path 139 to the position where the
By reversing the roller 145, the recording paper is
The sheet is returned to the sheet ejection roller 144 side. Reference numeral 190 denotes the recording paper discharged from the main body 100.
Records ejected one sheet at a time by the paper ejection processor that closes and aligns
The paper is stacked on the processing tray 194 and aligned. Some image shapes
Stapled the recording paper bundle and discharged
The bundle is discharged to the tray 192 or the discharge tray 193.
You. The output tray 193 is moved up and down by a motor (not shown).
The position of the processing tray 194 is controlled before the image forming operation starts.
And then the discharged recording paper is stacked
The height of the paper will be the position of the processing tray 194
To move. Further, the lower limit of the discharge tray 193 is detected.
There is a tray lower limit sensor (not shown), and the discharge tray 193
Detects when about 2000 sheets of recording paper are stacked
Swelling. 191 is inserted between the discharged recording paper
Paper tray 195 on which the separator paper to be stacked is loaded is discharged.
Z-folder 196 that Z-folds the recording paper that has been ejected
A part of the recording paper is folded at the center and stapled.
A bookbinding machine that performs bookbinding by binding
The paper is discharged to the paper discharge tray 197. FIG. 3 shows the structure of the control system of the digital copying machine.
It is a block diagram showing composition. In the figure, reference numeral 11 denotes a digital compound.
CPU that performs basic control of the copying machine.
2 and the ROM 13 in which the control program is written
RAM 14 for a work area for performing
And a data bus. A digital copier is connected to the input / output port 12.
Motors, solenoids, clutches, etc. necessary to control
Various loads (not shown), sensors to detect paper position, temperature
Input / output terminals (not shown) such as a degree sensor are connected.
Then, the CPU 11 enters and exits according to the contents of the ROM 13.
Input / output control is performed sequentially through the
Execute the operation. The operation unit 4 is connected to the CPU 11.
Control the display means and the key input means of the operation unit 4.
You. The operator operates the image forming operation mode through the key input means.
Table of scan mode, print mode and print output mode
Display switching is instructed to the CPU 11, and the CPU 11
Display of copy machine status and operation mode setting by key input
I do. The CPU 11 also sends an electric signal to the document reading means 1.
The signal converted into the air signal is printed on recording paper by the printing means 3.
An image processing unit 15 that converts the signal into a crisp electrical signal is connected.
Have been. FIG. 4 shows the internal configuration of the image processing unit 15.
FIG. The mirrors 102, 105, 1 of FIG.
06 and the lens 107, the image sensor unit 108
The original image formed by the CCD sensor is black (black).
Input as luminance data and analyze by CCD sensor
Are converted to electrical signals. The converted image information is
Log signal processing unit (not shown)
A / D after processing such as dark and dark level correction
The analog / digital conversion (A / D conversion) is performed by the conversion unit 21.
Shading on this digitized signal
Correction (variation of sensors such as CCD for reading originals and
Correction of the light distribution characteristics of the document illumination lamp)
The log is sent to the log converter 22. The log conversion unit 22 outputs the input luminance data.
(Look-u) for converting data into density data
p-table) is stored and input from this LUT.
Output table values corresponding to the input data
Therefore, the luminance data is converted into the density data. afterwards,
The image is scaled to a desired magnification by the scaling unit 23, and γ
It is input to the correction unit 24. In the gamma correction unit 24, the density data
Is output to the LUT in consideration of the characteristics of the printing unit 3.
Is performed according to the density value set in the operation unit 4.
Adjust the output. The density data obtained as described above is
The image is sent to the image memory 16 and the image is stored. Image
The memory 16 has a high-speed page memory and images of multiple pages.
Have a large capacity hard disk that can store data
The multiple image data stored on this hard disk
Are output in the order corresponding to the edit mode specified by the operation unit 4.
Is forced. For example, in the case of electronic sorting, automatic document feeder
The images of the bundle of documents placed on the
After storing the image data in the original,
Read from disk and repeat this multiple times for output
I do. This allows them to play the same role as sorters with multiple bins.
Can fulfill. The image data output from the image memory 16 is
The data is sent to the exposure control unit 109 in FIG.
Thus, image data is formed on the recording paper. Next, a trial copy, which is a feature of the first embodiment, is described.
Ensure that the minimum print quality is sufficient to achieve
A mode that saves toner (called trial copy mode)
(B) will be described. In the test copy mode, a normal image
Before copying in the first mode in which image formation is performed at the formation density
While having enough information for confirmation,
Copying in the reduced second mode and toner consumption
Must be effectively suppressed. For this, the whole
Image with a high average density of
By lowering the density for pixels with higher degrees,
More than necessary while maintaining the density that ensures the required print quality
Waste of the toner can be prevented. That is, the trial copy mode is
Is selected, the image stored in the image memory 16 is displayed.
Instead of sending data directly to the exposure control unit 109,
First, it is sent to the density counter 5 and the image density automatic reduction processing means 7.
The density of all pixels in the image data is stored in the density counter 5
According to the average density result of all pixels obtained by adding
The image density automatic reduction processing means 7 performs density reduction processing.
The image data is returned to the image memory 16 and the exposure control
What is necessary is just to transmit to the control part 109. FIG. 5 is a flowchart showing the operation of this embodiment.
The image density reduction process performed by the image processing unit 15.
It shows a specific procedure flow. This floater
The control process shown in FIG.
What is executed according to the program stored in M13
It is. First, the image data on the image memory 16 is marked.
Is sent to the image processing unit 15 for transmission to the printing means 3.
The test copy mode is set on the operation unit 4
Is checked (S1). Here, the normal copy mode
In this case, the image density
The exposure control unit 109 returns the data to the image processing unit 15 and
Send to If you are in trial copy mode,
Using the density counter 5, the density of the pixel in the image data is calculated.
Counting is performed for all pixels (S2). At this time
Divided by the total number of pixels gives the average
A concentration is obtained. Next, the image data obtained by the above processing is
The average density of the data is compared with a predetermined threshold (S3).
If the threshold is higher, the image data
Judgment that concentration reduction is not necessary because concentration is low enough
And the exposure control unit 10 keeps the density data unchanged.
9 is transmitted. Here, the above threshold is
If lowering the density interferes with checking the copy finish,
Image density. The flatness of the image data is larger than the threshold value.
If the average density is higher, the current density of the image data
Confirm that the copy finish will not hinder
It is determined that the density is at a level that can save
In S6, the density of the image data is reduced.
Such density conversion processing is performed on each pixel. That is, density conversion is performed for each pixel (S
4) The density is converted by sequentially moving to the next pixel (S
5) After density conversion is completed for all pixels (S
6), transmitting the image data to the exposure control unit 109 (S)
7). Regarding the above-mentioned method of density conversion,
Although several methods have been proposed for
The LUT shown in FIG. 6 is used. Next, this image density change
The exchange table will be described. The solid line in FIG. 6 indicates the input data in the density conversion.
6 is a graph showing a relationship between data and output data. here,
256 floors of black and white of 0x00 to 0xFF as input / output data
Set key data. 0x00 indicates white at the density 0, and the value
Becomes larger as the value becomes larger.
It becomes. In this table, the value is larger than a certain threshold value.
Values are set to lower at a fixed rate
And the density corresponding to the shaded area in FIG.
Has the effect of lowering This threshold value is the low
The color development sensitivity of the density on the recording paper with respect to the density data is not good.
This is a value provided for
Ensure that the actual density on the recording paper is
Therefore, there is no change for the density from 0x00 to the threshold.
Table so that the density does not decrease due to
I have decided. As a result, even low-density data can be recorded.
While ensuring the minimum required density on paper,
Management can be performed. The slope of the solid line in the figure changes.
Minimum copy finish even after density reduction
This is to set a value that can be secured. Using the above table, the density data of 0xA0
Data, 0xA0 in normal copy mode
Is transmitted to the exposure control unit 109 as it is.
However, density conversion was performed in the trial copy mode.
According to the result, 0x60 density data is sent to the exposure control unit 109.
This means that image formation is performed with the density suppressed.
Be done. As described above, in the trial copy mode,
High-density pixels for images with high overall average density
By performing the process of lowering, the print quality can be
However, it is possible to save toner consumption. [Embodiment 2] As Embodiment 2 of the present invention, a sentence
A digital copying machine with a character determination function will be described as an example.
In addition, about the basic structure of a present Example, FIGS.
6, and the description is omitted. Digital Copying Machine with Character Judgment Function
Is basically the same as the first embodiment, but
The area in which the image density automatic reduction processing means 7 operates is different.
Has become. Hereinafter, the image density different from the first embodiment will be described.
An area in which the motion reduction processing means 7 operates will be described. In this embodiment, the selection of the trial copy mode
Regardless of the result, the original is read by the original reading means 1.
When the processing is performed, the image processing unit 15
By performing character judgment based on luminance data, the entire image
For each area that is sufficiently small compared to
Recognize and have the area information paired with the image data
Keep it. Also, the image density in the trial copy mode
Image necessary for determining whether or not the operation of the
The image density threshold and the image density automatic reduction processing means 7
In each area, an LUT for density conversion that has the effect of
Prepare by area type. Then, in the trial copy mode,
When requested, the area information for each image area
Is read out, and the density
Judgment of the necessity of automatic concentration reduction processing
If necessary, use the above LU for density conversion for each area type.
Density conversion by T and exposure control of the density data
The density is suppressed on the recording paper by transmitting to the
Image formation. In this method, a smaller area than in the first embodiment is used.
The necessity of automatic concentration reduction processing can be determined for each
It is possible to reduce the concentration effectively according to the area type
And maintain print quality to a minimum with higher accuracy.
Can be saved. [Embodiment 3] As Embodiment 3 of the present invention,
A digital color copying machine will be described as an example. In addition, the real
As for the basic configuration of the embodiment, FIGS.
The description is omitted because it is similar. In a digital color copier,
The basic part is the same as that of the first embodiment, but a multi-color image
They differ in their treatment of Examples below
About the handling of multi-color image formation different from 1.
Will be explained. In a digital color copying machine, an original reading
After reading a multicolor original by the reading means 1,
The image information is stored in the image memory 16 as multi-color image data.
You. Naturally, the multi-color image
Multicolor image formation for image data is possible. In this embodiment, in the trial copy mode
Independent image density for each color when printing is requested
An image necessary for determining whether or not the automatic lowering processing means 7 can be operated.
The image density threshold and the image density automatic reduction process for each color
L for density conversion having a density lowering effect in
Prepare UT. Then, in the test copy mode,
When requested, the image area for each color is
Necessity of automatic density reduction processing using threshold of image density
Judgment is necessary, and if there is a need for automatic concentration reduction processing
Is the density conversion by the density conversion LUT for each color.
And sends the density data to the exposure control unit 109 for each color.
To form images on recording paper with reduced density.
I do. According to this method, for example, the entire screen is yellow.
Yellow toner is effective even for images with such uneven color balance.
It is possible to save only money. As described above, in Examples 1 to 3,
By setting the copy mode,
Minimum print quality without interfering with confirmation
In addition, effective saving of toner consumption can be achieved. You
That is, only when the average density of the entire image is high,
A toner saving mode that reduces density for pixels with high density
To ensure effective printing while ensuring print quality.
Digital image forming device that can save toner
Can be realized. Therefore, in the trial copy,
Automatically without the user setting the toner savings
To save toner while ensuring minimum print quality
It is possible to perform balanced printing. As described above, according to the present invention,
Individual users can save toner in trial copy
Automatically secures the minimum print quality without setting
Performs well-balanced printing while saving toner.
It becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a functional configuration of a digital copying machine according to the present invention. FIG. 2 is a cross-sectional view illustrating an overall configuration of a digital copying machine according to an embodiment of the present invention. FIG. 4 is a block diagram illustrating a configuration of a control system of the digital copying machine according to the embodiment. FIG. 4 is a block diagram illustrating an internal configuration of an image processing unit according to the embodiment. FIG. 5 is a flowchart illustrating an operation of the embodiment. Explanatory diagram showing a conversion table of density [Description of symbols] 1 Document reading means 2 Image processing means 3 Printing means 4 Operation unit 5 Density counter 6 Automatic image density reduction instruction means 7 Automatic image density reduction processing means 11 CPU 12 I / O port 13 ROM 14 RAM 15 Image processing unit 16 Image memory 21 A / D conversion unit 22 Log conversion unit 23 Magnification processing unit 24 Gamma correction unit 25 Image memory 100 Copy machine body 01 Platen glass 102 Scanner 103 Document illumination lamps 104, 105, 106 Scanning mirror 107 Lens 108 Image sensor unit 109 Exposure control unit 110 Image forming unit 111 Photoreceptor drum 112 Primary charger 113 Developing unit 114 Pre-exposure lamp 115 Cleaning device 116 Transfer charger 117 Separation charger 119 Laser beam 121 Right cassette deck 122 Left cassette deck 123 Upper cassette 124 Lower cassette 125, 126, 127, 128, 152 Pickup rollers 129, 130, 131, 132, 153 Feed roller 133 Registration roller 134 Transfer belt 135 Fixing units 136, 144 Discharge rollers 137 Discharge flapper 138 Convey path 139 Reverse path 140 Lower conveying path 141 Re-feed path 142 Re-feed roller 143 Discharge Path 145 reversing roller 150 deck 151 lifter 154 multi-manual feed 180 automatic document feeder 190 paper discharge processor 191 paper trays 192, 193, 197 paper discharge tray 194 processing tray 195 Z-folder 196 bookbinding machine

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hideyuki Ikegami             3-30-2 Shimomaruko, Ota-ku, Tokyo             Within Non Corporation (72) Inventor Mitsuhiko Sato             3-30-2 Shimomaruko, Ota-ku, Tokyo             Within Non Corporation (72) Inventor Eiichi Motoyama             3-30-2 Shimomaruko, Ota-ku, Tokyo             Within Non Corporation (72) Inventor Huang Matsuqiang             3-30-2 Shimomaruko, Ota-ku, Tokyo             Within Non Corporation (72) Inventor Takashi Fujimori             3-30-2 Shimomaruko, Ota-ku, Tokyo             Within Non Corporation F term (reference) 2H027 DB01 DE07 EA18

Claims (1)

  1. Claims: 1. A document reading means for reading a document, a detecting means for detecting an image density of the read document, a setting means for setting a threshold value for lowering the image forming density, Instruction means for switching between a first mode in which image formation is performed at a normal image density setting and a second mode in which the image density is lower than the first mode, and Processing means for performing a density conversion process so as to automatically reduce the image forming density when the image density detected by the detecting means exceeds the set threshold value. apparatus. 2. The document reading means reads a document placed on a document table and converts it into digital image information, and the detection means has a counting means for obtaining a sum of densities of respective pixels in all images. In the second mode, the average density of the digital image information obtained from the count value of the counting means for storing the sum of the densities of the pixels in all the images of the digital image information obtained by the document reading means in the second mode is set. 2. The image forming apparatus according to claim 1, wherein a density conversion for automatically lowering the image forming density is performed when the threshold value is exceeded. 3. An original reading means for reading an original, an identification means for identifying a character area or an image area for a divided area in an image of the read original, and a detecting means for detecting an image density of the read original. Setting means for setting a threshold value for lowering the image formation density for each of the divided areas; a first mode in which image formation is performed at a normal image density setting; and an image density higher than the first mode. Instructing means for switching between the second mode to be reduced, and automatically operating the image when the image density detected by the detecting means exceeds the set threshold value while operating in the second mode. An image forming apparatus comprising: a processing unit configured to perform a density conversion process for each of the divided areas so as to reduce a formed density. 4. A document reading means reads a document placed on a document table and converts it into digital image information, and a detection means has a counting means for obtaining a sum of densities of respective pixels in each divided area. The processing means stores the sum of the densities of the pixels in each divided area of the digital image information obtained by the document reading means in the second mode, the average density of the digital image information obtained from the count value of the counting means; 4. The image forming apparatus according to claim 3, wherein a density conversion for automatically lowering an image forming density is performed when the value exceeds a set threshold value. 5. The image forming apparatus according to claim 1, further comprising an instruction unit configured to change the threshold value to two or more values. 6. The image forming apparatus according to claim 1, wherein when forming an image on a multi-color original, the threshold value and the processing unit are held for each color. apparatus. 7. The image forming apparatus according to claim 6, further comprising an instruction unit for changing the threshold value held for each color to two or more values for each color independently. 8. A control method of an image forming apparatus for reading a document on a document table and forming an image, wherein the image density of the read document is detected, and the image forming density is reduced according to an instruction from an operation unit. A threshold value is set, and a first mode in which image formation is performed at a normal image density setting and a second mode in which the image density is lower than in the first mode are switched. A method for controlling an image forming apparatus, wherein the image forming density is automatically reduced when the detected image density exceeds the set threshold value during operation. 9. An original is read and converted into digital image information, the sum of the densities of each pixel in all the images is counted, and the image density of the original is detected. In the second mode, the detected digital image information is detected. 9. The method according to claim 8, wherein when the average density exceeds a set threshold value, density conversion for automatically lowering the image forming density is performed. 10. A method of controlling an image forming apparatus for reading a document on a platen to form an image, comprising: identifying a divided region in an image of the read document as a character region or an image region; Detecting the image density of the read document, and setting a threshold value for reducing the image forming density for each of the divided areas according to an instruction on the operation unit,
    Switching between a first mode in which image formation is performed at a normal image density setting and a second mode in which the image density is lower than that of the first mode, and the detected image density is reduced during operation in the second mode. A method for controlling an image forming apparatus, wherein density conversion for automatically lowering image formation density when the set threshold value is exceeded is performed for each of the divided areas. 11. An original is read and converted into digital image information, the image density of the original is detected by counting the sum of the densities of pixels in each divided area, and the detected digital image information is detected in a second mode. 11. The control method for an image forming apparatus according to claim 10, wherein when the average density exceeds a set threshold value, density conversion for automatically lowering the image forming density is performed. 12. The method according to claim 8, wherein the threshold value is changed to two or more values. 13. The image forming apparatus according to claim 8, wherein, when an image is formed on a multi-color document, the setting of the threshold value and the density conversion are performed for each color. The control method of the image forming apparatus described in the above. 14. The control method according to claim 13, wherein the threshold value held for each color is changed to two or more values for each color independently.
JP2001320513A 2001-10-18 2001-10-18 Image forming device and control method therefor Withdrawn JP2003122063A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001320513A JP2003122063A (en) 2001-10-18 2001-10-18 Image forming device and control method therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001320513A JP2003122063A (en) 2001-10-18 2001-10-18 Image forming device and control method therefor

Publications (1)

Publication Number Publication Date
JP2003122063A true JP2003122063A (en) 2003-04-25

Family

ID=19137893

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001320513A Withdrawn JP2003122063A (en) 2001-10-18 2001-10-18 Image forming device and control method therefor

Country Status (1)

Country Link
JP (1) JP2003122063A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7738800B2 (en) 2006-12-04 2010-06-15 Brother Kogyo Kabushiki Kaisha Printing device having plural print density range settings
KR101062058B1 (en) 2007-04-18 2011-09-02 캐논 가부시끼가이샤 Image processing apparatus and image processing method for reducing consumption of recording material
KR101520151B1 (en) 2011-08-11 2015-05-13 캐논 가부시끼가이샤 Image processing apparatus, image processing method and computer-readable storage medium

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7738800B2 (en) 2006-12-04 2010-06-15 Brother Kogyo Kabushiki Kaisha Printing device having plural print density range settings
KR101062058B1 (en) 2007-04-18 2011-09-02 캐논 가부시끼가이샤 Image processing apparatus and image processing method for reducing consumption of recording material
KR101520151B1 (en) 2011-08-11 2015-05-13 캐논 가부시끼가이샤 Image processing apparatus, image processing method and computer-readable storage medium

Similar Documents

Publication Publication Date Title
US6701110B2 (en) Image forming apparatus having change-over type developing device
US7813010B2 (en) Document reading apparatus, image processing apparatus, image forming apparatus, and copying machine
EP1703714B1 (en) Image data processing device and method for processing image data
US8223401B2 (en) Image processing apparatus, image processing system, and image processing method
JP4269521B2 (en) Image processing apparatus and image forming apparatus
JP4323993B2 (en) Sheet feeding device, sheet feeding method, and control program
DE60106702T2 (en) Image data correction apparatus for correcting image data
JP3935252B2 (en) Image forming apparatus and job processing method
US7889393B2 (en) Document reading apparatus and an image formation apparatus therewith
EP0629926B1 (en) Image processor
US7742180B2 (en) Dust and/or dirt detection in image reading apparatus having read-while-feed function
US20060103881A1 (en) Image forming system
US7119926B2 (en) Dust and dirt detection in image reading apparatus having original flow scanning function
US6504628B1 (en) Color image-forming apparatus capable of discriminating the colors of the original image
US6393232B1 (en) Image forming apparatus capable of selecting discharge means according to material selection
US7403308B2 (en) Image forming apparatus
EP0557099A1 (en) Image processing apparatus
JP4495201B2 (en) Image processing apparatus, image forming apparatus, image processing method, image processing program, and recording medium for recording image processing program
JP3715711B2 (en) Image processing apparatus and image processing method therefor
JP2005249873A (en) Image forming apparatus and image stabilizing processing execution method
US8237997B2 (en) Image reader and image forming device
US5999646A (en) Image forming apparatus with image storage and image selection based on feature extraction
US6833926B1 (en) Image processing apparatus
JP4018568B2 (en) Image forming apparatus and paper setting control method
US8243347B2 (en) Image processing apparatus and method with reading mistake preventing function during document reading

Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20050104