JPH0349967A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image which is always stable by a method wherein a required range of a plurality of recording elements is specified and alteration of a correction state in the specified required range is collectively inputted. CONSTITUTION:When ten-key 207, 208, 209 are inputted, an input value at which a cursor exists among a start value C1, an end point value C2, and a correction data value C3 of a correction range is obtained. That is, establishment of C1, C2 data among indications of 'Range' by using ten-key 207 to 209 with the cursor corresponds to input of a required range of multi-nozzles of a recording head. Further, that indication of 'Data' is selected with an implicated cursor 203 and data is set by using the ten-key 207 to 209 corresponds to that a correc tion state of a RAM 271 is collectively inputted. Then, when a cursor transfer key 210 is inputted, the cursor moves successively under an altered correction rage and F45B expressing the correction data. When a color selection key 211 is inputted, indication is performed in the order of C,M,Y,K, and Y.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that forms images using multiple heads.

[Conventional technology]

This type of recording head has variations in output characteristics due to constituent materials, manufacturing processes, and the like. Therefore, if the recording head is used as is, density unevenness will occur in the output image. In particular, when a multi-recording head is used to form a color image, color unevenness occurs, which is even more serious. Therefore, the present applicant has proposed an image forming apparatus that corrects input image data using correction data that corresponds to the output characteristics of the recording head to prevent density unevenness.

Incidentally, actual density unevenness and color unevenness slightly change depending on the usage environment of the recording head, changes over time, and the like.

[Problem to be solved by the invention]

However, in the past, changes could not be dealt with unless the recording head was replaced or the correction ROM was rebuilt. For this reason, it is difficult to maintain image quality after shipment from the factory, and the cost of replacement parts is high.

The present invention eliminates the above-mentioned drawbacks of the prior art, and its purpose is to provide stable images at all times by eliminating density unevenness or color unevenness with simple operations and without replacing recording heads, etc. An object of the present invention is to provide an image forming apparatus that can obtain the following.

[Means to solve the problem]

In order to achieve the above object, the image forming apparatus of the present invention has the following features:
a correction means for correcting each recording condition of a plurality of recording elements constituting a multi-head for image formation; a specification means for specifying a desired range of the plurality of recording elements; and the correction in the desired range specified by the specification means. and input means for collectively inputting changes in the correction state of the means.

[For production]

In the above configuration, changes in the correction state within a desired range designated by the designation means are inputted all at once by the input means, and the correction state is changed by the correction means.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples. In the following embodiments, an image forming apparatus using an inkjet recording method will be described. In such inkjet recording, a head having a multi-nozzle provided with a plurality of nozzles for ejecting ink will be described as an example of a multi-head.

(Explanation of external appearance) FIG. 5 shows a sectional view of a digital color copying machine to which the present invention is applied.

The whole can be divided into two parts.

The upper part of Figure 4 shows the color image scanner section 1 (which reads the original image and outputs digital color image data).
The controller section 2 is built in the scanner section 1 and has processing functions such as an interface with external devices, as well as performing various types of image processing on digital color image data.

The scanner unit l has a built-in mechanism for reading a three-dimensional object and a sheet original placed downward under the original presser 11, and also for reading a large-sized sheet original.

Further, the operation section 10 is connected to the controller section 2, and is used to input various information regarding the copying machine. The controller section 2 instructs the scanner section 11 and printer section 3 regarding operations according to the input information. Further, when it is necessary to perform complicated editing processing, a digitizer or the like is attached in place of the document presser 11, and this is connected to the controller section 2, thereby making it possible to perform sophisticated processing.

The lower part of FIG. 5 is a printer section 3 for recording the color digital image signal output from the controller section 2 on recording paper. In this embodiment, the printer section 3 is a full color ink jet printer using an ink jet recording head described in Japanese Patent Laid-Open No. 54-59936.

The two parts described above can be separated, and can be installed at separate locations by extending the connecting cable.

(Printer section) First, the exposure lamp 14, the lens 15, and the image sensor 16 (in this embodiment, a C0D capable of reading full-color images) move the original table to the rear 17.
The original image placed on top and the sheet original image by the sheet feeding mechanism 12 are read. Next, various image processing is performed by the scanner section 1 and the controller section 2, and the image is recorded on recording paper by the printer section 3.

In FIG. 5, recording paper is stored in a paper feed cassette 20 that stores cut paper of small standard sizes (A4 to A3 size in this embodiment) and large size (A2 to Al size in this embodiment). It is supplied from a roll paper 29 for carrying out the process.

Further, paper feeding from outside the apparatus (manual paper feeding) is also possible by inserting recording paper one sheet at a time through the manual feed port 22 shown in FIG. 5 along the paper feeding unit cover 21.

The big up roller 24 is a roller for feeding cut sheets one by one from the paper feed cassette 20, and the fed cut sheets are conveyed to the 10th feed roller 26 by the cut paper feed roller 25. be done.

The roll paper 29 is sent out by a roll paper feed roller 30, cut into a standard length by a cutter 31, and conveyed to the first paper feed roller 26.

Similarly, the recording paper inserted through the manual feed slot 22 is conveyed to the paper feed roller 26 by the manual feed roller 32.

Pick up roller 24, cut paper feed roller 25
, the roll paper feed roller 30, the 10th paper feed roller 26, and the manual feed roller 32 are connected to a paper feed motor (not shown in the drawings, D
It is driven by a C servo motor (using a C servo motor), and can be turned on and off at any time by electromagnetic clutches attached to each roller.

When the printing operation is started in response to an instruction from the controller unit 2, recording paper selectively fed from one of the above-mentioned paper feeding paths is conveyed to the first paper feeding roller 26. In order to eliminate the skew of the recording paper, after forming a predetermined amount of paper loops, the first paper feed roller 26 is turned on and the recording paper is conveyed to the 20th paper feed roller 27.

When printing with the recording head 37, the recording head 3
A scanning carriage 34 on which a device 7 or the like is attached performs reciprocating scanning on a carriage rail 36 by a scanning motor 35.

Then, in the outward scan, the image is printed on recording paper,
In the backward scan, the paper feed roller 28 performs an operation to feed the recording paper by a predetermined amount.

The printed recording paper is discharged to the paper discharge tray 23, and the printing operation is completed.

Next, the scanning carriage 3 and the invention will be described in detail using FIG.

In FIG. 6, a paper feed motor 40 is a drive source for intermittently feeding the recording paper, and a paper feed roller 28,
The 20th paper feeder 27 is driven via the 0-ra clutch 43.

The scanning motor 35 moves the scanning carriage 34 to the scanning belt 34.
This is a drive source for scanning in the directions of arrows A and B. In this embodiment, since accurate paper feed control is required, the paper feed motor 40. A pulse motor is used as the scanning motor 35.

When the recording paper reaches paper feed number 20-27, paper feed number 20
-La clutch 43 and paper feed motor 4o are turned on, and the recording paper is conveyed over the platen 39 to the paper feed roller 28.

The recording paper is detected by a paper detection sensor 44 provided on the platen 39.
The sensor information is used for position control, jam control, etc.

When the recording paper reaches the paper feed roller 28, the paper feed number 20-
The clutch 43 and paper feed motor 4o are turned off, and a suction operation (not shown) is performed from inside the platen 39 to bring the recording paper into close contact with the platen 39.

Prior to the image recording operation on recording paper, the scanning carriage 34 is moved to the position of the home position sensor 41,
Next, forward scanning is performed in the direction of arrow A, and cyan, magenta, yellow, and black inks are ejected from the recording head 37 from predetermined positions to record an image. After recording the image for a predetermined length, the scanning carriage 34 is stopped, and reverse scanning is started in the direction of arrow B to return the scanning carriage 34 to the position of the home position sensor 41. During the backward scan, the paper is fed by the length recorded by the recording head 37 in the direction of arrow C by driving the paper feed roller 28 by the paper feed motor 40.

In this embodiment, the recording head 37 is an ink jet nozzle that uses heat to form air bubbles and uses the resulting pressure to eject ink droplets, and uses four ink jet nozzles with 256 nozzles each assembled. ing.

Scanning carriage 34 is home position sensor 41
When it stops at the home position detected by , the recording head 37 performs a recovery operation. This is a process for stable printing operation, and in order to prevent unevenness at the start of ejection caused by changes in the viscosity of the ink remaining in the nozzles of the print head 37, paper feed time, device This is a process in which pressure is applied to the recording head 37, ink is idly ejected, etc., based on preprogrammed conditions such as internal temperature and ejection time.

By repeating the operations described above, an image is recorded on the entire surface of the recording paper.

(Scanner Section) Next, the operation of the scanner section 1 will be explained using FIGS. 7 and 8.

FIG. 7 is a diagram for explaining the mechanical mechanism inside the scanner section 1.

The CCD unit 18 is a unit composed of a CCD 6, a lens 15, etc., and a main scanning motor 50 fixed on a rail 54, a pulley 51 . Boo U52, wire 53
It moves on the rail 54 by a drive system in the main scanning direction consisting of the following, and reads the image on the document platen glass 17 in the main scanning direction. The light shielding plate 55 and the home position sensor 56 are used for position control when moving the CCD unit 18 to the main scanning home position in the correction area 68 in the figure.

The rail 54 rests on rails 65 and 69, and includes a sub-scanning motor 60, pulleys 67, 68, 71, and 76, and a shaft 72.
73, is moved by a drive system in the sub-scanning direction consisting of wires 66 and 70. Light shielding plate 57, home position
Sensors 58-59 are used to move the rail 54 to the home position for each sub-scan in the book mode for reading a document such as a book placed on the document platen glass 17, and the sheet mode for sheet reading. Used for position control.

Sheet feeding motor 61. Sheet feed rollers 74 and 75,
The pulleys 62 and 64 and the wire 63 are mechanisms for feeding the sheet original. This mechanism is located on the document table glass 17, and transports the sheet document placed face down to the sheet feed roller 7.
This is a mechanism for feeding a predetermined amount at a time of 4.75.

FIG. 8 is an explanatory diagram of the reading operation in book mode and sheet mode.

In the book mode, the CCD unit 18 is moved to the illustrated book mode home position (book mode HP) in the correction area 68 in FIG. Start reading the entire surface.

Prior to scanning the original, data settings necessary for processing such as shading correction, black level correction, and color correction are performed in the correction area 68. Thereafter, scanning in the main scanning direction is started by the main scanning motor 50 in the direction of the illustrated arrow. When the reading operation in the area indicated by ■ is completed, the main scanning motor 50
and drive the sub-scanning motor 60,
The correction area 68 of the area is moved in the sub-scanning direction.

Subsequently, similarly to the main scanning of the area (2), processing such as shading correction, black level correction, color correction, etc. is performed as necessary, and the reading operation of the area (2) is performed.

By repeating the above scanning, the entire areas ① to ② are read, and after the reading operation in the area ② is completed, the CCD unit 18 is returned to the book mode home position.

In this embodiment, the document platen glass 17 can read a maximum A2 size document, so in reality it must perform more scanning, but in this explanation, the operation will be simplified to make it easier to understand. ing.

In the seat mode, the CCD unit 18 is moved to the seat mode home position (seat mode H) shown in the figure.
P), and repeatedly reads the sheet document in the area (3) while operating the sheet feed motor 61 intermittently, thereby reading the entire sheet document.

Prior to scanning the document, processing such as shading correction, black level correction, and color correction is performed in the correction area 68, and then scanning in the main scanning direction is started by the main scanning motor 50 in the direction of the arrow shown in the figure. When the forward scanning operation of the area (3) is completed, the main scanning motor 50 is reversed, and during this backward scanning, the sheet feed motor 61 is driven to move the sheet original by a predetermined amount in the sub-scanning direction. Subsequently, the same operation is repeated to read the entire sheet document.

Assuming that the reading operation described above is a reading operation at the same magnification, the area that can be read by the CCD unit 18 is actually a wide area as shown in FIG. this is,
This is because the digital color copying machine of this embodiment has a built-in magnification/reduction function. That is, as explained above (
This is because the area that can be recorded by the recording head 37 is fixed at 256 bits at a time, so when performing a 50% reduction operation, for example, image information of at least twice the area of 512 bits is required. be. Therefore, the scanner unit l has a built-in function of reading and outputting image information of an arbitrary image area by one main scanning reading.

(Overall Functional Block Description) Next, the functional blocks of the digital color copying machine of this embodiment will be described using FIG. 9.

Control unit 102. Reference numerals 111 and 121 are control circuits that control the scanner section 1, controller section 2, and printer section 3, respectively.
Consists of OM, data memory, communication circuit, etc. The control units 102 to 111 and the control units 111 to 121 are connected by a communication line, and the control units 102 . A so-called master-slave control mode is adopted in which the controller 121 performs the operation.

When operating as a color copying machine, the control section 111 performs control operations in accordance with input instructions from the operation section IO and the digitizer 114.

The digitizer 114 is used to input position information necessary for trimming, masking processing, etc., and is connected as an option when complex editing processing is required.

The control unit 102 controls the mechanical drive unit 105 that controls the drive of the mechanism of the scanner unit 1 described above, and the exposure control unit 103 that controls the exposure of the lamp when reading a reflective original. The control unit 102 also includes an analog signal processing unit 100 that performs various types of processing related to images, and an input image processing unit 10 that performs various types of processing related to images.
1 is also controlled.

The control unit 121 includes a mechanical drive unit 105 that controls the drive of the mechanism of the printer unit 3 described above, and a mechanism that absorbs time variations in the mechanical operation of the printer unit 3 and compensates for delays due to the mechanical arrangement of the recording heads 117 to 120. The synchronization delay memory 115 is controlled to carry out the synchronization.

Next, the image processing block shown in FIG. 9 will be further explained in detail along the flow of the image.

The image formed on the C0D 16 is converted into an analog electrical signal by the CCD 16. The converted image information is
The signals are serially processed in the order of red → green → blue and input to the analog signal processing section 100. The analog signal processing unit 100 performs sample-and-hold, correction of dark medium level, dynamic range control, etc. for each color of red, green, and blue, and then performs analog-to-digital conversion (A/D conversion) and serial multi-color signal processing. The digital image signal is converted into a digital image signal with a value (in this embodiment, each color has a length of 8 bits) and is output to the input image processing unit 101.

The input image processing unit 101 similarly performs correction processing necessary in the reading system, such as CCD correction and γ correction, on the serial multivalued digital image signal.

The image processing unit 107 performs smoothing processing, edge enhancement,
This circuit performs black extraction, masking processing for color correction of recording ink used in the recording heads 117 to 120, and the like. The serial multilevel digital image signal output is input to the binarization processing unit 108 and the buffer memory 110, respectively.

The binarization processing unit lO8 is a circuit for binarizing a serial multilevel digital image signal, and can select simple binary processing using a fixed slice level, pseudo halftone processing using a dither method, etc. Here, the serial multi-value digital image signal is converted into a four-color binary parallel image signal.

Image data of four colors is sent to the binary synthesis unit 109, and image data of three colors is sent to the buffer memory 110.

The synchronization delay memory 115 of the printer section 3
Absorption of time variations in mechanical operation and recording head 117~
This is a circuit for correcting the delay due to the mechanical arrangement of the recording heads 117 to 120, and internally also generates the timing necessary for driving the recording heads 117 to 120.

The head driver 116 drives the recording heads 117 to 120.
This is an analog drive circuit for driving the recording heads 117 to 120, and internally generates signals that can directly drive the recording heads 117 to 120.

The recording heads 117 to 120 each eject cyan C1 magenta M1 yellow Y1 black ink,
Record an image on recording paper.

FIG. 10 is an explanatory diagram of the timing of images between the circuit blocks described in FIG. 9.

Signal BVE is a signal indicating the image valid section for each scan in the main scanning reading operation explained in FIG. Signal B
Full-screen image output is performed by outputting VE multiple times.

The signal VE is a signal indicating the valid section of the image read by the CCD 16 for each line. Only the signal VE is valid when the signal BVE is valid.

Signal VCK is a clock signal for sending out image data VD. Signal BVE and signal VE also change in synchronization with this signal VCK.

The signal H8 is a signal used when the valid and invalid sections are repeated discontinuously while the signal VE outputs one line.
If the signal VE is continuously valid while outputting one line, it is an unnecessary signal. This is a signal indicating the start of image output for the l line.

Next, the rough signal processing in the image processing section will be explained using FIG. 11.

In FIG. 9, a serial number (for example,
2. The image data (hereinafter referred to as input image data) input in the order of Y(
After converting into parallel signals of yellow), 9M (magenta), and C (cyan), the signals are sent to the masking unit 202 and the selector 203.

The masking unit 202 is a circuit for correcting cloudiness in the color of output ink, and performs calculations as shown in the following equation.

Therefore, the A/D converter 110 has B, G, R, B,
G.

Digital data is output in the order of R...

The obtained digital data is converted into complementary color data Y, M, and C by the complementary color conversion circuit 120.

Y, M, C, etc. are output in this order.

The obtained color sequential color image data is sent to the time axis conversion unit 20.
Sent to 0a. Since the input image data and subsequent image data have different frequencies, the time axis converter 200a changes the frequency according to the time axis conversion control signal sent from the control unit 200 and outputs the time axis converter. .

The output image data (hereinafter referred to as input image data) is sent to a serial/parallel converter 201, where it is converted into parallel signals of Y (yellow), M (magenta), and C (cyan), and then sent to a masking unit 202 and It is sent to the selector 203.

The masking unit 202 is a circuit for correcting cloudiness in the output ink color, and performs calculations as shown in the following equation.

Y, M, C: Input data Y', M', C': Output data These nine coefficients are determined by the masking control signal from the control unit 200. After correcting the ink cloudiness in the masking unit 202, the serial signal The data is input to the selector section 203 and the UCR section 205 as a.

Input image data and image data output from the masking unit 202 are input to the selector 203 .

The selector 203 normally selects input image data based on the selector control signal 1 sent from the control section 200. If the color correction in the input system is not sufficiently performed, the image data output from the masking unit 202 is selected and output by the control signal l. The serial image data output from the selector 203 is input to the black extraction section 204. Y, M in one pixel.

In order to use the minimum value of C as black data, the black extraction unit 204 uses Y
, M, and C are detected. The detected black data is input to the UCR section 205.

The UCR unit 205 subtracts the extracted black data from each of the Y, M, and C signals. Also, regarding black data,
It is simply multiplied by a coefficient. After correcting the time difference between the black data input to the UCR unit 205 and the image data sent from the masking unit 202, the following calculation is performed.

Y'=Y-alBk M'=M-a2Bk C'=C-a3Bk Bk'=a4Bk Here, Y, M, C, and Bk indicate the extraction unit input data,
Y'M', C', and Bk' indicate extraction unit output data. And the coefficient (a I+ a2+ a3
．． a4) is determined by the UCR control signal sent from the control section 200.

The data output from the UCR unit 205 is then input to the γ, offset 206.

At the γ, offset 206, gradation correction is performed as shown in the following equation.

Y' = b+ (Y C+) M' = b 2 (MC2) c' =
b3 (c-c3) Bk' = b 4 (Bk C4) where Y, M,
C, Bk are γ, offset part has large input data, Y',
M', C', and Bk' are γ and small offset part output data.

Further, the coefficients (b+~b4.c,~C4) in the above equation are determined by the γ and offset control signals sent from the control unit 200.

The signal gradation-corrected by the offset 206 is then sent to the line buffer 20 which stores image data for N lines.
7 is input. This line buffer 207 outputs 5 lines of data necessary for the subsequent smoothing and edge emphasis section 208 in 5 lines in parallel according to the memory control signal sent from the control section 200. These 5 lines worth of signals are input to a spatial filter whose filter size is variable according to a filter control signal from the control unit 200, and smoothed.
Edge enhancement is then performed.

The image data output from the smoothing and edge enhancement unit 208 is input to a color conversion unit 209, and color conversion is performed in response to a color conversion control signal from the control unit 200.

The color to be converted, the color to be converted, and the area in which the signal is valid are input in advance from the digitizer device 114 in FIG. 8, and the color conversion unit 209 replaces the image data based on the data.

In this embodiment, a detailed explanation of the color conversion unit 209 will be omitted. The image signal output from the smoothing and edge emphasis section 208 and the image signal after color conversion are input to the selector 210, and the selector control signal 2 selects the image data to be output. Which image data to select is determined by specifying a valid area input from the digitizer device 114. The image signal selected by the selector 210 is input to the buffer memory 110 and the binarization processing section 108 in FIG.

Next, the head correction section 211 will be explained using FIG. 3.

FIG. 3 is a block diagram of the head correction section 211 shown in FIG.
This is a 10-bit counter that generates 60 addresses (hereinafter referred to as selection RAM), and in this embodiment, a 256-nozzle head is a 10-bit counter that counts values corresponding to 4 colors, that is, a total of 1024 nozzles. Controlled by VE.

The ROMs 265 to 268 are characteristic ROMs in which characteristic information of density unevenness of 256 nozzles provided in each of the C, M, Y, and Bk heads is written. ~268 are written with head density unevenness correction data corresponding to the number of nozzles. VDin has digital image data of C, M, Y, K, C, M, Y.

Color component image data for each pixel, such as K, is input point by point. Data is taken out from the ROMs 265 to 268 and stored in the selection RAM 260 in accordance with the order of input image data. 263 is ROM265~2
This is a bidirectional buffer for writing data retrieved from 68 into RAM 260.

A selector 259 selects either the lower 10 bits of the 16-bit address bus output from the CPU 258 or the 10-bit output of the counter 250. When writing data to the RAM 260, the selector 259 selects the output of the CPU 258, and
When reading data from M260, counter 250
Select the output of

The data output from the RAM 260 is input to the address of the correction table ROM (hereinafter referred to as correction ROM) 262 together with the image data VDin via the flip-flop 252.

In the correction ROM 262, correction tables as shown in 1 to 5 in FIG. 12 are written in advance. Although five types of correction tables are shown in FIG. 12, there are actually many more correction tables. For example, the range may be within ±30% in 1% increments. Further, the table written in the correction ROM 262 is written so as to output the correction data ΔA for the input A, and the correction data ΔA is selected according to the image signal VDin input to the address of the ROM 262 and the selection data, and the flip-flop The input image data A is once latched by the input image data A by the adder 256.
and is outputted via the flip-flop 257 as corrected data A+ΔA.

The RAM 271 is a working RAM used when writing characteristic data from the characteristic ROMs 265 to 268 into the selection RAM 260. Also, the backup RAM 272 retains the data written in the selection RAM 260 (R
AM, and is constantly backed up by a battery 273. Both the RAM 271 and the backup RAM 272 are used by an operator from the operation unit 10 when changing the characteristics of each head to characteristics different from the contents of the characteristics ROMs 265 to 268.

Next, a method for rewriting the data held in the RAM 271 in this embodiment will be described with reference to FIG. 1-1 and subsequent figures.

1-1 to 1-3 are diagrams for explaining the range to be corrected and the procedure for changing correction data, and FIG.

When changing the correction data is selected using a key (not shown) on the operation unit 10 shown in FIG. 5, the screen shown in FIG. 1-1 is first displayed. The same figure shows 30 on the 300 operation section in Figure 3-1.
This is a screen displayed on the LCD touch panel of No. 1. Incidentally, FIG. 3-1 is a diagram showing the top and vicinity of the document table glass 17 shown in FIG. 5.

In the figure, a ◎ key 200 is a key for returning to the previous screen, that is, a standard screen (not shown), and a ■ key 201 is a key for returning to the “Ra”
The ← and → keys 203 are keys for clearing the value (correction range) that is displayed as “nge” (correction range) and the value (correction data) that is displayed as “Data”. Range” (correction range) start point value CI, end point value C
2. Keys for sequentially moving below the values of 'Data' (correction data), the (mouth) key 204 changes the color to C,
This key is used to switch in order from M to Y. (<Key 2
05 is the displayed "Range (correction range)" and "D"
This key is used to set the next correction range and correction data after completing the setting of "ATA" (correction data). (3 key 202 is used to display all changed correction ranges and correction data and confirm the changed values. This key is used to move from the display shown in Fig. 1-1 to the display shown in Fig. 1-3.

In addition, the numeric keys 207, 208, and 209 in Figure 1-2 are keys for setting the value at the position of the cursor while displaying the drawing 1-1, and the S key 208 is the key for setting the value at the position of the cursor while displaying the drawing in Figure 1-1. The keys used in settings are the boxed keys 2 shown in Figure 1-2.
09 is a key for clearing the value at the cursor position. This numeric keypad is located at 299 of the operation section 300 in FIG. 3-1.

FIG. 1-3 shows a screen displayed on the liquid crystal touch panel 301 on the operation unit 300 in FIG. 3-1 when the CEED key 202 in FIG. 1-2 is pressed. In the same figure, e
, e key 210 is a key for sequentially moving the cursor to the black clay representing the pair of the set correction range and correction data. (D key 212 saves the data of the displayed color (ex, cyan) to the ROM 265-26.
The (tE) key 213 is a key for loading from one of 8 and returning (clearing) to the initial value before change. This key is used to return to the screen shown in FIG. 1-1 and display the correction range and correction data.

The (correct) key 214 is a key for returning to the standard screen (not shown) by pressing it when the correction range and correction data for all C, M, Y, and K colors have been changed.

Next, using FIG. 2, the operation of the CPU in which data is input using the displays shown in FIGS. 1-1 and 1-2 and the numeric keypad shown in FIG. 1-3 will be shown in a flowchart, and this will be explained below. do.

First, when you enter this correction data change mode,
The figure is displayed on the screen (STPlooO). Then, a cursor is displayed (STPlooI).

Then, it waits for key input (STP1002), and if a key is input, the corresponding process is performed. If the return to previous screen key 200 is input, the process returns to the standard screen (not shown) and ends (STP1003). When the clear key 0201 is input, it is shown as “Range” (correction range)
Clear the starting point value, ending point value, and value of "Data" (correction data), redisplay Figure 1-1, and ask the user to re-enter (STP1004).If the cursor movement keys 0 and 02oa are input, , move the cursor to the starting point value C1 of "Range"
, end point value C2, and move sequentially below the value of "Data" (STP1005).

If the color selection key (m) 204 is input, C, M.

Display C, M, Y, K in the order of Y and K, and then
-1 Redisplay the diagram (STP1006). (Kada D205
When the key is input, the modification of the correction data for the currently displayed correction range is completed, and FIG. 1-1 is redisplayed for setting the next correction range and correction data (STPIO07).

If the numeric keys 207, 208, and 209 are input, the input value will be the value at the cursor among the correction range start point value C1, end point value C2, and correction data value C3 (STP1008
).

That is, in this embodiment, the cursor 203 selects "Ra".
Data on CI and C2 displayed on nge using numeric keypad 20
7 to 209 corresponds to inputting the desired range of the multi-nozzle of the recording head.

Furthermore, selecting the "Data" display with the primary cursor 203 and setting data using the numeric keys 207 to 209 corresponds to inputting the correction state of the RAM 271 all at once. If confirmation key CWT> 202 is input, the screen shown in Figure 1-3 will be displayed (STP100
9).

Then, a cursor is displayed (STPIOIO). Then, it waits for key input (if the STPIO key is input, it performs the corresponding process.Cursor movement key e,
When e210 is input, it sequentially moves under Nα representing the changed correction range and correction data (STPIOI2
). If color selection key (mouth ff1) 211 is input,
Display C, M, Y, K in the order of C, M, Y, K and redisplay Figure 1-3 (STPIOI3)
.

When the all clear key (Th212) is input, the data of the displayed color is loaded from any of ROM265 to 268, cleared to the initial value, and the initial value is set to 1-3.
Redisplay in the figure (STPIOI4). ([) key 214
If is input, all correction changes are considered to have been completed and confirmed, and the screen returns to the standard screen (not shown), and the settings are completed (
STPIOI6).

When the correction key ([) 213 is input, the screen shown in Fig. 1-1 is displayed in order to correct the correction range or correction data where the cursor is located, and waits for the operator's correction input ( STPIOI5).

FIG. 3 shows a method for specifying in which part (range) of a test pattern the density unevenness is easily determined. In the embodiment shown in FIG. 3-1, scanner 298
A density unevenness measurement case 304 is provided on the original pressure plate 302 (this density unevenness measurement case does not need to be on the original pressure plate and may be portable).

This density unevenness measurement case 304 is composed of a ruler 303 and a transparent cover 305, and an image 306 for unevenness measurement is inserted between the covers 305. or,
The ruler 303 shown in FIG. 3-1 moves in directions A and B (therefore, it is possible to measure the tip of the image 306 by aligning it with the reference of the ruler 303. The image for measuring unevenness is limited to the above example. Other images may be used, for example, the image shown in FIG. By printing out a pattern 307 that has a margin around the center and a scale that can be used as a ruler, the range of density unevenness can be measured without the use of tools such as those shown in FIG. 3-1.

Further, FIG. 3-3 shows an apparatus having a digitizer 308, and it is easy to specify the range of density unevenness using a pen 309, which is a range specifying means.
This eliminates the need for input, improving operability.

Such a digitizer 308 corresponds to the digitizer shown in FIG. 9 114. The density unevenness correction data set in the above-mentioned procedure is stored in the RAM 271 by the CPU 258.
As described above, the heads 117 to 117 shown in FIG.
The image data to be given to the binarization processing unit 120
8 is corrected before the binarization process.

[Embodiment 2] In this embodiment, the same correction data is given to all the set correction ranges, but the present invention is not limited to this.If predetermined correction data is given to the set correction range, the correction range Correction data that draws a gentle curve may be automatically written into the RAM 271 based on the predetermined correction data.

Also, if you apply certain correction data to the set correction range, a gentle curve with a certain width will be drawn based on the correction data for a certain range before and after the correction range that is outside the correction range. It may also be possible to provide corrective correction data.

As a result, the correction time can be shortened, and stable correction can be performed without setting a very accurate range.

[Embodiment 3] In the above embodiment, the liquid crystal touch panel 301 is used as a means for displaying, adjusting, and changing the correction range and amount of correction, but the present invention is not limited to this, and other means may be used. For example, if the variable range of the correction level is relatively narrow, L E D 250 a ~ 2 as shown in FIG.
50 f and keys 207 to 209 may be used. In this case, if the nozzle range to be corrected can be set using the digitizer as shown in Figure 3-3, a gentle curve will be drawn based on the correction data given by the key 207 within that correction range. If data is provided, sufficient correction can be made without compromising operability, and the simple configuration reduces costs.

In addition, if such correction adjustment is to be performed at the time of shipment from the production factory or by a market service person, there is no need to have the above digitizer in the main body, but a simple digitizer ( In this embodiment, the heads 117 to 120 each have 256 nozzles and 1 nozzle.
6mm, so it would be better if you could specify a range of 16mm).

Next, a method of operating the operating section shown in FIG. 13 will be explained.

When the correction key 251 is pressed, the LED 250a displays a message such as "H" to indicate that the correction mode has been entered.

By pressing the correction key 251 in sequence, the color can be switched to cyan, magenta, yellow, and black. Next, a correction range is specified using a digitizer as shown in FIG. 3-3, and when two points are specified, the LEDs 250c to 250f are turned on to indicate that the correction range has been determined. For example, the LED 250c indicates cyan, the LED 250d indicates magenta, the LED 250e indicates yellow, and the LED 25Of indicates black. If you want to change this correction range, click
D-209 clears the correction range and LED2
50c to 250f are turned off. Once the correction range is confirmed,
Correction data is input using the numeric keypad 207 and the [:] key 208, and the input value is displayed on the LED 250b. If this correction data is desired to be changed, the correction data is cleared to "D" using group-209. Correction mode status (
If the m key 252 is pressed while the LED 250a is in the "H" display state, a test pattern that makes it easy to determine density unevenness is output.

The m key 253 exits from the correction mode state and enters the normal copy state. "H" of the LED 250a disappears. Here, it goes without saying that the LEDs 250a, 250b, and 250c are used to display the number of copies in the normal copying state.

Furthermore, when specifying and correcting multiple correction ranges in one setting, a key for inputting a command to move on to specifying the next correction range may be added.

Furthermore, a key such as the 'f key 212 in Figure 1-3 may be added to load the data of the displayed color from the ROM and return (clear) it to the initial value before change. .

According to the embodiments of the present invention described above, there is a means for correcting image data according to the output characteristics of each nozzle of a multi-head for image formation, a means for setting a range to be corrected, and a means for changing the amount of correction within that range, and a display. By providing a means, the above-mentioned problems can be solved, the correction can be made arbitrarily variable, the density unevenness of the recording head can be dealt with with easier operation, the operation time can be shortened, and the image can always be stable and without unevenness. I can do what I get.

Further, depending on the case, a display means is not particularly necessary.

Furthermore, although the above embodiments have been described using an inkjet recording method, the present invention is not limited thereto. It is also applicable to other wire tod methods, electrostatic methods, and thermal transfer methods.

Also, for example, an image capture memory for -image information is added, a test pattern image that is easy to judge density unevenness is printed on the other hand, and the printed test pattern image is read from the scanner section and the image information is stored in the added memory. The correction data may be changed automatically by storing the image information and comparing and calculating the image information with the image information of the test pattern image.

Furthermore, in the embodiments described above, when correcting the printing conditions of the printing elements, the image data given to each printing element is corrected, but the present invention is not limited to this. For example, a method may be used in which the electric energy given to each recording element is changed. Furthermore, when using an inkjet method that ejects ink using air pressure and electrostatic force as a multi-head, for example, the printing conditions of each printing element can be changed by correcting the air pressure and/or electrostatic force mentioned above. Good too. In this way, the correction method can be modified in various ways depending on the recording method of the image forming head.

〔Effect of the invention〕

As described above, according to the present invention, even if the density variation of the recording head changes, it is possible to input the density variation in a desired range of multiple elements at once, and it is possible to respond to changes in density variation with a simple operation. , can always provide stable and even images.

[Brief explanation of drawings]

Figures 1-1, 1-2, and 1-3 are explanatory diagrams of the correction range setting screen, operation keys, and correction data change screen of one embodiment of the present invention, and Figure 2 is an illustration of the CPO 258 shown in Figure 4. FIG. 3-1, FIG. 3-2, and FIG. 3-3 are diagrams showing an example of a correction range setting means; FIG. 4 is a diagram showing a detailed circuit of an embodiment of the present invention; Fifth
The figures are a sectional view of a digital color copying machine embodying the present invention, Figure 6 is a detailed explanatory view of the area around the scanning carriage, and Figure 7 is
The figure is a diagram of the mechanical mechanism inside the scanner unit, Figure 8 is a diagram explaining the reading operation of the scanner unit, Figure 9 is an explanatory diagram of the functional blocks of the digital color copying machine shown in Figure 4, and Figure 1O is an image between circuit blocks. FIG. 11 is a block diagram of a color image processing device; FIG. 12 is a diagram illustrating correction data written in a correction table; FIG. 13 is a diagram illustrating an operation unit of another embodiment of the present invention. . 260...Selection RAM 262...Correction ROM 256...Adder 258...CPU 10...Operation unit 265-268...Characteristics ROM 271...Work RAM 272...Backup RAM 203 ...Key for specifying range setting mode 207...Numeric keypad 2/Z Figure 3-7

Claims (3)

[Claims] (1) A correction means for correcting each recording condition of a plurality of recording elements constituting a multi-head for image formation, a designation means for designating a desired range of the plurality of recording elements, and a desired range designated by the designation means. An image forming apparatus comprising: input means for collectively inputting changes in the correction state of the correction means. (2) The image forming apparatus according to claim 1, wherein the correction means is a means for correcting image data given to each recording element as the recording condition. (3) The image forming apparatus according to claim 1, wherein a color image is formed using a multi-head.