JPH11177822A - Image forming device, image processing method and record medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the frequency of calibration processing and to shorten queuing time by providing an image forming device with a calibration means for updating an output condition processed in accordance with an output characteristic and a means for storing calibration timing information, controlling execution timing and executing image processing corresponding to an output mode set up for an inputted image. SOLUTION: Received data are stored in a transmitting/receiving buffer 103, and when a received command is a correction table updating interval setting command, a table updating interval setting part 112 stores a correction table updating interval in a correction interval data storing part 116. When the received command is not the interval setting command, a color correction part 110 executes color correction for a plotting command by the use of a correction table 115 and a plotting part 109 plots the corrected plotting command in a raster storing part 114. Since the setting part 112 sets up the number of correction intervals and updates the correction table 115, queuing time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, an image processing method, and a recording medium for controlling a calibration execution timing.

[0002]

2. Description of the Related Art In a conventional printer having a calibration function for periodically measuring density characteristics from output results and correcting the density characteristics according to the measurement results, the interval at which the calibration process is performed is constant.
Correction was performed periodically every time 0 sheets were printed.

[0003]

However, since the calibration process takes a certain amount of time, some users desire to reduce the frequency of the calibration process and reduce the waiting time that can be caused by the calibration process.

In particular, depending on the output mode, there is no problem in image quality even if the frequency of the calibration processing is reduced. Therefore, there is a demand to control the interval at which the calibration processing is automatically performed according to the output mode.

[0005] An object of the present invention is to provide an image forming apparatus, an image processing apparatus, and a recording medium that meet the above demands.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided an image forming apparatus for processing an image in accordance with a set output condition and forming an image, wherein a calibration means for updating an output condition in accordance with an output characteristic; Storage means for storing calibration timing information corresponding to each of the output modes; input means for inputting an image; setting means for setting an output mode for the image; and image processing according to the set output mode And a control unit for controlling the calibration execution timing based on calibration timing information corresponding to the set output mode.

[0007]

(Embodiment 1) Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic block diagram showing a printing apparatus according to this embodiment.

In FIG. 1, reference numeral 100 denotes a host computer, which is connected to a control unit 101 of a printer shown by a broken line via a connector / network or the like. The control unit 101 is configured to receive print data from the host computer 100 and print out the print data. Reference numeral 102 denotes a CPU, which performs calculations and controls for performing the entire control of the printer device control unit 101. A transmission / reception buffer 103 temporarily stores transmission / reception data exchanged with the host computer 100. 104 is a program ROM
And stores a program and the like for implementing a series of printer controls. An image output unit 105 outputs the image data stored in the raster storage unit 108 to the printer engine unit. A scanner unit 106 reads an image output from the image output unit 105. A font ROM 107 stores character fonts. Reference numeral 108 denotes a RAM that stores a work area when the CPU 102 executes each program, a raster storage unit 115 that stores a drawn image of one page, and a correction table that stores a correction table used for color correction of a drawing command. Function as a correction table update interval storage unit 116 for storing an interval for updating the correction table.

Further, a power supply device (not shown) is connected to the control unit 101.

The program ROM 104 includes, as programs, a drawing unit 109 for drawing a print command input from a host in a raster storage unit 115, and a correction unit 11 for performing color correction on a received drawing command.
0 or the number of output sheets and the data in the correction table update interval storage section 116, and a correction table update interval detection section 111 for periodically detecting the timing of updating the correction table.
A correction table update interval setting unit 112 that sets an interval for updating the correction table from the host or the panel; and a correction table creation unit 113 that updates the correction table at the timing detected by the correction table update interval detection unit 111.
Is stored.

The correction unit 110 performs a masking process, a quantization process (such as a dither process or an error diffusion process) in accordance with a user's manual instruction, and a gradation correction using a correction table stored in a correction table storage unit. The masking process and the quantization process performed on the color data are performed in an output mode (high precision, high speed or resolution emphasis, gradation emphasis) set by the user interface of the driver software for the printer device stored in the host computer. , Etc.), the processing content is set. The set output mode information is sent / received from the host computer.
The content of each process of the correction unit 110 is input via the reception buffer, and is set by the CPU 102 according to the output condition information.

The correction table updating unit 113 includes an output patch creating unit 117 for creating data indicating an output patch to be formed when performing correction, and an output patch creating unit 11 for creating output data.
7, an output patch output unit 118 that outputs the data created by the image output unit 105 to the image output unit 105, an output patch reading unit 119 that reads the density of the output patch created by the image output unit using a scanner unit, and an output patch creation unit A correction table creation unit 120 that creates a correction table based on the data created in 117 and the data read by the output patch reading unit 119 is included.

The programs of the respective parts stored in the program ROM are read out under the control of the CPU 102 and executed using the RAN 108 as a work memory in order to realize the flowchart shown in FIG.

Next, a printer 101 having the configuration shown in FIG.
Will be described with reference to the flowchart shown in FIG.

First, in step S201, data is received from the host computer 100, the received data is stored in the reception buffer 103, and data of one unit code is read from the stored reception buffer 103.

Next, in step S202, it is determined whether or not the received command is an end command.

If the received command is not the end command in step S202, the process proceeds to step S203,
It is determined whether the received command is a correction table update interval setting command.

If the received command is a correction table update interval setting command in step S203, the process proceeds to step S206, and the correction table update interval setting section 112
Thus, the correction table update interval is stored in the correction interval data storage unit 116, and the process returns to step S201.

If it is determined in step S203 that the received command is not the correction table update interval setting command, the process proceeds to step S204, where the drawing command is subjected to color correction by the color correction unit 110 using the correction table 115. Next, in step S205, the drawing command with the color corrected is drawn by the drawing unit 109 in the raster storage unit 114, and the process returns to step S201.

If it is determined in step S202 that the received command is the end command, the flow advances to step S207 to send the drawn raster in the raster storage unit 114 to the image output unit 105 and perform printing.

Next, the number of output sheets is counted in step S208, and the number of output sheets is compared with the number of sheets in the correction interval data storage section 116 by the correction table update interval detecting section 111.

If it is determined in step S208 that the correction table is not updated, the process returns to step S201.

If it is determined in step S208 that the correction table is to be updated, steps S209 to S21 are performed.
A calibration process for updating the correction table shown in FIG. 2 is executed. First, the process proceeds to step S209, where the output patch creating unit 117 creates data indicating an output patch for updating the correction table. Next, the process proceeds to step S210, where the output patch output unit 118 outputs the created data to the image output unit 105 to form an output patch. Next, the process proceeds to step S211 and the output patch reading unit 119 reads the output patch using the scanner 106. Next, step S212
The correction table creation unit 120 creates a color correction table from the output data and the read data.

FIG. 3 shows an example of an output patch created by the output patch creating section 117.

Depending on the configuration of the scanner unit 106, the output patch may be formed on a recording medium, or may be formed so that only a latent image is formed on a photosensitive drum. The output patch has a plurality of different gradations for each of the recording materials.

The recording material output patch creating unit 11 shown in FIG.
7 shows an example of the relationship between the density created in Step 7 and the density read by the output patch reading unit 119.

Output density 0 for input density 0, output density 0.5 for input density 0.25, output density 0.75 for input density 0.5, output for input density 0.75 The density is 0.875, and the output density is 1 for the input density 1. In this case, since the output density is higher than the input density as compared with the linear ideal density indicated by the dotted line, printing is performed in a darker color than the desired result.

FIG. 5 shows the relationship between the density of the input data received by the transmitting / receiving section 103 and the density corrected by the correction table.

The corrected density is 0 for an input density of 0, the corrected density is 0.125 for an input density of 0.25, the corrected density is 0.25 for an input density of 0.5, and the input density is 0.75.
The corrected density is 0.5 for the input density 1 and the corrected density 1 for the input density 1. By correcting the input data in this manner, printing can be performed at a desired density.

In the case of the output characteristics in the example of FIG. 4, by applying the correction in the example of FIG. 5, it is possible to output an appropriate density.

Therefore, the correction table creating unit 120 creates a correction table for each recording material based on output characteristics obtained by output patches independently.

As described above, the correction table updating interval setting unit 112 is provided, and the means for setting the number of correction intervals and updating the correction table accordingly is provided, so that the user can independently set the interval for performing the periodic correction. As a result, unnecessary waiting time can be reduced.

(Second Embodiment) In the first embodiment, the interval set by the correction table update interval setting unit 112 is the number of sheets, but a time may be set. In this case, step S
Every time an image is output in step S207, the correction table update interval detecting unit 111 determines the elapsed time from the previous update of the correction table by the correction interval data storage unit 11 in step S208.
The correction table is updated based on the comparison result as compared with the time of No. 6.

Thus, since the user can set the interval for performing the periodic correction independently, unnecessary waiting time can be reduced.

(Embodiment 3) In the first embodiment, one type of correction interval is stored in the correction interval storage unit 116. However, a plurality of values are stored in correspondence with the type of output mode, and the set output mode is set. May be set in the table update interval detection unit 111 in step S208 of FIG. 2 to control the update timing of the correction table.

As described in the first embodiment, the output mode is set by the user interface of the driver software for the printer stored in the host computer.

For example, when high precision is set as the output mode, it is considered that the user desires high-speed processing and high-precision color reproduction. Therefore, the value at which the correction interval is shortened is stored in the correction interval storage unit 116 in correspondence with the high-accuracy output mode. On the other hand, when high speed is set as the output mode, it is considered that the user desires a processing speed. Therefore, the value at which the correction interval becomes longer is stored in the correction interval storage unit 116 in correspondence with the high-accuracy output mode.

Then, in accordance with the output mode (type of output quality) information received from the host computer, the correction unit 1
In addition to setting the processing contents of No. 10, a value is set in the table update interval detecting unit 111.

The output mode is not limited to the above example, but may be a color / monochrome mode, a printer language type, an application type, or the like.

For example, in the color / monochrome mode, color reproducibility is more important in the color mode than in the monochrome mode. Therefore, a value at which the correction interval is shorter in the color mode than in the monochrome mode is stored in the correction interval storage unit 116.

With respect to application types, for example, color reproducibility is more important for DTP software than for spreadsheet software or word processing software. Therefore, a value at which the correction interval is shorter in the DTP software than in the spreadsheet software or word processing software is stored in the correction interval storage unit 116.

Further, a value for controlling the correction interval may be stored corresponding to a combination of a plurality of output modes.

As described above, according to the present embodiment, the optimum correction interval can be automatically set according to the output mode, so that unnecessary waiting time can be reduced.

[0045]

As described above, according to the present invention,
The frequency of the calibration process can be reduced, and the waiting time caused by the calibration process can be reduced.

In particular, by controlling the execution timing of the calibration process according to the output mode, the frequency of the calibration process can be reduced without significantly affecting the image quality, and the waiting time caused by the calibration process can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a printing apparatus according to an embodiment.

FIG. 2 is a flowchart illustrating an operation of the printing apparatus 101.

FIG. 3 is a schematic diagram illustrating an example of an output patch.

FIG. 4 is a schematic diagram showing a relationship between patch density and output density.

FIG. 5 is a schematic diagram illustrating a relationship between input data density and corrected density.

Claims (6)

[Claims] An image forming apparatus that processes an image according to a set output condition and forms an image, a calibration unit that updates an output condition according to an output characteristic, and a plurality of output modes corresponding to each of the plurality of output modes. Storage means for storing calibration timing information; input means for inputting an image; setting means for setting an output mode for the image; and image processing according to the set output mode for the input image. An image forming apparatus, comprising: an image processing unit for performing; and a control unit for controlling the calibration execution timing based on calibration timing information corresponding to the set output mode. 2. The image forming apparatus according to claim 1, wherein the calibration timing information is the number of images to be formed. 3. The image forming apparatus according to claim 1, wherein the output mode is a mode relating to output quality. 4. The calibration processing means outputs the output patch information to an image output unit to form an output patch, and reads the formed output patch based on the image data obtained by reading and the output patch information. 2. The image forming apparatus according to claim 1, wherein a gradation correction table corresponding to each recording material is created as an output condition. 5. An image processing method applied to an image forming apparatus for processing an image according to a set output condition and forming an image, comprising: a calibration function for updating an output condition according to an output characteristic; And setting an output mode for the image, performing image processing on the input image according to the set output mode, and a plurality of calibrations stored corresponding to each of the output modes. Selecting, from the timing information, calibration timing information corresponding to the set output mode, and controlling the calibration execution timing based on the calibration timing information corresponding to the set output mode. Characteristic image processing method. 6. A recording medium for storing a program for realizing an image processing method applied to an image forming apparatus for processing and forming an image according to a set output condition, wherein the output condition corresponds to an output characteristic. A calibration function for updating the image, and an output mode for the image are set. Image processing is performed on the input image in accordance with the set output mode, and stored for each of the output modes. An image selecting calibration timing information corresponding to the set output mode from a plurality of pieces of calibration timing information, and controlling the calibration execution timing based on the calibration timing information corresponding to the set output mode; A recording medium for storing a program for implementing a processing method.