JP2010201901A - Image forming apparatus having image quality-correcting function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To timely provide a printing device notifying a user of information regarding color calibration. <P>SOLUTION: An image forming apparatus controlling color calibration which is done for correcting the fluctuation of the image quality of an output image has: a printing means for printing a print pattern for color calibration; a concentration-measuring means for measuring a concentration of the printed print pattern; a level calculation means for calculating a level at a color calibration state by a difference between a target value of the concentration preliminarily stored and the measured concentration; and a setting means for setting information expressing a print-executing condition corresponding to characteristics of the level and printing data. The image forming apparatus decides whether executing printing of the printing information, or displaying a warning or an error corresponding to the characteristics of the printing data received from a host computer, and the level according to the information set by the setting means, and executes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a color calibration function that is performed in order to stably maintain a desired printing characteristic in an image forming apparatus.

  In a printing apparatus that prints characters and images on a print medium such as paper, the print output characteristics such as output density characteristics or gradation in the print results generally change as the printing environment changes or the printing progresses. It has been known.

  The printing environment is, for example, the ambient temperature or humidity where the apparatus is placed. By changing these, the amount of ink ejected from the print head to the print medium changes in the printer, and a desired output is obtained. May differ from characteristics.

  Further, when printing is performed continuously for a relatively long time, the temperature of each part of the apparatus changes, and the output characteristics may change accordingly.

  The change in the print output characteristics in each printing apparatus causes another problem when a plurality of printing apparatuses are used via a network. That is, the output characteristics change due to the various factors described above, and as a result, the output characteristics may differ among a plurality of printing apparatuses.

  In this case, as described above, not only the desired printing characteristics cannot be obtained in each printer, but also the printing result varies depending on the printer selected by the user in the printing system.

  In order to solve the problems related to the print output characteristics as described above, it is generally known to perform color calibration. There is an apparatus in which the color calibration is automatically executed by the printing apparatus itself.

  In the color calibration, for example, in a printer device, a print pattern is formed on a print medium, the density of the print pattern is optically read, and the content of the gamma correction table relating to the output density characteristic is updated based on the read result. It is processing to do.

  In the printing apparatus, the color calibration is executed at a fixed timing. The certain timing is a timing when the temperature or humidity detected in the printing apparatus becomes a certain value or more, a timing when the number of printed sheets becomes a certain number or more, or a timing when a certain time has passed.

  When the color calibration is executed, a certain amount of time is generally required. Therefore, when the color calibration is executed, an operation other than the color calibration such as printing cannot be executed. Therefore, it is necessary to inform the user at an appropriate timing that it is necessary to perform color calibration.

  For this purpose, the following method is known. In other words, the elapsed time from the color calibration performed immediately before is detected, and if the detected time is more than a certain time, a warning is displayed on the printing device so that calibration is performed, and the color calibration timing is The method of detecting is known.

  Moreover, the following method is also known (for example, refer patent document 1). That is, the density difference between the density at the time of the previous color calibration and the current density is obtained, and the density difference information is notified to a plurality of printing apparatuses in the printing system via the network. Thus, a method of adjusting the timing of color calibration execution is known.

JP 2003-276278 A

  However, in the invention described in Patent Document 1, since only a warning is displayed, there is a possibility that the user may perform printing without executing color calibration.

  Also, there are various types of images output by the user who uses the printing apparatus. For example, a certain user requires a color calibration execution request warning when printing a graphic image. However, there is a problem that another user who does not care much about the output density such as a CAD image does not need a color calibration execution request warning and may feel that the display on the printing apparatus or the host is troublesome. .

  An object of the present invention is to provide a printing apparatus that notifies a user of information related to color calibration at an appropriate timing.

  The present invention relates to a printing unit that prints a color calibration print pattern and a density of the printed print pattern in an image forming apparatus that controls color calibration performed to correct a change in image quality of an output image. Corresponding to the density measurement means, the level calculation means for calculating the level of the color calibration state according to the difference between the density target value stored in advance and the measured density, and the characteristics of the level and the print data Setting means for setting information indicating a print execution condition to be performed, and printing the print data according to the characteristics of the print data received from the host computer and the level according to the information set in the setting means The image forming apparatus is characterized in that it is determined and executed whether or not a warning or an error is displayed.

  According to the present invention, it is possible to notify the user of information related to color calibration at an appropriate timing.

1 is a system configuration diagram of an image forming apparatus 100 according to an embodiment of the present invention. It is a figure which shows test chart TC1 with which the printing pattern 21 is printed. It is a flowchart which shows a color calibration process process. It is a flowchart which shows execution of color calibration. It is a flowchart of the level determination of a color calibration state. 6 is a flowchart for determining execution of print data. It is a figure which shows the determination table T1 for determining print data.

  The mode for carrying out the invention is the following embodiment.

  FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus 100 that is Embodiment 1 of the present invention.

  The image forming apparatus 100 is an image forming apparatus that controls color calibration performed to correct a change in image quality of an output image. The image forming apparatus 100 is connected to an external host computer 1 via a connector, receives print data using a page description language from the host computer 1, analyzes the print data, and prints out the print data.

  Further, the image forming apparatus 100 includes a reception buffer 2, an output unit 3, a reading sensor 4, an operation panel 5, a CPU 6, a RAM 7, a boot ROM 8, a flash ROM 9, and an NVRAM 10.

  The CPU 6 loads the execution program stored in the Flash ROM 9 on the RAM 7 according to the control procedure of the boot program stored in the boot ROM 8, and the entire image forming apparatus 100 according to the control procedure of the loaded execution program. Control.

  The reception buffer 2 temporarily stores print data using the page description language received from the host computer 1.

  The boot ROM 8 stores a program for loading the execution program stored in the Flash ROM 9 onto the RAM 7 in order to cause the CPU 6 to execute the initial operation of the CPU 6.

  The RAM 7 has an execution program storage area for the CPU 6 and functions as a work area when the execution program is executed.

  FIG. 2 is a diagram illustrating an example of the test chart TC1.

  The output unit 3 forms an image of the developed output data according to a certain process. Further, every time color calibration is executed, a fixed test chart TC1 shown in FIG. 2 is output on the print medium.

  In FIG. 2, a sheet 20 is a sheet to be printed when color calibration is performed, and a print pattern 21 is a print pattern 21 with a constant color for each color of the test chart TC1 to be printed on the sheet 20.

  The reading sensor 4 detects the density of the print pattern 21. The Flash ROM 9 stores an execution program. The operation panel 5 is a panel that displays errors and warnings and instructs the execution of color calibration.

  The reading sensor 4 detects the density of a certain print pattern when performing calibration. The NVRAM 10 stores the correction values for each color and each density generated by executing color calibration.

  FIG. 3 is a flowchart showing a series of processing steps when the user performs color calibration via the operation panel 5 in the image forming apparatus 100.

  In S01, color calibration is executed, and in S02, processing is performed in the order of color calibration state level determination processing.

  FIG. 4 is a flowchart illustrating a series of operations in the color calibration execution process in the first embodiment.

  When a user as a user inputs a calibration execution request via the operation panel 5 of the image forming apparatus, in S11, the image forming apparatus outputs a test chart TC1 (print pattern 21) shown in FIG.

  When the printing of the test chart TC1 (printing pattern 21) is completed, in S12, the reading sensor 4 provided as a standard in the image forming apparatus 100 (printing apparatus) prints the printing pattern 21 of each density of the printed test chart TC1. read. In S13, the density value in each print pattern 21 is detected based on the read result. The detected density value is compared with the theoretical density value, and other correction factors are taken into consideration. In S14, correction values for each color and each density are calculated, and in S15, they are stored in the NVRAM 10.

  When the color calibration is finished, the level of the color calibration state is determined.

  FIG. 5 is a flowchart illustrating an operation of determining the level of the color calibration state of the image forming apparatus 100 (printing apparatus) after executing calibration.

  In S21, the correction data stored in the NVRAM 10 is read out. In S22, the printed color calibration print pattern is printed by applying correction data. In S23, the reading sensor reads the print patterns 21 of the respective densities of the printed test chart TC1 in the same manner as described above. In S24, the density value for each print pattern 21 is detected from the result of reading the print pattern 21. In S25, the detected density value is compared with the theoretical density value, and in S26, the level of the color calibration state of the image forming apparatus is determined from the comparison result.

  The level information of the determined color calibration state is stored in the NVRAM 10 in S27. The level information of the determined color calibration state transitions according to the passage of time, the number of printed sheets, and the environment in which the image forming apparatus is installed.

  FIG. 6 is a flowchart illustrating a print data execution determination operation based on the color calibration state and print data parameters in the first embodiment.

  FIG. 7 is a diagram illustrating a determination table T1 for determining print data.

  When print data is received from the host computer 1 in S31, based on the determination table T1 shown in FIG. 7 according to the level of the current color calibration state held and the parameters of the print data in S32. The print execution determination result is acquired.

  The above parameters are “fast”, “normal”, “clean”, etc., the print quality that represents the printing method, the type of print media that is the print medium, “line drawing data”, “image data”, etc. Print data type indicating the type of data.

  For example, if the color calibration status is “normal”, the print paper type is “coated paper”, the print quality is “normal”, and the print data type is “image print data”, the color calibration is performed. An execution request warning is displayed and the printing operation is started.

  Send the color calibration status is "Performance degraded", the print paper type is "Glossy paper", the print quality is "Pretty", and the print data type is "Image print data" . In this way, a color calibration execution request error is displayed and the printing operation is not executed.

  If it is determined in S33 that the acquired print execution determination result is “error”, in S36, “error” is displayed on the display unit of the operation panel 5, and the print data is not temporarily printed but is paused. To do. If the determination result is “warning” in S34, “Warning” is displayed on the display unit of the operation panel 5 in S37, and the print data is printed in S35. If it is not “warning”, the print data is printed as it is.

  The output unit 3 is an example of a printing unit that prints a color calibration print pattern. The reading sensor 4 and the CPU 6 are examples of density measuring means for measuring the density of the printed pattern. The CPU 6 is an example of level calculation means for calculating the level of the color calibration state in accordance with the difference between the density target value stored in advance and the measured density. The CPU 6 is an example of setting means for setting information indicating a print execution condition corresponding to the level and the characteristics of the print data. In this case, according to the information set in the setting means, it is determined whether to print the print data or display a warning or error according to the characteristics of the print data received from the host computer and the level. And run.

  In this case, depending on the characteristics of the print data received from the host computer and the level, the print data is printed, the warning is displayed and the print data is printed, or an error is displayed. . The characteristics of the print data are characteristics indicating line drawing or image data. Further, the characteristic of the print data is a characteristic indicating print quality. In addition, depending on the level and the type of print paper, printing of the print data received from the host computer is executed, a warning is displayed and printing of the print data is executed, or an error is displayed.

  According to the above embodiment, the user can know an appropriate color calibration execution timing in consideration of the color calibration state of the image forming apparatus and various characteristics of the print data.

  In the above embodiment, the following switching is performed according to the leveled color calibration state and the type of print data received (graphic data or CAD data). That is, switching between executing a printing operation, printing while displaying a warning, or stopping printing with an error displayed. Therefore, according to the above-described embodiment, it is possible to inform the user that it is desirable to perform color calibration at an appropriate timing in consideration of how to use the image forming apparatus.

  In addition, according to the above-described embodiment, it is desirable to perform color calibration at a highly accurate timing in consideration of print quality such as fast, normal, and beautiful, and the type of paper to be printed, for the determination of print data. Can be notified to the user.

100: Image forming apparatus,
3 ... output part,
4 ... Reading sensor,
6 ... CPU,
7 ... RAM,
20 ... printing paper,
21 ... print pattern,
T1 ... judgment table,
TC1 ... Test chart.

Claims (5)

In an image forming apparatus that controls color calibration performed to correct fluctuations in image quality of an output image,
Printing means for printing a color calibration print pattern;
Density measuring means for measuring the density of the printed pattern;
Level calculation means for calculating the level of the color calibration state according to the difference between the target value of density stored in advance and the measured density;
Setting means for setting information indicating a print execution condition corresponding to the level and the characteristics of the print data;
Whether to execute printing of the print data or display a warning or error according to the characteristics of the print data received from the host computer and the level according to the information set in the setting means. An image forming apparatus that determines and executes the image forming apparatus. Claim 1 wherein
According to the characteristics of the print data received from the host computer and the level, the print data is printed, the warning is displayed and the print data is printed, or an error is displayed. An image forming apparatus. Claim 2.
An image forming apparatus characterized in that the characteristic of the print data is a characteristic indicating a line drawing or image data. Claim 2.
An image forming apparatus characterized in that the characteristic of the print data is a characteristic indicating print quality. Claim 1 wherein
According to the above level and the type of printing paper, printing of print data received from a host computer is executed, a warning is displayed, printing of the print data is executed, or an error is displayed. Image forming apparatus.

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