JP2006082243A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which optimizes the timing of the performance of calibration. <P>SOLUTION: This image forming apparatus comprises: a printing means for performing printing processing of a printing job; a calibration performance means for performing the calibration of the printing means; and a control means for giving instructions on the performance of the calibration to the calibration performance means, when the number of sheets to be printed after the performance of the last calibration falls within a predetermined calibration performance range, at the completion of the printing job. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that optimizes the execution time of calibration.

  In color printing devices, calibration (calibration) processing is generally performed under regular or fixed trigger conditions in order to suppress gradation changes due to development and environmental fluctuations and ensure tone reproducibility. Is. In this calibration, a specific pattern is printed on a drum or an intermediate transfer body without actually printing on a sheet, and the density value is read by a sensor, and the difference between the read value and a predetermined value is determined in advance. The process control correction operation corresponding to that is performed.

2. Description of the Related Art Conventionally, there has been known an image processing apparatus that can arbitrarily select a calibration execution time immediately after execution of a job, according to the remaining pages, or automatically (executed according to the number of pages of the job). (See Patent Document 1). Also known are those that perform calibration before a printing operation (see Patent Document 2) and those that divide a job according to calibration execution timing information (number of execution intervals) and perform calibration immediately before each divided job. (See Patent Document 3). In addition, in the case of color printing, calibration is performed before the printing process, and in the case of monochrome printing, the printing apparatus executes calibration after the printing process or after a predetermined number of monochrome printing processes (see Patent Document 4). For example, an image processing apparatus that waits for a job during calibration (performs the process until the PDL is developed into image data regardless of the calibration) and executes printing after the calibration is completed (patent) Reference 5).
JP-A-11-114128 JP 2000-227684 A JP-A-11-157177 JP 2000-324279 A JP 2004-074561 A

  By the way, some image forming apparatuses that require calibration require certain calibrations to be executed for each predetermined number of sheets due to process limitations. However, in the case of such a model, it is not practical to limit the number of jobs to be printed for the user. Therefore, as an actual operation of the apparatus, it is necessary to interrupt the calibration process in one job. At this time, when printing a larger number of jobs than the number of sheets that need to be calibrated, it is inevitable that the calibration cannot be avoided in the middle of the job. If the number of print jobs that need to be calibrated is reached in the middle of the number of print jobs, the print job is interrupted, which causes a problem that the user who uses it feels great stress. In addition, if calibration is performed in the middle of one print job, there is a problem that print quality differs before and after calibration.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an image forming apparatus that optimizes the execution time of calibration.

  According to the present invention, a printing unit that performs print processing of a print job, a calibration execution unit that performs calibration of the printing unit, and the number of prints after the last calibration is determined at the end of the print job. Control means for instructing the calibration execution means to execute calibration when the number is within the calibration execution range.

  In the present invention, when the number of prints after the calibration has been performed reaches a predetermined number of calibrations during execution of the print job, the control unit interrupts the print job being executed, and The calibration execution unit is instructed to execute calibration.

  The present invention includes a printing unit that performs print processing of a print job, a calibration execution unit that calibrates the printing unit, a print number acquisition unit that acquires the number of prints of a print job, and a post-calibration execution When the value obtained by adding the number of prints of the print job to the number of prints exceeds a predetermined number of calibration executions, the calibration execution unit is instructed to perform calibration before executing the print job. And a control means for performing the above.

  According to the present invention, when the number of printed sheets after the calibration reaches the number of calibrated sheets during execution of the print job, the control unit interrupts the currently executed print job and performs the calibration. The means is instructed to execute calibration.

According to the present invention, at the end of the print job, the calibration is performed when the number of printed sheets after the previous calibration is within the predetermined calibration execution range. The effect that the execution time of can be optimized can be obtained.
In addition, when the value obtained by adding the number of print jobs to the number of prints after the previous calibration execution exceeds the predetermined number of calibration executions, calibration is performed before execution of the print job. Therefore, the effect that the execution time of calibration can be optimized can be obtained.
As a result, calibration can be avoided as much as possible during execution of the print job, so that the print quality of the printed matter printed in one print job can be kept constant.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. The image forming apparatus shown in FIG. 1 is a multifunction machine having a copying function, a printer function, a FAX transmission / reception function, and an image reading function. In this figure, reference numeral 1 denotes a control unit that controls the overall processing operation of the image forming apparatus. Reference numeral 2 denotes an input unit including a touch panel, numeric keys, function keys, and the like. Reference numeral 3 denotes a display unit composed of a liquid crystal display or the like. Reference numeral 4 denotes an image reading unit that includes a color CCD and reads an image of a document. Reference numeral 5 denotes an image memory for storing image data read by the image reading unit 4 or image data based on print data sent from a host computer. Reference numeral 6 denotes a printing unit that performs printing based on image data stored in the image memory 5. Reference numeral 7 denotes a number counter that counts the number of printed sheets in the printing unit 6. Reference numeral 8 denotes a calibration execution unit that executes calibration of the printing unit 6 when the count value of the number counter 7 exceeds a predetermined threshold value for the number of sheets that needs to be calibrated. The value of the sheet counter 7 is reset to zero after the execution of the operation. Reference numeral 9 denotes a communication unit that receives print data from a host computer when the image forming apparatus functions as a printer.

  Next, referring to FIGS. 2 and 3, before explaining the operation of controlling the calibration start timing so that the calibration execution timing is optimized, the values used in FIGS. 2 and 3 are shown. The symbols will be described. The value N is a value that is predetermined and stored in the image forming apparatus, and the threshold value of the number of sheets that needs to be calibrated when the number of printed sheets after the previous calibration exceeds the value N. This is called the number of calibrations performed. Here, the description will be made assuming that the calibration execution number N is 80. The value M is a value for giving a predetermined range to the calibration execution number N, and is referred to as an execution range number. Here, description will be made assuming that the number M of implementation ranges is 10. Therefore, the calibration execution range is NM (70 sheets) to N (80 sheets). The value P is the number of printed sheets after the previous calibration, and corresponds to the count value of the number counter 7. The value J is the number of prints that need to be printed in the target print job. In the case of copying, the value is “number of originals × number of copies”, and in the case of a printer, “print data × number of copies”. However, in the case of a printer, the number of prints J of a print job is not always known in advance. Also, in the case of copying, when an image is read and copied one by one, the number of documents is not always known in advance. Therefore, the value of the number of printed sheets J may not be known before executing the print job.

  Next, an operation for controlling the calibration start timing will be described. First, the control unit 1 receives a print job execution instruction (step S1). This execution instruction corresponds to a case where the user places a document on the document table and presses the start key of the input unit 2 in the case of copying, and in the case of a printer, print data is transmitted via the communication unit 9. It corresponds to receiving.

  Next, the control unit 1 determines whether or not the number of prints of the print job that has received the execution instruction is known (step S2). When the print number J is known, the control unit 1 performs the calibration by adding a value (P + J) obtained by adding the print number J to the count value (print number after calibration) P of the number counter 7. It is determined whether the value is smaller than the number N (step S3). If P + J <N is “true” as a result of this determination, the control unit 1 outputs a print instruction to the printing unit 6. In response to this, the printing unit 6 reads out the image data for one sheet stored in the image memory 5 and executes the printing process for one sheet (step S4), and sets the value P of the number counter 7 to “1”. "Is added (step S5). Subsequently, the control unit 1 determines whether or not the print job is finished (step S6), repeats the printing operation until the print job is finished, and waits for an execution instruction in the print job when the print job is finished. It becomes.

  On the other hand, if P + J <N is “false” in step S <b> 3, the control unit 1 outputs a calibration execution instruction to the calibration execution unit 8. In response to this, the calibration execution unit 8 executes the calibration of the printing unit 6 (step S7). And the calibration execution part 8 resets the number counter 7 to zero after completion | finish of calibration (step S8).

  Next, the control unit 1 compares the value P of the number counter 7 with the number N of calibrations to determine whether P <N (step S9). This determination is a determination for performing calibration during a print job when the print number J of one job is larger than the calibration execution number N. If P <N is “false” as a result of this determination, calibration is performed (steps S7 and S8). If P <N is “true”, the control unit 1 outputs a print instruction to the printing unit 6. In response to this, the printing unit 6 reads out the image data for one sheet stored in the image memory 5 and executes the printing process for one sheet (step S10), and sets the value P of the sheet counter 7 to “1”. "Is added (step S11). Subsequently, the control unit 1 determines whether or not the print job is completed (step S12), and repeats the printing operation while performing the determination of step S9 until the print job is completed. The print job waits for an execution instruction.

Next, a description will be given of the control operation in the case where the number J of print jobs is unknown in the determination in step S2.
The control unit 1 compares the value P of the number counter 7 with the number N of calibrations to be executed, and determines whether P <N (step S21). This determination is a determination for performing calibration during a print job when the print number J of one job is larger than the calibration execution number N. If P <N is “false” as a result of this determination, the control unit 1 outputs a calibration execution instruction to the calibration execution unit 8. In response to this, the calibration execution unit 8 executes the calibration of the printing unit 6 (step S22). And the calibration execution part 8 resets the number counter 7 to zero after completion | finish of calibration (step S23).

  On the other hand, if P <N is “true”, the control unit 1 outputs a print instruction to the printing unit 6. In response to this, the printing unit 6 reads out one sheet of image data stored in the image memory 5, executes one sheet of printing processing (step S24), and sets the value P of the number counter 7 to “1”. "Is added (step S25). Subsequently, the control unit 1 determines whether or not the print job is completed (step S26), and repeats the printing operation while performing the determination of step S21 until the print job is completed.

  Next, the control unit 1 compares the value P of the sheet counter 7 with the lower limit value (N−M) of the calibration execution range at the time when the print job is finished, and whether or not N−M <P. Is determined (step S27). If NM <P is “true”, the control unit 1 outputs a calibration execution instruction to the calibration execution unit 8. Receiving this, the calibration execution unit 8 executes the calibration of the printing unit 6 (step S28), and after the calibration is completed, the number counter 7 is reset to zero (step S29). When the calibration is completed, the control unit 1 waits for an execution instruction for the print job. If NM <P is “false”, the control unit 1 waits for an execution instruction for the print job without executing calibration.

  Thus, at the end of the print job, if the number P of prints after the previous calibration is within the predetermined calibration execution range (range NM to N), calibration is performed. Since this is performed, the calibration execution time can be optimized. In addition, when the value obtained by adding the print number J of the print job to the print number P after the previous calibration execution exceeds a predetermined calibration execution number N, calibration is performed before the execution of the print job. As a result, the calibration execution time can be optimized. As a result, calibration can be avoided as much as possible during execution of the print job, so that the print quality of the printed matter printed in one print job can be kept constant.

  It should be noted that values such as the average number of sheets per job and the maximum number of sheets per job are tabulated inside the image forming apparatus, and the values of the calibration execution sheet number N and the execution range sheet number M are managed with reference to the total value. It may be possible to provide setting means that can be set by a person.

  Further, calibration execution control is performed by recording a program for realizing the function of the processing unit in FIG. 1 on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium. Processing may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a flowchart which shows operation | movement of the apparatus shown in FIG. It is a flowchart which shows operation | movement of the apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Control part, 2 ... Input part, 3 ... Display part, 4 ... Image reading part, 5 ... Image memory, 6 ... Printing part, 7 ... Sheet counter 8: Calibration execution unit, 9 ... Communication unit

Claims (4)

Printing means for performing print processing of a print job;
Calibration execution means for calibrating the printing means;
Control for instructing the calibration execution means to execute calibration when the number of printed sheets after the previous calibration is within the predetermined calibration execution range at the end of the print job And an image forming apparatus. The control means includes
If the number of printed sheets after the calibration has reached a predetermined number of calibrations during execution of the print job, the print job being executed is interrupted and the calibration execution unit is calibrated. The image forming apparatus according to claim 1, wherein execution of the image is instructed. Printing means for performing print processing of a print job;
Calibration execution means for calibrating the printing means;
A number-of-prints acquisition means for acquiring the number of copies of a print job;
When the value obtained by adding the number of prints of the print job to the number of prints after the previous calibration is performed exceeds the predetermined number of calibrations, the calibration execution unit is requested before executing the print job. An image forming apparatus comprising: a control unit that instructs execution of calibration. The control means includes
When the number of printed sheets after the calibration is reached during the execution of the print job, the print job being executed is interrupted and the calibration execution unit is calibrated. The image forming apparatus according to claim 3, wherein

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