JP2006272607A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a color tone from being changed in the same job or in the same bundle even if an interruption occurs in the middle of the job in such a manner that when the job which has performed printing on even one sheet is interrupted or stopped, or the printing is interrupted at an odd place (in the middle of a section) in a section unit printing, the result of a simple density measuring process (ARCDAT) is not reflected. <P>SOLUTION: This printer comprises a density measuring means 203, the simple density measuring means 201, a half tone means, a judging means, and a control means. In this case, the density measuring means 203 measures the densities for a plurality of density levels. The simple density measuring means 201 measures the density of a specified dot pattern. The half tone means forms a half tone pattern of an input density level from a dither matrix which controls the formation of the dot pattern, and a dither density table which controls the density characteristics to the input density level. The judging means judges whether a simple density measurement has been performed in the middle of the job or not. The controlling means holds a plurality of simple density measurement results, and performs the control by which printing is performed without reflecting the latest result measured by the simple density measuring means within the same job. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus, an image processing method, and a program storage medium, and more particularly to a printing apparatus having a density correction function.

  In a conventional printing apparatus, in order to realize linear density characteristics, an input density level converted by a dither density table is used as an input of a dither matrix, a dot pattern is formed using the dither matrix, and printing is performed. To adjust the density, calculate the density characteristic of the dither matrix by measuring the density of the dot pattern formed in the dither matrix in advance in the standard density characteristic state. This is done by creating a dither density table that converts an input density level that achieves a target density characteristic (linear characteristic) into an input level to the dither matrix.

  For density fluctuations, measure density at several density levels at a specific timing, obtain density characteristic fluctuations from the measured density values, and create a density correction table that makes the density characteristics the target density characteristics. Created and corrected for density. In addition, when the job is finished and the engine is stopped, the density characteristic is kept as it is, and the simple density measurement process (ARCAT) that adjusts only the density level by simple measurement is used together to suppress the density fluctuation due to the change with time as much as possible. I was in control.

Also, a technique is known in which the calibration process is not executed until the job is interrupted even when a calibration request is received from the engine, and the calibration process is executed in the middle of the job only when the specific number of jobs are not interrupted (for example, , See Patent Document 1).
JP 2002-229278 A

  However, the conventional density control methods have the following problems.

  In the above conventional method, when printing is interrupted by an operator call such as interrupt printing or out of paper, the engine performs post-rotation processing and stops, so the engine performs simple density measurement processing. However, despite the same job, there was a problem that the color changed before and after the interruption. In general, when the engine performs post-rotation processing, it is at the end of the job, so simple density control is performed. The color sometimes changed.

  The present invention has been made in view of the above, and when a job for which even one sheet has been printed is interrupted or stopped, or when printing is interrupted at a place where printing is poor (part way) By preventing the result of the simple density measurement process (ARCDAT) from being reflected, even if the job is interrupted in the middle of the job, it is possible to prevent the color from changing in the same job or the same bundle. An object of the present invention is to provide a printing device that can be used.

  In order to achieve the above object, the present invention has a printing apparatus having the following configuration.

  Density measuring means for measuring the density of a plurality of density levels, simple density measuring means for measuring the density of a specific dot pattern, a dither matrix for controlling the formation of the dot pattern, and a dither density for controlling density characteristics with respect to the input density level Halftone means for forming a halftone pattern of the input density level from the table, judgment means for judging whether or not simple density measurement has been performed in the middle of the job, and a plurality of simple density measurement results are held in the same job. A printing apparatus comprising: control means for controlling printing so as not to reflect the latest result measured by the density measuring means.

  According to the present invention, when a job in which even one sheet of printing such as no paper is being analyzed during PDL analysis is interrupted or stopped, or when interrupted at a place where printing is poor (part way) By preventing the result of the simple density measurement process (ARCDAT) from being reflected, even if the job is interrupted in the middle of the job, it is possible to prevent the color from changing in the same job or the same bundle. It becomes possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
A printing apparatus according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram for explaining a control configuration in an embodiment of a printing apparatus (hereinafter referred to as a printer) of the present invention. In FIG. 1, reference numeral 101 denotes a host computer, and color information, characters, graphics, image images, Print information for performing print processing such as the number of copies is sent to the printer 102.

  The printer 102 is roughly divided into an image processing unit 103 and a printer engine 114 that performs actual image formation based on the image signal transmitted from the image processing unit 103.

  The main configuration and operation of the image processing unit will be described below.

  In the image processing unit 103, reference numeral 104 denotes an interface for controlling transmission / reception of print information to / from the host computer 101, and reference numeral 105 denotes a reception buffer for holding input print information. In the object generation unit 106, information such as colors, characters, graphics, and image images, which are print information input from the host computer 101, is converted into intermediate information (hereinafter referred to as an object) and stored in the object buffer 107. At this time, if the print information is color-related data such as gray level setting, color level setting, multi-value image, etc., a density correction table is created in the density correction processing unit 115 described later, and the density level correction processing unit 116 sets the density. The density level is corrected using the correction table.

  Next, based on the object stored in the object buffer 107, the rendering unit 108 generates a bit image to be rendered. At this time, the dither processing unit 110 performs halftone processing using the dither density table 111b selected by the density correction processing unit 115 and the dither matrix, and converts it into a bit image of output gradation for printing. The generated bit image is stored in the band buffer 109. In this way, the bit image stored in the band buffer 109 is sent to the printer engine 114 and formed on the recording medium.

  A central processing unit (CPU) 112 determines and controls various processes according to a control program 111 a stored in the ROM 111. Reference numeral 111 denotes a ROM (Read Only Memory), which stores various control programs 111a including the programs shown in the flowcharts of FIGS. 3, 8, and 12, and a dither matrix and dither density table 111b to be described later.

  113 stores data and status information for the CPU 112 to perform judgment control of each process according to a program stored in the ROM 111, and a density correction table 113b created by the density correction processing unit 115, and is used as a work area 113a. RAM (random access memory).

  FIG. 2 is a block diagram for explaining a control configuration in an embodiment of the density correction processing unit 115 of the present invention. In a simple density measurement unit 201 described later, a dot pattern for each color is printed on paper and paper at the time of printing processing. The dither density table is measured by using the sensor, and the dither density table selection unit 202 selects the dither density table for adjusting the density characteristics from the measured density value. Further, the density measuring unit 203 forms a plurality of density level test patterns, measures the density value using a sensor, the density characteristic calculating unit 204 calculates the density characteristic from the measured density value, and the density correction table creating unit 205. A density correction table for correcting the input density level so that the density characteristic becomes the target density characteristic is created, and the density level correction processing unit 116 corrects the input density data of the object generation unit 106 using the density correction table. As a result, density correction is performed.

  Hereinafter, the printing process in the present embodiment will be described with reference to the flowchart shown in FIG. Note that the control program for realizing the processing shown in the flowchart shown in FIG. 3 is stored in the ROM 111 and executed by the CPU 112 as described above.

  In FIG. 3, first, print data is received from the host computer 101 (S301) and held in the reception buffer 105 (S302). Then, the data for one processing unit is extracted from the reception buffer 105 (S303), and it is determined whether or not all the data extraction has been completed (S304). If it is determined that the processing has not been completed, it is determined whether or not the data processing for one page has been completed (S305).

  If it is determined that the printing has not ended, it is determined whether the print data is color-related data such as color information or a color image (S306). If it is determined that the data is color-related data, the density level correction processing unit 116 corrects the density level (S307). Then, an object is created (S308), stored in the object buffer 107 (S309), and the process returns to step S303 to retrieve the next data.

  On the other hand, if it is determined in step S306 that the data is not color-related data, it is determined whether the data is mask data for characters, figures, etc. (S310). If it is determined that the data is mask data, an object of mask data is created (S308), and the process returns to step S309. On the other hand, if it is determined that the data is not mask data, print data processing corresponding to the type of data is performed (S311), and the process returns to step S303.

  If it is determined in step S305 that one page of data has been completed, rendering processing is performed based on the object held in the object buffer 107 (S312), and a bit image is transmitted to the printer engine 114 to be printed on the paper. A printing process for printing on top is performed (S313). If it is determined in step S304 that the data is complete, the process ends.

  Next, density correction processing in the present embodiment will be described with reference to FIGS. The density correction process is performed for each color (C, M, Y, K).

  FIG. 4 is a diagram illustrating an example of the simple concentration measurement unit 201 in FIG.

  In the printer 102, between the step of transferring the print data formed on the intermediate transfer body 402 for normal printing processing to the printing paper and the step of transferring the printing data of the next page to the printing paper, so-called inter-page or job A specific dot pattern is formed in the gap between them, and the density is measured by the sensor 401. Simple density measurement is performed for each color (C, M, Y, K).

  FIG. 5 is a diagram illustrating an example of the concentration measurement unit 203 in FIG.

  In the printer 102, the density of a plurality of density levels is adjusted on the intermediate transfer body 402 using a dither density table, and a test pattern (FIG. 6) is formed in each color Y, M, C, K using a dither matrix. The sensor 401 measures the density.

  FIG. 7 is a diagram illustrating an example of the dither density table 111b.

  The dither density table is a table for converting the input density level to the input level of the dither matrix so that the density characteristic with respect to the input density level becomes the target density characteristic in the dither processing unit 110. A plurality of dither density tables are prepared corresponding to the density fluctuation state. For example, the density fluctuation state is classified into three states: (a) a standard density characteristic state, (b) a high density state, (c) a low density state, and three density fluctuation states. Each has a dither density table.

  FIG. 7A shows the density characteristic of the dither matrix in a standard density characteristic state, and the density characteristic is the density characteristic shown by a solid line. At this time, the dither density table in which the density characteristic is adjusted to the target density characteristic (broken line: linear characteristic) with respect to the input density level is the dither density table shown by the solid line in the left figure, and the dither density in the standard density characteristic state The table is held in the ROM 111 (dither density table 1). FIG. 7B shows the density characteristics of the dither matrix in a state where the density is higher than the standard density characteristics and the density is higher. Similarly, the dither density table is the dither density table shown by the solid line in the left diagram. Is held in the ROM 111 as a dither density table in a high state (dither density table 2). FIG. 7 (c) shows the density characteristics of the dither matrix in a state where the density is larger and lower than the standard density characteristics. Similarly, the dither density table is the dither density table shown by the solid line in the left figure. Is held in the ROM 111 as a dither density table in a low state (dither density table 3).

  The dither density table for each density fluctuation state is selected according to the density fluctuation state, and the selected dither density table is used for adjustment of density characteristics in the dither processing unit 110 and creation of a test pattern in the density measurement unit 203. .

  Next, the dither density table selection process in the density correction processing unit (FIG. 2) will be described with reference to FIGS.

  FIG. 8 is a flowchart showing an example of the dither density table selection process 202, and FIG. 9 is a diagram showing an example of the relationship between the measured density value of the dot pattern and the density variation state in the simple density measurement process.

  In FIG. 8, first, the dot pattern of each color characteristic is measured by the simple density measurement process (FIG. 4) (S801), and the density variation state is detected from the measured density value (S802). For example, a characteristic dot pattern (for example, a dot pattern corresponding to an input level of 50% of a dither matrix) is measured in a simple density measurement process. 9A shows the standard density characteristic state, FIG. 9B shows the density characteristic of the dither matrix in the high density state, and FIG. 9C shows the low density state. The density fluctuation state is determined depending on which characteristic (● black dot) is close to. In FIG. 9, when the measured density value is 30% to 65% (variation state level 1), it is determined that the density characteristic is close to (a), and the density fluctuation state is the standard density characteristic state (a). And When the measured density value exceeds 65% (variation state level 2), it is determined that the density characteristic is close to (b), and the density variation state is a high density state (b). When the measured density value is less than 30% (variation state level 3), it is determined that the density characteristic is close to (c), and the density variation state is a low density state (c).

  Next, the dither density table shown in FIG. 7 is selected from the determined density fluctuation state (S803). The dither density table 1 is selected for the standard density characteristic state (a), the dither density table 2 is selected for the high density state (b), and the dither density table 3 is selected for the high density state (c). .

  FIG. 10 shows an example of using the dither density table 1 adjusted with the standard density characteristics when the measured density value measured by the simple density measuring unit 201 is the fluctuation state level 3 (◯ white dot in FIG. 9). FIG. 6 shows density characteristics with respect to an input density level when tone processing is performed. It can be seen that the density varies greatly with the target density characteristics (broken line). At this time, in the dither density table selection process, the dither density table 3 adjusted in the low density state (c) corresponding to the fluctuation state (low density state) is selected and halftone processing is performed. The density characteristic with respect to the density level is the density characteristic shown in FIG. 11, and it is possible to suppress a variation from the target density characteristic (broken line).

  FIG. 12 is a flowchart showing an example of processing for creating a density correction table by density measurement in the density correction processing unit (FIG. 2).

  In FIG. 12, first, the density is adjusted with the dither density table selected in the dither density table selection process for a plurality of density levels, a test pattern (FIG. 6) is created using the dither matrix (S1201), and the patch pattern is changed. The density is measured by the density measurement process (FIG. 5) (S1202), the current density characteristic is calculated from the measured density value (S1203), and the density for converting the input density level so that the current density characteristic becomes the target density characteristic. A correction table is created (S1204). FIG. 13 shows the current density characteristics. In the density measurement process, density levels of 10%, 30%, 50%, and 70% are measured, and when the measured density values are density values of ● (black dots), the current density characteristics are indicated by solid lines. Concentration characteristics. A broken line indicates a target density characteristic (linear characteristic). When the input density level indicating the current density characteristic (solid line in FIG. 10) is corrected to a density level that achieves the target density characteristic (dashed line in FIG. 10), the one-dimensional density correction indicated by the solid line in FIG. It becomes a table. Using this density correction table, the density level correction processing unit 116 corrects the density level.

  The color data input from the host computer is converted into YMCK data, the density level is corrected by the density correction table (solid line in FIG. 11), and the dither processing unit 110 uses the dither density table selected by the dither density table selection process. By adjusting the density, it is possible to perform printing with a stable color (density).

  Next, timing for reflecting the simple density measurement result will be described with reference to FIG. In FIG. 15, when printing is interrupted, such as the end of a job or no paper, the engine performs simple density measurement and notifies the controller to that effect (S1501). The notification is used as a trigger to acquire an ARCDAT sensor value, which is a simple concentration measurement result (S1502). At that time, in S1502, it is determined whether there is a job under PDL interpretation (S1503). If there is no job under PDL interpretation, the newly acquired ARCDAT result is reflected in the current table, and color correction is performed based on the latest information. (S1504). If there is a job that is being interpreted in PDL in S1503, the newly acquired ARCDAT result is not reflected in the current table, but is saved for later use (S1505). The currently used ARCDAT result is used as it is until the PDL interpretation of the job currently being processed is completed. When the interpretation is completed (S1506), the previously stored ARCDAT result is reflected in the current table (S1504). ).

  In this way, even if the simple density measurement is performed while being interrupted in the middle of the job, it is controlled not to be updated during the same job.

[Second Embodiment]
In the first embodiment, an example of a case where a normal job is interrupted due to no paper or the like has been described. However, in the present embodiment, a case where an interrupt job is interrupted or a suspension process is interrupted will be described.

  In the second embodiment, only portions different from the first embodiment will be described.

  In FIG. 16, when an interruption instruction or a pause instruction is received, interruption of the interrupted job or interruption of the job with the pause instruction occurs. At that time, printing may be temporarily stopped, followed by a rotation process, and simple density measurement may be performed. When these jobs are resumed, first, in S1601, it is determined whether the job is an interrupted job or a resume job. If so, the ARCDAT result used for processing the job is reflected (S1602), and the job The remaining processing is performed, and the processing is continued until the PDL interpretation is completed. When the PDL interpretation is finished (S1603), the latest ARCDAT result is reflected in the current and the process is finished (S1604). Control is performed so that the simple density measurement result is not reflected in the interrupted job or the resume job so that the color does not change in the same job.

It is a block diagram for demonstrating the control structure in one Embodiment of the printing apparatus of this invention. It is a block diagram for demonstrating the density correction process part in this embodiment. 3 is a flowchart illustrating a print information processing method according to an embodiment of the present invention. It is a figure which shows an example of the simple density | concentration measurement process in embodiment of this invention. It is a figure which shows an example of the density | concentration measurement process in embodiment of this invention. It is a figure which shows an example of the test pattern of the density | concentration measurement process in embodiment of this invention. It is a figure which shows an example of the dither density | concentration table in embodiment of this invention. It is a flowchart which shows the dither density | concentration table selection processing method in embodiment of this invention. It is a figure which shows an example of the density fluctuation state in embodiment of this invention. It is a figure which shows an example of the density characteristic at the time of use of the dither density table in the state of the standard density characteristic in the embodiment of the present invention. It is a figure which shows an example of the density | concentration characteristic at the time of use of the dither density table in the state where the density | concentration is low in embodiment of this invention. It is a flowchart which shows the density | concentration correction table creation process in embodiment of this invention. It is a figure which shows an example of the present density | concentration characteristic in embodiment of this invention. It is a figure which shows an example of the density | concentration correction table in embodiment of this invention. It is a flowchart which controls simple density | concentration measurement result reflection in embodiment of this invention. In a 2nd embodiment, it is a flowchart which controls simple concentration measurement result reflection at the time of interruption.

Explanation of symbols

101 Host computer 102 Printer 103 Image processing unit 104 Interface 105 Reception buffer 106 Object generation unit 107 Object buffer 108 Rendering unit 109 Band buffer 110 Dither processing unit 111 ROM
112 CPU
113 RAM
114 Printer Engine 115 Density Correction Processing Unit 116 Density Level Correction Processing Unit 201 Simple Density Measurement Unit 202 Dither Density Table Selection Unit 203 Density Measurement Unit 204 Density Characteristic Calculation Unit 205 Density Correction Table Creation Unit 401 Density Measurement Sensor 402 Intermediate Transfer Member

Claims (2)

  Density measuring means for measuring the density of a plurality of density levels, simple density measuring means for measuring the density of a specific dot pattern, a dither matrix for controlling dot pattern formation, and a dither density for controlling density characteristics with respect to the input density level Halftone means for forming a halftone pattern of the input density level from the table, judgment means for judging whether or not simple density measurement has been performed in the middle of the job, and a plurality of simple density measurement results are held in the same job. A printing apparatus comprising: control means for controlling printing so as not to reflect the latest result measured by the density measuring means.   Density measuring means for measuring the density of a plurality of density levels, simple density measuring means for measuring the density of a specific dot pattern, a dither matrix for controlling the formation of the dot pattern, and a dither density for controlling density characteristics with respect to the input density level Halftone means for forming a halftone pattern of the input density level from the table, judgment means for judging whether or not simple density measurement has been performed in the middle of a job, and a plurality of simple density measurement results are held within the same number of copies. A printing apparatus comprising: control means for controlling printing so as not to reflect the latest result measured by the density measuring means.