JP2014113688A - Printer, printer control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a frequency of noise following a thinning process on print data based on an input synchronizing clock not to exceed a specified value.SOLUTION: A printer for processing input print data includes: input means to which a frequency of a synchronizing clock for performing image processing on the print data is input; selection means for selecting a thinning pattern in which a noise level identified by the frequency of the input synchronizing clock does not exceed a predetermined threshold; and thinning processing means for performing thinning processing on the print data on the basis of the selected thinning pattern.

Description

  The present invention relates to a printing apparatus, a printing apparatus control method, and a program.

  With regard to a printing apparatus using toner or ink, there is a process of thinning out print image data at regular intervals during printing for confirming a toner or ink save mode or a print output image (see Patent Document 1).

  In addition, there is a process of thinning out print data at regular intervals in order to prevent an image defect or ink bleeding at the time of fixing due to an increase in the amount of toner or ink loaded on a solid printed portion.

JP 09-027041 A

By performing thinning processing of print data, there is a problem that radiation noise (switching noise) of a specific frequency is generated and emitted as radiation noise.
Here, since radiation noise may cause malfunction of other electronic devices, it is necessary to suppress the generation as much as possible.
Further, the regulations for the radiated noise are also determined for each electronic device in each country, and products that cannot comply with the standards cannot be sold.
20 to 22 are diagrams for explaining the operation of the conventional printing apparatus. Hereinafter, with reference to each figure, the problem regarding the radiation noise in the thinning-out process of the conventional print image data is demonstrated.
FIG. 20 is a block diagram illustrating the configuration of the printing apparatus. In this example, an example of thinning out print data will be described.

  In FIG. 20, an image processing unit 43-3 inputs RGB image data from the scanner 43-1, and an RGB image processing unit 43-6 performs image processing on the RGB data. Then, after color space conversion is performed by the RGB / CMYK conversion unit 43-7, the CMYK image processing unit 43-8 performs various image processing on the CMYK data and outputs print data.

  In the image processing unit 43-3, after the PDL data is input from the computer 43-2 (hereinafter referred to as PC), the PDL image processing unit 43-9 converts the PDL into CMYK print data. Perform conversion. Then, the CMYK image processing unit 43-8 performs various image processing on the CMYK data and outputs CMYK data for printing.

  The print data thinning unit 43-4 performs the thinning process as shown in FIG. 21B on the CMYK data for printing, and outputs the thinned image data to the printer 43-5. .

When the data output part of the print data thinning unit 43-4 and the printer 43-5 are connected by a cable or the like, switching noise generated in the data output part of the print data thinning unit 43-4 is caused by the cable. It will be released into the air via That is the radiation noise of the printing device. Hereinafter, the feature will be described with reference to FIG.
Standards for radiation noise are set for printing apparatuses and the like, and a prescribed value is set for the level of radiation noise for each frequency.
FIG. 21 is a diagram schematically showing a print output image, a synchronization clock for outputting the image data, and image data.
In FIG. 21A, the white portion of the output image is a background portion, and the black portion is a printed portion with toner or ink, and in this example, image output for four lines is performed.

  The waveform below shows the synchronous clock and image data when the output image is output from the image processing system (ASIC). In this example, at the rising edge of the synchronous clock, An image signal is output.

  In this example, when the image data is a print portion, the image signal is “High” (hereinafter referred to as “H”), and the image signal of the base portion where printing is not performed is “Low” (hereinafter referred to as “L”). Represented by

Normally, when image data as shown in FIG. 21 is printed, the image signal is changed from “H” to “L” or “L” to “H” only at the switching portion between the background portion and the print portion. Transition at the rising edge of the synchronous clock.
FIG. 21B is a diagram schematically showing a print output image when the thinning process is performed on the normal image data, a synchronization clock for outputting the image data, and the image data. .
In this example, an example is given in which data is thinned out for each pixel so as to form a checkered pattern with respect to the print image data in FIG.
When the image data as shown in FIG. 21A is thinned out and printed, an image is output as in the output image shown in FIG.

Therefore, as represented by the image signal of FIG. 21B, the image signal is a portion of the output image of FIG. 21A that is solidly printed at each rising edge of each clock. "" To "L" or "L" to "H".
The difference in the image signal due to the presence or absence of the thinning process appears as a difference in radiation noise of the printing apparatus.
In this way, in the printing apparatus, during normal print output as shown in FIG. 21A, noise that does not exceed a certain standard value in all frequency regions as shown in FIG. 22A. Suppose that it is a characteristic.

For this reason, when printing is performed by performing a thinning process on the printing apparatus as shown in FIG. 21B, the image data has a high frequency according to the synchronous clock as shown in the image signal of FIG. ON / OFF will be repeated.
Therefore, it becomes a noise source of a large switching noise in the data output part of the print data thinning part.

In this case, as shown in FIG. 22B, the noise radiated from the printing apparatus has a large noise peak at a specific frequency. Depending on the noise level, the standard value for the radiated noise may be changed. It will be over.
The frequency at which the noise peaks is a frequency corresponding to the synchronous clock of the print image signal.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to control the frequency of noise associated with the thinning-out process for print data based on an input synchronous clock so as not to exceed a specified value. It is to provide a mechanism.

The printing apparatus of the present invention that achieves the above object has the following configuration.
A printing apparatus for processing input print data, wherein input means for inputting a frequency of a synchronous clock for performing image processing on the print data, and a noise level specified by the frequency of the input synchronous clock are predetermined. Selecting means for selecting a thinning pattern that does not exceed the threshold value, and thinning processing means for performing a thinning process on the print data based on the selected thinning pattern.

  According to the present invention, it is possible to control so that the frequency of noise accompanying the thinning process for print data based on the input synchronous clock does not exceed a specified value.

It is a block diagram explaining the structure of the printing apparatus which shows this embodiment. It is a figure which shows an example of a thinning-out block pattern. It is a figure which shows the frequency characteristic of the switching noise according to a thinning-out block pattern. It is a figure which shows the frequency characteristic of the switching noise according to a thinning-out block pattern. It is a figure which shows the frequency characteristic of the switching noise according to a thinning-out block pattern. It is a figure which shows the frequency characteristic of switching noise. It is a figure which shows a response | compatibility with the thinned block pattern and the thinned print data. 6 is a flowchart illustrating a method for controlling the printing apparatus. 6 is a flowchart illustrating a method for controlling the printing apparatus. It is a figure which shows an example of a thinning-out block pattern. It is a figure which shows the frequency characteristic of switching noise. It is a figure which shows a response | compatibility with the thinned block pattern and the thinned print data. It is a figure which shows the frequency characteristic of switching noise. 6 is a flowchart illustrating a method for controlling the printing apparatus. It is a block diagram explaining the structure of the printing apparatus which shows this embodiment. 6 is a flowchart illustrating a method for controlling the printing apparatus. It is a figure which shows an example of a thinning-out block pattern. It is a figure which shows a response | compatibility with the thinned block pattern and the thinned print data. It is a figure which shows the frequency characteristic of switching noise. 2 is a block diagram illustrating a configuration of a printing apparatus. FIG. It is a figure which shows a response | compatibility with the thinned block pattern and the thinned print data. It is a figure which shows the frequency characteristic of switching noise.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
<Description of system configuration>
[First Embodiment]
FIG. 1 is a block diagram illustrating the configuration of the PC 1-2 and the printing apparatus according to the present embodiment. In this example, the printing apparatus receives data from the scanner 1-1 or the PC 1-2, executes predetermined image processing, performs print data thinning processing to be described later, and then performs color printing with the printer 1-5. An example will be described. Note that the printing apparatus may include a scanner 1-1. The printing apparatus includes a CPU, a RAM, and a ROM (not shown) in addition to the image processing unit 1-3 and the print data thinning unit 1-4 described below. The CPU comprehensively controls the printing apparatus including the image processing unit 1-3 and the print data thinning unit 1-4. The ROM stores a program read by the CPU. The RAM functions as a work area for the CPU. In the first embodiment, an example will be described in which a thinning pattern is generated by preparing a plurality of thinning patterns according to a target density per unit area and switching them in the printing apparatus.

At that time, based on the radiation noise characteristics of the printing device and the frequency information of the synchronous clock at the time of print data output, the radiation noise due to the print data output after the thinning process is “moved” to the portion of the printing device where the radiation noise is low. The thinning pattern is generated so that Thus, a method for reducing the peak of radiation noise will be described.
Further, since the internal configuration of the image processing unit 1-3 is illustrated in advance using FIG. 20, the internal configuration is the same as that of FIG. 20, and detailed illustration is omitted.

In FIG. 1, an image processing unit 1-3 inputs RGB image data from the scanner 1-1, performs various image processing on RGB and CMYK data, and outputs CMYK data for printing. . In addition, the image processing unit 1-3 performs CMYK after inputting PDL data from the PC 1-2 connected via a network using a network cable, a wireless LAN, or the like, or the PC 1-2 connected locally via a USB cable. Perform various image processing on data. Output of CMYK data for printing is performed.
The print data thinning unit 1-4 performs a thinning process on the CMYK data for printing, and outputs the thinned image data to the printer 1-5.
The print data thinning unit 1-4 includes a print data input unit 1-6, a thinning processing unit 1-7, a print data output unit 1-8, and a thinning pattern generation unit 1-9.
The thinning pattern generation unit 1-9 includes a selection information input unit 1-10, a thinning pattern selection unit 1-11, and a thinning block pattern storage unit 1-12.
The CMYK data for printing output from the image processing unit 1-3 is input from the print data input unit 1-6 and output to the thinning processing unit 1-7.

The print data input unit 1-6 is configured by a memory such as SRAM, and stores print data input for each line for each color of CMYK in a memory for a plurality of lines, and is an area of n lines and m pixels. The output is performed in units to the thinning processing unit 1-7.
In the present embodiment, a memory for two lines is provided, and output is performed to the thinning processing unit 1-7 in units of areas of two lines and twelve pixels.

The thinning processing unit 1-7 performs a thinning process on the print data input from the print data input unit 1-6 based on the thinning pattern generated from the thinning pattern generation unit 1-9.
In the present embodiment, it is assumed that the thinning pattern generates a pattern of pixels to be printed and pixels not to be printed in an area unit of 2 lines and 12 pixels.

For the CMYK data for printing input in units of 2 lines and 12 pixels, the thinning processing unit 1-7 is the same data for the pixels to be printed. Clear the data. As a result, the print data is thinned out. As shown in FIG. 3 and the like, the thinning pattern in the present embodiment is configured by a pattern that converts a pixel group of print data into a pixel that is not to be printed for each specific pixel group.
The CMYK data after the thinning process that has been subjected to the thinning process is output from the thinning processing unit 1-7 and is input to the print data output unit 1-8.

The print data output unit 1-8 is configured by a memory such as an SRAM. The print data input for each area of CMYK is stored in a memory for a plurality of areas, and pixel data for one line is prepared. Then, output is performed to the printer 1-5 in units of one line.
In the present embodiment, the memory for 2 lines is provided, and the CMYK data after the thinning process is input for each area of 2 lines and 12 pixels, and output to the printer for each line.
Next, the thinning pattern generation unit 1-9 will be described in detail.
The thinning pattern generation unit 1-9 includes a selection information input unit 1-10, a thinning pattern selection unit 1-11, and a thinning block pattern storage unit 1-12.

The thinning block pattern is a block that constitutes the thinning pattern described above. In this embodiment, four types of patterns having 2 × 2 pixels as one block as shown in FIG. 2 are set. It shall be.
In the thinned-out block pattern in FIG. 2, the pattern is indicated by a black part for pixels to be printed and a white part for pixels not to be printed.
The thinning block pattern storage unit 1-12 is configured by a memory such as SRAM, and stores the plurality of thinning block pattern information.

The thinning pattern selection unit 1-11 determines a thinning pattern based on information from the selection information input unit 1-10, and obtains a thinning block pattern necessary for generating the determined pattern. The thinning block selection information is output to 1-12.
The thinning block pattern storage unit 1-12 receives thinning block selection information and outputs thinning block pattern information.

  The thinning pattern selection unit 1-11 generates a thinning pattern based on the thinning block pattern information from the thinning block pattern storage unit 1-12, and outputs the thinning pattern to the thinning processing unit 1-7.

  In this embodiment, the thinning pattern selection unit 1-11 receives information on a thinning block pattern of 2 × 2 pixels in the thinning block pattern storage unit 1-12, and generates a thinning pattern for an area of 2 lines and 12 pixels. Do. Then, a thinning pattern is output to the thinning processing unit 1-7.

  The selection information input unit 1-10 receives the noise characteristics of the printing apparatus and the frequency of the synchronization clock of the image signal for printing. Based on the information, the thinning pattern selection unit 1-11 determines the thinning pattern. Will be done.

Although not shown in detail in the selection information input unit 1-10, a memory such as an SRAM is incorporated, and the noise characteristics of the printing apparatus are stored as noise level values for each frequency as a table. Suppose that
Next, a detailed description will be given regarding a method for determining a thinning pattern in the thinning pattern selection unit 1-11. The frequency of the synchronous clock of the image signal for printing is input to the thinning pattern selection unit 1-11 from the selection information input unit 1-10.
From the frequency of the synchronous clock of the image signal for printing, a frequency of switching noise that occurs when a pixel to be printed and a pixel not to be printed are switched is assumed.
In this embodiment, it is assumed that the frequency of the synchronization clock of the print image signal is 800 MHz.
In that case, when the pixels to be printed one pixel at a time and the pixels not to be printed are switched as shown in FIG. 3A, the image signal is generated at a cycle twice that of the clock as shown in FIG. It will be switched.
Therefore, the frequency of the switching noise generated by the image signal is 400 MHz, which is half of the synchronous clock.
In addition, when the pixel to be printed and the pixel not to be printed are switched every two pixels as shown in FIG. 4A, the image signal is switched at a cycle four times the clock as shown in FIG. It will be a thing.
Therefore, the frequency of the switching noise generated by the image signal is 200 MHz, which is a quarter of the synchronous clock.
Similarly, when the pixels to be printed are switched every three pixels as shown in (A) of FIG. 5 and the pixels not to be printed are switched, as shown in (B) of FIG. It will be switched.
Therefore, the frequency of the switching noise generated by the image signal is 133 MHz, which is 1/6 of the synchronous clock.

  As described above, the thinning pattern selection unit 1-11 assumes a frequency at which a switching noise peak occurs from the frequency of the synchronization clock of the print image signal input from the selection information input unit 1-10.

Next, the thinning pattern selection unit 1-11 calculates a margin up to the standard value of the radiation noise of the printing apparatus with respect to the frequency portion where the switching noise peak assumed from the print synchronous clock previously occurs.
The memory in the selection information input unit 1-10 stores the radiation noise characteristics of the printing apparatus during normal image data printing operation as shown in FIG.
In this embodiment, the value of the noise level for each frequency from 0 to 1000 MHz is stored at a specific frequency interval (1 MHz in this embodiment).

The noise level of the switching noise generated from the thinned image data synchronized with the synchronization clock of 800 MHz is referred to in the radiation noise characteristic data of the printing apparatus in the memory.
In the present embodiment, reference is made to the noise level value of each frequency of 400 MHz, 200 MHz, and 133 MHz.
When the characteristic of the radiation noise of the printing apparatus is shown in FIG. 6A, the noise level at 400 MHz is 20 dB for the bell, the noise level at 200 MHz is 23 dB, and the noise level at 133 MHz is 10 dB.

  Assuming that the standard value of a certain radiation noise is less than 30 dB in all frequency regions as shown in FIG. 6A, the margin at 400 MHz is 10 dB, the margin at 200 MHz is 7 dB, and the margin at 133 MHz. Is 20 dB.

In determining the thinning pattern, the thinning pattern selection unit 1-11 determines the thinning pattern so that the frequency at which the switching noise peak occurs is a frequency having a specific amount of margin with respect to the reference value. To do.
In the present embodiment, the frequency at which the switching noise peak occurs is matched with the frequency having a margin of 15 dB or more.
Since the margin at 400 MHz is 10 dB, it is not possible to select a pattern in which the pixels to be printed one pixel at a time and the pixels not to be printed are switched as shown in FIG.

If a pattern in which the pixels to be printed one pixel at a time and the pixels not to be printed are selected as shown in FIG. 3, switching noise is generated at a frequency of 400 MHz as shown in FIG. For this reason, the level of radiation noise of the printing apparatus exceeds the specified value.
Similarly, since the margin at 200 MHz is 7 dB, it is not possible to select a pattern that switches every two pixels as shown in FIG.

In the case of a pattern in which the pixels to be printed and the pixels not to be printed are switched every three pixels as shown in FIG. 5A, the frequency at which the switching noise peak occurs is 133 MHz, and the margin for the specified value is 20 dB. It will be selectable.
When a pattern in which pixels that are printed every three pixels are switched and pixels that are not printed is selected as shown in FIG. 5A, switching noise is generated at a frequency of 133 MHz as shown in FIG. 6C. It will be a thing.
Since the 133 MHz frequency portion has a sufficient margin with respect to the standard value, the level of radiation noise of the printing apparatus will be less than the specified value.
Therefore, the thinning pattern in the thinning pattern selection unit according to the present embodiment is a pattern of 2 lines and 12 pixels as shown in FIG.

  As shown in FIG. 7B, the pattern of the thinning block pattern required to realize the thinning pattern of 2 lines and 12 pixels as shown in FIG. There are three types of pattern 4.

  The thinning pattern selection unit 1-11 outputs the three patterns as thinning block selection information to the thinning block pattern storage unit 1-12, and obtains three thinning block pattern information from the thinning block pattern storage unit 1-12. It will be a thing.

  The thinning pattern selection unit 1-11 arranges the three types of thinning block patterns of input pattern 1, pattern 3, and pattern 4 in the order of pattern 3, pattern 1, pattern 4, pattern 3, pattern 1, and pattern 4. Thereby, a thinning pattern of 2 lines and 12 pixels is generated.

  The thinning pattern of 2 lines and 12 pixels is input to the thinning processing unit 1-7, and is used for thinning processing for CMYK data for printing input in units of areas of 2 lines and 12 pixels from the print data input unit 1-8. Will be used.

  The thinning processing unit 1-7 performs thinning processing on the print data input from the print data input unit 1-6 based on the thinning pattern generated from the thinning pattern generation unit 1-9.

In this embodiment, when a thinning pattern as shown in FIG. 7A is generated and thinning processing is performed on print data as shown in FIG. 7C, FIG. Thus, the print data after the thinning process is output.
FIG. 8 is a flowchart for explaining a control method of the printing apparatus according to the present embodiment. This example is an example of data processing in the thinning pattern generation unit 1-9 shown in FIG. Note that each step is realized by executing a control program stored in a ROM or the like by a CPU or the like (not shown), but in the description of this processing, it will be described as the hardware processing shown in FIG.
In the case of the present embodiment, the print synchronization clock frequency input and the radiation noise characteristic information of the printing apparatus are stored in advance in the selection information input unit 1-10.

  In S16-1, when it is set to execute the thinning process in the printing apparatus, information related to the synchronous clock frequency for printing stored in the selection information input unit 1-10 in advance is used as the thinning pattern selection unit 1-11. Print synchronous clock frequency input processing is performed. Next, in S16-2, “Noise characteristic information input processing for inputting the noise characteristic information of the printing apparatus stored in the selection information input unit 1-10 in advance to the thinning pattern selection unit 1-11 is performed.

In S16-3, a switching pattern candidate selection is performed for each pixel based on the input print synchronization clock frequency and the noise characteristic information of the printing apparatus. A switching pattern candidate selection process is performed. A detailed flow of selecting a switching pattern candidate will be described later with reference to FIG.
In 16-4, a switching pattern selection process is performed to determine which of the patterns that are candidates for switching in the switching pattern candidate selection is to be used as a pattern for the thinning process.

  In this embodiment, the pattern having the largest margin value among the candidates is the thinning pattern, but other selection methods such as switching with the smallest number of pixels may be used. .

  In S16-5, using the thinning pattern selected in S16-4, thinning pattern generation processing is performed to generate a thinning pattern for a predetermined n-line / m-pixel area.

  In S16-6, a determination is made as to which block pattern stored in the thinning block pattern storage unit 1-12 is used for the thinning pattern of the n-line / m-pixel area generated in S16-5. A thinning block pattern selection process is performed.

  Also, in 16-7, a decimation block pattern arrangement order determination process is performed for determining in what order the block patterns selected in S16-6 are arranged and realizing a decimation pattern.

  In S16-8, thinning block pattern information input processing is performed in which the information of the block pattern selected in S16-6 is input from the thinning block pattern storage unit 1-12 to the thinning pattern selection unit 1-11.

In S16-9, the decimation block patterns input to the decimation pattern selection unit 1-11 are arranged in the predetermined arrangement order. As a result, a thinning pattern is generated for an area of n lines and m pixels, and a thinning block pattern output process is performed for output to the thinning processing unit 1-7.
In step S16-10, the thinning process for the print data is executed based on the thinning pattern input to the thinning processing unit 1-7, and the process ends.

FIG. 9 is a flowchart for explaining a control method of the printing apparatus according to the present embodiment. This process is a detailed procedure of the switching pattern candidate selection process shown in S16-3 in FIG. Note that each step is realized by executing a control program stored in a ROM or the like by a CPU or the like (not shown), but in the description of this processing, it will be described as the hardware processing shown in FIG.
In S17-1, the thinning pattern selection unit 1-11 calculates a frequency at which switching noise peaks when a pixel to be printed and a pixel to be printed are switched for each pixel from the input print synchronization clock frequency 1 A peak frequency calculation process at the time of pixel switching is performed.
In S17-2, the noise characteristic information reference process for referring to the margin value from the noise level and the standard value of the frequency portion is performed by referring to the input noise characteristic information of the printing apparatus.
In S17-3, as a result of referring to the noise characteristic, it is determined whether the margin value is larger or smaller than a preset value. As a result of referring to the noise characteristics, when it is determined that the margin value is larger than a preset value (Yes in S17-3), in S17-4, switching for each pixel is set as a thinning pattern candidate and this processing is performed. To return.
On the other hand, if it is determined that the margin value is smaller than the preset value as a result of referring to the noise characteristics (No in S17-3), the process returns without switching pixel by pixel as a thinning pattern candidate. To do.

In S <b> 17-6, the thinning pattern selection unit 1-11 calculates the frequency at which switching noise peaks when the pixels to be printed and the pixels not to be printed are switched every two pixels from the input print synchronization clock frequency 2. A peak frequency calculation process at the time of pixel switching is performed.
In step S17-7, the input noise characteristic information of the printing apparatus is referred to, and the margin value is referred to from the noise level and the reference value of the frequency portion. In S17-8, as a result of referring to the noise characteristic, it is determined whether the margin value is larger or smaller than a preset value.
As a result of referring to the noise characteristics, when it is determined that the margin value is larger than a preset value (Yes in S17-8), in S17-9, the process is performed using the switching of every two pixels as a thinning pattern candidate. Return.

On the other hand, if it is determined that the margin value is smaller than a preset value as a result of referring to the noise characteristics (No in S17-8), switching for every two pixels is not regarded as a thinning pattern candidate in S17-10. The process is returned.
Similar processing is repeated up to a preset number of pixels, and it is determined whether switching of each number of pixels becomes a thinning pattern candidate. (17-11 to 17-15)

As described above, the printing apparatus that performs the print data thinning process performs the process for reducing the peak of the radiation noise based on the radiation noise characteristics of the printing apparatus and the frequency information of the synchronous clock when the print data is output. . Specifically, the printing apparatus generates a thinning pattern so that the radiation noise due to the print data output after the thinning process is “moved” to a portion where the radiation noise of the printing apparatus is low. Thereby, the peak of radiation noise can be reduced.
[Second Embodiment]
In the first embodiment, a plurality of thinning patterns are prepared and placed according to the target density per unit area, and the thinning patterns are generated by switching them.

  At that time, based on the radiation noise characteristics of the printing device and the frequency information of the synchronous clock at the time of print data output, the radiation noise due to the print data output after the thinning process is “moved” to the portion of the printing device where the radiation noise is low. The thinning pattern is generated so that Thus, the method for reducing the peak of radiation noise has been described.

  In the second embodiment, a method of reducing the peak of radiation noise by another method when generating a thinning pattern will be described. Based on the radiation noise characteristics of the printing device and the frequency information of the synchronous clock at the time of print data output, the radiation noise due to the print data output after the thinning process is “distributed” in the low portion of the radiation noise of the printing device. Generate a thinning pattern. Thus, a method for reducing the peak of radiation noise will be described. Note that the configuration of the printing apparatus according to the second embodiment is the configuration illustrated in FIG. 1 as in the first embodiment. In addition, regarding the configuration of the image processing unit 1-3, since the internal detailed configuration is illustrated with reference to FIG. 20, the internal configuration is the same as that of FIG. 20, and detailed illustration is omitted. To do.

In this embodiment, the image processing unit 1-3 inputs RGB image data from the scanner 1-1, performs various image processing on RGB and CMYK data, and outputs CMYK data for printing. Become.
The image processing unit 1-3 performs various image processing on the CMYK data after inputting the PDL data from the PC 1-2, and outputs the CMYK data for printing.
The print data thinning unit 1-4 performs a thinning process on the CMYK data for printing, and outputs the thinned image data to the printer 1-5.
The print data thinning unit 1-4 includes a print data input unit 1-6, a thinning processing unit 1-7, a print data output unit 1-8, and a thinning pattern generation unit 1-9.
The thinning pattern generation unit 1-9 includes a selection information input unit 1-10, a thinning pattern selection unit 1-11, and a thinning block pattern storage unit 1-12.
The CMYK data for printing output from the image processing unit 1-3 is input from the print data input unit 1-6 and output to the thinning processing unit 1-7.

The print data input unit 1-6 is configured by a memory such as SRAM, and stores print data input for each line for each color of CMYK in a memory for a plurality of lines, and is an area of n lines and m pixels. The output is performed in units to the thinning processing unit 1-7.
In the present embodiment, a memory for two lines is provided, and output is performed to the thinning processing unit 1-7 in units of areas of 2 lines and m pixels.
In this case, the value of m pixels is a value that matches the number of pixels of the thinning pattern created by the thinning pattern generation unit.

The thinning processing unit 1-7 performs a thinning process on the print data input from the print data input unit 1-6 based on the thinning pattern generated from the thinning pattern generation unit 1-9.
In the present embodiment, it is assumed that a thinning pattern generates a pattern of pixels to be printed and pixels not to be printed in an area unit of 2 lines / m pixels.

For the CMYK data for printing input in units of 2 lines / m pixels, the thinning processing unit 1-7 is the same data for the pixels to be printed. Clear the data. As a result, the print data is thinned out.
The CMYK data after the thinning process that has been subjected to the thinning process is output from the thinning processing unit 1-7 and is input to the print data output unit 1-8.

The print data output unit 1-8 is configured by a memory such as an SRAM. The print data input for each area of CMYK is stored in a memory for a plurality of areas, and pixel data for one line is prepared. Then, output is performed to the printer 1-5 in units of one line.
In the present embodiment, the memory for two lines is provided, the CMYK data after the thinning process is input in units of areas of 2 lines and m pixels, and output to the printer 1-5 in units of lines. .
Next, the thinning pattern generation unit 1-9 will be described in detail.
The thinning pattern generation unit 1-9 includes a selection information input unit 1-10, a thinning pattern selection unit 1-11, and a thinning block pattern storage unit 1-12.
With respect to the selection information input unit 1-10, the input information and operation are the same as those in the first embodiment, and detailed description thereof will be omitted.
Also, with regard to the thinned block pattern storage unit 1-12, the stored block pattern information and operations are the same as those in the first embodiment, and a detailed description thereof will be omitted.
Next, a detailed description will be given of a thinning pattern determination method in the thinning pattern selection unit 1-11, which is a feature of the present embodiment.
The frequency of the synchronous clock of the image signal for printing is input to the thinning pattern selection unit 1-11 from the selection information input unit 1-10.
From the frequency of the synchronous clock of the image signal for printing, a frequency of switching noise that occurs when a pixel to be printed and a pixel not to be printed are switched is assumed.
In this embodiment, it is assumed that the frequency of the synchronization clock of the print image signal is 800 MHz.
In that case, when the pixels to be printed one pixel at a time and the pixels not to be printed are switched as shown in FIG. 3A, the image signal is generated at a cycle twice that of the clock as shown in FIG. It will be switched.
Therefore, the frequency of the switching noise generated by the image signal is 400 MHz, which is half of the synchronous clock.
In addition, when the pixel to be printed and the pixel not to be printed are switched every two pixels as shown in FIG. 4A, the image signal is switched at a cycle four times the clock as shown in FIG. It will be a thing.
Therefore, the frequency of the switching noise generated by the image signal is 200 MHz, which is a quarter of the synchronous clock.
Similarly, when the pixels to be printed are switched every three pixels as shown in (A) of FIG. 5 and the pixels not to be printed are switched, as shown in (B) of FIG. It will be switched.
Therefore, the frequency of the switching noise generated by the image signal is 133 MHz, which is 1/6 of the synchronous clock.
In the present embodiment, a case where a pixel to be printed every four pixels and a pixel to be not printed are switched as shown in FIG.
In that case, as shown in FIG. 10B, the image signal is switched at a period of 8 times the clock.
Therefore, the frequency of the switching noise generated by the image signal is 100 MHz, which is 1/8 of the synchronous clock.

  As described above, the thinning pattern selection unit 1-11 assumes a frequency at which a switching noise peak occurs from the frequency of the synchronization clock of the print image signal input from the selection information input unit 1-10.

Next, the thinning pattern selection unit 1-11 calculates a margin up to the standard value of the radiation noise of the printing apparatus with respect to the frequency portion where the switching noise peak assumed from the print synchronous clock previously occurs.
The memory in the selection information input unit 1-10 stores the radiation noise characteristics of the printing apparatus during normal image data printing operation as shown in FIG.
Also in this embodiment, it is assumed that the noise level value for each frequency from 0 to 1000 MHz is stored at a specific frequency interval (1 MHz in this embodiment).

The noise level of the switching noise generated from the thinned image data synchronized with the synchronization clock of 800 MHz is referred to in the radiation noise characteristic data of the printing apparatus in the memory.
In the present embodiment, reference is made to the noise level value of each frequency of 400 MHz, 200 MHz, 133 MHz, and 100 MHz.

  If the characteristics of the radiation noise of the printing apparatus are as shown in FIG. 11, the noise at 400 MHz is 20 dB for the bell, the noise level at 200 MHz is 20 dB, the noise level at 133 MHz is 10 dB, and the noise level at 100 MHz. Is 23 dB.

  Assume that the standard value of a certain radiation noise standard is less than 30 dB in all frequency regions as shown in FIG. Then, the margin at 400 MHz is 10 dB, the margin at 200 MHz is 10 dB, the margin at 133 MHz is 20 dB, and the margin at 100 MHz is 7 dB.

In determining the thinning pattern, the thinning pattern selection unit 1-11 determines the thinning pattern so that the frequency at which the switching noise peak occurs is distributed to the frequency having a specific amount of margin with respect to the reference value. I will do it.
In the present embodiment, the frequency at which the switching noise peak occurs is dispersed in the frequency having a margin of 10 dB or more.
Since the margin at 400 MHz is 10 dB, it is possible to select a pattern in which a pixel to be printed and a pixel to be not printed are switched as shown in FIG.

Similarly, since the margin at 200 MHz is 10 dB and the margin at 133 MHz is 20 dB, a pattern for switching every two pixels as shown in FIG. 4A and FIG. The pattern that changes over time is selectable.
However, since the margin at 100 MHz is 7 dB, it is not possible to select a pattern in which a pixel to be printed and a pixel to be not printed are switched as shown in FIG.
In other words, in the present embodiment, it is possible to select a pattern for switching between pixels that are not printed and pixels that are printed by one pixel, two pixels, and three pixels.

  In the present embodiment, the three patterns are used to repeat the pattern for switching between pixels to be printed and pixels not to be printed by every one pixel, every two pixels, and every three pixels, as shown in FIG. A pattern of 2 lines and 12 pixels as shown in FIG.

  As shown in FIG. 12B, the thinning block pattern necessary to realize the thinning pattern of 2 lines and 12 pixels as shown in FIG. There are three types of pattern 4.

  The thinning pattern selection unit 1-11 outputs the three patterns as thinning block selection information to the thinning block pattern storage unit 1-12, and obtains three block pattern information from the thinning block pattern storage unit 1-12. It becomes.

  The thinning pattern selection unit 1-11 arranges the input three types of block patterns of pattern 1, pattern 3, and pattern 4 in the order of pattern 1, pattern 3, pattern 4, pattern 3, pattern 1, and pattern 4. Thereby, a thinning pattern of 2 lines and 12 pixels is generated. That is, the thinning pattern selection unit 1-11 continuously selects each thinning pattern stored in the thinning block pattern storage unit 1-12.

  The thinning pattern of 2 lines and 12 pixels is input to the thinning processing unit 1-7, and is used for the thinning process for CMYK data for printing input from the print data input unit 1-6 in the area unit of 2 lines and 12 pixels. Will be done.

  In this embodiment, when a thinning pattern as shown in FIG. 12A is generated and thinning processing is performed on the print and data as shown in FIG. 12C, (D) in FIG. The print data after the thinning process such as () is output.

When the thinning process is performed with a pattern as shown in FIG. 12A, switching noise is generated at frequencies of 400 MHz, 200 MHz, and 133 MHz as shown in FIG. However, since the peak frequency is dispersed, the radiation noise level of the printing apparatus falls below a specified value.
FIG. 14 is a flowchart for explaining a control method of the printing apparatus according to the present embodiment. This example is a processing example in the thinning pattern generation unit 1-9 shown in FIG. In the present embodiment as well, as in the first embodiment, the print synchronous clock frequency input and the radiation noise characteristic information of the printing apparatus are stored in advance in the selection information input unit 1-10. Note that each step is realized by executing a control program stored in a ROM or the like by a CPU or the like (not shown), but in the description of this processing, it will be described as the hardware processing shown in FIG.

In S26-1, when it is set to execute the thinning process in the printing apparatus, the information regarding the synchronous clock frequency for printing stored in the selection information input unit 1-10 in advance is used as the thinning pattern selection unit 1-11. To input.
In S26-2, the noise characteristic information of the printing apparatus stored in the selection information input unit 1-10 in advance is input to the thinning pattern selection unit 1-11.

In S26-3, the thinning pattern selection unit 1-11 selects a switching pattern candidate for how many pixels to perform printing switching based on the input print synchronization clock frequency and the noise characteristic information of the printing apparatus. I do. Note that the detailed flow of selecting a switching pattern candidate is performed according to the flow shown in FIG. 9 as in the first embodiment, and thus detailed description thereof is omitted.
Subsequently, in S26-4, in the switching pattern candidate selection, it is determined which of the patterns that are candidates for switching is to be used as the pattern for the thinning process. In the present embodiment, all the candidate patterns are used, but a pattern that is prohibited to be used may be set depending on other factors such as image quality.

  In S26-5, using the thinning pattern selected in S26-4, a thinning pattern is generated for a predetermined area of n lines and m pixels.

  In the second embodiment, using all the thinning patterns selected in S26-4, a pattern for switching between pixels to be printed and pixels to be printed by one pixel and two pixels by three pixels is repeated. Such a thinning pattern of an area of 2 lines and 12 pixels is generated. However, pattern generation methods with other arrangements are also possible.

  Further, although detailed explanation by illustration is omitted here, the area size information of n lines and m pixels of the thinning pattern created in S26-5 is sent to the print data input unit 1-6.

  The print data input unit 1-6 controls the print data storage memory based on the information, and outputs the print data to the thinning processing unit 1-7 in a form that matches the area size of the thinning pattern. Will be.

  In S26-6, a determination is made as to which block pattern stored in the thinning block pattern storage unit 1-12 is used for the thinning pattern of the n-line / m-pixel area generated in S26-5. I do.

  In S26-7, it is determined in what order the block patterns selected in S26-6 are arranged to realize the thinning pattern.

  In S26-8, the information of the block pattern selected in S26-6 is input from the thinning block pattern storage unit 1-12 to the thinning pattern selection unit 1-11.

In S26-9, the thinning-out block patterns input to the thinning-out pattern selection unit 1-11 are arranged in the predetermined arrangement order to generate a thinning pattern for an area of n lines / m pixels. Output to the processing unit 1-7.
In step S26-10, the print data is thinned based on the thinning pattern input to the thinning processing unit 1-7, and the process ends.

As described above, the printing apparatus that performs the print data thinning process performs the process for reducing the peak of the radiation noise. Specifically, based on the radiation noise characteristics of the printing device and the frequency information of the synchronous clock at the time of print data output, the radiation noise due to the print data output after the thinning process is “distributed in a portion where the radiation noise of the printer is low ”To generate a thinning pattern. Thereby, the peak of radiation noise can be reduced.
[Third Embodiment]

  In the first and second embodiments, an example has been described in which the following processing is performed based on the radiation noise characteristics of the printing apparatus and the frequency information of the synchronous clock at the time of print data output. The printing apparatus generates a thinning pattern so that the radiation noise due to the print data output after the thinning process is “moved” or “dispersed” in a portion where the radiation noise of the printing apparatus is low. Thus, the method for reducing the peak of radiation noise has been described.

In the present embodiment, a method will be described for a method of performing control so as to generate a “random” thinning pattern and “disperse” switching noise peaks without particularly considering the characteristics of radiation noise of the printing apparatus.
FIG. 15 is a block diagram illustrating the configuration of the printing apparatus according to the present embodiment. Since the internal detailed configuration of the image processing unit 27-3 is shown in FIG. 20 in advance, the internal configuration is the same as that of FIG.

  In FIG. 15, an image processing unit 27-3 inputs RGB image data from the scanner 27-1, performs various image processing on RGB and CMYK data, and outputs CMYK data for printing. .

In addition, after inputting the PDL data from the PC 27-2, the image processing unit 27-3 performs various image processing on the CMYK data and outputs CMYK data for printing.
The print data thinning unit 27-4 performs the thinning process on the CMYK data for printing, and outputs the thinned image data to the printer 27-5.

  The print data decimation unit 27-4 includes a print data input unit 27-6, a decimation processing unit 27-7, a print data output unit 27-8, and a decimation pattern generation unit 27-9.

The thinning pattern generation unit 27-9 includes a selection information input unit 27-10, a thinning pattern selection unit 27-11, a thinning block pattern storage unit 27-12, and a random number generation unit 27-13.
The print CMYK data output from the image processing unit 27-3 is input from the print data input unit 27-6 and output to the thinning processing unit 27-7.

The print data input unit 27-6 includes a memory such as an SRAM, and stores print data input for each line for each color of CMYK in a memory for a plurality of lines, and an area of n lines and m pixels. The output is performed in units to the thinning processing unit 27-7.
In the third embodiment, a memory for two lines is provided, and output is performed to the thinning processing unit 27-7 in units of areas of two lines and twelve pixels.

The thinning processing unit 27-7 performs a thinning process on the print data input from the print data input unit 27-6 based on the thinning pattern generated from the thinning pattern generation unit 27-9.
In the present embodiment, it is assumed that the thinning pattern generates a pattern of pixels to be printed and pixels not to be printed in an area unit of 2 lines and 12 pixels.

For the CMYK data for printing input in units of 2 lines and 12 pixels, the thinning processing unit 27-7 is the same data for the pixels to be printed. Clear the data. As a result, the print data is thinned out.
The CMYK data that has been subjected to the thinning process is output from the thinning process unit 27-7 and is input to the print data output unit 27-8.

  The print data output unit 27-8 includes a memory such as an SRAM, and stores print data input in units of areas for each color of CMYK in a memory for a plurality of areas. Then, when the pixel data for one line is prepared, the data is output to the printer 27-5 in units of one line.

In this embodiment, the memory for 2 lines is provided, the CMYK data after the thinning process is input in the area unit of 2 lines and 12 pixels, and output to the printer 27-5 in the line unit. .
Next, the thinning pattern generation unit 27-9 in the present embodiment will be described in detail.

The thinning pattern generation unit 27-9 includes a selection information input unit 27-10, a thinning pattern selection unit 27-11, a thinning block pattern storage unit 27-12, and a random number generation unit 27-13. Here, in the selection information input unit 27-10, selection information is designated as to whether the thinning pattern is a fixed pattern or a random pattern.
Regarding the thinned block pattern storage unit 27-12, the stored block pattern information and operations are the same as those in the first embodiment, and a detailed description thereof will be omitted.

The thinning block pattern setting information is setting information indicating which pattern is used to generate the thinning pattern among the thinning block patterns stored in the thinning block pattern storage unit 27-12.
In the present embodiment, all four types of thinned block patterns stored in the thinned block pattern storage unit 27-12 are used.

  Further, the pattern fixed / random setting information is a switching setting of whether a fixed pattern set in advance is used as a thinning pattern or a thinning block pattern is randomly switched to generate a thinning pattern.

In this embodiment, when a fixed pattern is used as a thinning pattern, a thinning pattern as shown in FIG. 7A is stored in the thinning pattern selection unit 27-11 for an area of 2 lines and 12 pixels. It will be used during the thinning process.
Next, a detailed description will be given regarding a method for determining a thinning pattern in the thinning pattern selection unit 27-11 in the present embodiment.

  As described above, the thinning pattern selection unit 27-11 receives the thinning block pattern setting information and the pattern fixing / random setting information from the selection information input unit 27-10.

  When the fixed pattern / random setting information is set to a fixed pattern and a thinned pattern, a thinned pattern as shown in FIG. 11 is stored and used during the thinning process.

When the pattern fixed / random setting information is random setting, the four types of thinned-out block patterns stored in the thinned-out block pattern storage unit 27-12 are randomly selected for the area of 2 lines and 12 pixels. Use it to generate a thinning pattern.
FIG. 16 is a flowchart for explaining a control method of the printing apparatus according to the present embodiment. This example is an example of data thinning processing in the thinning pattern generation unit 27-11 shown in FIG. Note that each step is realized by executing a control program stored in a ROM or the like by a CPU or the like (not shown), but in the description of this processing, it will be described as the hardware processing shown in FIG.

  If it is determined in S28-1 that the thinning process is performed on the printing apparatus, in S28-2, the content of the pattern fixing / random setting information is referred to and the thinning pattern is used as a fixed thinning pattern. Determine whether to use a random pattern.

If it is determined that the setting is to use a fixed thinning pattern (Yes in S28-2), the thinning pattern preset in the thinning pattern selection unit 27-11 in S28-3 is It is sent to the thinning processing unit 27-7.
In S28-4, a thinning process is performed on the print data. Specifically, the thinning process is performed for each area of 2 lines and 12 pixels with a thinning pattern as shown in FIG.
In S28-5, it is determined whether or not all print data thinning processing has been completed. If it is determined that the thinning process has been completed for all print image data (Yes in S28-5), the thinning process is terminated in S28-13.
On the other hand, when it is determined in S28-5 that the thinning process has not been completed for all print image data (No in S28-5), the thinning process is repeated according to the fixed thinning pattern.
In step S28-13, the thinning process ends when the thinning process is performed on all print image data.

On the other hand, if it is determined in S28-2 that the setting is to use a random thinning pattern with reference to the contents of the pattern fixing / random setting information (No in S28-2), the thinning block pattern is determined in S28-6. Refer to the setting information.

Here, the thinning block pattern setting information is setting information indicating which pattern is used to generate the thinning pattern among the thinning block patterns stored in the thinning block pattern storage unit 27-12.
In the present embodiment, it is assumed that all four types of thinned-out block patterns stored in the thinned-out block pattern storage unit 27-12 shown in FIG. 15 are used.

In S28-7, the thinning block pattern information in the thinning block pattern storage unit 27-12 is input to the thinning pattern selection unit (27-11) based on the thinning block pattern setting information.
Subsequently, in S27-11, a thinning pattern is generated based on the random number input from the random number generator 27-13 and the random number.
The method of generating a thinning pattern based on the input random number is performed as follows.

  In the case of this embodiment, the thinning pattern to be generated is an area of 2 lines and 12 pixels, and the thinning block pattern is 4 patterns having an area of 2 lines and 2 pixels as shown in FIG. ing.

Therefore, in S28-8, the random number generated from the random number generator 27-13 is set to a random number from 0 to 3, and when 0 is input, the thinned block pattern of pattern 4 and when 1 is input, A thinned block pattern of pattern 1 is selected. If 2 is input, the thinned block pattern of pattern 2 is selected. If 3 is input, the thinned block pattern of pattern 3 is selected.
In S28-9), six patterns are selected by random numbers by the above selection method and arranged in order in an area of 2 lines and 12 pixels to generate a thinning pattern.
For example, when the six random numbers input from the random number generator 27-13 become “3”, “1”, “2”, “0” “1”, “3”, the thinning pattern is as shown in FIG. The pattern is as shown in 17 (A).

When thinning processing is performed with a pattern such as that shown in FIG. 17A, as shown in FIG. 17B, the portion to be printed and printed for every one pixel, two pixels, and three pixels with respect to the synchronous clock. The part not to be switched will be switched randomly.
In this embodiment, it is assumed that the frequency of the synchronization clock of the print image signal is 800 MHz.
In that case, when the pixel to be printed and the pixel not to be printed are switched one by one, the frequency of the switching noise generated by the image signal is 400 MHz, which is half of the synchronous clock.
In addition, when the pixels that are printed two pixels at a time and the pixels that are not printed are switched, the frequency of the switching noise is 200 MHz, which is a quarter of the synchronous clock.
When the pixels that are printed three pixels at a time and the pixels that are not printed are switched, the frequency of the switching noise is 133 MHz, which is 1/6 of the synchronous clock.

Therefore, in the present embodiment, since the decimation between 1 to 3 pixels occurs at random, a switching noise peak does not occur only at a specific frequency. The peak is dispersed at the frequency of 1 / 1/6.
The thinning pattern generated in S28-9 is output to the thinning processing unit 27-7 in S28-10). In step S28-11, thinning processing is performed on the print data.
In step S28-12, it is determined whether or not all print data thinning processing has been completed.
If it is determined that the thinning process has been completed for all print image data (Yes in S28-12), the thinning process is terminated in S28-13.

On the other hand, if it is determined that the thinning process has not been completed for all print image data (No in S28-12), the process returns to S28-8, and the thinning process is repeated from the generation of the thinning pattern using random numbers. It becomes.
When it is determined that the thinning process has been performed on all print image data (Yes in S28-12), the thinning process is terminated in S28-13.
In the present embodiment, it is assumed that the thinning process is performed on a 4-line / 24-pixel print and data as shown in FIG.
In this case, a thinning pattern as shown in FIG. 17 (A), FIG. 18 (A), FIG. 18 (B), or FIG. 18 (C) is randomly generated, and thinning processing is performed for each area. The thinning pattern is a pattern as shown in FIG.

  Accordingly, if the thinning process is performed on the 4-line / 24-pixel print and data as shown in FIG. 18D using the thinning pattern as shown in FIG. The print data after the thinning process such as () is output.

  In the present embodiment, when the radiation noise characteristic of the printing apparatus is as shown in FIG. 19A, switching noise occurs at frequencies of 400 MHz, 200 MHz, and 133 MHz as shown in FIG. 19B. Will occur. However, since the peak frequency is dispersed, the radiation noise level of the printing apparatus falls below a specified value.

  As described above, in a printing apparatus that performs a thinning process of print data, it is possible to reduce the peak of radiation noise by distributing the noise level peaks by randomly switching the thinning pattern.

  Each process of the present invention can also be realized by executing software (program) acquired via a network or various storage media by a processing device (CPU, processor) such as a personal computer (computer).

  The present invention is not limited to the above embodiment, and various modifications (including organic combinations of the embodiments) are possible based on the spirit of the present invention, and these are excluded from the scope of the present invention. is not.

1-3 Image processing unit 1-7 Thinning processing unit 1-9 Thinning pattern generation unit 1-10 Selection information input unit 1-11 Thinning pattern selection unit 1-12 Thinning block pattern storage unit

Claims (9)

A printing device that processes input print data,
Input means for inputting a frequency of a synchronous clock for performing image processing on the print data;
When,
A selection means for selecting a thinning pattern that does not exceed a predetermined threshold for the noise level specified by the frequency of the input synchronous clock;
Thinning processing means for performing a thinning process on the print data based on the selected thinning pattern;
A printing apparatus comprising: Comprising storage means for storing a plurality of thinning patterns;
2. The printing apparatus according to claim 1, wherein the selection unit selects one thinning pattern in which a noise level calculated with a frequency of a synchronous clock input from the storage unit falls within a predetermined margin. Comprising storage means for storing a plurality of thinning patterns;
The printing apparatus according to claim 1, wherein the selection unit continuously selects each thinning pattern stored in the storage unit. A printing device that processes input print data,
Storage means for storing a plurality of thinning patterns;
Input means for inputting a thinning pattern used for thinning processing to the print data;
When,
A selecting means for selecting from the storage means a thinning pattern specified by an inputted thinning pattern;
Thinning processing means for performing a thinning process on the print data based on the selected thinning pattern;
A printing apparatus comprising: A designating means for designating whether the thinning pattern is a fixed pattern or a random pattern is provided.
The selection unit selects one thinning pattern stored in the storage unit when the fixed pattern is designated, and when the random pattern is designated, the selection unit selects any one of the storage patterns stored in the storage unit. The printing apparatus according to claim 4, wherein the thinning pattern is selected at random.   6. The thinning pattern according to claim 1, wherein the pixel group of the print data is a pattern for converting a pixel to be printed into a pixel that is not printed for each specific pixel group. Printing device. A method of controlling a printing apparatus that processes input print data,
An input step of inputting a frequency of a synchronous clock for performing image processing on the print data;
When,
A selection step of selecting a thinning pattern specified by the frequency of the input synchronous clock; a thinning processing step of performing a thinning process on the print data based on the selected thinning pattern;
A control method for a printing apparatus, comprising: A method of controlling a printing apparatus that processes input print data,
An input step of inputting a thinning pattern used for the thinning process to the print data;
When,
A selection step of selecting a thinning pattern specified by the input thinning pattern from a storage means for storing a plurality of thinning patterns;
A thinning process step for performing a thinning process on the print data based on the selected thinning pattern;
A control method for a printing apparatus, comprising:   A program for causing a computer to execute the method for controlling a printing apparatus according to claim 7 or 8.

Images