JP2015074141A - Image processing device, image formation device, and image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deviation of an image that occurs in a case where the number of lines in sub-scanning direction, which is calculated from a record length of a unit page of a recording medium and resolution at the time of image formation, is not divisible by a unit size of the image information in the sub-scanning direction based on a transportation unit of the recording medium.SOLUTION: An explanation is made with a case of paper length being 10 4/6 inches. Image formation is made with 1600 dpi for the amount of 16000 lines and 27.2727 μs per one scan. For the amount of remaining 1068 lines, scanning cycle is switched at 1602 dpi, to form an image at 27.2387 μs per one scan, for agreement of image size in the sub-scanning direction.

Description

  The present invention relates to an image processing apparatus, an image forming apparatus, and an image processing program.

  In an image forming apparatus that forms an image on a continuous recording medium, it is proposed to perform various corrections because an image shift occurs due to an error in conveying the recording medium.

  For example, in Patent Document 1, a conveyance unit that is driven by a pulse motor to convey a continuous sheet, a measurement unit that measures a sheet conveyance speed with respect to a print pattern formation speed, and a drive unit that inputs a drive pulse to the pulse motor. And a timer for measuring the predetermined time by integrating the clock a predetermined number of times, a counter for measuring the timer's time-up count a predetermined number of times, and when the value of the counter reaches the predetermined number of times Pulse generating means for determining the width of the drive pulse by adding or decreasing the number of clock integrations based on the input from the measuring means and totaling the measurement time due to the predetermined time-up of the timer and the measurement time of the corrected timer. There has been proposed a continuous paper transport device for a printer equipped with the printer.

  Further, in Patent Document 2, in a printing apparatus that continuously prints first image data and second image data on a first recording medium and a second recording medium, the first image data, the second image data, Blank data corresponding to the interval between the first image data and the second image data, a data creation unit for connecting the first image data and the second image data, a detection unit for detecting the position of the recording medium, and the first recording detected by the detection Based on the position of the medium and the position of the second recording medium, a shift detection unit that detects a shift and a blank data correction unit that corrects blank data according to the shift amount detected by the shift detection unit are connected. It has been proposed to include a data transfer unit that transfers image data to a printing unit.

JP-A-2-283468 JP 2011-39897 A

  The present invention divides the number of lines in the sub-scanning direction calculated from the recording length of the unit page of the recording medium and the resolution at the time of image formation by the unit size of image information in the sub-scanning direction based on the conveyance unit of the recording medium. An object of the present invention is to prevent an image shift that occurs when there is no image.

  The image processing apparatus according to claim 1, an acquisition unit that acquires image information of an image formation target and recording length information indicating a recording length of a unit page of a continuous recording medium, and the recording length acquired by the acquisition unit When the number of lines in the sub-scanning direction obtained from the information and the formation resolution at the time of image formation is not divisible by the unit size of the image information in the sub-scanning direction based on a predetermined transport unit of the recording medium, and a fraction occurs. And fraction processing means for processing the fraction by controlling the resolution and scanning cycle of the image information.

  The invention according to claim 2 is the invention according to claim 1, wherein the fraction processing means switches between the formation resolution and a predetermined fraction processing resolution in which the fraction does not occur in a unit page, and the formation. The fraction is processed by controlling the resolution and scanning cycle of the image information so as to switch to a predetermined scanning cycle for each resolution of the resolution and the fraction processing resolution.

  According to a third aspect of the invention, in the invention of the second aspect, the fraction processing means switches the scanning cycle so as to switch to the scanning cycle for each resolution calculated in advance based on a predetermined process speed. To control.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the fraction processing resolution is a minimum resolution among resolutions of an integral multiple of the unit size larger than the formation resolution.

  On the other hand, an image forming apparatus according to a fifth aspect includes a conveyance unit that conveys a continuous recording medium in a predetermined conveyance unit, the image processing apparatus according to any one of claims 1 to 4, and the image. Image forming means for forming an image on the recording medium conveyed by the conveying means based on a processing result of the processing apparatus.

  An image processing program according to a sixth aspect causes a computer to function as each unit of the image processing apparatus according to any one of the first to fourth aspects.

  According to the first aspect of the present invention, the number of lines in the sub-scanning direction calculated from the recording length of the unit page of the recording medium and the resolution at the time of image formation is compared with the case where no fraction processing means is provided. Thus, there is an effect that it is possible to provide an image processing apparatus that can prevent an image shift that occurs when it cannot be divided by the unit size of the image information in the sub-scanning direction based on the conveyance unit of the recording medium.

  According to the second aspect of the present invention, the number of lines in the sub-scanning direction calculated from the recording length of the unit page of the recording medium and the resolution at the time of image formation is set in the sub-scanning direction based on the conveyance unit of the recording medium. There is an effect that it is possible to process a fraction that occurs when it cannot be divided by the unit size of image information.

  According to the third aspect of the present invention, there is an effect that the size of the image in the sub-scanning direction can be prevented from changing even if the formation resolution and the fraction processing resolution are changed in the unit page.

  According to the fourth aspect of the present invention, there is an effect that the influence on the image due to the change in the resolution and the scanning cycle in the unit page can be minimized.

  According to the fifth aspect of the present invention, the number of lines in the sub-scanning direction calculated from the recording length of the unit page of the recording medium and the resolution at the time of image formation is compared with the case where no fraction processing means is provided. Thus, there is an effect that it is possible to provide an image forming apparatus that can prevent an image shift that occurs when the unit size of image information in the sub-scanning direction based on the recording medium conveyance unit cannot be divided.

  According to the sixth aspect of the present invention, the number of lines in the sub-scanning direction calculated from the recording length of the unit page of the recording medium and the resolution at the time of image formation is compared with the case where no fraction processing means is provided. Thus, there is an effect that it is possible to provide an image processing program capable of preventing an image shift that occurs when it cannot be divided by the unit size of the image information in the sub-scanning direction based on the conveyance unit of the recording medium.

1 is a diagram showing a schematic configuration of an image forming system according to an embodiment. 1 is a block diagram illustrating a configuration of an example of an image forming system of a comparative example. (A) is a table | surface which shows the logical value of the number of dots (line) of the subscanning direction for every paper length in the resolution of 1600 dpi, (B) is a figure which shows an example of the image shift | offset | difference which arises by a fraction. It is a table | surface which shows the value after the rounding operation | movement for every paper length at the time of rounding operation | movement like 1602 * m / 6 (m: natural number of 1-5) supposing the virtual resolution of 1602dpi. It is a table | surface which shows the value divided by the least common multiple of the receiving resolution and the scanning resolution, and each resolution. It is a figure which shows the example of a fraction adjustment performed by the fraction adjustment part. 6 is a flowchart illustrating an example of a flow of processing performed by a mechanical controller of the image forming system according to the embodiment of the present invention.

  Hereinafter, the present embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an image forming system 10 according to the present embodiment.

  The image forming system 10 according to the present embodiment forms an image using continuous paper as a recording medium.

  The image forming system 10 includes a host computer 12, a print controller 14, a mechanical controller 16, a mechanical mechanism unit 24, and a head 38.

  The host computer 12 transmits image information (hereinafter referred to as image data) representing an image to be formed to the print controller 14. When transmitting image data to the print controller 14, the host computer 12 transmits sheet length information indicating the recording length of a unit page (hereinafter, an example in which one page is a unit page) together with the image data. In the present embodiment, the resolution of the image data transmitted from the host computer 12 is transmitted to the print controller 14 with resolution of 240 dpi, 400 dpi, 600 dpi, or the like.

  In the print controller 14, the image data transmitted from the host computer 12 is converted into data in the bitmap format and transferred to the mechanical controller 16 together with the paper length information.

  The mechanical controller 16 includes a host connection unit 18, a mechanical control unit 20, a paper transport unit 22, an image reception unit 26, a resolution conversion unit 28, an image output unit 36, and a fraction adjustment unit 34.

  The host connection unit 18 functions as an interface to the print controller 14, receives the paper length information transferred from the print controller 14, and transmits it to the mechanical control unit 20.

  The mechanical control unit 20 controls the operation of the mechanical mechanism unit 24 that conveys the paper via the paper conveyance unit 22 based on the paper length information transmitted from the host connection unit 18.

  The paper transport unit 22 functions as a driver for driving the mechanical mechanism unit 24 and operates the mechanical mechanism unit 24 in accordance with an instruction from the mechanical control unit 20.

  The mechanical mechanism unit 24 includes a driving unit such as a motor for transporting the paper, and transports the paper by driving the driving unit in accordance with a driving instruction of the paper transporting unit 22.

  The image receiving unit 26 receives the image data transferred from the print controller 14 and transmits the received image data to the resolution conversion unit 28.

  The resolution conversion unit 28 includes a main scanning enlargement processing unit 30 and a sub-scanning enlargement processing unit 32, performs resolution conversion by each enlargement processing unit, and transmits to the image output unit 36. In this embodiment, the resolution of the image data (240 dpi, 400 dpi, 600 dpi, etc.) transferred from the print controller 14 is enlarged to 1600 dpi and transmitted to the image output unit 36.

  The image output unit 36 controls the head 38 based on the resolution-converted image data to form an image on a sheet. In addition, as a head, you may make it apply the exposure head which performs light exposure, and may apply the head which discharges inks, such as an inkjet.

  The fraction adjustment unit 34 adjusts the fraction that occurs when the number of lines in the sub-scanning direction calculated from the resolution of the image data and the sheet length cannot be divided by the unit size of the image data in the sub-scanning direction based on the transport unit. (The details will be described later).

  Here, before specifically describing the processing performed by the fraction adjustment unit 34, an image forming apparatus of a comparative example will be described. FIG. 2 is a block diagram illustrating a configuration of an example of an image forming system according to a comparative example. The same components as those in the present embodiment will be described with the same reference numerals.

  In the image forming system shown in FIG. 2, the image data transmitted from the host computer 12 is received by the print controller 13 and converted into data in a format such as a bitmap, and at the same time, converted to the resolution of the head 38 and the mechanical controller 15. Send to.

  In the mechanical controller 15, the paper length information is received by the host connection unit 18 and transmitted to the mechanical control unit 20. The mechanical control unit 20 operates the mechanical mechanism unit 24 via the paper transport unit 22 based on the paper length information.

  Further, the image receiving unit 26 receives the image data whose resolution has been converted by the print controller 13 and transmits it to the scanning processing unit 27.

  In the scanning processing unit 27, the main scanning processing unit 31 sequentially outputs image data in the main scanning direction to the image output unit 36, and the sub-scanning processing unit 33 outputs image data to the image output unit 36 in order to synchronize with the sheet conveyance. Control the timing.

  In the image forming system of FIG. 2, since the bitmap is developed with the paper length size in order to convert it into resolution data output by the print controller 13, the mechanical controller 15 performs the exposure operation at the timing of paper conveyance. At this time, since the mechanical mechanism section 24 is operated in units of 1/6 inch, the unit size of data in the sub-scanning direction is also 1/6 inch unit. However, when the resolution of the head 38 is 1600 dpi, The data size and resolution in the sub-scanning direction defined from the transport unit (1/6 inch) cannot be divided and a fraction is generated. Therefore, this fraction is accumulated on continuous paper and appears as an image shift.

  For example, the number of dots in the sub-scanning direction when the image formation resolution (formation resolution) is 1600 dpi is as shown in FIG. 3A when the paper length is 9 to 11 inches. In the portion indicated by hatching in FIG. That is, since the transport operation is in units of 1/6 inch, the number of dots does not logically match the paper length that is not divisible by 6, resulting in a fraction and an image shift with respect to the paper. For example, as shown in FIG. 3B, when the sheet length is 10.2 / 3 inches, dividing by 6 results in 17066.67 lines, but if 17066 lines are used, the error for one line is a fraction. Will occur. Since it is continuous paper, errors for one line accumulate, resulting in a large image shift.

  Therefore, in the present embodiment, the above-described fraction (a fraction that is not divisible by 6) is adjusted by the fraction adjustment unit 34 to prevent image shift.

  Specifically, in this embodiment, the image data sent from the host computer 12 is processed by the print controller 14 and the image data is sent to the mechanical controller 16 at the same resolution as the host computer 12. By performing resolution conversion with the mechanical controller 16 without performing resolution conversion with the print controller 14, the data transfer time can be afforded, and high-speed image formation is performed.

  In addition, the mechanical controller 16 performs enlargement processing in the main scanning direction and the sub-scanning direction, but at the same time, the print controller 14 notifies the mechanical controller 16 of sheet length information in units of 1/6 inch. In the mechanical controller 16, the mechanical control unit 20 notifies the paper conveyance unit 22 and the fraction adjustment unit 34 that processes the image data of the paper length information. In the fraction adjustment unit 34, when m / 6 inch is specified, for example, a virtual resolution (fractional processing resolution) of 1602 dpi is assumed, and 1602 × m / 6 (m: natural number of 1 to 5) is assumed. Perform rounding operation. The number of dots obtained by adding n × 1600 to this is processed as the number of data lines in the sub-scanning direction, and the data is output to the image output unit 36 and transferred to the head 38 to complement the data. The values after the rounding operation for each sheet length are as shown in FIG.

  Here, the fraction adjustment method performed by the fraction adjustment unit 34 will be described in more detail.

  The fraction adjustment unit 34 controls the sub-scanning enlargement processing unit 32 to process an amount of fraction that is output in 1/6 inch as 1602 dpi.

  Specifically, in the case where the paper length is 10.4 / 6 inch (hatched portion in FIG. 4), the 10 inch portion is processed as 1600 dpi and processed as 16000 lines, and the remaining 4/6 inch. Is converted to 1602 × 4/6 = 1068 lines with 1602 dpi. As a result, the number of lines in the sub-scanning direction is processed as 17068 lines. These conversions are not actually processed, but are determined in advance in the fraction processing table for each paper length setting, and the corresponding values are read from the received paper length information from the fraction processing table and processed.

  At this time, the scanning cycle becomes a problem. Here, an image forming apparatus having a process speed of 8250 LPL (34.9 m / min) will be described as an example. In the case of 1600 dpi, the time required to scan one line is 27.27272727 μs, and in the case of 1602 dpi is 27.2867789 μs, and for the above-mentioned paper length (10/4/6 inch), 16000 lines are 27 per scan. .2727 μs and the remaining 1068 lines need to be scanned at 27.2387 μs.

  Here, when the least common multiple of the reception resolution and the scanning resolution (240, 400, 600, 1200, 1600, 1602 dpi) is obtained, it is 1281600, and the value divided by each resolution is obtained as shown in FIG. become.

  Based on the value shown in FIG. 5 and the process speed, the base clock frequency is obtained by dividing one scanning time. As a result, a frequency of 29.37 MHz (34.05 ns per clock) common to each resolution is obtained.

  Accordingly, by counting different scanning frequencies for each resolution based on the above 29.37 MHz clock, the image is scanned while switching one raster cycle in one page.

  Specifically, as shown in FIG. 6, the fraction adjustment unit 34 forms an image at 1600 dpi for 1600 dpi and 27.2727 μs per scan, and the remaining 1068 lines for one scan by switching the scan cycle at 1602 dpi. An image is formed at 27.2387 μs. As a result, the images fit perfectly in units of 1/6 inch, which is the unit of paper conveyance.

  Here, there is a concern that changing the resolution in the sub-scanning direction in the middle may affect the image (in the above example, the image is extended), but there are also portions that are 1 inch or less and also affect the image. Since it is 1/1000 mm or less, it is not a problem substantially.

  In FIG. 6, switching from 1600 dpi to 1602 dpi is performed. However, the present invention is not limited to this, and switching from 1602 dpi to 1600 dpi may be performed, or a line with 1602 dpi may be inserted in the middle of 1600 dpi. Good.

  In the present embodiment, the resolution is switched to the minimum resolution (1602 dpi) out of the resolution (multiple of 6) which is larger than the formation resolution (1600 dpi) and is an integer multiple of the unit size of the image data defined from the transport unit. However, the present invention is not limited to this. For example, the resolution is smaller than the formation resolution (1600 dpi), and is the largest of the resolutions (multiples of 6) of the integer multiple of the unit size of the image data defined from the transport unit. The resolution (1596 dpi) may be switched and the scanning cycle may be switched accordingly. Even in this case, as in the present embodiment, image shift is prevented.

  Next, specific processing performed by the mechanical controller 16 of the image forming system 10 according to the embodiment of the present invention configured as described above will be described. FIG. 7 is a flowchart showing an example of the flow of processing performed by the mechanical controller 16 of the image forming system 10 according to the embodiment of the present invention.

  In step 100, the paper length information is acquired by the upper connection unit 18, and the process proceeds to step 102. That is, the host connection unit 18 acquires the paper information transmitted from the print controller 14 together with the image data.

  In step 102, the mechanical control unit 20 determines whether fraction processing is necessary. In this embodiment, since the transport unit is 1/6 unit in this embodiment, it is determined whether the sheet length is designated as m / 6 inch. If the determination is negative, the process proceeds to step 104. If the determination is affirmative, the routine proceeds to step 106.

  In step 104, resolution conversion is performed by the resolution conversion unit 28, and the image data is transferred to the head 38 in a prescribed scanning cycle, and the process proceeds to step 114. In other words, the main scanning enlargement processing unit 30 converts the resolution in the main scanning direction to 1600 dpi, the sub scanning enlargement processing unit 32 converts the resolution in the sub scanning direction to 1600 dpi, and the scanning cycle is calculated from the resolution of 1600 dpi. The image data is transferred to the head 38 so that

  On the other hand, in step 106, the fraction adjustment unit 34 reads a value corresponding to the sheet length from the fraction processing table, and the process proceeds to step 108. In other words, the fraction adjustment unit 34 reads out the number of lines to be processed at 1600 dpi, the number of lines to be processed at 1602 dpi, and the values of the respective scanning cycles from the fraction processing table stored in advance.

  In step 108, resolution conversion is performed, the image data is transferred to the head 38, and the process proceeds to step 110. For example, as in the above-described example, when the paper length is 10.4 / 6 inches, image formation is performed for 16000 lines with a scanning period of 27.2727 μs with a resolution of 1600 dpi in the main scanning direction and the sub-scanning direction. .

  In step 110, it is determined by the fraction adjustment unit 34 whether or not it is a scanning cycle change line. This determination is made based on the value corresponding to the sheet length read from the fraction processing table in step 106. If the determination is negative, the process returns to step 108, and if the determination is affirmative, step 112 is performed. Migrate to

  In step 112, the resolution and scanning cycle are changed, the image data is transferred to the head 38, and the process proceeds to step 114. That is, in the case of the above example, for the remaining 1078 lines after 16000 lines, the scanning cycle is changed to a scanning cycle of 27.2387 μs and the image data is transferred to the head 38 so that the resolution in the sub-scanning direction is 1602 dpi. .

  In step 114, it is determined whether or not the image formation is completed. If the determination is negative, the process returns to step 100 and the above-described processing is repeated. When the determination is affirmed, the series of processing ends.

  Note that the processing performed by the mechanical controller 16 in the above embodiment may be stored and distributed as a program in a storage medium.

DESCRIPTION OF SYMBOLS 10 Image forming system 16 Mechanical controller 18 Host connection part 20 Mechanical control part 22 Paper conveyance part 24 Mechanical mechanism part 26 Image receiving part 28 Resolution conversion part 30 Main scanning expansion process part 32 Sub-scanning expansion process part 34 Fraction adjustment part 36 Image output Part 38 head

Claims (6)

An acquisition means for acquiring image information to be imaged and recording length information representing a recording length of a unit page of a continuous recording medium;
The number of lines in the sub-scanning direction obtained from the recording length information acquired by the acquiring means and the formation resolution at the time of image formation is a unit of the image information in the sub-scanning direction based on a predetermined transport unit of the recording medium. A fraction processing means for processing the fraction by controlling the resolution and scanning cycle of the image information when a fraction occurs without being divisible by the size;
An image processing apparatus.   The fraction processing means switches between the formation resolution and a predetermined fraction processing resolution at which the fraction does not occur in a unit page, and at a predetermined scanning cycle for each of the formation resolution and the fraction processing resolution. The image processing apparatus according to claim 1, wherein the fraction is processed by controlling a resolution and a scanning cycle of the image information so as to be switched.   The image processing apparatus according to claim 2, wherein the fraction processing unit controls the scanning cycle so as to switch to the scanning cycle for each resolution calculated in advance based on a predetermined process speed.   The image processing apparatus according to claim 2, wherein the fraction processing resolution is a minimum resolution among resolutions of an integral multiple of the unit size larger than the formation resolution. Conveying means for conveying a continuous recording medium in a predetermined conveying unit;
The image processing apparatus according to any one of claims 1 to 4,
An image forming unit that forms an image on the recording medium conveyed by the conveying unit based on a processing result of the image processing apparatus;
An image forming apparatus.   The image processing program for functioning a computer as each means of the image processing apparatus of any one of Claims 1-4.

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