JP5730646B2 - Print inspection device, printer system - Google Patents

Description

  The present invention relates to a print inspection apparatus that inspects the quality of a print result of a printer, and a printer system that includes the print inspection apparatus and a printer.

  The following techniques are known for inspecting the print quality of an ink jet printer. In other words, a plurality of OCR (Optical Character Reader) cameras that capture images of printed paper are provided, and each of a plurality of print locations defined by verification data is captured by the plurality of OCR cameras to generate print status data. To do. Then, the print quality is compared with the verification data to determine the print quality (see, for example, Patent Document 1).

JP 2001-277676 A (FIG. 1)

  Increasing the printing speed of ink jet printers has led to the following problems. The camera captures the printed paper while scanning line by line, but this scanning speed is limited. For this reason, in the present situation, the scanning speed of the camera is not compatible with the printing speed (that is, the printing paper feed speed).

  When attempting to image an inspection character (such as a character) under the above situation, it is necessary to perform imaging after thinning out scanning lines. However, if the scanning lines are thinned out, the captured image is reduced in size in the vertical direction according to the scanning line thinning rate. This means that the aspect ratio of the character on the image obtained by imaging differs from the aspect ratio of the character actually printed on the paper.

  In order to interpret a character from a captured image, for example, a static image is captured in advance, the character to be inspected is read, and the interpretation value corresponding to the read character is taught to create a dictionary. Try to keep it. At the time of actual inspection, the character is read by collating the captured image data with the reading value registered in the dictionary.

In the case of the character interpretation method described above, the interpretation value of the dictionary corresponds to the original aspect ratio of the printed character.
It is assumed that a normally printed character is imaged with the same aspect ratio. For this reason, when scanning is performed by thinning out scanning lines as a countermeasure against high-speed printing, the characters on the image obtained by the imaging and the characters printed on the paper have different aspect ratios. This causes a problem that the character cannot be read.

  The technique described in Patent Document 1 is also for enabling inspection of all print results related to preset items in response to an increase in print speed. However, since a specific print location is imaged with an OCR camera, thinning out of the scanning lines is necessary to cope with further increase in speed. Therefore, the technique described in Patent Literature 1 cannot avoid the above-described problem that the image cannot be read due to the difference in aspect ratio between the captured character and the printed character.

  SUMMARY An advantage of some aspects of the invention is to make it possible to read a character for a print quality inspection regardless of an increase in the printing speed of a printer.

The present invention relates to a bitmap generation / decompression means for inputting print data for print control generated from drawing data by a printer apparatus, generating bitmap data reflecting the print contents from the input print data, and developing the bitmap data. And character reading means for reading an inspection character for print quality inspection printed on a margin portion of the paper from the developed bitmap data, and based on the result of reading the inspection character by the character reading means, And a print quality determination unit that determines a positional deviation of ink printed on a sheet or a deviation in units of pages .

The present invention also includes a printer device and a print inspection device, wherein the printer device generates print data for print control from the drawing data and outputs the generated print data to the print inspection device. Print data generating means, and the print inspecting device generates bitmap data reflecting the print contents from the print data and expands it, and forms the paper from the expanded bitmap data. Character reading means for reading an inspection character for print quality inspection printed in the margin portion of the paper, and positional deviation or page unit of ink printed on the paper based on the result of reading the inspection character by the character reading means Print quality judgment A printer system, characterized in that it comprises a means.

  According to the present invention, it is possible to obtain an effect that a character for print quality inspection can be read regardless of an increase in printing speed of a printer.

1 is a diagram illustrating a configuration example of a printer system 1 according to an embodiment of the present invention. It is a figure which shows the example of a printing content of the printing paper 50A printed by the printer of embodiment of this invention. It is a figure which shows typically the example of print quality determination processing in this Embodiment. It is a figure which shows the example of a process sequence which the printer system 1 in embodiment of this invention performs. It is a figure which shows the other example of the character for an inspection in embodiment of this invention. It is a figure which shows the other example of the character for an inspection in embodiment of this invention. It is a figure which shows the other example of the character for an inspection in embodiment of this invention.

[Example of printer system configuration]
FIG. 1 is a diagram illustrating a configuration example of a printer system 1 in an embodiment (embodiment) for carrying out the present invention. As shown in this figure, the printer system 1 of this embodiment includes a printer 10, an inspection apparatus 20, a host computer 30, and an input operation unit 40.

  The host computer 30 generates drawing data corresponding to the contents of the document file by the running application, and transfers the drawing data to the printer 10 via a predetermined interface.

  The printer 10 performs printing on the print paper 50. Note that the printing method of the printer 10 here is an inkjet method. The printer 10 shown in this figure includes a print data generation unit 11, heads 12 a to 12 d, and a paper transport mechanism 13.

  The print data generation unit 11 generates print data from the drawing data transferred from the host computer 30. This print data is, for example, dot data corresponding to each color of CMKY. The heads 12a to 12d are heads that discharge ink corresponding to black (K), cyan (C), magenta (M), and yellow (Y), respectively.

  The print data generation unit 11 executes print control. That is, while controlling the paper transport mechanism 13 to transport the print paper 50 at a predetermined speed timing, control is performed so that ink is ejected from each of the heads 12a to 12d at a predetermined timing based on the generated print data. . As a result, the contents of the document file opened by the application of the host computer 30 are printed on the print paper 50. Further, the print data generation unit 11 according to the present embodiment is configured to transfer the generated print data to the inspection apparatus 20 via a predetermined data interface.

  The inspection device 20 inspects the print quality of the printer 10. The inspection contents corresponding to the ink jet printer can be roughly divided into two. One is an inspection of a portion that has not been printed due to dirt or ink clogging adhering to the print paper due to ink dropping from the head. The other is an inspection for color misregistration. When some trouble occurs in the print data generation unit 11 corresponding to the controller of the printer 10, an error may occur in the contents of the print data generated by the print data generation unit 11. If printing is performed with print data including this error, color misregistration occurs as described later. The inspection apparatus 20 according to the present embodiment targets color misregistration caused by the latter printer data error as an inspection target.

  The inspection apparatus 20 shown in this figure includes a bitmap generation / development unit 21, a character reading unit 22, a print quality determination unit 23, and an inspection reference data holding unit 24. The bitmap generation / development unit 21 receives the print data transferred from the print data generation unit 11, generates bitmap data corresponding to the print contents from this print data, and expands it in the internal memory. Assuming that troubles such as ink drop and ink clogging are eliminated, the image content of the bitmap data developed in this way is printed on the print paper 50 by the print data generated by the print data generation unit 11. Matches the printed result.

  The character reading unit 22 reads and reads the inspection character from the bitmap data developed by the bitmap generation / decompression unit 21 by, for example, OCR processing. The print quality determination unit 23 can recognize the state of occurrence of color misregistration based on the reading result of the inspection character. Then, the print quality is determined based on these recognition results.

  The inspection reference data holding unit 24 is a part for holding inspection reference data registered by an operation on the input operation unit 40 described below. As hardware, a storage device such as a RAM, an HDD, or a flash memory is used. .

  The input operation unit 40 is provided for an operator to perform an input operation on the character reading unit 22. In the present embodiment, the operator operates the input operation unit 40 to register in advance inspection reference data serving as a reference for inspection. The inspection standard data holding unit 24 holds the inspection standard data registered in this way. The inspection reference data is data of correct coordinates to be printed with the inspection character, data of character contents indicating what character is to be printed at these coordinates, and the like. For example, if it corresponds to the management number 61 shown in FIG. 2, the character content data may be character code data indicating that the character content data is “100”.

[Example of inspection character]
An example of the inspection character in the present embodiment will be described with reference to FIG. FIG. 2 shows a print sheet 50A for one page after printing. In this print sheet 50A, together with the print contents of the main document, four management numbers 61 (C), 61 (M), “100” drawn as inspection characters in the lower left margin, respectively. 61 (K) and 61 (Y) are printed. The management numbers 61 (C), 61 (M), 61 (K), and 61 (Y) are printed in a single color only with cyan, magenta, black, and yellow inks, respectively.

  The numbers indicated by the management numbers 61 are serial numbers corresponding to the print order, for example. Here, it is “100”, which indicates that the print paper 50A shown in FIG. 2 is printed on the 100th (100th page). Therefore, for example, in the case of a page printed next to the printing paper 50A shown in FIG. 2, the management numbers 61 (C), 61 (M), 61 (K), and 61 (Y) are “101”, respectively. Become.

  Each of these management numbers 61 has a predetermined position, that is, coordinates, to be printed in one page of the print paper 50A. Therefore, when the print data generation unit 11 normally generates print data, the management number 61 is a number indicating the same number according to the print order, and has a predetermined coordinate on the print paper 50A. It will be printed at the corresponding position.

  On the other hand, when a trouble occurs in the print data generation unit 11 and an error occurs in the contents of the print data, a defect occurs in the print result. One of the defective print results may be a situation where a certain color is printed out of print on the printing paper 50A. Such a state of “color shift” is referred to as “position shift” here. The management number 61 corresponding to the color causing the positional deviation is printed with a deviation from the defined position on the printing paper 50A. Further, as the “color shift” state, in addition to the above-described position shift, a shift may occur in units of pages. Such “color shift” in page units is referred to as “page shift” here. The number indicated by the management number 61 corresponding to the color in which the page deviation has occurred is different from the number indicated by the management number 61 of the other color that has not undergone page deviation.

[Reading process of inspection character in this embodiment]
For example, in a configuration in which a print result is obtained by imaging a print paper after printing with a camera as in Patent Document 1, it is necessary to thin out scanning lines in response to an increase in print speed (print paper feed speed). For this reason, the aspect ratio of the captured character is different from the original one, leading to a problem that the character cannot be read. As a countermeasure for avoiding such a problem, it is conceivable to add a dedicated reader or the like corresponding to a barcode or an OCR number to the printer system. However, in this case, there is a problem that the scale of the printer system increases due to the addition of a dedicated reader.

  In the configuration in which the print quality is determined from the image of the printed paper after printing with the camera, as described above, the interpretation value corresponding to the character that has been captured and read in advance is taught. A dictionary is created. However, the print state at the time of dictionary registration is often not always reproduced after that, and an error occurs in interpretation as it is. For this reason, it is necessary to correct the data captured by the camera, and it is also necessary to make adjustments so that an appropriate correction result is obtained. In the adjustment, working time and working paper are consumed, which is disadvantageous in terms of work efficiency and cost.

  On the other hand, in the printer system 1 of the present embodiment, the print data generated by the print data generation unit 11 of the printer 10 is taken in instead of the image of the print paper 50 captured by the camera, and the print result is obtained. Treat as. This print data is obtained by converting drawing data input from the host computer 30 so as to be suitable for print processing in the printer 10. Therefore, if the print data generation unit 11 normally executes the print data generation process, the generated print data correctly reflects the contents of the document file to be printed. On the other hand, if an error has occurred in the print data generation process of the print data generation unit 11, the generated print data includes prints such as color shift (position shift, page shift) described with reference to FIG. It has data content that leads to poor quality. This means that the content of the print data directly reflects the result printed on the print paper 50 with respect to the color misregistration.

  As described above, in the inspection apparatus 20, the print data is expanded into a bitmap and the management number 61 is read. Since the bitmap data developed in this way is not the image data captured by the camera but the print data converted, the management number 61 on the bitmap data is reduced in size corresponding to the paper feed direction. Without changing the original aspect ratio. Therefore, when the character reading unit 22 reads the management number 61 from the bitmap data, it does not become unreadable. That is, in the present embodiment, the inspection character can be stably read and read accurately regardless of the increase in the printing speed of the printer 10. This eliminates the need for a dedicated reader. Further, with the configuration of the present embodiment, it is not necessary to prepare a dictionary for registering interpretation values based on previously captured images. For this reason, it is not necessary to correct the captured image at the time of inspection, and the work time and paper spent for dictionary registration and adjustment are saved, thereby saving labor and reducing costs. In addition, since the inspection character can be stably read regardless of the printing speed of the printer 10, it is possible to accelerate the printer 10 without considering the inspection performance.

[Print quality judgment operation example]
Then, the print quality determination unit 23 can determine the print quality related to color misregistration such as misregistration and page misregistration as described below by using the result of reading the inspection character by the character reading unit 22. .

  FIG. 3 schematically illustrates an example of a determination operation related to print quality performed by the print quality determination unit 23. In the description here, it is assumed that the inspection character is the management number 61 described in FIG. In this case, the inspection reference data includes, for each of the management numbers 61 of four colors, data of correct coordinate values to be printed and data indicating that the number is “100”.

  FIG. 3A shows the coordinate range defined by the inspection reference data with wavy lines for the management number 61 corresponding to a certain color. As shown in this figure, the number “100” is formed depending on the set of coordinates defined by the inspection reference data. Here, for convenience of the following description, out of the coordinates at “100” defined by the inspection reference data, the coordinates corresponding to the upper left corner in the numeric part “1” are (x1, y1).

  FIG. 3B shows a set range of coordinates on the bitmap data for the management number read from the bitmap data as corresponding to the same single color as in FIG. Here, out of the coordinates on the bitmap forming the management number “100”, the coordinates corresponding to the upper left corner in the numeric part “1” are (x2, y2). The print quality determination unit 23 collates, for example, the inspection reference data shown in FIG. 3A and the reading result shown in FIG.

  FIG. 3C schematically shows a collation process result when the coordinates of the read management number 61 are correct. In this case, as shown in the drawing, the coordinates indicated by the inspection reference data forming the same number “100” coincide with the coordinates of the read portion from the bitmap data. At this time, the coordinates (x1, y1) and the coordinates (x2, y2) have the same value. As described above, when the coordinates of the inspection reference data coincide with the coordinates of the portion read from the bitmap data, the actual print result can be regarded as being in a state where no color misregistration occurs. That is, the print quality determination unit 23 in this case determines that the print quality is good. In consideration of the deviation of the conveyed printing paper 50, a fixed margin is set for the coordinates indicated by the inspection reference data, and the coordinates of the reading portion are included within the set margin range. For example, it may be determined that the print quality is good.

  On the other hand, as illustrated in FIG. 3D, although the number read as the reading portion is “100”, which is the same as the inspection reference data, the coordinates indicated by the inspection reference data match the coordinates of the reading portion. Suppose that it was shifted without. When such a collation result is obtained, it can be considered that the single color corresponding to the management number 61 is printed on the print paper 50 in a state in which the positional deviation occurs in the page. Accordingly, the print quality determination unit 23 in this case determines that the print quality is poor due to the occurrence of the positional deviation.

  In the state illustrated in FIG. 3E, the coordinates (x1, y1) and the coordinates (x2, y2) are the same value. This indicates that no positional deviation has occurred. However, in this case, according to the inspection standard data, although the number “100” should be indicated as the management number 61, the number read from the bitmap data is read as “101”. .

  In such a state, the print quality determination unit 23 collates the number “100” indicated as the character content by the inspection reference data with the number “101” read from the bitmap data, thereby Recognize that they are different. The recognition result can be regarded as a state in which a page shift has occurred in the color corresponding to the management number 61. Therefore, the print quality determination unit 23 in this case determines that the print quality is poor due to occurrence of a page shift. Although there is a possibility that misregistration and misregistration occur simultaneously as the page misalignment state, as will be understood from the description of the determination method described above, the print quality judgment unit 23 merges misregistration and color misregistration. Can be determined. In the case of the present embodiment, since the character is stably read from the bitmap data, high reliability can be obtained for the above determination result.

[Example of printer system processing procedure]
The flowchart of FIG. 4 shows an example of a processing procedure executed by the printer 10 (print data generation unit 11) and the inspection apparatus 20 in the printer system 1 of the present embodiment. First, the print data generation unit 11 of the printer 10 inputs drawing data transmitted from the host computer 30 in step S101, and generates print data from the input drawing data in subsequent step S102.

  Next, in step S103, the print data generation unit 11 transfers the print data generated in step S102 to the inspection apparatus 20. In step S104, the print data generation unit 11 executes print control so that the print paper 50 is printed using the print data generated in step S102.

  In step S201, the bitmap generation / development unit 21 in the inspection apparatus 20 inputs the print data transferred from the printer 10 (print data generation unit 11) in step S103. In step S202, the bitmap generation / development unit 21 generates bitmap data from the input print data, and expands the generated bitmap data on the memory. That is, a process of expanding the print result on the memory as bitmap data is performed.

  Next, the character reading unit 22 in the inspection apparatus 20 executes a process of reading and reading the inspection character from the developed bitmap data. In this inspection character reading process, for example, in the developed bitmap data, a coordinate range around the inspection character indicated by the inspection reference data may be set as a processing target.

  Next, in step S204, the print quality determination unit 23 uses the inspection character read in step S203 and the inspection reference data held by the inspection reference data holding unit 24 to perform the printing described with reference to FIG. Execute quality judgment processing. Various operations for correction and adjustment executed in the printer system 1 according to the print quality determination result can be considered.

[Inspection character: other example]
For example, in the case of the configuration described in Patent Document 1, it is necessary to increase the size of the inspection character beyond a certain level so that the inspection character can be accurately read from the image captured by the camera. However, since the contents of advertisements, forms, and the like are originally printed on the print paper 50, if the inspection character is printed in a large size on the same print paper 50 even in the margin portion. It doesn't look good. In addition, since the inspection character must be printed in the margin of a relatively narrow range, there are many restrictions on the size and position of the inspection character.

  On the other hand, in the case of this embodiment, since the inspection character is read from the bitmap data developed from the print data, it is not necessary to use image data captured by the camera. When the inspection character is read from the developed bitmap data, it is not particularly necessary to enlarge the inspection character. Therefore, in the case of the present embodiment, for example, a very small size character (micro character) can also be used as an inspection character. Thereby, the degree of freedom with respect to the position where the inspection character is printed on the print paper 50 is remarkably increased. In addition, the appearance of the printed content can be improved.

  Further, under the configuration of the present embodiment in which the inspection character is read from the developed bitmap data, the above-described concept can be promoted to treat the dot unit as the inspection character. An example in which such a dot unit is used as an inspection character is shown in FIG. Note that, as an example, the size of one dot is about 42 μm in the case of 600 dpi (dot per inch).

  In the print paper 50A shown in FIG. 5, in addition to the original print contents, dots 71 (M), 71 (C), 71 (in the vicinity of the upper left, upper right, lower left, and lower right corners of the paper surface, respectively) Y), 71 (K) are shown. These dots 71 (M), 71 (C), 71 (Y), and 71 (K) are portions printed by one dot with only magenta, cyan, yellow, and black ink, respectively. The coordinates on which these dots 71 (M), 71 (C), 71 (Y), and 71 (K) are to be printed are all predetermined. Here, the coordinates of the dots 71 (M), 71 (C), 71 (Y), 71 (K) are represented by Pm (x, y), Pc (x, y), Py (x, y), Pk. It is shown as (x, y).

  In this case, the inspection reference data includes magenta, cyan, yellow, and black dots at coordinates Pm (x, y), Pc (x, y), Py (x, y), and Pk (x, y). It has contents indicating that it should be located. Then, the character reading unit 22 reads these dots 71 (M), 71 (C), 71 (Y), and 71 (K) as the inspection character reading process in step S203 of FIG. In this case, the character for inspection can be read by recognizing the color of the dot. In the print quality determination in step S204, the coordinates read from the bitmap data and the inspection reference data are defined for each of the dots 71 (M), 71 (C), 71 (Y), and 71 (K). For example, it is possible to determine whether or not a positional deviation has occurred based on an error of these coordinates. For example, the coordinates where the dots 71 (M), 71 (C), 71 (Y), and 71 (K) are to be printed are defined so as to be changed in a predetermined order for each page. In this way, it is possible to determine page misalignment by comparing the color of the dot 71 that has been read with the color indicated by the reference data.

  FIG. 6 shows an example in which an inspection character is formed by a set of dots and is used as an identification code. The identification code 80, which is an inspection character shown in this figure, has dots 71 (M), 71 (C), 71 (Y), 71 (K) arranged in a matrix composed of a predetermined number of vertical and horizontal dots. Is formed. A definition can be given for each arrangement pattern of the four color dots 71 arranged as the dot matrix. Such an identification code 80 can be used as an alternative to a management number, for example. In this case, it may be defined so that one management number corresponds to each predetermined arrangement pattern of the four color dots 71. The identification code 80 can be used as an alternative to the management barcode. When the main contents printed on the print paper 50 are various forms, a form identification function can be provided by defining the form type for each predetermined arrangement pattern.

  Also, the identification code can be formed as shown in FIG. First, the identification code 80A shown in FIG. 7A is formed by arranging dots 71 in a predetermined pattern in a coordinate range of a predetermined number of vertical and horizontal dots.

  Furthermore, as shown in FIG. 7B, a mode in which the identification code 80A is arranged in the area where the cue mark 90 is formed can be considered. The cue mark 90 is a mark arranged at a predetermined position on the print paper 50 so that the printer 10 recognizes the print timing in units of pages, for example, and is formed as a square filled with black, for example. The cue mark 90 is optically detected by a cue mark sensor (not shown in FIG. 1) provided in the printer 10, for example. When the identification code 80A is arranged in the area of the cue mark 90, if a pattern in which the dots 71 of each color forming the identification code 80A are diffused is arranged, the cue mark sensor has a black solid cue mark 90. Can be recognized. 7B, the identification code 80A is hidden by the cue mark 90 and cannot be seen by human vision, for example, so that the printed paper looks better.

  As described above, the concept as the inspection character in the present embodiment can first include a character string (including numbers) including one or more characters such as the management number 61. Moreover, it is not limited to a character string other than a character string, and can include a design. Furthermore, as illustrated in FIGS. 6 and 7, a dot pattern formed by arranging dots according to the colors of the respective inks can also be included.

  In the above embodiment, the operator operates the input operation unit 40 to register the inspection standard data in the inspection apparatus 20 (inspection standard data holding unit 24). It is also conceivable that the inspection reference data is created based on the data of the target document file and can be registered in the inspection apparatus 20 via the data interface.

  Further, in the above-described embodiments, the printer 10 is assumed to be an ink jet method. However, the configuration of the present embodiment can be applied to a printer using a print method other than the ink jet method.

  The processing procedure described in the embodiment of the present invention can be regarded as a method having a series of these procedures. Further, it can be understood as a program for causing a computer to execute these series of procedures or a recording medium for storing the program. Examples of the recording medium include a Blu-ray Disc (registered trademark), a DVD (Digital Versatile Disk), an HDD (hard disk), a memory card, and the like.

DESCRIPTION OF SYMBOLS 1 Printer system 10 Printer 11 Print data generation part 12a-12d Head 13 Paper conveyance mechanism 20 Inspection apparatus 21 Bitmap production | generation / expansion | deployment part 22 Character reading part 23 Print quality determination part 24 Inspection reference | standard data holding part 30 Host computer 40 Input operation part 50, 50A Print paper 61 Control number 71 dots 80, 80A Identification code 90 Cue mark

Claims (5)

Bitmap generation / expansion means for inputting print data for print control generated from the drawing data by the printer apparatus, generating bitmap data reflecting the print contents from the input print data, and developing the bitmap data;
Character reading means for reading an inspection character for print quality inspection printed on a margin portion of the paper from the developed bitmap data;
A print quality determination unit that determines a positional deviation or a page unit deviation of ink printed on the paper based on a result of reading the inspection character by the character reading unit;
A print inspection apparatus comprising: The character reading means reads from the bitmap data micro characters printed in a margin portion of the paper.
The print inspection apparatus according to claim 1. The character reading means reads, from the bitmap data, dot data corresponding to inks of different colors, which are printed near the upper left, upper right, lower left and lower right corners of the paper surface of the paper.
The print inspection apparatus according to claim 1 . The character reading means reads, from the bitmap data, the dot data defined to be changed in a predetermined order for each page with respect to coordinates to be printed.
The print inspection apparatus according to claim 3 . A printer device and a print inspection device;
The printer device includes print data generation means for generating print data for print control from the drawing data, and outputting the generated print data to the print inspection device.
The print inspection apparatus includes:
Bitmap generation / expansion means for generating and expanding bitmap data reflecting print contents from the print data;
Character reading means for reading an inspection character for print quality inspection printed on a margin portion of the paper from the developed bitmap data;
A printer system comprising: a print quality determination unit that determines a positional deviation of ink printed on the paper or a deviation in units of pages based on a result of reading the inspection character by the character reading unit .

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