WO2010024019A1

WO2010024019A1 - Printer and method for inspecting print

Info

Publication number: WO2010024019A1
Application number: PCT/JP2009/060861
Authority: WO
Inventors: 義和市岡
Original assignee: 大日本スクリーン製造株式会社
Priority date: 2008-08-25
Filing date: 2009-06-15
Publication date: 2010-03-04
Also published as: JP2010049616A

Abstract

A printer performs printing based on print data where a register mark (805) indicating the range of an inspection object region (801) in the conveyance direction is added to an original image, and inspection of print in the inspection object region (801) is performed by acquiring an inspection image (84), including the inspection object region (801), from an image of print result based on the register mark (805). Since the entire image of print result is not compared with the original image but only the inspection image (84), i.e. a part of the image of print result, is compared with the original image, inspection of print in the inspection object region (801) can be performed quickly. Furthermore, since the inspection image (84) is acquired based on the register mark (805) indicating the range of the inspection object region (801) in the conveyance direction, the whole inspection object region (801) can be included in the inspection image (84) with high precision even if a print medium expands or contracts, and inspection of print in the inspection object region (801) can be performed with high precision.

Description

Printing apparatus and printing inspection method

The present invention relates to a printing apparatus that performs printing on a printing medium while conveying the printing medium in a predetermined conveyance direction, and an inspection method that performs printing inspection in the printing apparatus.

2. Description of the Related Art Conventionally, an ink jet printing apparatus that performs printing on a print medium by scanning a discharge mechanism in which a plurality of discharge ports for discharging minute ink droplets are arranged relative to the print medium has been used. ing. In recent years, inkjet printing apparatuses are also used for printing (so-called variable printing) in which printing contents differ for each page, such as a credit card bill.

In such variable printing, it may be inspected whether or not the variable part of the print result (that is, the part having different print contents for each page) matches the print data input to the printing apparatus. If the entire page is compared with the printing data, the inspection time increases. Further, when the position of the variable portion differs depending on the page, if all pages are inspected with the same setting, the region to be inspected is not inspected, and an erroneous inspection result is output.

Therefore, in Japanese Patent Application Laid-Open No. 2007-233820, a variable part is extracted by masking a print result read by a scanner or the like with a form determined based on print data, and the variable part of the print data is used as a variable part. Techniques for inspecting printing defects by comparing with corresponding data are disclosed. Thereby, the inspection of printing can be performed quickly.

By the way, in an ink jet printing apparatus, the printing medium may be stretched due to application of ink to the printing medium and drying, and printing can be performed without considering the elongation of the printing medium as disclosed in JP 2007-233820A. In the method of extracting a predetermined area whose position is specified on the medium, the variable part is displaced from the extraction area, and the inspection accuracy is lowered. Further, when a printing device is provided with a scanner or the like to read a print result in parallel with printing, if the print medium is transported obliquely with respect to the transport direction due to a transport mechanism error or the like (so-called skew of the print medium is If it occurs, the variable part is displaced from the extraction region in the same manner as described above, and the inspection accuracy is lowered.

In order to cope with such a shift, it is conceivable to enlarge the area extracted from the print result. However, since the inspection time increases if the extraction area is enlarged, it is not possible to enlarge the extraction area more than necessary. It is not preferable. However, since the shift amount is not always constant, it is difficult to determine the minimum enlargement amount of the extraction region necessary for reliably including the variable part in the extraction region.

The present invention is directed to a printing apparatus that prints on a print medium while conveying the print medium in a predetermined conveyance direction, and has an object to quickly and accurately perform printing inspection in an inspection target area.

In the printing apparatus, a mark indicating the range in the transport direction of the inspection target area to be inspected after printing in the original image to be printed is added to one end of the original image in the width direction perpendicular to the transport direction. A print data generation unit that generates print data indicating a printed image, a printing mechanism that performs printing on the print medium based on the print data while conveying the print medium in the conveyance direction, and the print medium after printing An imaging unit that images, an inspection image acquisition unit that acquires, based on the mark, an inspection image that is an image including the inspection target region from a captured image output from the imaging unit, and the inspection image and the original image And an inspection unit that inspects the inspection target area of the inspection image by comparing.

In the printing apparatus, by comparing the inspection image that is a part of the captured image with the original image, it is possible to quickly inspect the printing in the inspection target area. In addition, the acquisition of the inspection image from the captured image is performed based on a mark indicating the range in the transport direction of the inspection target region, so that the entire inspection target region can be included in the inspection image with high accuracy, and the inspection target Printing inspection in the area can be performed with high accuracy.

In one preferable embodiment of the present invention, the original image is an image printed in an area corresponding to each of a plurality of pages on the print medium, and the image printed in the inspection target area is page by page. Different.

In another preferred embodiment of the present invention, in the image indicated by the print data, the mark is a straight line that coincides with a range in the transport direction of the inspection target region.

In still another embodiment of the invention, the print data generation unit may place another mark indicating the range in the transport direction of the inspection target region on the other end in the width direction of the original image. In addition, the range in the transport direction of the inspection image in the captured image is a range including both the range indicated by the mark and the range indicated by the other mark.

In still another embodiment of the present invention, the print data generation unit adds a width mark indicating a range in the width direction of the inspection target region to a region extending in the width direction of the original image, and the inspection An image acquisition unit acquires the inspection image based on the mark and the width mark.

In still another embodiment of the present invention, the original image includes another inspection target region that overlaps at least part of the inspection target region with respect to the transport direction, and the print data generation unit includes the other inspection target. Another mark indicating the range of the region in the transport direction is added to the one end in the width direction of the original image independently from the mark, and the inspection image acquisition unit is configured to add the other mark. Based on the captured image, another inspection image that is an image including the other region to be inspected is acquired, and the inspection unit compares the another inspection image with the original image to thereby compare the other inspection image. The other inspection object area of one inspection image is inspected.

In the printing apparatus, the inspection target region of the original image includes at least one character, number or symbol, or an information element indicating a code code, and the inspection unit is read from the inspection target region of the inspection image. After the information element is converted into character data or numerical data, it may be compared with character data or numerical data indicated by the original image.

In the printing apparatus, the imaging unit may be a line sensor that images a linear region parallel to the width direction on the printing medium, or the printing mechanism holds a roll of the printing medium before printing. In addition, a supply unit that feeds the print medium from the roll in the transport direction, and a winding unit that winds up a portion where the print medium is printed may be provided. In the printing apparatus, the printing mechanism may include an ink jet head that ejects micro droplets of ink from a plurality of ejection openings toward the printing medium.

The present invention is also directed to an inspection method for inspecting printing in a printing apparatus that performs printing on a printing medium while conveying the printing medium in a predetermined conveyance direction.

The above object and other objects, features, aspects, and advantages will become apparent from the following detailed description of the present invention with reference to the accompanying drawings.

1 is a perspective view of a printing apparatus according to a first embodiment. It is a block diagram which shows the function of a printing inspection part. It is a figure which shows the flow of a test | inspection of printing. It is a figure which shows an original image. It is a figure which shows a mark addition image. It is a figure which shows a printing result image. It is a figure which shows a test | inspection image. It is a figure which shows an original image. It is a figure which shows a mark addition image. It is a figure which shows a 1st test | inspection image. It is a figure which shows a 2nd test | inspection image. It is a figure which shows a test | inspection image. It is a figure which shows the mark addition image produced | generated with the printing apparatus which concerns on 2nd Embodiment. It is a figure which shows a printing result image. It is a figure which shows a test | inspection image. It is a figure which shows a printing result image. It is a figure which shows a printing result image. It is a figure which shows the mark addition image produced | generated with the printing apparatus which concerns on 3rd Embodiment. It is a figure which shows a test | inspection image. It is a figure which shows a mark addition image. It is a figure which shows a 1st test | inspection image. It is a figure which shows a 2nd test | inspection image.

FIG. 1 is a perspective view showing an appearance of the printing apparatus 1 according to the first embodiment of the present invention. The printing apparatus 1 is an apparatus that performs color printing by an inkjet method on a printing medium 9 that is a long printing paper, for example.

The printing apparatus 1 shown in FIG. 1 includes a print data generation unit 4 that generates print data indicating an image to be printed on the print medium 9, and the print medium 9 in the (−Y) direction in FIG. A printing mechanism 5 that performs printing based on the print data while being conveyed in the “conveying direction”), an imaging unit 6 that captures an image of the printed printing medium 9 (that is, a portion where printing of the printing medium 9 has been completed), A printing inspection unit 7 that performs printing inspection based on the output from the imaging unit 6 is provided. As shown in FIG. 2, the print inspection unit 7 includes a database storage unit 71, an inspection image acquisition unit 72, and an inspection unit 73.

The printing mechanism 5 transports the print medium 9 in the transport direction, and the ink droplets from the plurality of ejection openings arranged in the width direction toward the print medium 9 being transported by the transport mechanism 27. A discharge mechanism 3 which is an inkjet head for discharging is provided. The discharge mechanism 3 is disposed above the transport mechanism 27 and is fixed to a frame 25 provided on the base 20 so as to straddle the transport mechanism 27.

In the transport mechanism 27, a plurality of rollers 271 that are long in the X direction in FIG. 1 are arranged in the Y direction, and a roll of the printing medium 9 before printing is held on the (+ Y) side of the plurality of rollers 271. In addition, a supply unit 272 that feeds the print medium 9 from the roll in the transport direction is provided, and on the (−Y) side of the plurality of rollers 271, a portion where the print medium 9 is printed is wound up in a roll shape. A winding part 273 is provided for holding. In the following description, the print medium 9 simply means the print medium 9 being transported (that is, the print medium 9 on the plurality of rollers 271).

The roller 271a of the transport mechanism 27 is provided with an encoder 29 that detects the moving speed of the printing medium 9 in the printing direction, and the rotation of the motor of the winding unit 273 is controlled based on the output of the encoder 29. The print medium 9 moves in the (−Y) direction at a constant speed. At this time, by applying a load (tension) in the direction opposite to the moving direction (that is, (+ Y) direction) to the print medium 9 by the motor included in the supply unit 272, the print medium on the plurality of rollers 271. 9 moves smoothly without undulations.

The imaging unit 6 is arranged on the (−Y) side, which is downstream of the ejection mechanism 3 of the printing mechanism 5 in the transport direction of the printing medium 9, and on the (−Y) side of the ejection mechanism 3 on the printing medium 9. This is a line sensor that captures an image of a linear region parallel to the width direction (that is, the X direction) perpendicular to the set conveyance direction.

In the printing apparatus 1, the ejection mechanism 3 and the imaging unit 6 cover the entire print area on the print medium 9 (here, the X direction of the print medium 9) with respect to the width direction (that is, the X direction) perpendicular to the transport direction. The printing on the printing medium 9 is completed only once the printing medium 9 passes below the discharge mechanism 3 (so-called one-pass printing is performed). Further, when the print medium 9 passes below the imaging unit 6 once, the print medium 9 is imaged over the entire width, and the captured image is output from the imaging unit 6 to the print inspection unit 7.

In the printing apparatus 1, the original image scheduled to be printed on the print medium 9 is an image printed in an area corresponding to each of a plurality of pages on the print medium 9, and the predetermined area of the original image includes each page. Different images are inserted into In other words, the printing apparatus 1 performs variable printing in which an image to be printed in the predetermined area of each page is different for each page, and other areas are common to other pages. Then, in each of the plurality of pages, the image printed in the predetermined area is compared with the area of the original image to check whether the print result is the same as the original data. In the following description, the area compared in the print inspection is referred to as “inspection area”.

Next, the flow of printing inspection in the printing apparatus 1 will be described. FIG. 3 is a diagram showing a flow of print inspection, and FIG. 4 is printed in an area corresponding to one page on the print medium 9 in the original image 81 scheduled to be printed on the print medium 9. It is a figure which shows a part. In FIG. 4, a rectangular inspection target region to be inspected after printing (more specifically, a pair of long sides are parallel to the width direction and a pair of short sides is parallel to the transport direction) 801 is surrounded by a two-dot chain line, and the inspection target area 801 includes an information element indicating the character “ABCDE”. In the original image 81 printed in a plurality of areas corresponding to a plurality of pages on the print medium 9 (hereinafter simply referred to as “a plurality of pages”), each of the inspection target areas 801 of the plurality of pages includes at least one character. The information elements shown are included, and these information elements differ from page to page. In the following steps S11 to S18, processing for one page shown in FIGS. 4 to 6 among the plurality of pages will be mainly described. These processing are sequentially performed for all pages.

In the printing apparatus 1 illustrated in FIG. 1, first, in the print data generation unit 4, a mark 805 indicating a range in the transport direction (that is, the Y direction in FIG. 4) of the inspection target area 801 of the original image 81 illustrated in FIG. 4 is displayed. 5, printing showing an image 82 (hereinafter referred to as “marked additional image 82”) added to one end in the width direction of the original image 81 (the end on the (−X) side). Data is generated (step S11) The mark 805 is a straight line that faces the transport direction, and coincides with the range in the transport direction of the inspection target region 801. In other words, the positions of both ends of the mark 805 in the transport direction are It coincides with the positions of the long sides on both sides in the transport direction of the inspection target region 801. In the mark added image 82, a band-shaped region 821 extending in the Y direction in the vicinity of the (−X) side edge has a graphic element other than the mark 805 Is arranged Are not. It should be noted that the rectangle drawn by the two-dot chain line surrounding the inspected area 801 and the area 821 is not included in the print data not to be printed on the print medium 9.

In the print data generation unit 4, in parallel with the generation of the print data, the characters indicated by the plurality of information elements respectively included in the inspection target areas 801 of the plurality of pages in the original image 81 are printed as character data. The data is stored in the database storage unit 71 of the print inspection unit 7 in association with the page number (step S12). As a result, the database storage unit 71 stores a database that is a set of data elements in which the page number of each page of the print medium 9 and the character data of characters printed in the inspection target area 801 of each page are associated with each other. The When a plurality of inspection target areas 801 are included in one page, the character data is also associated with the appearance order of each inspection target area 801.

In step S12, the information element included in the inspection target area 801 may be converted into numerical data. Similarly, when the information element indicates a number or a symbol, the information is converted into character data or numerical data and is stored in the database storage unit 71. (Refer to FIG. 2) (the same applies to the second and third embodiments).

Subsequently, ink is ejected from the ejection mechanism 3 toward the printing medium 9 conveyed in the (−Y) direction by the conveyance mechanism 27 shown in FIG. In the printing mechanism 5, the ejection of ink from the ejection mechanism 3 is controlled based on the printing data generated in step S <b> 11, whereby the printing medium 9 of the mark additional image 82 (see FIG. 5) indicated by the printing data. Printing up is performed (step S13).

Next, the printing medium 9 after printing is imaged by the imaging unit 6 shown in FIG. 1, and the output from the imaging unit 6 is sent to the print inspection unit 7 (step S14). Note that steps S13 and S14 show a flow of processing when attention is paid to a part of the print medium 9, and actually, these steps are continuously performed on the print medium 9.

In the print inspection unit 7, the output from the imaging unit 6 is arranged in the order of imaging, whereby a print result image 83 similar to the mark addition image 82 is acquired as a captured image, as shown in FIG. 6. Then, from the print result image 83 output from the imaging unit 6 by the inspection image acquisition unit 72 (see FIG. 2), an inspection image 84 that is an image including the inspection target region 801 is displayed on the mark 805 as shown in FIG. It is acquired based on (step S15). Specifically, a mark 805 that is a straight line facing the transport direction is detected on the print result image 83 shown in FIG. 6, and both ends (that is, the (+ Y) side) of the mark 805 in the transport direction of the print result image 83 are detected. A portion between two straight lines extending in parallel with the width direction at the end of (−Y) and the end of (−Y) side) is acquired as an inspection image 84 shown in FIG.

When the inspection image 84 is acquired, the information element indicating the character “ABCDE” in the inspection target area 801 of the inspection image 84 is obtained by OCR (Optical Character Recognition) by the inspection unit 73 (see FIG. 2). It is converted into character data indicating the character “ABCDE” (step S16). In step S16, the information element included in the inspection target area 801 may be converted into numerical data. Similarly, when the information element indicates a number or a symbol, the information element is converted into character data or numerical data (second and second data). The same applies to the third embodiment).

Subsequently, using the page number corresponding to the print result image 83 (see FIG. 6) as a search key, the character data associated with the page number from the database stored in the database storage unit 71 (see FIG. 2) (or Numerical data) is extracted (step S17). Note that step S17 may be performed in parallel with step S16. When a plurality of inspection target areas 801 are included in one page, the appearance order of each inspection target area 801 is also used as a search key.

Then, the character data (or numerical data) obtained by converting the information element of the inspection target area 801 in step S16 is compared with the character data (or numerical data) extracted from the database in step S17. As a result, a print inspection is performed on the inspection target area 801 of the inspection image 84, and an error message is output if the character data do not match (step S18). In other words, character data (or numerical data) indicated by the information element read from the inspection target area 801 of the inspection image and character data (or numerical data indicated by the information element included in the inspection target area 801 of the original image) ) Is inspected for printing in the inspection object area 801 of the inspection image 84.

As described above, in the printing apparatus 1, the print data generation unit 4 generates print data indicating the mark-added image 82 in which the mark 805 indicating the range of the inspection target area 801 in the transport direction is added to the original image 81. The inspection image 84 including the inspection target area 801 is acquired based on the mark 805 from the print result image 83 of the print medium 9 that has been printed based on the print data, and the inspection image 84 and the original image 81 are further acquired. Are compared with each other to inspect the printing in the inspection target area 801.

As described above, the printing apparatus 1 does not compare the entire print result image 83 with the original image 81, but compares only the inspection image 84 that is a part of the print result image 83 with the original image 81. The print inspection in 801 can be performed quickly. In addition, the acquisition of the inspection image 84 from the print result image 83 is performed based on the mark 805 indicating the range of the inspection target area 801 in the transport direction, and thus the expansion or the like of the print medium 9 occurs. In addition, the entire inspection target region 801 can be included in the inspection image 84 with high accuracy, and printing inspection in the inspection target region 801 can be performed with high accuracy.

In the printing apparatus 1, only a part of the image printed on the print medium 9 can be extracted with high accuracy and quickly inspected. Therefore, inspection among images printed on a plurality of pages on the print medium 9 is performed. The image printed in the target area 801 is particularly suitable for inspection of variable printing in which each page differs from page to page. In the printing apparatus 1, the printing inspection of the inspection target area 801, which is a variable printing variable portion, is performed quickly and with high accuracy. Is called.

In the inspection unit 73 of the print inspection unit 7, the character data (or numerical data) indicated by the information element read from the inspection target area 801 of the inspection image 84 and the information elements included in the inspection target area 801 of the original image 81 are displayed. The character data (or numerical data) shown is compared. For this reason, compared with the case where the inspection image 84 and the original image 81 are compared in the state of an image, a quick printing inspection is realized.

As described above, in the print data generation unit 4, the mark 805 is a straight line that matches the range of the inspection target area 801 in the transport direction. As described above, since the mark 805 has a simple shape, generation of print data by the print data generation unit 4 can be simplified, and the inspection image acquisition unit 72 can easily recognize the mark 805. The inspection image 84 is easily acquired. Further, the width of the space required for printing the mark 805 is reduced.

Further, in the printing apparatus 1, since the imaging unit 6 is a line sensor that images a linear region parallel to the width direction of the print medium 9, the apparatus structure is simplified. Furthermore, the width of the imaging region of the imaging unit 6 (that is, the length in the width direction) is made larger than the width of the printing medium 9, whereby the imaging of the printing medium 9 by the imaging unit 6 is performed quickly.

In the printing apparatus 1, since printing is performed by applying fine droplets of ink to the print medium 9, the print medium 9 that has absorbed the ink may expand in the transport direction. For this reason, if an inspection image is acquired based on the position (coordinates) on the print medium on the premise that the print medium does not expand, a part of the inspection target area is detached from the inspection image, and the inspection accuracy is increased. It may decrease. On the other hand, in the printing apparatus 1 according to the present embodiment, the inspection image 84 is acquired based on the mark 805 corresponding to the inspection target region 801, whereby the entire inspection target region 801 is inspected with high accuracy. 84. Therefore, the configuration of the printing apparatus 1 is particularly suitable for a printing apparatus that performs printing by applying fine droplets of ink to the printing medium 9.

In the printing apparatus 1, since the long print medium 9 is conveyed by the conveyance mechanism 27 of the printing mechanism 5, the printing medium 9 meanders (that is, the print medium 9 is swung in the width direction while being conveyed in the conveyance direction). Phenomenon). For this reason, if an inspection image is acquired based on the position (coordinates) on the print medium on the premise that no meandering occurs, a part of the inspection target area is deviated from the inspection image due to the effect of meandering. May fall. On the other hand, in the printing apparatus 1 according to the present embodiment, as described above, the inspection image 84 is acquired based on the mark 805 corresponding to the inspection target region 801, so that the entire inspection target region 801 is obtained. The inspection image 84 can be included with high accuracy. Therefore, the configuration of the printing apparatus 1 is particularly suitable for a printing apparatus that transports the long print medium 9 by the supply unit 272 that holds the roll of the print medium 9 and the winding unit 273.

Next, as shown in FIG. 8, at least a part of the inspection target area 801 a and the inspection target area 801 a in the transport direction (that is, the Y direction) overlaps the original image 81 a scheduled to be printed by the printing apparatus 1. An inspection by the printing apparatus 1 when another inspection target area 801b is included will be described. In the following description, in order to distinguish between the inspection target area 801a and the inspection target area 801b, the inspection target area 801a and the inspection target area 801b are respectively referred to as “first inspection target area 801a” and “second inspection target area 801b”. That's it.

In the printing apparatus 1, in step S11 in FIG. 3, as shown in FIG. 9, the first mark 805a indicating the range in the transport direction of the first inspection target area 801a and the transport direction of the second inspection target area 801b. Print data indicating the mark additional image 82a in which the second mark 805b indicating the range is added to the original image 81a is generated by the print data generating unit 4 (see FIG. 1). The first mark 805a and the second mark 805b are straight lines that face the transport direction and coincide with the ranges in the transport direction of the first inspection target area 801a and the second inspection target area 801b. The first mark 805a and the second mark 805b are arranged independently of each other in the region 821 on the (−X) side which is one end in the width direction of the original image 81a (see FIG. 8).

In step S12, the character data of characters printed in the first inspection target area 801a and the character data of characters printed in the second inspection target area 801b are associated with page numbers, respectively, and (−Y The numbers indicating the order of appearance are assigned in order from the character data corresponding to the characters arranged on the) side and stored in the database storage unit 71. In this case, number 1 indicating the order of appearance is assigned to the character data in the first inspection target area 801a, and number 2 is assigned to the character data in the second inspection target area 801b.

In step S15, as shown in FIG. 10, a first inspection image 841a including the entire first inspection target region 801a is acquired based on the first mark 805a, and as shown in FIG. 11, the second inspection target region 801b. Is acquired based on the second mark 805b. The details of the acquisition method of the first inspection image 841a and the second inspection image 841b by the inspection image acquisition unit 72 (see FIG. 2) are the same as the acquisition of the inspection image 84 based on the mark 805 described above. As shown in FIG. 10, the first inspection image 841a includes a part of the second inspection target region 801b in addition to the first inspection target region 801a. Further, as shown in FIG. 11, the second inspection image 841b includes a part of the first inspection target region 801a in addition to the second inspection target region 801b.

In step S16, in the first inspection image 841a shown in FIG. 10, an information element that overlaps with the edge of the first inspection image 841a (that is, a part of the information element “FGH” arranged in the second inspection target region 801b). OCR processing is performed on the excluded information elements, and the information elements in the first inspection target area 801a are converted into character data indicating the characters “ABCDE”. Further, in the second inspection image 841b shown in FIG. 11, information elements excluding information elements that overlap with the edge of the second inspection image 841b (that is, a part of the information element “ABCDE” arranged in the first inspection image 841a). On the other hand, the OCR process is performed, and the information element of the second inspection target area 801b is converted into character data indicating the character “FGH”.

In steps S17 and S18, two character data associated with the page number are extracted from the database stored in the database storage unit 71, and (-Y) than the first character data and the second inspection target area 801b. The character data obtained from the first inspection image 841a including the entire first inspection target region 801a located on the side is compared (that is, the original image 81a and the first inspection image 841a are compared). ), A print inspection is performed in the first inspection object region 801a of the first inspection image 841a. Further, the second character data extracted from the database is compared with the character data obtained from the second inspection image 841b (that is, the original image 81a and the second inspection image 841b are compared). Thus, the printing inspection is performed in the second inspection target region 801b of the second inspection image 841b.

As described above, in the printing apparatus 1, printing is performed when the original image 81a includes the first inspection target region 801a and the second inspection target region 801b at least partially overlapping the first inspection target region 801a with respect to the transport direction. In the data generation unit 4, a first mark 805a indicating the range of the first inspection target area 801a is added to the original image 81a, and a second mark 805b indicating the range of the second inspection target area 801b is independent of the first mark 805a. Are added to the original image 81a. Accordingly, the first inspection image 841a including the entire first inspection target region 801a can be extracted from the print result image, and the printing inspection of the first inspection target region 801a can be performed quickly and with high accuracy. The second inspection image 841b including the entire inspection target region 801b can be extracted from the print result image, and the printing inspection of the second inspection target region 801b can be performed quickly and with high accuracy.

In the printing apparatus 1, as shown in FIG. 12, the entire first inspection target area 801a and the second inspection target area 801b are based on the first mark 805a and the second mark 805b from the same print result image as the mark addition image 82a. (Specifically, a position between the end on the (−Y) side of the first mark 805a and the end on the (+ Y) side of the second mark 805b in the transport direction is acquired. A region to be inspected may be an inspection image 84a). In this case, the information element of the first inspection target area 801a is extracted from the inspection image 84a based on the first mark 805a and converted into character data, and then compared with the character data of the original image 81a (see FIG. 8). Based on the second mark 805b, the information element of the second inspection target area 801b is extracted and converted into character data, and then compared with the character data of the original image 81a.

The acquisition of the inspection image 84a and the extraction of the information elements of the first inspection target area 801a and the second inspection target area 801b from the inspection image 84a are performed on the entire first mark 805a performed based on the first mark 805a. This corresponds to the acquisition of the inspection image including the inspection image including the entire second mark 805b performed based on the second mark 805b. Also in this case, as described above, it is possible to quickly and accurately perform printing inspections in a plurality of inspection target regions overlapping in the transport direction.

Next, a printing apparatus according to the second embodiment of the present invention will be described. The configuration of the printing apparatus according to the second embodiment is the same as that of the printing apparatus 1 shown in FIG. 1, and the same reference numerals are given to the corresponding configurations in the following description. In the printing apparatus according to the second embodiment, the first image except that a mark different from the first embodiment is added to the original image 81 (see FIG. 4) scheduled to be printed on the print medium 9. Printing inspection is performed by the same process as the embodiment. Hereinafter, a print inspection by the printing apparatus according to the second embodiment will be described with reference to FIG.

In the printing apparatus according to the second embodiment, first, as shown in FIG. 13, the mark 805 similar to that of the first embodiment is displayed by the print data generation unit 4 (see FIG. 1) as the width of the original image 81. Is added to one end of the direction (the end on the (−X) side), and another mark 806 indicating the range in the transport direction of the inspection target area 801 of the original image 81 is provided in the width direction of the original image 81. Print data indicating the mark-added image 82b added to the other end ((+ X) side end) is generated (step S11).

In the following description, the two

marks

805 and 806 will be referred to as “left mark 805” and “right mark 806”, respectively. In the present embodiment, each of the left mark 805 and the right mark 806 is a straight line facing the transport direction, and coincides with the range in the transport direction of the inspection target area 801 of the original image 81. In the mark addition image 82b, as in the first embodiment, graphic elements other than the left mark 805 are not arranged in the band-like region 821 extending in the Y direction in the vicinity of the (−X) side edge. Further, no graphic element other than the right mark 806 is arranged in the band-like region 822 extending in the Y direction in the vicinity of the edge on the (+ X) side.

In the print data generation unit 4, as in the first embodiment, characters indicated by a plurality of information elements respectively included in the inspection target areas 801 of a plurality of pages in the original image are associated with page numbers as character data. It is stored in the database storage unit 71 (see FIG. 2) (step S12). Subsequently, printing on the print medium 9 is performed by the printing mechanism 5 based on the print data generated by the print data generation unit 4 shown in FIG. 1 (step S13), and the printed print medium 9 is printed by the imaging unit 6. The image is picked up, and the output from the image pickup unit 6 is sent to the print inspection unit 7 (step S14).

Incidentally, as described above, in the printing mechanism 5, since the long print medium 9 is conveyed by the supply unit 272 and the winding unit 273 that hold the roll of the print medium 9, the width of the print medium 9 is increased. The skew of the print medium 9 (that is, a phenomenon in which the print medium 9 is transported obliquely with respect to the transport direction) may occur due to a difference in tension between the two sides. FIG. 14 shows a print inspection in the case where skew occurs when the print medium 9 moving in the transport direction below the printing mechanism 5 moves below the printing mechanism 5 and moves to the imaging unit 6. FIG. 10 is a diagram illustrating a print result image 83b acquired by the unit 7. FIG. 14 shows a print result image 83b acquired when the print medium 9 is skewed slightly toward the (−X) side from the (−Y) direction that is the transport direction.

When the print result image 83b is acquired, the inspection image acquisition unit 72 (see FIG. 2) converts the inspection image 84b including the inspection target area 801 from the print result image 83b into the left mark 805 and the right side as shown in FIG. Obtained based on the mark 806 (step S15). Specifically, on the print result image 83b shown in FIG. 14, the range in the transport direction (that is, the Y direction) of the inspection image 84b is the range in the transport direction indicated by the left mark 805 and the transport indicated by the right mark 806. The range includes both the range of directions. In the present embodiment, in the print result image 83b, two pieces extending in the width direction at the (+ Y) side end of the left mark 805 and the (−Y) side end of the right mark 806 are parallel. A portion between the straight lines is acquired as the inspection image 84b.

Subsequently, the information element in the inspection target area 801 of the inspection image 84b shown in FIG. 15 is converted into character data indicating the character “ABCDE” by the OCR process by the inspection unit 73 (see FIG. 2) (step S16). Next, character data associated with the page number corresponding to the print result image 83b is extracted from the database stored in the database storage unit 71 (see FIG. 2) (step S17), and in steps S16 and S17. By comparing the obtained two character data, the printing inspection in the inspection target area 801 of the inspection image 84b is performed (step S18).

In the printing apparatus according to the second embodiment, the inspection image 84b including the inspection target area 801 is acquired from the print result image 83b based on the left mark 805 and the right mark 806 indicating the range of the inspection target area 801 in the transport direction. Then, the inspection image 84b, which is a part of the print result image 83b, is compared with the original image 81, so that the inspection of the inspection target area 801 is inspected. Thereby, similarly to the first embodiment, the print inspection in the inspection object region 801 can be performed quickly and with high accuracy. The printing apparatus according to the second embodiment is particularly suitable for variable printing inspection, as in the first embodiment. In the printing apparatus, an inspection target area 801 that is a variable printing variable section is provided. The printing inspection is performed quickly and with high accuracy.

In the printing apparatus, the range in the transport direction of the inspection image 84b is a range including both the range in the transport direction indicated by the left mark 805 and the range in the transport direction indicated by the right mark 806, as described above. Even when the print medium 9 is skewed, the entire inspection target region 801 can be included in the inspection image 84 with high accuracy, and the print inspection in the inspection target region 801 can be performed with high accuracy.

By the way, in the printing apparatus, since the long print medium 9 is conveyed by the conveyance mechanism 27 of the printing mechanism 5, a plurality of standard (for example, A4 size) print media are sequentially supplied and conveyed. Compared with a device (a so-called sheet-fed printing device), skew of the print medium 9 is likely to occur. Therefore, the configuration of the printing apparatus capable of realizing a high-precision inspection even when skew is generated has a long shape by the supply unit 272 and the winding unit 273 that hold the roll of the print medium 9. It is particularly suitable for a printing apparatus that conveys the print medium 9.

In the present embodiment, as shown in FIG. 14, the edge in the width direction of the print medium 9 in the print result image 83b is inclined with respect to the Y direction that is the transport direction, and the pixel arrangement in the print result image 83 The case where one of the directions (that is, the direction in which the straight left mark 805 and the right mark 806 face) is parallel to the edge of the print medium 9 has been described. As shown in A, the edge of the print medium 9 in the print result image 83b is parallel to the Y direction, and the direction in which the left mark 805 and the right mark 806 face is inclined with respect to the edge of the print medium 9. In addition, the print inspection in the inspection target area 801 can be performed quickly and with high accuracy. Similarly, FIG. As shown in B, the edge in the width direction of the print medium 9 in the print result image 83b is inclined with respect to the Y direction as the transport direction, and the direction in which the left mark 805 and the right mark 806 face is the Y direction and printing. Even when it is inclined with respect to the edge of the medium 9, the print inspection in the inspection object region 801 can be performed quickly and with high accuracy.

Next, a printing apparatus according to the third embodiment of the present invention will be described. The configuration of the printing apparatus according to the third embodiment is the same as that of the printing apparatus 1 shown in FIG. 1, and the same reference numerals are given to the corresponding configurations in the following description. In the printing apparatus according to the third embodiment, the first image except that a mark different from the first embodiment is added to the original image 81 (see FIG. 4) scheduled to be printed on the print medium 9. Printing inspection is performed by the same process as the embodiment.

In the printing apparatus according to the third embodiment, in step S11 shown in FIG. 3, as shown in FIG. 17, a mark 805 indicating the range in the transport direction of the inspection target area 801 (hereinafter, distinguished from the width mark described later). Therefore, print data indicating a mark additional image 82c in which a width mark 807 indicating a range in the width direction of the inspection target area 801 is added to the original image 81 is referred to as a print data generation unit. 4 (see FIG. 1). As in the first embodiment, the left mark 805 is a straight line that faces in the transport direction, and is arranged in a region 821 at the end on the (−X) side that is one end in the width direction of the original image 81. The The width mark 807 is a straight line that faces in the width direction and matches the range in the width direction of the inspection target region 801, and is arranged in a band-shaped region 823 extending in the width direction on the (−Y) side of the original image 81. The The area 823 is located near the edge in the conveyance direction of one page on the print medium 9, and no graphic elements other than the width mark 807 are arranged in the area 823.

In step S15, as shown in FIG. 18, the inspection image 84c including the inspection target region 801 is acquired by the inspection image acquisition unit 72 (see FIG. 2) based on the left mark 805 and the width mark 807 (see FIG. 17). The Specifically, a left mark 805 and a width mark 807 are detected on the same print result image as the mark added image 82c shown in FIG. 17, and both ends of the left mark 805 in the transport direction (that is, in the print result image (that is, Two straight lines extending in the width direction at the (+ Y) side end and the (−Y) side end), and both ends in the width direction of the width mark 807 (that is, (+ X) side ends) A rectangular region surrounded by two straight lines extending in parallel with the conveyance direction at the (−X) side end portion) is acquired as an inspection image 84c shown in FIG. Then, in steps S16 to S18, the inspection image 84c and the original image 81 are compared, and a printing inspection is performed in the inspection target area 801 of the inspection image 84c.

In the printing apparatus according to the third embodiment, the inspection image 84c including the inspection target region 801 is acquired from the printing result image, and the inspection image 84c that is a part of the printing result image is compared with the original image 81. Thus, the printing inspection of the inspection target area 801 is performed. Thereby, similarly to the first embodiment, the print inspection in the inspection object region 801 can be performed quickly and with high accuracy. In particular, since the inspection image 84c is acquired from the print result image based on the left mark 805 and the width mark 807 indicating the ranges in the transport direction and the width direction of the inspection target area 801, the inspection target area 801 is inspected with high accuracy. The inspection image 84c can be reduced in size while being included in the image 84c. As a result, the time required to compare the inspection image 84c and the original image 81 can be shortened, and the printing inspection in the inspection object region 801 can be performed more quickly.

In the printing apparatus according to the third embodiment, when the original image 81a shown in FIG. 8 is printed, as shown in FIG. 19, the first image arranged in the region 821 at the end on the (−X) side. In addition to the first mark 805a and the second mark 805b, the first width mark 807a and the second width mark 807b that indicate ranges in the width direction of the first inspection target area 801a and the second inspection target area 801b, respectively, are on the (−Y) side. Print data indicating the mark-added image 82d added to the area 823 is generated in the print data generation unit 4 (see FIG. 1). In this case, based on the first mark 805a and the first width mark 807a, as shown in FIG. 20, a first inspection image 841c including the entire first inspection target region 801a is acquired, and as shown in FIG. A second inspection image 841d including the entire second inspection target region 801b is acquired. As a result, the printing inspection in each of the first inspection target region 801a and the second inspection target region 801b is performed quickly and with high accuracy.

As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

For example, in the printing inspection by the printing apparatus according to the above-described embodiment, in step S11 illustrated in FIG. 3, the mark added to the original image does not necessarily need to be a straight line, and the conveyance direction (or width) of the inspection target region. The shape may be another shape (such as a wavy line or an ellipse) from the position of one end in the direction) to the position of the other end. In addition, a graphic indicating the position of one end in the conveyance direction (or width direction) of the inspection target area, and another graphic indicating the position of the other end independent of the graphic are the inspection target. It may be a mark indicating the range of the region.

The information element included in the inspection target area does not necessarily indicate a character or a number. For example, an information element indicating a code code such as a barcode or a two-dimensional code (for example, QR code (registered trademark)) is inspected. It may be included in the target area. In this case, in step S12, the character data or numerical data indicated by the code code in the inspection target area of the original image is stored in the database storage unit 71. In step S16, the code code in the inspection target area of the inspection image is character data. Or converted to numeric data. In addition, the print inspection may be performed by comparing the inspection image and the original image as image data without converting the information elements included in the inspection target area into character data or numerical data. When the print result image is acquired in a state where the inspection target area is tilted with respect to the transport direction due to the skew of the print medium 9, the print result image is rotated based on the tilt of the mark with respect to the transport direction, and the original image and The inspection may be performed after the orientation is the same.

In step S15, the print result image does not necessarily have to be formed from the output from the imaging unit 6, and the output sequentially sent from the imaging unit 6 to the print inspection unit 7 (that is, the captured image output from the imaging unit 6). Among them, the inspection image may be acquired by extracting only the output corresponding to the inspection image based on the mark. That is, the inspection image acquisition unit 72 only needs to acquire the inspection image from the captured image output from the imaging unit 6 based on the mark.

In the above printing apparatus, it is not always necessary to inspect the variable printing variable part. For example, a graphic element common to all pages, such as a logo indicating a company name or the like, may be an inspection target. In the printing apparatus, printing other than variable printing may be performed.

In the printing apparatus according to the above-described embodiment, the transport mechanism 27 of the printing mechanism 5 winds and holds the supply unit 272 that holds the roll of the printing medium 9 before printing and the printed portion of the printing medium 9. Although the winding unit 273 is provided, the transport mechanism 27 may have various other structures. For example, instead of the long print medium 9, a plurality of print sheets corresponding respectively to a plurality of pages of the original image 81 are sequentially supplied to the printing apparatus, and includes a roller that rotates with the print sheets sandwiched from above and below. The printing paper may be transported in the transport direction by the transport mechanism. The imaging unit 6 is not necessarily limited to a line sensor, and may be, for example, a two-dimensional CCD (Charge-Coupled Device) camera.

The printing medium in the above-described printing apparatus may be a sheet-like base material having liquid repellency such as a film or a plate-like member formed of plastic. In addition, a printing mechanism that prints on a print medium does not necessarily include an inkjet head. For example, a toner image is formed by applying toner to an electrostatic latent image on a photoreceptor layer provided on the surface of the print medium. A developing unit may be provided.

Although the present invention has been described in detail, the above description is illustrative and not restrictive. Therefore, it will be understood that many variations and embodiments are possible without departing from the scope of the invention.

Claims

A printing apparatus (1) for printing on a print medium (9) while conveying the print medium (9) in a predetermined conveyance direction,
Marks (805, 805a, 805b) indicating ranges in the transport direction of the inspection target areas (801, 801a, 801b) to be inspected after printing in the original images (81, 81a) to be printed are in the transport direction. A print data generation unit (4) for generating print data indicating an image added to one end of the original image (81, 81a) in the vertical width direction;
A printing mechanism (5) for printing on the print medium (9) based on the print data while conveying the print medium (9) in the conveyance direction;
An imaging unit (6) for imaging the print medium (9) after printing;
The inspection images (84, 84a to 84c, 841a to 841d), which are images including the inspection target areas (801, 801a, 801b), from the captured images (83, 83b) output from the imaging unit (6), are the marks. (805), 805a, 805b) based on the inspection image acquisition unit (72),
By comparing the inspection image (84, 84a to 84c, 841a to 841d) with the original image (81, 81a), the inspection object region (801) of the inspection image (84, 84a to 84c, 841a to 841d). , 801a, 801b), an inspection unit (73) for inspecting,
Is provided.
A printing device (1) according to claim 1,
The original image (81, 81a) is an image printed in a region corresponding to each of a plurality of pages on the print medium (9);
Images printed in the inspection target areas (801, 801a, 801b) are different for each page.
The printing apparatus (1) according to claim 1 or 2,
In the image indicated by the print data, the mark (805, 805a, 805b) is a straight line that matches the range in the transport direction of the inspection target area (801, 801a, 801b).
A printing device (1) according to any of claims 1 to 3,
The print data generation unit (4) displays another mark (806) indicating the range in the transport direction of the inspection target area (801, 801a, 801b) in the width of the original image (81, 81a). Add to the other end in the direction,
The range in the transport direction of the inspection image (84b) in the captured image (83b) includes both the range indicated by the mark (805, 805a, 805b) and the range indicated by the other mark (806). It is said.
A printing device (1) according to any of claims 1 to 3,
The print data generation unit (4) displays width marks (807, 807a, 807b) indicating ranges in the width direction of the inspection target areas (801, 801a, 801b) in the original image (81, 81a). Add to the area extending in the width direction,
The inspection image acquisition unit (72) acquires the inspection images (84c, 841c, 841d) based on the marks (805, 805a, 805b) and the width marks (807, 807a, 807b).
A printing device (1) according to any of claims 1 to 3,
The original image (81a) includes another inspection target region (801b) at least partially overlapping the inspection target region (801a) with respect to the transport direction,
The print data generation unit (4) displays another mark (805b) indicating the range in the transport direction of the other inspection target region (801b) on the one side in the width direction of the original image (81a). Add to the end independently from the mark (805a),
The inspection image acquisition unit (72) acquires another inspection image (841b) that is an image including the other inspection target region (801b) from the captured image based on the other mark (805b). ,
The inspection unit (73) compares the other inspection image (841b) with the other inspection target region (801b) of the other inspection image (841b) by comparing the other inspection image (841b) with the original image (81a). inspect.
A printing device (1) according to any of claims 1 to 6,
The inspection target area (801, 801a, 801b) of the original image (81, 81a) includes at least one character, number or symbol, or an information element indicating a code code,
The inspection unit (73) converts the information elements read from the inspection target areas (801, 801a, 801b) of the inspection images (84, 84a to 84c, 841a to 841d) into character data or numerical data. Later, it is compared with character data or numerical data indicated by the original image (81, 81a).
Printing device (1) according to any of claims 1 to 7,
The imaging unit (6) is a line sensor that images a linear region parallel to the width direction on the print medium (9).
A printing device (1) according to any of claims 1 to 8,
The printing mechanism (5)
A supply unit (272) for holding a roll of the print medium (9) before printing and feeding the print medium (9) from the roll in the transport direction;
A winding unit (273) that winds up a printed portion of the print medium (9);
Is provided.
A printing device (1) according to any of claims 1 to 9,
The printing mechanism (5) includes an inkjet head (3) that ejects micro droplets of ink from a plurality of ejection openings toward the printing medium (9).
An inspection method for inspecting printing in a printing apparatus (1) that performs printing on a printing medium (9) while conveying the printing medium (9) in a predetermined conveyance direction,
a) Marks (805, 805a, 805b) indicating ranges in the transport direction of the inspection target areas (801, 801a, 801b) to be inspected after printing in the original images (81, 81a) to be printed are Generating print data indicating an image added to one end of the original image (81, 81a) in the width direction perpendicular to the direction;
b) printing the print medium (9) based on the print data while transporting the print medium (9) in the transport direction;
c) imaging the print medium (9) after printing;
d) The inspection images (84, 84a to 84c, 841a to 841d) that are the images including the inspection object regions (801, 801a, 801b) from the captured images (83, 83b) acquired in the step c) are described above. Acquiring based on landmarks (805, 805a, 805b);
e) The inspection target region of the inspection image (84, 84a to 84c, 841a to 841d) by comparing the inspection image (84, 84a to 84c, 841a to 841d) with the original image (81, 81a). Inspecting (801, 801a, 801b);
Is provided.
The inspection method according to claim 11,
The original image (81, 81a) is an image printed in a region corresponding to each of a plurality of pages on the print medium (9);
Images printed in the inspection target areas (801, 801a, 801b) are different for each page.
The inspection method according to claim 11 or 12,
In the image indicated by the print data, the mark (805, 805a, 805b) is a straight line that matches the range in the transport direction of the inspection target area (801, 801a, 801b).
The inspection method according to any one of claims 11 to 13,
In the step a), another mark (806) indicating the range in the transport direction of the inspection target area (801, 801a, 801b) is the other mark in the width direction of the original image (81, 81a). Added to the end,
The range in the transport direction of the inspection image (84b) in the captured image (83b) includes both the range indicated by the mark (805, 805a, 805b) and the range indicated by the other mark (806). It is said.
The inspection method according to any one of claims 11 to 13,
In the step a), width marks (807, 807a, 807b) indicating ranges in the width direction of the inspection target regions (801, 801a, 801b) extend in the width direction of the original image (81, 81a). Added to the area,
In the step d), the inspection images (84c, 841c, 841d) are acquired based on the marks (805, 805a, 805b) and the width marks (807, 807a, 807b).
The inspection method according to any one of claims 11 to 13,
The original image (81a) includes another inspection target region (801b) at least partially overlapping the inspection target region (801a) with respect to the transport direction,
In the step a), another mark (805b) indicating the range in the transport direction of the other inspection target region (801b) is formed on the one end in the width direction of the original image (81a). Added independently from the landmark (805a),
In the step d), another inspection image (841b), which is an image including the other region to be inspected (801b), is acquired from the captured image based on the other mark (805b),
In the step e), the other inspection object region (801b) of the other inspection image (841b) is inspected by comparing the other inspection image (841b) with the original image (81a). The
The inspection method according to any one of claims 11 to 16,
The inspection target area (801, 801a, 801b) of the original image (81, 81a) includes at least one character, number or symbol, or an information element indicating a code code,
In the step e), after the information elements read from the inspection target areas (801, 801a, 801b) of the inspection images (84, 84a to 84c, 841a to 841d) are converted into character data or numerical data. The character data or numerical data indicated by the original image (81, 81a) is compared.