JP2011167920A - Printer - Google Patents

Abstract

Provided is a printing apparatus that can use both an offset printing method and an ink jet method together and can perform printing with high accuracy.
A printing pattern to be printed on a printing paper is divided into a first printing area to be printed by an offset printing method and a second printing area to be printed by an inkjet method, and the first printing area is divided using an offset printing machine. Color printing is performed, and the second printing area is printed in a single color by an ink jet printer. In this case, since monochrome printing is performed by the ink jet method, it is possible to prevent the ink from spreading on the printing paper and the back side. In addition, when the image data after printing is photographed, and the relative position between the printing area by the offset printing method and the printing area by the ink jet method is shifted in the image data, the printing position by the ink jet printer is corrected. As a result, the positional deviation can be corrected.
[Selection] Figure 1

Description

  The present invention relates to a printing apparatus used for newspaper printing or the like, and more particularly to a printing apparatus capable of performing printing processing by changing a part of contents to be printed by a simple method.

  In general, a rotary printing press for newspaper printing uses a plate printing system such as an offset printing system. Such a rotary press is equipped with printing plate cylinders of four colors of black, cyan, magenta, and yellow in the printing paper feeding direction, and printing is performed on each plate cylinder with ink of each color. Then, color printing or single color printing is performed.

  Also, in recent years, ink jet printing apparatuses are often used in businesses and general households, and attempts have been made to use such ink jet printing apparatuses for newspaper printing. For example, in Japanese Patent Laid-Open No. 10-286939 (Patent Document 1), a fixed portion of a print pattern is printed in a single color using an offset printing method, and further, for example, changed for each region such as dealer information described in an advertisement. It is disclosed that newspaper printing processing can be performed without stopping the rotary press for a long time by color-printing information that requires printing using an ink jet printer.

  However, the conventional example disclosed in Patent Document 1 described above prints an area that is mainly monochrome printing using an offset printing method, and a specific area (for example, an area that describes dealer information) is blank. Since the area that becomes the blank portion is color-printed by the ink jet method, there arises a problem that the ink is smeared or back-faced. That is, when ink of four colors is jetted onto a printing paper for newspaper printing by using an ink jet method, there arises a problem that the ink oozes on the paper surface or is backed.

  Further, when newspaper printing is performed by using both the offset printing method and the ink jet method, there is a case where the relative positional relationship between the two may be shifted, and this positional shift needs to be corrected. Does not mention correction of this misalignment. Furthermore, since the black density printed by the offset printing method and the black density printed by the ink jet method may not match, it is necessary to match these densities, but this content is also referred to in Patent Document 1. Not.

JP-A-10-286939

  As described above, the conventional example disclosed in Patent Document 1 is configured to perform color printing using an inkjet printer, and in this case, four colors of black, cyan, magenta, and yellow are used on the printing paper. Ink needs to be ejected, and there is a problem in that the ink is smudged on the printing paper or the back surface of the printing paper. Therefore, there is a disadvantage that a special printing paper processed so that the ink does not spread must be used.

  Further, when both offset printing and ink jet printing are used, positional deviation and density change may occur. However, Patent Document 1 has a drawback that these are not mentioned.

  The present invention has been made in order to solve such a conventional problem, and the object of the present invention is to use both the plate printing method and the ink jet method together and to print with high accuracy. It is to provide a possible printing apparatus.

  In order to achieve the above object, an invention according to claim 1 of the present application is a printing apparatus that prints a predetermined printing pattern on a printing paper, and includes a paper feeding unit that feeds the printing paper, and the printing pattern is a color printing region. A print area setting means for setting a first print area including the first print area and a second print area that is only a monochrome print area, and the first print area set on the printing paper is color-coded using a plate printing method. It is characterized by comprising: a first printing means for printing; and a second printing means for monochromatically printing the second printing area set on the printing paper by an ink jet method.

  The invention according to claim 2 is provided on the downstream side of the second printing means, the image reading means for photographing the image printed by the second printing means, and the image data read by the image reading means The density of the portion printed in monochrome by the second printing means is compared with the density of preset reference image data, and the density when performing monochrome printing by the second printing means is the density of the reference image data. Density adjusting means for adjusting the printing density by the second printing means so as to coincide with the second printing means.

  According to a third aspect of the present invention, the second printing unit prints a density calibration target on a predetermined position of the printing paper, and the density adjustment unit detects the density of the density calibration target, and The printing density by the second printing unit is adjusted so as to match the density of the reference image data.

  According to a fourth aspect of the present invention, the printing paper is white, provided on the downstream side of the second printing unit, and an image reading unit that captures an image printed by the second printing unit, and the image reading unit Based on the density comparison with respect to the white color of the portion of the image data read by the means that is monochrome printed by the second printing means, the density at the time of monochrome printing by the second printing means becomes a desired density. And density adjusting means for adjusting the printing density by the second printing means.

  According to a fifth aspect of the invention, the second printing unit prints a density calibration target at a predetermined position of the printing paper, and the density adjustment unit is based on a density comparison of the density calibration target with respect to the white color. Then, the printing density by the second printing unit is adjusted so that the density at the time of monochrome printing by the second printing unit becomes a desired density.

  The invention according to claim 6 is provided on the downstream side of the second printing unit, and is an image reading unit that captures an image printed by the second printing unit, and among the image data read by the image reading unit. The density of the portion printed in the single color by the second printing means and the density of the portion printed in the same color as the single color of the second printing means by the first printing means are compared, and the respective densities match. As described above, the image forming apparatus includes a density adjusting unit that adjusts at least one of a printing density by the first printing unit or a printing density by the second printing unit.

  According to a seventh aspect of the present invention, the second printing unit includes an inkjet head that ejects a single color ink onto the printing paper, and an airflow stabilization cover is provided around the ink protrusion of the inkjet head. It is characterized by that.

  The invention according to claim 8 is provided on the downstream side of the first printing unit and the second printing unit, and is read by the image reading unit that reads the print pattern printed on the printing paper, and the image reading unit. Relative position detection means for detecting the relative positions of the printing area by the first printing means and the printing area by the second printing means based on the image data, and the relative position data detected by the relative position detection means, And a positioning unit that calibrates the printing position by the second printing unit based on preset relative position data of the reference image data.

  In the first aspect of the invention, the entire printing paper is divided into a first printing area and a second printing area, and the first printing area is formed by a first printing means (for example, an offset printing machine) using a plate printing system. Color printing is performed, and the second printing area is printed in a single color by a second printing unit (for example, an ink jet printer) using an ink jet method. Accordingly, since printing by the ink jet method becomes a single color, it is not necessary to eject four colors of ink for color printing onto the printing paper, and it is possible to prevent the ink from spreading or back-sided on the printing paper. In addition, since the ink jet printer uses digital data to print on printing paper, the contents of printing can be easily changed by changing the digital data. Therefore, for example, when printing a dealer for each area on a newspaper advertisement, it is possible to switch the printing contents with a very simple operation and without requiring a long time.

  Furthermore, since printing is performed on printing paper using digital data, the printing timing can be easily changed, and deviation of the printing position with respect to the printing paper can be corrected by a simple operation.

  In the invention of claim 2, the image printed by the second printing means is read by the image reading means, and the density of the monochrome printed portion of the image data and the density corresponding to this portion included in the reference image data are obtained. Since the density of monochromatic printing by the second printing unit is adjusted so as to match, the printing density in the second printing unit can be adjusted to an appropriate density, and as a result, the monochromatic density printed on the first printing unit (for example, Black density) and the monochrome density printed by the second printing means can be matched.

  According to the third aspect of the present invention, the density calibration target is printed at a predetermined position on the printing paper by the second printing means, and the density adjustment is performed using the density calibration target, so the density at the determined position is measured. Thus, the density can be adjusted and the density can be adjusted with high accuracy.

  In the invention of claim 4, since the white color of the printing paper is compared with the single color density printed by the second printing unit and the single color density is adjusted to a desired density, the print density in the second printing unit is adjusted. Can be adjusted to an appropriate concentration.

  In the fifth aspect of the invention, since the density calibration target is printed at a predetermined position on the printing paper by the second printing means and the density calibration target is used for comparison with the white density, The density can be adjusted by measuring the density, and the density can be adjusted with high accuracy.

  In the invention of claim 6, in the image data read by the image reading means, the density of the portion printed in monochrome by the first printing means is compared with the density of the portion printed in monochrome by the second printing means. Since the density of either the first printing unit or the second printing unit is adjusted so that they match, the monochrome density printed on the same printing paper can be reliably matched, and there is no high density unevenness. Printing is possible.

  In the invention of claim 7, since the inkjet head is provided with the cover, the ink ejected from the inkjet head can be prevented from being bent due to the turbulence of the air flow, and high-precision printing is possible.

  In the invention of claim 8, relative position data of the area printed by the first printing means and the area printed by the second printing means is obtained based on the image data photographed by the image reading means, and this relative Since the position data is compared with the relative position data of the reference data set in advance and the printing position by the second printing unit is calibrated so that they match, the position data is positioned at the printing position of the first printing unit and the second printing unit. Even when a deviation occurs, the positional deviation can be easily calibrated, and high-precision printing is possible.

1 is an explanatory diagram schematically showing the overall configuration of a printing apparatus according to an embodiment of the present invention. It is a block diagram which shows the electrical constitution of the control apparatus provided in the printing apparatus which concerns on one Embodiment of this invention. 4A and 4B are explanatory views showing a configuration of an inkjet head used in a printing apparatus according to an embodiment of the present invention, where FIG. It is explanatory drawing which shows the structure of the ink ejection nozzle of the inkjet head used for the printing apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the process sequence of the control apparatus provided in the printing apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows the reference | standard image and read image which are used with the printing apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the image image | photographed with the image reading sensor of the printing apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing a configuration of a printing apparatus 100 according to an embodiment of the present invention and sheet feeding rolls (sheet feeding units) 61 to 65 that supply the printing sheet P to the printing apparatus 100. . As shown in FIG. 1, the printing apparatus 100 includes five systems of printing units U <b> 1 to U <b> 5, and among the printing units U <b> 1 to U <b> 5, the left four printing units U <b> 1 to U <b> 4 include a paper feed roll 61. To offset printing machines (first printing means) 11 to 14 for printing on the printing paper P supplied from .about.64 by the offset printing method. Note that the printing paper is, for example, white.

  Further, each of the printing units U1 to U4 includes inkjet printers 21 to 28 (hereinafter referred to as IJ printers, second printing means) that perform printing by an inkjet method after printing by the offset printers 11 to 14 is completed. ing.

  The rightmost printing unit U <b> 5 includes ink jet printers 29 and 30 that print on the printing paper P supplied from the paper feed roll 65 by an ink jet method. That is, each of the printing units U1 to U5 is provided with two IJ printers in order to perform inkjet printing on both the front surface and the back surface of the printing paper P.

  The offset printing machine 11 provided in the printing unit U1 includes four sets of plate cylinders 31a to 31d. The plate cylinders 31a to 31d are each provided with a paper feed roll 61 using four colors of ink of black, cyan, magenta, and yellow. Color printing is performed on both sides of the printing paper P supplied from the printer.

  Guide rolls 41 and 42 are provided on the downstream side of the offset printing machine 11, and are guided by the guide rolls 41 and 42 so that the printing paper P is sent to the downstream side. Further, the IJ head of the IJ printer 21 is provided on the opposite surface of the guide roll 41 with the print paper P in between, and one side of the print paper P can be printed by the IJ printer 21. Further, an IJ head of the IJ printer 22 is provided on the opposite surface of the guide roll 42 across the printing paper P, and the other surface of the printing paper P can be printed by the IJ printer 22.

  Further, guide rolls 51 and 52 are provided on the downstream side of the IJ printers 21 and 22, and an image that captures an image printed on the printing paper P is provided on the opposite surface of the guide roll 51 across the printing paper P. A reading sensor (image reading means) 71 is provided. Furthermore, an image reading sensor 72 that captures an image printed on the printing paper P is provided on the opposite surface of the guide roll 52 across the printing paper P. Therefore, the image reading sensor 71 can take an image of one side of the printing paper P, and the image reading sensor 72 can take an image of the other side of the printing paper P.

  The image data photographed by the image reading sensors 71 and 72 is transmitted to the control device 33. Since the printing units U2 to U4 have the same configuration as that of the printing unit U1, description of the configuration is omitted.

  The printing unit U5 does not include an offset printing machine, is guided by guide rolls 49 and 50, and is sent downstream. Further, the IJ head of the IJ printer 29 is provided on the opposite surface of the guide roll 49 across the printing paper P, and one surface of the printing paper P is printed by the IJ printer 29. Further, an IJ head of the IJ printer 30 is provided on the opposite surface of the guide roll 50 across the printing paper P, and the other surface of the printing paper P is printed by the IJ printer 30.

  Further, guide rolls 59 and 60 are provided on the downstream side of the IJ printers 29 and 30, and an image that captures an image printed on the printing paper P is provided on the opposite surface of the guide roll 59 across the printing paper P. A reading sensor 79 is provided. Furthermore, an image reading sensor 80 that captures an image printed on the printing paper P is provided on the opposite surface of the guide roll 60 across the printing paper P. Accordingly, the image reading sensor 79 can take an image of one side of the printing paper P, and the image reading sensor 80 can take an image of the other side of the printing paper P.

  Then, the printing paper P printed by each of the printing units U1 to U5 is sent to a folding machine (not shown) by a feed roller 32 to create a newspaper.

  Next, a detailed configuration of the control device 33 will be described. FIG. 2 is a block diagram showing an electrical configuration of the control device 33. As shown in FIG. 2, the control device 33 includes a CPU 331, a ROM 333 that stores a system program related to processing of the entire printing apparatus, a RAM 332 that stores various data used for arithmetic processing of the CPU 331, a hard disk 334, An image data input unit 335, a display 336 for displaying various images and notifying the operator, and communication I / Fs 337 to 339 are provided.

  The RAM 332 has a function of storing various data used for arithmetic processing of the CPU 331, and further has a function of temporarily storing image data photographed by the image reading sensors 71 to 80.

  The image data input unit 335 inputs image data (hereinafter referred to as “reference image data”) output from a host system (not shown) and indicating a print pattern to be printed on the printing paper P from the outside.

  The hard disk 334 stores various application programs, and stores an alignment program, a density adjustment program, a print area setting program, and the like. Among these, the alignment program is based on the image data captured by the image data reading sensors 71 to 80 and the reference image data, and the images printed by the offset printers 11 to 14 and the IJ printers 21 to 30. If the printed image is misaligned, processing for correcting the printing position by the IJ printers 21 to 30 is executed.

  The density adjustment program is printed by the black density of the image printed by the IJ printers 21 to 30 and the offset printers 11 to 14 based on the image data captured by the image data reading sensors 71 to 80. Processing for correcting the black print density by the IJ printers 21 to 30 or the black print density by the offset printers 11 to 14 so that the density of the black portion matches the black density included in the reference image data. Execute. Specifically, the density is corrected using any one of the following methods (A) to (C).

  (A) The black print density of the IJ printers 21 to 30 is compared with the black print density included in the reference image data, and the print densities of the IJ printers 21 to 30 are adjusted so that they match.

  (B) The black print density by the IJ printers 21-30 and the density of the black printed part by the offset printers 11-14 are compared, and the IJ printers 21-30 or the offset are set so that they match. The printing density of at least one of the printing presses 11 to 14 is adjusted.

  (C) By adjusting the density of black printed by the IJ printers 21 to 30 and the density of the white printing paper P, the density is adjusted so that the black density printed by the IJ printers 21 to 30 matches the reference density.

  The print area setting program executes processing for setting an area to be printed by the offset printers 11 to 14 and an area to be printed by the IJ printers 21 to 30 among the image data to be printed on the printing paper P.

  The CPU 331 performs overall control of the entire printing apparatus. In particular, the print region setting program is executed to perform processing for determining a region for color printing by the offset printing method and a region for monochrome printing by the IJ printing method based on the printing pattern input from the image data input unit 335. . That is, the CPU 331 has a function as a print area setting unit that divides and sets a print pattern into a first print area including a color print area and a second print area including only a monochrome print area.

  Further, the CPU 331 executes an alignment program to correct a positional deviation between the image printed by the offset printer 11 and the images printed by the IJ printers 21 to 30. That is, the CPU 331 functions as a relative position detection unit that detects the relative positions of the printing area by the first printing unit and the printing area by the second printing unit based on the image data read by the image reading unit, and the relative position. A function as an alignment unit that calibrates the printing position by the second printing unit based on the relative position data detected by the detection unit and the relative position data of preset reference image data is provided.

  Further, the CPU 331 executes a density adjustment program to correct the density of the black portion of the image printed by the offset printer 11 and the density of the black portion of the image printed by the IJ printers 21 to 30. . That is, for example, the CPU 331 compares the density of the portion of the image data read by the image reading unit with the monochrome printing by the second printing unit and the density of the reference image data set in advance, and performs the second printing. A function as density adjusting means for adjusting the printing density by the second printing means is provided so that the density at the time of monochrome printing by the means matches the density of the reference image data.

  The communication I / F 337 is connected to each of the image reading sensors 71 to 80, receives the image data transmitted from each of the image reading sensors 71 to 80, and stores it in the RAM 332.

  The communication I / F 338 is connected to each of the offset printers 11 to 14 and outputs an operation command signal to each of the offset printers 11 to 14.

  The communication I / F 339 is connected to each IJ printer 21 to 30 and transmits single color print data including a print area to each IJ printer 21 to 30. In addition, an operation command signal is output to each IJ printer 21 to 30.

  Next, the configuration of the IJ head provided in the IJ printers 21 to 30 will be described with reference to FIG. FIG. 3A is an explanatory view schematically showing a configuration of the IJ head 21a disposed to face the guide rolls 41 to 50, and FIG. 3B is a side view thereof. As shown in FIG. 3A, the printing paper P fed by the guide roll 41 passes through the vicinity of the ink ejection surface q1 of the IJ head 21a, and black ink is transferred from the ink ejection surface q1. The black print pattern is printed on the surface of the printing paper P by being ejected.

  Further, a cover 34 is provided on the front surface of the IJ head 21a so as to cover the periphery of the guide roll 41, and the cover 34 avoids the influence of the airflow caused by the printing paper P being sent out. That is, by providing the cover 34, the inside of the cover 34 is kept in a windless state, and the direction of the ink ejected from the IJ head 21a is prevented from being bent.

  FIG. 4 is an explanatory diagram showing the arrangement of the ink nozzles provided on the ink ejection surface of the IJ head 21a. FIG. 4A shows a configuration in which the ink nozzles r1 are arranged in a line with respect to the ink ejection surface q1. 4B includes a configuration in which two rows of ink nozzles r2 are arranged in parallel with respect to the ink ejection surface q2, and FIG. 4C illustrates a staggered configuration of the ink nozzles r3 with respect to the ink ejection surface q3. The configuration is arranged in four rows. In addition, each of the ink nozzles r1 to r3 has a jet nozzle area of r1> r2> r3. A predetermined printing pattern can be printed on the printing paper P by ejecting black ink from the ink nozzles r1 to r3. Further, the higher the feed speed of the printing paper P, the higher the resolution of printing possible by using the IJ head 21a having more ink nozzles.

  Next, the operation of the printing apparatus according to the present embodiment configured as described above will be described. FIG. 5 is a flowchart showing a processing procedure by the CPU 331 shown in FIG.

  In step S <b> 11, the CPU 331 sets an initial preset value of image data to be printed by the offset printers 11 to 14 based on the image data to be printed input from the image data input unit 335.

  In step S <b> 12, the CPU 331 sets initial preset values of image data to be printed by the IJ printers 21 to 30 based on the image data to be printed input from the image data input unit 335.

  In step S <b> 13, the CPU 331 outputs the initial preset value set in step S <b> 11 and the print start command signal to the offset printers 11 to 14 via the communication I / F 338. Since the printing patterns for color printing are set on the plate cylinders of the offset printing machines 11 to 14, when the offset printing machines 11 to 14 are operated, the printing paper P sent out from the paper feed rolls 61 to 64 is printed. A predetermined color image is printed on both the front surface and the back surface.

  In step S14, the CPU 331 transmits the image data to be printed by the IJ printing method to the IJ printers 21 to 30 via the communication I / F 339, and additionally, the initial preset set in the process of step S12. Value and a print start command signal are output. As a result, the IJ printers 21 to 30 provided in the printing units U1 to U5 operate to print a predetermined black image on both the front and back surfaces of the printing paper P delivered from the paper feed rollers 61 to 65. .

  In step S <b> 15, the CPU 331 reads the image printed on the printing paper P after passing through the IJ printers 21 to 30 by the image reading sensors 71 to 80 provided at the subsequent stage of the IJ printers 21 to 30. That is, taking the printing unit U1 as an example, the images on the front and back sides of the printing paper P that has passed the offset printing machine 11 and the IJ printing machines 21 and 22 and have been subjected to the offset printing and IJ printing are respectively shown. Reading is performed by the image reading sensors 71 and 72. The acquired image data is stored in the RAM 332.

  In step S <b> 16, the CPU 331 compares the image data read by the image reading sensors 71 and 72 with the reference image data input by the image data input unit 335 and performs a print timing correction process. Specifically, when the read image data D2 (image data read by the image reading sensor) shown in FIG. 6B is acquired with respect to the reference image data D1 shown in FIG. The image data D1 and D2 are compared to determine the displacement of the digital data with respect to the offset print data.

  For example, in the reference image data D1 shown in FIG. 6A, areas a1 and a4 are offset print data, areas a2 and a3 are digital data, and each area a1 to a4 is shown in FIG. 6B. When the areas b1 to b4 of the read image data D2 shown in FIG. 4 correspond to each other, the amount of positional deviation between the distance L1 between the area a1 and the area a2 and the distance L2 between the area b1 and the area b2 is obtained. Alternatively, the amount of displacement between the distance L3 between the area a3 and the area a4 and the distance L4 between the area b3 and the area b4 is obtained.

  Then, based on this positional deviation amount, a correction value of the print start timing by the IJ printers 21 to 30 is obtained, and the obtained correction value is transmitted to the IJ printers 21 to 30 via the communication I / F 339. As a result, the IJ printers 21 to 30 are controlled so that the printing timing of the digital image data is appropriate, and the relative position of the digital data with respect to the offset print data is controlled to match the reference image data.

  In step S17, the CPU 331 compares the black density included in the read image data read by the image reading sensors 71 and 72 with the black density included in the reference image data. Is output to the IJ printers 21-30. For example, as shown in FIG. 7, the reference image is detected by detecting the density of a target C1 (in this example, a portion where a newspaper is described) printed on a specific portion of a newspaper included in the read image data D3. The concentration displacement can be obtained by comparing with the concentration of the target C1 of the data. Further, a target C3 for density measurement is printed in advance, a density displacement is obtained based on the density of the target C3, a target area C2 is set, standard density data in this area is taken out, and reference image data By comparing with the standard density data, it is also possible to obtain the density displacement.

  As a result, the IJ printers 21 to 30 adjust the amount of ink ejected from the ink nozzles, and control so that the density of the black portion matches the reference image data.

  In this way, the printing position and printing density by the IJ printers 21 to 30 are controlled to be appropriate. After that, the quality control device provided in the subsequent stage determines whether the printed newspaper is a good product or a defective product, and if it is a good product, it is used as a newspaper to be shipped. Sent to defective product processing.

  In this way, in the printing apparatus 100 according to the present embodiment, the black (which occupies most of the reference image data) using the two IJ printers 21 to 30 provided for each of the printing units U1 to U5. A single color) printing area is printed, and the area not printed by the IJ printing machines 21 to 30 is color-printed using the offset printing machines 11 to 14. Therefore, even if the print content is changed, it can be easily changed by changing the digital image data. For example, when changing the print content for each region, such as dealer information described in the advertisement Even so, the change operation can be easily performed.

  Further, since the digital data printed by the IJ printers 21 to 30 occupies most of the entire print pattern, the print start timing can be easily set, and alignment can be easily performed.

  Furthermore, since the IJ printers 21 to 30 are used for single color printing (for example, black) and are not used for color printing as in the past, four colors of ink are not ejected onto the same portion of the printing paper P. Further, it is possible to prevent the ink from spreading on the printing paper P and the back surface.

  Further, the image printed on the printing paper P after the printing is taken by the image reading sensors 71 to 80, and the read image data and the reference image data are compared to thereby shift the printing position by the IJ printers 21 to 30. Since the black density is corrected, it is possible to avoid the occurrence of misalignment in the printed content of the printed newspaper, and to prevent the occurrence of density unevenness in the black portion.

  Next, a first modification of the above-described embodiment will be described. In the above-described embodiment, the black printed by the IJ printers 21 to 30 in the read image data read by the image reading sensors 71 to 80 is compared with the black contained in the reference image data, and they match. In the first modification, the black portion printed by the IJ printers 21 to 30 included in the read image data and the offset printing are described. By comparing the print density of either the IJ printers 21 to 30 or the offset printers 11 to 14 so that the black portions printed by the printers 11 to 14 are compared and these densities are matched, Match the black density of each printing press. Even in such a system, the black densities printed by the respective printing presses can be matched, so that it is possible to prevent density unevenness from occurring in the black portions.

  Further, as a second modified example, the black density printed by the IJ printers 21 to 30 included in the read image data read by the image reading sensors 71 to 80 is compared with the white density of the printing paper P. However, it is also possible to adopt a configuration in which the printing density by the IJ printers 21 to 30 is adjusted to a predetermined density. Even when such an adjustment method is used, the black densities printed by the respective printing presses can be matched, so that it is possible to prevent density unevenness from occurring in the black portions. Further, the density of the IJ printers 21 to 30 can be adjusted to a desired density by detecting the density of the target C1 shown in FIG.

  Although the printing apparatus of the present invention has been described based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each unit can be replaced with an arbitrary configuration having the same function. it can.

  For example, although an example of newspaper printing has been described in the present embodiment, the present invention can also be used for printing of horse racing newspapers and other printed materials.

  INDUSTRIAL APPLICABILITY The present invention can be used to change the printing content of a specific part with a simple operation in newspaper printing or the like.

11-14 Offset printing machine 21-30 Inkjet (IJ) printing machine 31a-31d Plate cylinder 32 Delivery roller 33 Controller 34 Cover 41-50 Guide roll 51-60 Guide roll 61-65 Paper feed 71-80 Image reading sensor 100 Printing device 331 CPU
332 RAM
333 ROM
334 Hard disk 335 Image data input unit 336 Display 337 to 339 Communication I / F
U1 to U5 Printing unit P Printing paper

Claims (8)

In a printing apparatus that prints a predetermined printing pattern on printing paper,
Paper feeding means for feeding out the printing paper;
Print area setting means for setting the print pattern to a first print area including a color print area and a second print area including only a monochrome print area;
First printing means for color-printing the first printing area set on the printing paper using a plate printing method;
A second printing unit configured to perform monochromatic printing on the second printing region set on the printing paper by an inkjet method;
A printing apparatus comprising: An image reading means provided on the downstream side of the second printing means for capturing an image printed by the second printing means;
In the image data read by the image reading means, the density of the portion printed in monochrome by the second printing means is compared with the preset density of reference image data, and the monochrome printing is performed by the second printing means. Density adjusting means for adjusting the printing density by the second printing means so that the density at the time of matching the density of the reference image data;
The printing apparatus according to claim 1, further comprising:   The second printing unit prints the density calibration target at a predetermined position on the printing paper, and the density adjustment unit detects the density of the density calibration target and matches the density of the reference image data. The printing apparatus according to claim 2, wherein a printing density by the second printing unit is adjusted. The printing paper is white;
An image reading means provided on the downstream side of the second printing means for capturing an image printed by the second printing means;
Based on the density comparison with respect to the white color of the portion of the image data read by the image reading means that is monochrome printed by the second printing means, the density at the time of monochrome printing by the second printing means is a desired density. Density adjusting means for adjusting the printing density by the second printing means,
The printing apparatus according to claim 1, further comprising:   The second printing unit prints a density calibration target on a predetermined position of the printing paper, and the density adjustment unit is a single color printer by the second printing unit based on the density comparison of the density calibration target with respect to the white color. The printing apparatus according to claim 4, wherein the printing density by the second printing unit is adjusted so that the density at the time of printing becomes a desired density. An image reading means provided on the downstream side of the second printing means for capturing an image printed by the second printing means;
In the image data read by the image reading means, the density of the portion printed in the single color by the second printing means and the portion printed in the same color as the single color of the second printing means by the first printing means A density adjusting unit that adjusts at least one of the printing density by the first printing unit or the printing density by the second printing unit so that the respective densities match.
The printing apparatus according to claim 1, further comprising:   The said 2nd printing means is provided with the inkjet head which ejects a monochrome ink to the said printing paper, The cover for the airflow stabilization was provided in the circumference | surroundings of the ink protrusion part of this inkjet head. The printing apparatus according to claim 6. An image reading unit that is provided on the downstream side of the first printing unit and the second printing unit and reads a print pattern printed on the printing paper;
A relative position detecting means for detecting a relative position of the printing area by the first printing means and the printing area by the second printing means based on the image data read by the image reading means;
Alignment means for calibrating the printing position by the second printing means based on the relative position data detected by the relative position detecting means and the relative position data of preset reference image data;
The printing apparatus according to claim 1, further comprising:

Images