JP2006198919A - Online printing adjustment device - Google Patents

Abstract

An object of the present invention is to convert a reflected light amount signal from a light receiving element attached to a printing press into data such as color values used for printing quality control, and online with image quality data such as color values as a reference prepared in advance. Provided are a method and an apparatus that enable instant comparison and confirmation.
A quality inspection apparatus for a printed matter being printed by a printing press, comprising a light emitting element and a light receiving element installed in the printing press, wherein the print image information of the printed matter is separated into three primary colors and read. Necessary for print quality control by comparing input means, conversion means for converting the three primary colors and the like into color values, values obtained by the conversion means, and values prepared in advance by taking into account the printing state An on-line print adjusting apparatus comprising: an analyzing unit that converts the information into simple information; and a display unit that displays a result obtained by the analyzing unit in real time during operation of the printing press.
[Selection] Figure 1

Description

  The present invention relates to a method and an apparatus for adjusting a printed material that are inspected and adjusted online to stabilize the quality of a printed material printed by a printing press.

Conventional quality inspections of printed matter include on-line inspection for smudges, irregularities, creases, tears, etc., and on-line inspection for density, dot gain, and color tone after printing is completed or after stopping. It was broken.
The former uses a reading device such as a CCD camera installed on a printing press such as a rotary press to continuously read the printed matter and detect and display printing defects such as dirt, irregularity, folding, and tearing online. . However, with this method, it has been impossible to inspect and manage changes in printing density.

On the other hand, the latter removes the printed matter printed by the printing press, measures the data used for printing management such as density, color value, dot gain, etc. with a commercially available densitometer or colorimeter, and manages the quality. In order to check the quality, the printing operator stopped the printing machine each time, measured the machine, adjusted the machine accordingly, and managed the printing quality offline.
JP-A-7-323526 JP-A-7-323525

  In view of the above, the present invention converts a reflected light amount signal from a signal detection device attached to a printing press into density value data used for printing management, and provides image density data as a reference prepared in advance. It is intended to propose a method and apparatus for making an on-line comparison and confirmation instantly and adjusting a printing press.

The present invention is an on-line print adjustment device for inspecting the quality of printed matter being printed by a printing press and adjusting the printing state of the printing press, comprising a light emitting element and a light receiving element installed in the printing press, and a printed image of the printed matter. A first input means for reading information by separating it into three primary colors, or three primary colors and an infrared color;
Conversion means for converting the three primary colors, or the three primary colors and the infrared color into print density values;
A second input means for inputting the density value for the print image prepared in advance in consideration of the print state;
An analysis unit that compares the value obtained by the conversion unit with the value input from the second input unit, and converts the value into information necessary for quality control of the printing press;
According to the result obtained by the analyzing means, an adjusting means for adjusting the printing press in real time during operation of the printing press;
Display means for displaying the results obtained by the analyzing means in real time;
The present invention relates to an on-line print adjustment apparatus.

  Further, according to the present invention, the first input means irradiates the print image with light of three primary colors or three primary colors and infrared light from three or four types of light emitting elements when the printing press is operated, By continuously detecting the print image using the light receiving element that reacts to the light provided in the input means and averaging the detected signals, the signals of the three primary colors or the three primary colors and the infrared color of the print image are obtained. The present invention relates to the above-described online print adjustment apparatus.

  In the present invention, the conversion unit converts the three primary colors of the print image obtained from the first input unit or signals of the three primary colors and the infrared color into a print density by a logarithmic approximation formula. The present invention relates to an adjusting device.

  In the present invention, the second input means converts the RGB value or CMYK value of the print image to be targeted into a density value reproduced by a printing machine using a known color management system. The present invention relates to a certain online printing adjustment apparatus.

In the present invention, the analyzing means compares the density value obtained by the converting means with the density value obtained by the second input means, and whether or not the analyzing means conforms to a preset density management reference value. The present invention relates to the above-mentioned online print adjustment apparatus that analyzes the image in real time and converts it into the density adjustment amount of the printing press.

According to the present invention, in view of the above points, a reflected light amount signal from a signal detection device attached to a printing press is converted into density value data used for print management, and a reference image density prepared in advance. This has the effect of making it possible to instantly compare and check data and online and adjust the printing press.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an example of the configuration of the apparatus of the present invention. The apparatus includes a first input unit installed on a printing machine for capturing an image, an inspection unit for comparing and analyzing the input image with a reference prepared in advance and inspecting the print density, and a printing machine in real time according to the inspection result An adjustment unit for adjusting the density and a display unit for displaying the inspection result are included.

  The first input unit as the first input means includes a light emitting element and a light receiving element. As the light emitting element, for example, three colors of light of red, green, and blue, or four colors of red, green, blue, and infrared are used. It is possible to use a light emitting diode such as an LED that can irradiate the light. The three or four colors are not particularly limited as long as data conversion described later is possible, but the RGB three primary colors are preferable in terms of convenience and the like, and the RGB three primary colors will be described below as representative examples.

  The light emitting element irradiates a printed material during operation of the printing press. The light emitting element is not particularly limited as long as it can monitor the printed matter, and may be inside or outside the printing press. Irradiation may be direct irradiation or via a mirror or a color filter. Irradiated and reflected light is detected by the light receiving element. The positional relationship among the light emitting element, the printed material, and the light receiving element is not particularly limited as long as the printed image can be detected. For example, it arrange | positions so that it may reflect in the running direction of the base material printed. As the light receiving element, a semiconductor element that reacts to light, such as a CCD, a CMOS, or a photodiode, can be used. Further, it can also be used when a light-emitting element or a light-receiving element that is more effective in the future is developed.

  The light-emitting element may be one light-emitting element capable of emitting two or more colors by filter replacement or the like, or may be one light-emitting element for one color. The light receiving element may be capable of receiving two or more colors by exchanging filters or the like, or may be one light receiving element for one color. There is no particular limitation on the order of the colors to be irradiated, and light of several colors may be simultaneously irradiated as long as the reading can be performed independently on the apparatus.

  There may be one first input unit or two or more first input units in the online print adjustment apparatus. For example, the first input unit may be arranged at equal intervals in the horizontal direction of the paper to be printed.

  The inspection unit which is a main part of the apparatus includes an instruction unit, a conversion unit which is a conversion unit, a second input unit which is a second input unit, an analysis unit which is an analysis unit, and a storage unit. The inspection unit may be a normal personal computer to which an instruction unit such as a keyboard is connected. From the instructing unit, a start signal for data input to the first input unit and the second input unit, the start of inspection to the conversion unit, the analysis unit, and the storage unit, setting of various inspection conditions, and instructions are performed. Also, the inspection result output to the display unit may be made from the instruction unit.

The conversion unit converts the RGB three primary color signals into density values for printing CMYK (cyan, magenta, yellow, black) by, for example, logarithmic approximation.
Using (Equation 1)

denC = a ln (R) + b
denM = a'ln (G) + b '(Formula 1)
deny = a "ln (B) + b"

The characteristics of the light receiving element of the input device are set in advance as variables a, a ′, a ″, b, b ′, b ″, and the input RGB signal is converted into the output density signal den at the time of conversion. In addition to the logarithmic approximation method, a function approximation method using a second-order, third-order, or polynomial function may be used.

  The second input unit inputs a density value that serves as a reference for an image to be printed. The reference density value is prepared by taking into account the printing characteristics and printing conditions of the printing machine to which this apparatus is connected. Usually, the RGB value or CMYK value of the print image to be targeted is commercially available. A density value converted by a known color management system can be used. In addition, as a reference density value, a standard value in standard printing, a value of a different printing machine, or a value at a different time of the same printing machine may be used.

  The analysis unit compares both density values obtained from the conversion means and the second input unit, analyzes in real time whether the density management reference value is set in advance, and is necessary for adjusting the printing press. It is possible to convert it into various information.

  The adjustment unit, which is an adjustment means, adjusts the printing machine according to the information necessary for adjustment of the printing machine obtained by the analysis unit. For example, according to the density adjustment amount data, the ink amount control key or the printing with water In this case, it controls the printing press adjusting system such as the water supply amount.

  Note that the inspection unit preferably includes a storage unit. The storage unit stores the analysis result as digital data.

  Further, the display unit, which is a display unit, displays the inspection results sequentially sent from the inspection unit during operation of the printing press in real time, and a monitor or a printer can be used.

FIG. 2 is an example of a flowchart showing processing of the online print adjustment apparatus.
First, the reference density value input at the second input unit and the print density management reference value for managing it are taken into the inspection unit. These values are input using, for example, a network, various storage media, or the instruction unit. Next, printing of the image is started. By sending an analysis start instruction from the inspection unit to the first input unit during operation of the printing press, the image input of the first input unit starts.

  Next, the print image data consisting of four primary colors RGB, or three primary colors plus an infrared color, sequentially sent in accordance with the operation of the printing machine is averaged according to a predetermined number of readings, and then logarithmically. The density is converted to the density value of printing CMYK (cyan, magenta, yellow, black) by an approximation method.

  Then, the converted density value and the reference density value input by the second input unit are transmitted to the analysis unit.

  The analysis unit derives a density difference or the like from the two image density values, and displays a result of comparative analysis such as a deviation from the reference density value on a display unit such as a monitor or a printer. At this time, the adjustment unit transmits the analysis result as a signal to the inking device for adjusting the ink supply amount provided in the printing press only when there is a problem such as a large deviation from the print density management reference value. Controls the press adjustment system such as the ink amount control key to adjust to the optimum ink supply amount.

  Finally, when the analysis result is stored, it can be stored in the storage unit in a reusable form by a storage instruction.

FIG. 1 shows an example of the configuration of the apparatus. FIG. 2 shows an example of a flowchart showing a printed matter inspection process.

Claims (5)

An online printing adjustment device that inspects the quality of printed matter being printed on a printing press and adjusts the printing status of the printing press,
A first input means comprising a light-emitting element and a light-receiving element installed in a printing press, wherein the print image information of a printed matter is separated into three primary colors, or three primary colors and an infrared color and read;
Conversion means for converting the three primary colors, or the three primary colors and the infrared color into print density values;
A second input means for inputting the density value for the print image prepared in advance in consideration of the print state;
An analysis unit that compares the value obtained by the conversion unit with the value input from the second input unit, and converts the value into information necessary for quality control of the printing press;
According to the result obtained by the analyzing means, an adjusting means for adjusting the printing press in real time during operation of the printing press;
Display means for displaying the results obtained by the analyzing means in real time;
An on-line printing adjustment apparatus comprising: The first input means can irradiate the printed image with light of three primary colors or three primary colors and infrared light from three or four types of light emitting elements when the printing press is operating, and each input light quantity can be provided in the input means. A print image is continuously detected using a light receiving element that reacts to the light, and the detected signals are averaged to obtain signals of the three primary colors or the three primary colors and the infrared color of the print image. The online printing adjustment apparatus according to claim 1. 3. The online system according to claim 1, wherein the converting means converts the signals of the three primary colors or the three primary colors and the infrared color of the print image obtained from the first input means into a print density by a logarithmic approximation formula. Print adjustment device. 4. The second input means converts and calculates from a RGB value or CMYK value of a print image to be targeted into a density value reproduced by a printing machine using a known color management system. The online printing adjustment apparatus described in any one. The analysis means compares the density value obtained by the conversion means with the density value obtained by the second input means, and analyzes in real time whether or not it conforms to a preset density management reference value. The on-line printing adjustment apparatus according to claim 1, wherein the on-line printing adjustment apparatus converts the density adjustment amount into a printing machine density adjustment amount.

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