JPH04353451A - Apparatus for measuring pattern area ratio of press plate - Google Patents

Abstract

PURPOSE:To provide the apparatus capable of regulating the key opening degree of each ink key so as to approach desired printing quality as near as possible. CONSTITUTION:An imaging means 11 takes the images of respective color press plates 10 exposed on the basis of patterns 3 at every press plates 10 and memory means 14-17 store the intensities of the reflected lights from the press plates 10 in the addresses thereof at every pixels. An image signal constructing means constructs color image signals based on the intensities of the reflected lights from the press plates 10 and a display means 22 displays images based on the color image signals. Reflected light intensity regulating and altering means 23-26, 32-34 are prepared corresponding to the memory means 14-17 in order to regulate and alter the key opening degree of an ink key 2 while the patterns 3 displayed on the display means 22 is looked to regulate and alter the intensities of the reflected lights at every pixels of the memory means 14-17. A key opening degree data operation means 29 calculates respective pattern area ratios on the basis of the intensities of the reflected lights stored in the memory means 14-17 to obtain key opening degree data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing plate pattern area ratio measuring device for measuring the pattern area ratio of a printing plate such as a PS plate.

0002

[Prior Art] Conventionally, when printing a pattern on printing paper by supplying ink to a printing plate such as a PS plate wound around a plate cylinder, printing defects due to excessive supply of ink to the plate cylinder,
In order to prevent printing defects due to insufficient supply of ink to the plate cylinder (so-called curling), the amount of ink supplied to the printing plate is adjusted by adjusting the opening degree of the ink key.

FIG. 1 is an explanatory diagram schematically showing the correspondence relationship between printing paper and ink keys. In FIG. 1, 1 indicates printing paper,
2 is an ink key, and 3 is a circular pattern printed on the printing paper 1, for example. The ink key 2 is used to adjust the amount of ink supplied to the printing paper 1. Each ink key 2' corresponds to a divided area (1 to n) that is virtually equally divided into the width of the printing paper 1 in the direction perpendicular to the conveyance direction, and this divided area (1 to n) is a division of each printing plate. There is a one-to-one correspondence with the area.

The key opening degree of each in-key key 2' is determined with respect to the picture area ratio (hereinafter referred to as area ratio) of each divided area 1 to n, and each area ratio is determined based on the area ratio of each area of each area 1 to n. It is determined based on the proportion of the drawing area of the pattern 3 printed in the area.For example, if the area of the i-th divided area is b, and If the area of the drawing part is a, the area ratio S of the i-th divided area is a
Defined by /b. The opening degree of each ink key 2' is set for each area ratio, and the amount of ink supplied to each divided area 1 to n is set according to the opening degree.

[0005]

However, there is not necessarily a one-to-one linear correspondence between the area ratio and the opening degree of the ink key 2, and it varies from printing machine to printing machine and from worker to worker. As a rough guide, area ratio and ink key 2
The relationship between the area ratio and the opening of the ink key 2 is determined so that the desired print quality can be obtained by repeating trial printing over and over again, which makes trial printing time-consuming. . Further, the customer may request changes to the print quality based on the finished result of the proof print. In such a case, it is possible to change the tone of the printed matter by changing the amount of ink supplied without remaking the printing plate, but it is necessary to perform trial printing one by one and finely adjust the opening degree of each ink key 2'. This is troublesome and requires a great deal of effort and time to adjust the opening of each in-key key 2'.

Therefore, an object of the present invention is to perform trial printing many times to check the printing quality of the image, and to adjust the printing quality of each ink key as close as possible to the desired print quality without having to adjust the opening degree of each ink key. An object of the present invention is to provide a printing plate pattern area ratio measuring device that can adjust the key opening degree.

[0007]

[Means for Solving the Problems] The device for measuring the picture area ratio of a printing plate according to the present invention includes a photographing means for photographing each printing plate for color printing which has been exposed based on the picture; each storage means for storing the reflected light intensity of each printing plate prepared corresponding to the printing plate and photographed by the photographing means at each address for each pixel; and the reflected light intensity of each of the storage means for each storage means. a color image signal construction means for constructing a color image signal based on the reflected light intensity of each of the printing plates; a display means for displaying an image based on the color image signal output from the color image signal construction means; A predetermined relationship is given between the image area ratio, which is defined as the ratio of the area of the print area to the area of the divided area of each printing plate divided corresponding to each ink key that adjusts the ink supply amount. In order to adjust and change the key opening degree while viewing the picture displayed on the display means, reflected light intensity adjustment is prepared corresponding to each of the storage means and adjusts and changes the reflected light intensity for each pixel of each storage means. The present invention is characterized by comprising: a changing means; and a key opening degree data calculation means for calculating the respective picture area ratios based on the intensity of reflected light stored in the respective storing means to obtain key opening degree data. .

[0008]

According to the device for measuring the picture area ratio of a printing plate according to the present invention, the photographing means photographs each color printing plate exposed to light based on the picture. Each storage means is prepared corresponding to each printing plate and stores the reflected light intensity of each printing plate photographed by the photographing means at each address for each pixel. The color image signal construction means reads the reflected light intensity of each pixel of each storage means and constructs a color image signal based on the reflected light intensity of each printing plate. The display means displays an image based on the color image signal output from the image signal construction means. On the other hand, the reflected light intensity adjustment and change means prepared in correspondence with each storage means can adjust and change the reflected light intensity for each pixel of each storage means, and is made to correspond to each ink key that adjusts the ink supply amount. The pattern displayed on the display means has a predetermined relationship between the key opening degree and the area ratio defined as the ratio of the area of the drawing area of the pattern to the area of the divided area of each divided printing plate. It is used to make changes and adjustments while looking at the

The operator compares the proof print with the image displayed on the display means and adjusts the reflected light intensity at each address of each storage means using the reflected light intensity adjustment/changing means so that the image approaches the desired print quality. Correct. Based on this result, the key opening degree data calculation means calculates the virtual area ratio of each divided area based on the intensity of the reflected light stored in each storage means to obtain key opening degree data.

0010

EXAMPLE In FIG. 2, numeral 10 indicates each printing plate such as a PS plate which has been exposed, Y is a yellow plate, M is a magenta plate, C is a cyan plate, and K is a black plate. Each of the Y, M, C, and K plates has an image area and a non-image area formed in correspondence with the pattern, and the reflectance of the image area is lower than that of the non-image area. The Y, M, C, and K versions each have a CCD camera 11 as a photographing means.
Photographed by. The CCD camera 11 outputs a voltage corresponding to the intensity of reflected light for each pixel. The respective voltages are applied to each Y,
The images are input to frame memories 14 to 17, which serve as storage means dedicated to the M, C, and K versions. Each frame memory 14-17
At each address, there is a voltage value (
(hereinafter referred to as reflected light intensity data) is stored.

The reflected light intensity data of each of the frame memories 14 to 17 is sequentially inputted via a reading circuit 18 to a color image signal processing circuit 19 serving as color image signal construction means. The color image signal processing circuit 20 has Y, M, C,
It has a matrix circuit that converts each reflected light intensity data information of K into R, G, and B signal information, and has a matrix circuit that converts each reflected light intensity data information of
The information signal is converted into an image signal by the A/D converter 21,
Pattern 3 based on each printing plate Y, M, C, K10 is displayed on the display means 2
2.

Each reflected light intensity data stored in each address of each of the frame memories 14 to 17 is adjusted and changed by adjusting circuits 23 to 26 as reflected light intensity adjusting and changing means. Dedicated frame memory 1
The adjustment circuit 24 changes the reflected light intensity data stored in each address of the frame memory 15 dedicated to M, and the adjustment circuit 25 changes the reflected light intensity data stored in each address of the frame memory 15 dedicated to M. The reflected light intensity data stored in each address of the frame memory 16 is changed, and the adjustment circuit 26 changes the reflected light intensity data stored in each address of the K-dedicated frame memory 17. Data input to each of the adjustment circuits 23 to 26 is performed by an operation panel 27 that constitutes a part of the reflected light intensity adjustment and change means. The output data of each adjustment circuit 23-26 is inputted to each frame memory 14-17 via a write circuit 28. Based on the adjustment change of the reflected light intensity data,
The hue, saturation, and brightness of the image are changed. The operator compares the image displayed on the display means 22 with the image on the proof sheet and determines whether or not the print quality is close to the desired print quality.

The reflected light intensity data at each address of each frame memory 14 to 17 is sent to the CPU via a reading circuit 18.
29. The CPU 29 integrates the reflected light intensity data stored at each address for each divided area, and calculates the standard total reflected light amount data for that divided area (inside the divided area when no pattern is formed in that divided area). (total reflected light amount data). The division data obtained for each divided area corresponds to an area ratio defined as the ratio of the area of the picture portion to the area of each divided area of each printing plate 10. This area ratio data for each divided area of each printing plate 10 is converted into key opening data, which will be described later, and is stored in, for example, a floppy disk 31 via a writing circuit 30. For example, as shown in FIG.
, M, C, and K, a curve R is given in advance as a predetermined relational expression between the area ratio and the key opening degree. This curve R uses data accumulated up to now through proof printing by operators. The white circle indicates the relationship between the area ratio based on the proof and the opening degree of the ink key 2. The curve R is set slightly lower for each data of this proof in order to avoid oversupply of ink.

Here, for example, the hue, saturation, and brightness of the picture displayed on the display means 21 can be adjusted by appropriately adjusting the reflected light intensity of a certain address group corresponding to each printing plate Y, M, C, and K. Suppose you change . As a result, for example, if the area ratio is changed from 10% to 15%, the opening degree of the in-key key 2 is changed from A1 to A2. Also, as a result, if the area ratio value is changed from 20% to 25%, for example,
The key opening degree of the in-key key 2' is changed from B1 to B2. That is, the CPU 29 functions as a key opening degree data calculation means that calculates each area ratio based on the intensity of reflected light stored in each storage means and obtains key opening degree data.

If these change adjustment data are stored in the floppy disk 31 and the key opening degree data stored in the floppy disk 31 is used as preset data to drive the printing device, the desired print quality can be achieved as close as possible. In this state, the opening degree of the in-key key 2 can be adjusted. Therefore, when performing regular printing, the operator can reduce the amount of time required for final adjustment of color tone.

FIG. 4 shows a second embodiment of the printing plate pattern area ratio measuring device according to the present invention, in which adjusting circuits 32, 33, and 34 for adjusting R, G, and B signals are used as reflected light intensity adjusting and changing means. R, G, B signal generation circuits 32', 33', 3
4', thereby adjusting and changing the hue, saturation, and brightness of the picture displayed on the display means 22 based on the R, G, and B signals. By converting the reflected light intensity data of each printing plate Y, M, C, and K into reflected light intensity data and writing it into each frame memory 14 to 17, the reflected light intensity data of each address corresponding to the changed picture area is rewritten. This is what I did.

[0017] The tone of the picture is highlight, middle,
It may be possible to change it for each area of the shadow.

[0018]

Effects of the Invention As explained above, the printing plate pattern area ratio measuring device according to the present invention allows each ink key to be opened while looking at the screen so that the pattern can be printed as close to the desired print quality as possible. Since the structure is configured so that each area ratio corresponding to the degree can be changed, the print quality can be as close as possible to the desired one without having to adjust the key opening degree of the ink key while checking the print quality of the image by repeatedly making trial prints. This has the effect that the key opening degree of the in-key key can be adjusted in a state where the in-key key is opened.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the correspondence between printing paper and ink keys.

FIG. 2 is a block circuit diagram of a printing plate area ratio adjusting device according to the present invention.

FIG. 3 is a schematic diagram for explaining the relationship between area ratio and key opening degree.

FIG. 4 is a block circuit diagram showing another example of the printing plate area ratio adjusting device according to the present invention.

[Explanation of symbols]

10 Printing plates 14 to 17 Frame memory (storage means) 20 Image signal processing circuit 22 Display means

Claims (1)

[Claims] 1. Photographing means for photographing each printing plate for color printing exposed based on a pattern, and each printing plate prepared corresponding to each printing plate and photographed by the photographing means. each storage means for storing the reflected light intensity of each printing plate at each address for each pixel; and each storage means reads the reflected light intensity of each of the storage means and constructs a color image signal based on the reflected light intensity of each printing plate. color image signal construction means;
A display means for displaying an image based on the color image signal output from the color image signal construction means, and an image displaying means for displaying an image based on the color image signal outputted from the color image signal construction means, and an image for the area of the divided region of each printing plate divided correspondingly to each ink key for adjusting the ink supply amount. In order to adjust and change the key opening degree, which has a predetermined relationship with the picture area ratio defined as the percentage of the area of the line part, while viewing the picture displayed on the display means, reflected light intensity adjusting and changing means prepared in correspondence and adjusting and changing the reflected light intensity for each pixel of each storage means; and calculating the respective picture area ratios based on the intensity of the reflected light stored in each of the storage means. A device for measuring the picture area ratio of a printing plate, comprising: a key opening degree data calculation means for obtaining key opening degree data.