JP2957678B2 - Plate pattern area ratio measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Constitution of the Invention] (Field of Industrial Application) The present invention relates to a plate image area ratio measuring device.

(Prior Art) A device that irradiates a printing plate with light, measures the amount of reflected light, and measures the pattern area ratio of the printing plate based on the measured value is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-77609. Are known.

(Problems to be Solved by the Invention) However, in the pattern area ratio measuring device, prior to measuring the pattern area ratio of the printing plate, the reference portion of the printing plate is set by the plate setting device using the plate setting device. It is necessary to match the reference setting and thereby position the printing plate at a specific position with respect to the plate support means.

For this reason, in the conventional apparatus, there is a problem that the configuration of the apparatus for positioning the printing plate is complicated, the positioning operation time is required, and the operation rate of the apparatus is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plate pattern area ratio measuring device capable of measuring a pattern area ratio even when the plate is not positioned at a specific position with respect to the plate supporting means.

[Constitution of the Invention] (Means for Solving the Problems) According to the first aspect of the present invention, there is provided a plate supporting means for supporting a plate, and a specific positional relationship with respect to the plate supporting means. An irradiation device disposed on the printing plate and a detection head having a sensor array for receiving reflected light from the printing plate, a moving device for relatively moving the detection head and the printing plate,
A storage device for storing output values from individual sensors constituting the sensor array for each predetermined relative movement amount during the relative movement, a plate inclination detecting device for detecting an inclination state of the plate with respect to the sensor array direction, A plurality of ink adjusters included in a printing machine of the printing plate in accordance with the inclination of the printing plate on the printing plate support means, based on a detection value of the printing plate inclination detection device and a known size of the printing plate. And, from the output value group stored in the storage device, select an output value for each of the obtained areas for each of the areas, and, based on the selected output value, a pattern area for each area. And an arithmetic unit for calculating the rate.

According to a second aspect of the present invention, a sensor array of a detection head is used as a plate inclination detection device.

(Operation) According to the present invention, the plate inclination state of the detection head with respect to the sensor row direction is detected by the plate inclination detection device.
Then, based on the detected value of the plate inclination detecting device and the known dimensions related to the plate, the arithmetic unit selects the sensor output value from each region of the plate corresponding to each ink adjuster from the storage device for each region. Then, the pattern area ratio for each region is calculated based on the selected output value.

(Embodiment) FIG. 1 is a schematic diagram showing a pattern area ratio measuring system of a printing plate, FIG. 2 is a schematic diagram showing an operation state of the pattern area ratio measuring system, and FIG. 3 is a pattern area ratio detecting head. FIG. 4 is a schematic diagram showing the principle of detecting the inclination angle of the plate inclination detecting device, and FIGS. 5A and 5B are schematic diagrams showing the principle of detecting the inclination direction of the plate inclination detecting device. The figure is a schematic diagram showing the principle of calculating the pattern area ratio by the arithmetic unit, and FIG.
(C) is a schematic diagram showing the calculation processing of the position of each region of the printing plate, and FIG. 8 is a schematic diagram showing the principle of correcting the received light value at the periphery of the printing plate region.

1 and 2, reference numeral 11 denotes a developing device, and reference numeral 12 denotes a picture area ratio measuring device.

The developing device 11 develops and fixes the printing plate 13 on which the image of the original film is printed. In FIG. 1, reference numeral 11A denotes a developing solution supply nozzle, 11B denotes a washing nozzle, 11C denotes a fixing solution supply nozzle, 11D denotes a washing nozzle, and 11E denotes a drying roller. At this time, as shown in FIG. 2, the printing plate 13 is provided with a calibration mark 13A used for measuring the pattern area ratio and an identification mark 13B such as a barcode in its sub-zone 13C.

The picture area ratio measurement device 12 includes a plate transport device 14, a detection head 16, a storage device 17, and an arithmetic device 18.

The plate transport device 14 has both a function as a plate supporting means for supporting the plate 13 and a function as a moving device for relatively moving the plate 13 with respect to the detection head 16.

Specifically, as shown in FIG.
The printing plate 13 is placed on a plurality of rotating rollers 21 arranged side by side, and is supported and transported. In FIG. 1, 21A is an encoder.

At this time, the plate transport device 14 provides an air chamber 22 that is substantially closed except for the plate transport surface region below and outside the plate transport surface formed by the rotating roller 21. In addition, the plate transport device 14
Has an exhaust fan 28 at the bottom of each air chamber 22. When the printing plate 13 is transported, the exhaust fan 28
The air pressure inside the air chamber 22 is adjusted so that the air pressure acting on the surface on the side of the rotating roller 21 is higher than the air pressure acting on the surface on the side of the rotating roller 21. As a result, the plate transport device 14 presses the plate 13 against the rotating roller 21 due to the difference in air pressure acting on the surface of the printing plate 13 on the side of the anti-rotation roller 21 and the surface of the printing plate 13 on the side of the rotation roller 21. And as a result, the printing plate
The contact resistance between the roller 13 and the rotating roller 21 is increased, and the printing plate 13 can be transported without slippage.

The detection head 16 is disposed above the plate transport device 14 in a specific positional relationship, and receives an irradiation device 31 for the plate 13 and a light reflected from the plate 13 as shown in FIG. Sensor row
32. With this, in the detection head 16, for each predetermined relative movement amount of the plate 13 by the plate transport device 14, each sensor 33 of the sensor array 32 outputs a light reception value received from reflected light of a corresponding detection area. it can. In FIG. 3, A to E defined in the printing plate 13 are areas corresponding to a plurality of ink adjusters of the printing press.

The storage device 17 stores an output value from each sensor 33 of the detection head 16 for each predetermined relative movement amount of the printing plate 13 when the printing plate 13 is relatively moved with respect to the detection head 16.

At this time, the detection head 16 also functions as a plate inclination detecting device, and the inclination angle of the plate 13 with respect to the direction of the sensor row 32,
The inclination direction is detected as shown in (A) and (B) below, and is conveyed by the plate conveying device 14 as described above, and is detected by the detection head 16.
Thereby, the inclination state of the printing plate 13 receiving the reflected light can be detected.

(A) The inclination angle of the printing plate 13 (see FIG. 4) At this time, at the position facing the sensor row 32,
A reflection plate having a high reflectance is laid below the transfer mounting surface. Thereby, the light reception value voltage of the sensor 33 is as follows.

When the printing plate 13 is not provided below the sensor array 32, the amount of light reflected from the reflector is large, so the received light voltage of the sensor 33 is a high voltage P (V). When there is, since the amount of reflected light from the non-pattern portion is medium, the light reception value voltage of the sensor 33 is Q (V) of the medium voltage.
Since the amount of light reflected from the picture portion is small, the light reception value voltage of the sensor 33 is low (R (V)). In FIG. 4, the sensor 33 of No. (u-1) (u: the direction of the sensor row 32 (Y axis) The light-receiving value voltage at the position (on the direction)) is almost equal to Q (V) representing the non-pattern portion of the printing plate 13;
Since the received light voltage of the (u + 1) sensor 33 is P (V) indicating the absence of the printing plate 13, the leading edge of the printing plate 13 is the sensor of No. (u) sandwiched between the two sensors. It will be caught at 33. Then, after the plate 13 has been moved by Δl (Δl can be measured by the encoder 21A of the plate transport device 14), the sensor for catching the front edge of the plate 13 is No. (u +
Suppose that the sensor 33 of 3) is used. At this time, assuming that the interval between the sensors is p, the inclination angle θ of the printing plate 13 is expressed by the following equation (1).

θ = tan ⁻¹ (△ l / 3p) (1) (B) The inclination direction of the printing plate 13 (see FIGS. 5A and 5B). Each sensor
With respect to the received light value voltage of 33, the storage data of the storage device 17 is subjected to the binarization processing of “1” or “0” depending on whether the data is P (V) or not, and as shown in FIG. By detecting the boundary between "" and "0", the inclination direction of the printing plate 13 can be detected.

As another method, among the light reception value voltages of the sensors 33, the voltage of P (V) is not stored in the storage device 17, and the storage data of the storage device 17 exists as shown in FIG. By detecting the outermost peripheral line of the distribution, the inclination direction of the printing plate 13 can be detected.

The arithmetic unit 18 is a detection head as a plate inclination detecting device.
16 detection values (tilt angle and tilt direction of plate 13) and plate
On the basis of the known dimensions of the printing plate 13, the printing plate 13 is obtained from the output value group of each sensor 33 of the detection head 16 stored in the storage device 17.
The output values for each of the regions A to E described above are selected for each region, and the pattern area ratio for each region is calculated based on the selected output value.

Here, the arithmetic unit 18 calculates the image area ratio of the printing plate 13 from which the inclination angle and the inclination direction are detected, specifically, the following (1) to (1).
The calculation is performed as in (3).

(1) For example, the coordinate axes X and Y as shown in FIG. In the case of FIG. 6, the coordinate origin (0,0) is set at a position facing the lowermost sensor 33A on the sensor array 32. Thereby, the position of each sensor 33 can be set on the coordinates (the X coordinates are all 0). Further, although the printing plate 13 actually moves, if the sensor array 32 is considered to move, in FIG.
Each time it moves, the received light value of each sensor 33 is stored in the storage device 17 together with the coordinate value of the detected position. For example, the received light value at the detection position (xi, yi) is stored as m (V).

(2) Next, the positions of the respective areas A to E of the printing plate 13 in the inclined state and the positions of the calibration marks 13A can be calculated as follows.

First, in the state as shown in FIG. 7A where the printing plate 13 has no inclination, for example, the corner a of the printing plate 13 is set to the coordinate origin (0,0) from the known dimensions of the printing plate 13 which has been input in advance. )
For example, four corner positions (X1, Y1) of area A ... (X4, Y
4) and the position of the calibration mark 13A (Xa, Ya) ...
(Xd, Yd) can be calculated as coordinate values.

Further, as shown in FIG. 7 (B), when the plate 13 is rotated by an angle θ about the corner a, the four corner positions of the area A and the position of the calibration mark 13A are coordinate values by coordinate conversion. Can be calculated as

Further, as shown in FIG. 7 (C), when the corner a of the printing plate 13 in FIG. 7 (B) is translated from the coordinate origin (0,0) to the coordinate (0, k), the same applies. By the coordinate transformation, the four corner positions of the area A and the position of the calibration mark 13A are coordinate values (x1, y1)... (X4, y4),
(Xa, ya) ... can be calculated as (xd, yd).

(3) After calculating the positions of the areas A to E and the calibration marks 13A for the printing plate 13 in the inclined state as described above, the pattern area ratio of each area is obtained as follows. The area A will be described.

The area A is an area surrounded by four points (x1, y1)... (X4, y4). Therefore, a light reception value corresponding to a coordinate value existing in the area A is selected from the light reception value group stored in the storage device 17 based on the coordinate values stored together with the respective light reception values.

The received light value for the calibration mark 13A is selected in the same manner.

Then, the light reception value group selected as the light reception value in the area A is averaged, and the average light reception value and the calibration mark are averaged.
The pattern area ratio of the area A is calculated from the calibration value of 13A.

 Next, the operation of the above embodiment will be described.

According to the above embodiment, the state of inclination of the plate 13 with respect to the direction of the sensor array 32 of the detection head 16 is detected by the detection head 16 which also functions as a plate inclination detection device. Then, based on the inclination state of the printing plate 13 detected by the detection head 16 and the known dimensions of the printing plate 13, the arithmetic unit 18 detects the sensor 33 from each region of the printing plate 13 corresponding to each ink adjuster.
An output value is selected from the storage device 17, and a pattern area ratio for each region is calculated based on the selected output value.

Therefore, the printing plate is placed at a specific position with respect to the Saipan transport device 14.
Even if 13 is not positioned, the pattern area ratio can be measured.

In the above embodiment, for example, in calculating the pattern area ratio of the area A, first, four corner coordinate values (x1, y1)... (X4, y4) of the area A are obtained, and then the area is surrounded by the coordinate values. The received light value corresponding to the coordinate value in the region to be selected is selected from the stored value 17, and the pattern area ratio is obtained from the average value of the selected received light values.

However, in the case of the above embodiment, as shown in FIG. 8, in the calculation of the area A, the received light value of the coordinate value (xp, yp) is a part of the detection area (range of one square) in the area A. However, since the coordinates (xp, yp) are outside the area A, they are not used at all in the calculation of the pattern area ratio of the area A. Conversely, the received light value of the coordinate value (xr, yr) is used for calculating the pattern area ratio of the area A as it is, even though a part of the detection area is out of the area A. It is to be done.

Therefore, in order to improve the calculation accuracy of the pattern area ratio, the selection of the received light value from the storage device 17 may be performed as follows. That is, in consideration of the detection area of each sensor, if a part of the detection area is within the area A, the received light value is used when calculating the picture area ratio. However, weighting is performed.

The weighting described above is, for example, in the case of coordinate values (xP, yP),
The ratio pa / (pa + p0) of the area (pa) belonging to the area A to the detection area (pa + p0) is multiplied by the light receiving value of the coordinate value (xp, yp), and the result of the multiplication is used for calculating the picture area ratio.

In the case of the coordinate value (xr, yr), the detection area (ra + r)
Ratio of area (ra) belonging to area A to 0)
(Ra + r0) multiplied by the received light value of the coordinate value (xr, yr),
The result of the multiplication is used for calculating the pattern area ratio.

Although the calculation accuracy of the pattern area ratio is reduced, the above coordinate values (x
In the case of (p, yp) and (xr, yr), the light receiving amount of those coordinate values may be multiplied by, for example, 50%, and the result of the multiplication may be used for the calculation of the pattern area ratio.

Further, in the above embodiment, since the detection head of the pattern area ratio is also used as the plate inclination detection device,
The device configuration can be simplified. However, in the embodiment of the present invention, a dedicated device can be used as the plate inclination detecting device.

[Effects of the Invention] As described above, according to the present invention, it is possible to obtain a plate pattern area ratio measuring device capable of measuring a pattern area ratio even when the plate is not positioned at a specific position with respect to the plate supporting means. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a plate image area ratio measuring system,
FIG. 2 is a schematic diagram showing an operation state of the pattern area ratio measuring system, FIG. 3 is a schematic diagram showing a pattern area ratio detection head, and FIG.
The figure is a schematic diagram showing the principle of detecting the inclination angle of the plate inclination detection device,
5 (A) and 5 (B) are schematic diagrams showing the principle of detecting the inclination direction of the plate inclination detecting device, FIG. 6 is a schematic diagram showing the principle of calculating the picture area ratio by the arithmetic device, and FIGS. FIG. 8C is a schematic diagram showing the principle of calculating the position of each region of the printing plate, and FIG. 8 is a schematic diagram showing the principle of correcting the received light value at the periphery of the region of the printing plate. 12… Pattern area ratio measurement device, 13… Print plate, 14… Print plate transport device, 16… Detection head, 17… Storage device, 18… Computing device.

Claims (2)

(57) [Claims] 1. A printing plate supporting means for supporting a printing plate, a device for irradiating the printing plate, which is disposed in a specific positional relationship with respect to the printing plate supporting means, and receiving reflected light from the printing plate. A detection head having a sensor array to be moved, a moving device for relatively moving the detection head and the printing plate, and an output value from each sensor constituting the sensor array during the relative movement is stored for each predetermined relative movement amount. A printing plate tilt detecting device for detecting a tilt state of the printing plate with respect to the sensor row direction, and a printing plate support means based on a detection value of the printing plate tilt detecting device and a known dimension of the printing plate. According to the inclination of the printing plate, an area corresponding to each of the plurality of ink adjusters of the printing press in the printing plate is obtained, and the individual area obtained from the output value group stored in the storage device is obtained. Out about With selecting a value for each said region, the plate image area ratio measuring apparatus according to Mezzanine further comprising an arithmetic unit for calculating the pattern area ratio of each area based on the selected output value. 2. The plate picture area ratio measuring device according to claim 1, wherein a sensor array of a detection head is used as the plate inclination detecting device.