JPH0623969A - Device for monitoring both-face printed matter - Google Patents

Abstract

PURPOSE:To monitor register marks on both faces with one set of a flashing light source and an image pickup means. CONSTITUTION:A television camera 4 and a strobo 2, which hold therebetween a printing matter 1 with register marks 2 printed thereon, are provided so as to be opposed to each other. A light emitting pulse, which has corrected time when the register marks 2 come to a position of the television camera 4, is generated by an encoder pulse delay circuit 6 on the basis of the output of an encoder 5 adapted to detect the positions of the register marks 2 and, according to the light emitting pulse, the strobo 3 is permitted to emit light. A write signal generating circuit 8, which receives the light emitting signal and a vertical synchronizing signal from a synchronizing signal generating circuit 7, generates a write signal by which an image memory 9 writes therein a video signal from the television camera 4. An image display unit 10 displays the content of the image memory 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided printed matter monitoring apparatus for monitoring features printed on both sides.

[0002]

2. Description of the Related Art Many business forms such as slips are printed on both the front and back sides, and most of them place importance on the relationship between the front and back sides. Many. For this reason, it is necessary to detect the deviation between the front and back in the running state.

As an inspection method for an object that moves at high speed,
The object is irradiated with a momentary flashlight such as a stroboscope, the instantaneous image obtained thereby is accumulated on the imaging surface of the image sensor, and the image signal for one scan is stored in a storage device, and then this memory is stored. A method of monitoring the image of the target object as a still image by displaying the image on a display device such as a television monitor while sequentially reading the image from the device is adopted.
Such techniques are disclosed in Japanese Patent Laid-Open Nos. 54-138954 and 56-51181.

As a method of monitoring the deviation between the front and back of a printed matter printed on both sides, register marks are printed together with a pattern on the front surface and the back surface at a constant pitch during printing, and the register marks on the front and back are detected. For this reason, a method of arranging a flash light source and a television camera on the front and back sides of a double-sided printed matter and displaying each image obtained by them on the same screen by operating a video signal or an image memory is used.

[0005]

However, since it is necessary to provide a flash light source and a TV camera on both sides of the double-sided printed matter, and it is difficult to match the installation position and optical conditions of the TV camera, it is difficult. There was a problem that it was difficult to recognize the same position on the front and back.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a double-sided printed matter monitoring apparatus for recognizing a feature on both front and back sides by a set of flash light sources and image pickup means.

[0007]

In order to achieve the above object, an image pickup means for picking up an image of the characteristic body of a printed matter which has characteristic bodies printed at a predetermined interval at substantially the same positions on both sides and runs at a predetermined speed. A flash light emitting means provided to face the image pickup means with the printed matter sandwiched therebetween, a sync signal generating means for outputting a sync signal to the image pickup means, and a light emission signal of the flash light emitting means and a vertical direction of the sync signal. A writing signal generating circuit for outputting a writing signal in response to a synchronizing signal; an image memory for writing the video signal of the image pickup means from the writing signal; and an image display section for displaying the video signal of the image memory. is there.

Rotational position detecting means for outputting a rotational position signal when the flash light emitting means detects a predetermined rotational position of the plate cylinder for printing the printed matter or a rotating body rotating in synchronization with the plate cylinder, A rotation position delay means for generating a rotation position delay signal by delaying the rotation position signal for a predetermined time is provided, and flash light is emitted using the rotation position delay signal as the light emission signal.

Further, the flash light emitting means outputs a feature detection signal when the feature is detected, and a feature delay which delays the feature detection signal by a predetermined time to generate a feature delay signal. Means for emitting flash light using the feature delay signal as the light emission signal.

Further, an image pickup means having a feature printed at a predetermined interval at substantially the same position on both sides and having a one-dimensional image sensor for picking up the feature of the printed matter traveling at a predetermined speed, and the printed matter. An illuminating means provided to face the image pickup means with a sandwiching therebetween, an image sensor drive circuit for outputting a drive pulse for driving the one-dimensional image sensor, and a pulse indicating a position of a feature of the printed matter. An encoder that generates an encoder pulse of a number corresponding to the traveling distance of the printed matter, and a delay obtained by delaying the output of this encoder by the time that one of the features travels to the position of the image pickup means from the time of generation of the pulse indicating the position of the feature. An encoder pulse delay means for generating a pulse and the drive pulse after the input of the delay pulse corresponding to the position of the feature are output as a write signal. A write signal generating circuit, an image memory an image signal written in synchronization with the write signal of said 1-dimensional image sensor, in which an image display unit for displaying a video signal of the image memory.

Further, an image pickup means having a one-dimensional image sensor for picking up the characteristic bodies of the printed matter traveling at a predetermined speed, which has the characteristic bodies printed at a predetermined interval at substantially the same positions on both sides, and the printed matter. An illuminating unit provided to face the image pickup unit with sandwiching the image pickup unit, a feature detection unit that detects a feature of the printed matter and outputs a feature detection signal, and a drive pulse that drives the one-dimensional image sensor. Image sensor drive circuit, and detection for outputting a delay pulse obtained by delaying the feature detection signal from the time when the feature detection unit detects a feature until one of the features reaches the position of the imaging unit. A pulse delay circuit, a write signal generation circuit for outputting the drive pulse after the input of the delayed pulse as a write signal, and a video signal of the one-dimensional image sensor for the write signal. And writing the image memory in synchronism with, in which an image display unit for displaying a video signal of the image memory.

[0012]

Function: The features are printed on the both surfaces at substantially the same positions at predetermined intervals. The feature may be a register mark, a part of the design, or the entire design. Although printing is performed so that the features on both sides are completely the same, a shift may occur, so this shift is detected. The image pickup means and the flash light emitting means are installed so as to face each other across the position where the feature of the printed matter passes. The write signal generating circuit generates a write signal by the vertical synchronizing signal of the light emitting signal of the flash light emitting means and the synchronizing signal from the synchronizing signal generating means, and the image memory takes in the video signal from the image pickup means by the writing signal. . The captured video signal is displayed on the image display unit.

When the features printed on both the front and back sides are illuminated from one side and imaged on the other side, the flash light passes through the printing paper and the features printed on both sides are incident on the imaging means. In this case, since the feature on the flash surface is transmitted through the printing paper, the image becomes less clear than the feature on the imaging surface. Thereby, the features on both sides can be identified on the image display screen. Since the feature is printed by the plate cylinder, it is printed at a constant pitch. A still image can be obtained because a flash image is captured in accordance with this feature.

The timing at which the flash generation means emits light is when the area to be detected on the printed matter, that is, the area on which the feature is printed, reaches the position of the image pickup means. The plate cylinder continuously prints the same pattern including a feature on a printed matter. Therefore, the position of the characteristic body is detected from the plate cylinder or a rotating body that rotates in synchronization with this, and the time required for one of the characteristic bodies to travel to the position of the image pickup means is determined as a delay time. If a flash light is emitted after the delay time has elapsed after the position is detected, a desired area can be irradiated with the flash light. The characteristic body whose position is detected and the characteristic body imaged by the image capturing means are not necessarily the same. That is, since the feature is printed at a constant pitch, if the position of one feature is known, the position of the other feature can be known.

The features are printed by the plate cylinder at each pitch (the length of the pattern printed by the plate cylinder). This feature is detected, and the travel time of one of the features from the time of detection of this feature to the position of the image pickup means is obtained as a delay time, and after detecting the feature, flash light is emitted after this delay time. May be. Also in this case, the detected feature and the imaged feature do not necessarily have to be the same.

The printed matter printed on both sides runs between the illumination means and the image pickup means. The encoder will generate a number of encoder pulses according to the distance traveled on the printed material. Among the encoder pulses, the encoder pulse generating means generates a delay pulse which is delayed from the time of generation of the pulse indicating the position of the characteristic body to the time required for one of the characteristic bodies to travel to the position of the imaging means. The write signal generation circuit outputs the drive pulse after the delay pulse input corresponding to the position of the feature as a write signal, writes the video signal from the one-dimensional image sensor in the image memory, and outputs the written video signal as an image. Display on the display.

The printed matter printed on both sides runs between the illumination means and the image pickup means. The feature detecting means detects the feature and outputs a feature detection signal. The image sensor drive circuit outputs a drive pulse for driving the one-dimensional image sensor. The detection pulse delay circuit generates a delay pulse in which the feature detection signal is delayed for a time period during which one of the features travels to the position of the image pickup unit after the feature detection signal is output. The write signal generation circuit outputs the drive pulse after this delay pulse input as a write signal. The image memory writes the video signal of the one-dimensional image sensor in synchronization with the write signal, and the image display section reads the video signal from the image memory and displays it.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. Reference numeral 1 denotes a printed matter printed on both sides, and a register mark 2 (a cross-shaped mark in the figure) as a feature is printed at the same position on both sides, which is running at high speed. A stroboscope 3 is installed on the back side of the printed matter 1 and emits a flash light in response to a light emission pulse. Reference numeral 4 denotes a television camera as an image pickup means, which uses a two-dimensional CCD solid-state image pickup element as an image pickup element. Reference numeral 5 denotes an encoder as a rotational position detecting means, which is provided on a plate cylinder of a rotary press (not shown) or a rotating body that rotates in synchronization with this, and detects the position of the register mark 2 printed on the printed material 1. Reference numeral 6 denotes an encoder pulse delay circuit as a rotation position delay means, which delays the output of the encoder 5 so as to emit a flash when one of the register marks 2 comes to the position of the television camera 4, and outputs the delayed output of the encoder as a light emission pulse. Flashes strobe 3 as. Reference numeral 7 denotes a sync signal generation circuit built in the television camera 4 for driving the two-dimensional CCD solid-state image pickup device by the sync signal. A write signal generation circuit 8 generates a write signal by the light emission pulse from the encoder pulse delay circuit 6 and the vertical synchronization signal from the synchronization signal generation circuit 7 input immediately after this light emission pulse. 9
Is an image memory for writing and storing a video signal from the television camera 4 by a writing signal. An image display unit 10 displays the contents of the image memory 9.

FIG. 2 is a diagram showing the structure and timing of the write signal generating circuit. (A) shows the relationship between the circuit configuration and peripheral circuits, and (b) shows a timing chart. The flip-flop 11 becomes low level when a light emission pulse is input, and rises and becomes high level when the first vertical synchronizing signal is input in this state. This rising is the write signal.

Next, the operation will be described. On the plate cylinder of a rotary press (not shown), one pattern is printed by one rotation of the plate cylinder, and the register mark is also included in this pattern. The same pattern is printed at the same pitch and runs at high speed. There is. The flash of the strobe 3 emits light every time 10 or 20 of these patterns pass, but a static image of the register mark 2 cannot be obtained unless it emits light when it reaches the position where the inner register mark of the pattern is printed.
The encoder 5 is attached to a rotating mechanism that mechanically interlocks with the plate cylinder, and generates a pulse including the position of the register mark 2 on the plate cylinder. However, after the encoder 5 detects the position of the register mark 2, the register mark 2 is detected. One of them represents the time for traveling to the position of the television camera 4 as a delay time, and a pulse generated by the encoder 5 detecting the position of the register mark 2 is delayed by this delay time to generate a light emission pulse as an encoder delay circuit 6
Output more. Since the register mark is printed at a constant pitch, the register mark 2 detected by the encoder 5 and a mark or a pattern printed at a constant pitch may be at the position of the television camera 4 instead.

The strobe 3 emits light in response to this light emission pulse, and the television camera 4 images the register marks printed on the front and back of the printed matter 1 at this time. The write signal generation circuit 8 is shown in FIG.
As described above, a write signal is generated from the light emission pulse and the vertical synchronizing signal, and the image memory 9 writes the video signal from the television camera 4 using this write signal. Image display section 10
By displaying the contents of the image memory 9, the register marks 2 printed on the front and back are displayed as a clear image on the strobe 3 side and on the television camera 4 side, respectively. When the two registration marks are misaligned, they both look like this, but when they match, the registered registration marks that match each other are displayed. In addition, instead of the register mark, a part of the design or the entire design may be used. When using the whole pattern, determine the reference position in the pattern and use that position instead of the registration mark.

FIG. 3 is a diagram showing a second embodiment of the present invention. In this embodiment, a register mark detector 12 for detecting the register mark 2 is provided in place of the encoder 5 of the first embodiment, and after the register mark detector 12 detects the register mark 2,
A detection pulse delay circuit 13 for delaying the registration mark detection pulse and outputting it as a light emission pulse is provided as a feature delay means, with the time taken for one of the registration marks to reach the position of the television camera 4 as a delay time. Others are the same as those of the first embodiment shown in FIG.

FIG. 4 is a diagram showing a third embodiment of the present invention. This embodiment and a fourth embodiment to be described next are a lighting device.
Reference numeral 14 has a rod-shaped light source that emits continuous light in a direction perpendicular to the traveling direction of the printed matter 1, and the image pickup device 15 uses a one-dimensional image sensor as an image pickup device. The encoder 5 generates a pulse including the position of the register mark 2 on the plate cylinder (not shown). The time required for one of the register marks to travel to the position of the image pickup device 15 from the time when the position of the register mark 2 is detected is a delay time. Then, a pulse generated by the encoder 5 is delayed by the encoder pulse delay circuit 6 by this delay time to generate a delayed pulse. The image sensor drive circuit 16 generates a drive pulse for driving the one-dimensional image sensor of the image pickup device 15, and the write signal generation circuit 8 generates a drive pulse after the delay pulse input corresponding to the position of the register mark 2 as a write signal. Then, the video signal from the one-dimensional image sensor is written in the image memory 9. Others are the same as the first embodiment.

FIG. 5 shows the plate cylinder 17, the encoder 5, the image pickup device 15,
It is a figure which shows the relationship of the register mark 2. When the plate cylinder 17 makes one rotation, one pattern is printed, and the register mark 2 is included in this pattern. The encoder 5 rotates coaxially with the plate cylinder 17 and generates 1000 pulses per rotation. In the figure, it is assumed that the reference position of the plate cylinder 17 and the first pulse generation position of the encoder 5 are combined and the position of the register mark 2 can be known by counting the number of pulses. In the figure, the register mark 2 is picked up by the one-dimensional image sensor at the 200th pulse after the reference position is detected by the encoder.
It indicates that the imaging of the register mark 2 is completed at the pulse eye.

FIG. 6 shows a video signal for each drive pulse of the one-dimensional image sensor. The register mark 2 appears from 200 pulses, and it is shown that it ends at 400 pulses.

FIG. 7 shows the image signal of FIG. 6 on the screen, and FIGS. 7A to 7D show the relationship between the number of each drive pulse (encoder pulse) and the image. The number of drive pulses is selected and the image display unit is adjusted so as to be (c).

FIG. 8 shows a fourth embodiment of the present invention. In this embodiment, a register mark detector 12 is provided instead of the encoder 5 of the third embodiment, and a detection pulse delay circuit 13, an image sensor drive circuit 16 for driving a one-dimensional image sensor, and a writing to the image memory 9. The embedded signal generating circuit 8 is provided. When the register mark detector 12 detects the register mark 2, it outputs a register mark detection pulse. Detection pulse delay circuit 13
Is the register mark 2 after the register mark detection pulse is output.
One of the two is generated by delaying the time register mark detection pulse until it reaches the position of the image pickup device 15. The write signal generation circuit 8 outputs the drive pulse after the input of this delay pulse as a write signal, and the image memory 9 writes the video signal of the one-dimensional image sensor in synchronization with this write signal. The image display unit 10 displays the contents of the image memory 9.

FIG. 9 shows an example of the register mark 2 other than the cross. In addition, about the cross mark
It is described in Japanese Patent No. 6629. The arrow indicates the traveling direction of the printed matter. (A) is an isosceles right triangle, yellow, red,
The four-color register marks of blue and black are shown, and the register marks for each color are printed on the front and back sides to detect the deviation of each color (deviation between the front and back surfaces and the deviation between the front and back surfaces). (B) is "ha"
It is in the shape of. (C) is the one described in JP-A-58-20457, and (d) is the one described in JP-A-62-502601. The present invention can be applied to any of these register marks.

FIG. 10 is an explanatory diagram for detecting the deviation between the front surface and the back surface of the register mark 2 for each color shown in FIG. 9A.
The solid line indicates the registration mark on the front surface (imaging side), and the broken line indicates the registration mark on the back surface (light source side). (A) shows the case where the registration marks of the respective colors on the front and back sides are the same, and (b) shows the state where the blue registration mark 2 on the back surface is displaced to the upper right in the figure. (C) shows the state where the red surface is displaced to the lower left in the figure. In this way, the misalignment of the color-based register marks 2 on the front and back can be monitored.

[0030]

As is apparent from the above description, according to the present invention, since both sides of a printed matter are simultaneously monitored by transmission, the optical, mechanical, and It is possible to accurately detect the register marks on the front and back without causing a shift due to an electrical factor. Further, since the television camera, the detection device, the optical system and the electronic circuit are also one system, an inexpensive system can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment.

FIG. 2 is a diagram showing the configuration and operation of a write signal generation circuit.

FIG. 3 is a block diagram showing a configuration of a second embodiment.

FIG. 4 is a block diagram showing a configuration of a third embodiment.

FIG. 5 is a diagram showing a relationship between encoder pulses and register marks.

FIG. 6 is a diagram showing a relationship between a video signal of a one-dimensional image sensor and an encoder pulse.

7 is a diagram showing the relationship between the video signal shown in FIG. 6 and screen display.

FIG. 8 is a block diagram showing a configuration of a fourth exemplary embodiment.

FIG. 9 is a diagram showing a specific example of a registration mark.

FIG. 10 is a diagram for explaining misalignment of color-based registration marks on the front and back sides.

[Explanation of symbols]

 1 Printed matter 2 Register mark 3 Strobe 4 Television camera 5 Encoder 6 Encoder pulse delay circuit 7 Synchronous signal generation circuit 8 Write signal generation circuit 9 Image memory 10 Image display section 12 Register mark detector 13 Detection pulse delay circuit 14 Illuminator 15 Imaging Device 16 Image sensor drive circuit 17 Plate cylinder

Claims (5)

[Claims] 1. An image pickup means for picking up an image of the characteristic body of a printed matter having a characteristic body printed at a predetermined interval at substantially the same positions on both sides and traveling at a predetermined speed; and an image pickup means sandwiching the printed matter. Flash light emitting means provided facing each other, sync signal generating means for outputting a sync signal to the image pickup means, and a write signal for outputting a write signal from the light emitting signal of the flash light emitting means and the vertical sync signal of the sync signal. A double-sided printed matter monitoring apparatus comprising: a generation circuit, an image memory for writing a video signal of the image pickup means by the write signal, and an image display unit for displaying the video signal of the image memory. 2. A rotation position detecting means for outputting a rotation position signal when the flash light emitting means detects a predetermined rotation position of a plate cylinder for printing the printed matter or a rotating body rotating in synchronization with the plate cylinder, 2. A rotary position delay means for generating a rotary position delay signal obtained by delaying the rotary position signal for a predetermined time, wherein flash light is emitted by using the rotary position delay signal as the light emission signal. Monitoring device for double-sided printed matter described. 3. A feature detection unit that outputs a feature detection signal when the flash emission unit detects a feature, and a feature delay that generates a feature delay signal by delaying the feature detection signal by a predetermined time. The double-sided printed matter monitoring apparatus according to claim 1, further comprising means for emitting a flash light using the feature delay signal as the light emission signal. 4. An image pickup means having a feature printed at a predetermined interval at substantially the same position on both sides and having a one-dimensional image sensor for picking up the feature of a printed matter traveling at a predetermined speed, and the printed matter. An illuminating unit that is provided to face the image pickup unit with the image pickup unit interposed therebetween, and an image sensor drive circuit that outputs a drive pulse that drives the one-dimensional image sensor,
An encoder that generates a number of encoder pulses corresponding to the traveling distance of the printed matter, including the pulse that represents the position of the characteristic body of the printed matter, and the output of this encoder from the time when the pulse that represents the position of the characteristic body is generated. Encoder pulse delay means for generating a delay pulse delayed by the time one travels to the position of the image pickup means, and write signal generation for outputting the drive pulse as a write signal after input of the delay pulse corresponding to the position of the feature Monitoring of double-sided printed matter, comprising a circuit, an image memory for writing the video signal of the one-dimensional image sensor in synchronization with the write signal, and an image display unit for displaying the video signal of the image memory apparatus. 5. An image pickup device having a feature printed at a predetermined interval at substantially the same position on both sides and having a one-dimensional image sensor for picking up the feature of the printed matter traveling at a predetermined speed, and the printed matter. An illuminating unit provided to face the image pickup unit with sandwiching the image pickup unit, a feature detection unit that detects a feature of the printed matter and outputs a feature detection signal, and a drive pulse that drives the one-dimensional image sensor. Image sensor drive circuit, and detection for outputting a delay pulse obtained by delaying the feature detection signal from the time when the feature detection unit detects a feature until one of the features reaches the position of the imaging unit. A pulse delay circuit, a write signal generation circuit that outputs the drive pulse after the input of the delayed pulse as a write signal, and a video signal of the one-dimensional image sensor is the same as the write signal. A double-sided image object monitoring device comprising: an image memory for writing in time; and an image display unit for displaying a video signal of the image memory.