JP2688901B2 - Automatic mark extraction device for printed matter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is an automatic register mark or a pattern edge that can substitute for a register mark in a printed pattern for controlling the registration between printing and subsequent processing in a printing machine or the like. The present invention relates to a device for performing extraction. [Prior Art] It is a common technique to print a register mark on a printed material for cutting or registration of the printed material in offset printing, gravure printing, etc., and perform desired operation control by detecting this. It is also known to use an edge in a printed pattern instead of the register mark. Furthermore, one mark detector installed on the web is moved to the left or right direction of the web manually or by a remote control device to a position where there is a register mark or a pattern that can be used as a substitute for the register mark, and the detected one round of the pattern of the mark detector is detected. It is also known to automatically extract a register mark or a pattern edge used for registering or the like from a signal. This will be described in detail. As shown in FIG. 10, a signal 92 obtained by scanning a pattern 91 for one round by one mark detector 90 is set to "0" by an appropriate slice level 93.
It is known that a binarized signal 94 of "1" is created and a portion 95 where "0" changes to "1" or "1" changes to "0" is regarded as a pattern edge and is extracted as a control mark. There is. Further, as shown in FIG.
When there are a plurality of picture edges 95 in the binarized signal 94, a gate 96 having an appropriate length is set before and after the picture edge to be extracted so that only one picture edge can be extracted. It is known that only one of "0" to "1" and "1" to "0" is regarded as a picture edge. [Problems to be Solved by the Invention] In the above-mentioned conventional technique, even if the method for automatically extracting the registration mark is adopted, since the number of the light receiving units of the mark detector is only one, as shown in FIG. When a mark oblique to the horizontal direction of the web is detected, the digital signal obtained when the web shifts to the left or right due to the meandering of the web is C
It changes from C to C'and it is mistaken for a vertical displacement.
This causes misregistration between printing and post-processing. The present invention has been made in view of the above points, and an object of the present invention is to provide a device for automatically extracting only a register mark that is not affected by the meandering of a web or a suitable pattern edge as a substitute for the register mark. [Means for Solving Problems] In order to achieve the above-mentioned object, in the present invention, a mark automatic extraction of a printed matter is performed in which a registration picture edge including a register mark is automatically extracted from a printed picture in order to adjust a printing registration. A device, and a detection means,
The detecting means comprises at least one light receiving element in which at least two light receiving elements are arranged along a direction perpendicular to the transfer direction of the printed matter, and the detecting means is arranged in a direction perpendicular to the transfer direction of the printed matter. A light receiving signal obtained from each of these light receiving elements is output, and the extraction means is a pattern edge extending in a direction perpendicular to the transfer direction of the printed matter based on the received light signal, and in the transfer direction of the adjacent pattern edge and the printed material. (EN) An automatic mark extraction device for printed matter, which extracts picture edges having a predetermined interval or more as picture edges for registration. In the mark automatic extraction device of the printed matter, a light receiving signal output by the light receiving element of the detection means and a selection signal for selecting the light receiving element are input, and the light receiving signal output by the selected light receiving element is selectively selected. The present invention provides an automatic mark extraction device for printed matter, which extraction means has a multiplexer for outputting. [Operation] At least one light receiving element in which at least two light receiving elements are arranged along a direction (that is, left-right direction) perpendicular to the transfer direction of the printed matter (that is, the vertical direction) is arranged in a direction perpendicular to the transfer direction of the printed matter. The detecting means composed of outputs the light receiving signal obtained from each of the light receiving elements. The extracting means calculates the position of the picture edge detected by each light receiving element based on the light receiving signal. If there is a difference in position between the respective light receiving elements, it means that it is a position of a different picture edge or a position of a picture edge having an inclination with respect to the direction perpendicular to the transport direction of the printed matter. Therefore, the extraction means extracts a pattern edge having a small difference between the light receiving elements as a candidate pattern edge. The extracted candidate picture edges are the picture edges that extend in the direction perpendicular to the direction in which the printed material is conveyed and are slightly inclined even if they are inclined. Further, the extracting means extracts a candidate picture edge having a predetermined distance or more in the transfer direction of the printed matter from the adjacent picture edge based on the position of the extracted picture edge as a picture edge for registration (that is, a registration mark). To do. Further, when the multiplexer selects one of the light receiving elements arranged in the direction perpendicular to the printed material transfer direction, the multiplexer selectively outputs the light receiving signal output by the light receiving element of the selected light receiving element. As a result, the range in which the picture edge is detected is widened in the direction perpendicular to the direction in which the printed material is conveyed, and a more appropriate portion is selected. EFFECTS OF THE INVENTION According to the present invention, when there is a fluctuation in the transfer of printed matter, other picture edges are erroneously detected, or the printed matter is displaced in the direction perpendicular to the direction in which the printed matter is transferred, that is, the printed matter meanders. In this case, it is possible to prevent the misregistration amount from being erroneously detected.
A registration mark that enables stable registration control is extracted. Furthermore, by arranging multiple light-receiving elements in the direction perpendicular to the direction in which the printed material is transferred, the outputs of these light-receiving elements are sequentially switched by the multiplexer and read out, without moving the mark detection unit as in the past. The registration mark can be extracted quickly and quickly. [Embodiment] FIG. 1 is a block diagram showing a conceptual configuration of an embodiment of the present invention. That is, the device of the present invention has a mark detection head and a mark automatic extraction circuit 2. 2 and 3 show the configuration of the light receiving element 10 in the mark detection head 1 and the internal configuration of the mark automatic extraction circuit 2. FIG. First, in the mark detection head 1 shown in FIG. 2, two light receiving elements 11 and 12 are arranged in parallel with each other with a central boundary therebetween.
What is important here is that the edge of each light receiving element is straight. This makes it possible to accurately extract register marks arranged in the left-right direction of the web. Next, in the mark automatic extraction circuit 2 in FIG. 3, the photocurrents obtained from both the light receiving elements 11 and 12 according to the density of the pattern on the web are given to the current-voltage conversion circuits 13 and 13 ', respectively, and the voltage signals are outputted. Is converted into a binary signal and given to the binarization circuits 14 and 14 '. The binarization circuits 14 and 14 'have a fixed slice level 15
Is binarized to obtain a binarized pulse corresponding to the mark signal for each light receiving element. FIG. 4 shows a light receiving element 11 when the light receiving element detects a bar-shaped or rectangular figure as shown in FIG.
The output waveform for each 12 is shown. The light receiving elements 11 and 12 are adapted to pass through the central portions of these figures, and each element produces an output of the same waveform. However, as shown in waveforms a and b, output is generated at the same timing for figures that are not inclined with respect to the web flow direction, but output for figures 21 and 22 that are inclined with respect to the web flow direction. The timing of the appearance of is off. Looking at those binarized pulses, timing deviations α and β occur in the figures 21 and 22 inclined with respect to the web flow direction. A figure with such a large deviation is unsuitable as a registration mark. Therefore,
A figure with a small timing deviation α or β is selected as a registration mark. 5 and 6 show an element array of the mark detecting head 1 using the plurality of light receiving elements 10 shown in FIG. The light receiving element 10 has two light receiving elements as described above, and is arranged on the substrate 30 at a predetermined pitch as shown in FIG. An illumination device 31 is provided below the substrate 30 as shown in FIG. 5 to illuminate the printing paper surface. The illuminating device 31 is, for example, an LED array having a long life and a stable light amount, and is arranged on both sides of the center line of the light receiving element 10 in the arrangement direction. Thereby, the web can be evenly illuminated in the left-right direction. Light reflected from the paper surface due to the illumination forms an image on the light receiving surface of the light receiving element 10 via the lens 32.
The lens 32 may be an ordinary curved lens, but if a rod lens array (Selfoc lens array) is used, the lens 32 can be easily mounted and has excellent brightness. The substrate 30, the LED array 31, and the lens 32 are fixed to a metal member 33 that also functions as a heat dissipation member and housed in a metal housing 34. FIG. 7 shows registration mark extraction using the mark detection head 1 using a plurality of light receiving elements 10 shown in FIG.
9 illustrates a method of generating a gate. This extraction is performed for those that satisfy the following conditions. 1) When using a pattern edge, a pattern edge parallel to the horizontal direction of the web, that is, a pattern edge for preventing misalignment of the horizontal position of the web from a vertical displacement is used. 2) There is no other pattern edge in the specified length range before and after the vertical direction of the pattern edge to be extracted as a mark. This length is related to the expected amount of misregistration and the gate length, and is determined, for example, by the following equation. Gate length = (expected misalignment on one side in the vertical direction) x 2 = 2X (1) Length = (gate length) x 2 = 4X (2) In Fig. 7, the maximum X misregistration is shown. It shows a state in which a gate having a length of ± X (2X) is provided before and after the mark M when expected. If a misregistration X occurs and the mark signal M is shifted to the left in the figure with respect to the gate signal, the mark signal a 'is obtained. In this case, only the mark M exists in the gate, and there is no problem. On the other hand, if the mark signal deviates in the opposite direction, that is, to the right in the figure with respect to the gate signal, it becomes a mark signal a ″, and another mark M ′ is newly present in the gate. , M ′ misrecognize the misregistration amount. This is because another mark exists before and after the original mark M in the range of twice the gate length, that is, ± 2X. Equations (1) and (2) are required: Next, the procedure for automatically extracting a picture edge satisfying the above conditions as a mark will be described with reference to Fig. 8. Fig. 8 shows a circuit configuration using a two-division photodiode. 6, a plurality of elements are arranged as shown in Fig. 6. Photocurrents from the respective light receiving elements in the photodiodes 10-1, 10-2, ... are converted into voltages by the current-voltage conversion circuit 15. Turn into a signal The signal from the light receiving element 11 is applied to the multiplexer 60, and the signal from the light receiving element 12 is applied to the multiplexer 60 '.
The multiplexers 60 and 60 'are selectively controlled by the CPU 74. And CPU74 is the first photodiode 10-1
The channels of the multiplexers 60 and 60 'are selected so as to obtain the signal of. Ie two multiplexers 60,
The signals 41 and 42 appear at the output terminals of 60 '.
Then, each signal is converted into a binary signal by the binarization circuits 61 and 61 '.
The value is converted into pulse signals 62 and 62 '. The binarized slice level in this case is given from the CPU 74 via the latch 63 to the binarized circuits 61 and 61 'by the D / A converter 64. On the other hand, the signal from the rotary encoder 70 attached to the rotary shaft of the post-processing portion of the printing machine is constantly counted by the counter 71. For example, when the rotation is performed once, the count is cleared by the zero signal from the encoder 70 and is again reset from zero. Only the pulse corresponding to one rotation is counted. In the gate generation circuit 72, the counter
The count signal of 71, the gate start point and the numerical value of the gate length given from the CPU 74 via the latch 73 are monitored, and the gate can be generated at an arbitrary part of one rotation of the encoder. Then, in the automatic mark extraction, in order to detect the edge position for one rotation of the picture, for example, a gate having a length of one rotation from the encoder count zero is heard from the CPU 74 once by the command signal 76. When the gate signal 77 is given, the binarized pulses 62 and 62 'are
It is given to the RAMs 65 and 65 'and the RAM address counters 66 and 66' through the AND gates 64 and 64 '. On the other hand, RAM65, 65 '
Since the count signal 79 of the encoder 70 is always input to the, the pulse is set as the memory write signal 81, 81 'every time the binarized pulse 62, 62' is generated, and the encoder count number 79 at that time is left and right on the web. The two mark signals in the respective directions are sequentially stored in the RAMs 65 and 65 'independently. Then, the RAM address is automatically incremented by counters 66 and 66 'for counting the binarized pulses and given to the RAMs 65 and 65' through selectors 67 and 67 '. Such an operation is also performed on the photodiode 10-1 and subsequent photodiodes 10-2 and thereafter by the switching operation of the multiplexers 60 and 60 '. FIG. 9 shows the operation of the circuit shown in FIG.
From the data of the pattern edge position (encoder count number) for one rotation of the pattern stored in 5 ', the above-mentioned two conditions as the mark are satisfied, that is, 1) they are parallel, and 2) there is no pattern edge before and after. A procedure for searching for a picture edge is shown. In this flowchart, procedure 1 and procedure 2 are the contents described in the explanation of the operation in FIG. Therefore, procedure 3 will be described. In step 3, the contents of the left and right RAM1 and RAM2, that is, the encoder count numbers of the picture edge positions are sequentially read to search for a portion parallel to the left and right direction of the web. Specifically, this means that data satisfying the following conditions is regarded as parallel pattern edge positions and such data is searched for. | (Content of RAM1)-(content of RAM2) | ≦ δ (3) where δ is zero or a small integer, and if there is data satisfying formula (3), the address of RAM1 or RAM2 having that data All of the above are stored in the data temporary save memory 80. On the other hand, when there is no data satisfying the expression (3), the multiplexers 60 and 60 'are switched to the next channel and the same processing is performed (judgment 1). When there is even one data that satisfies the formula (3), the procedure proceeds to the next step 4. In this procedure 4, the addresses of RAM1 and RAM2 in the parallel part that were stored in the memory in procedure 3 are read again, and the data of RAM1 and RAM2 at that address and the data of the address before and after that are calculated. If (4) to (7) are satisfied, it is adopted as a mark without other edges before and after, but if they are not satisfied, the multiplexers 60 and 60 'are switched to the next channel and the same processing is performed. (Contents of ADR11)-(Contents of ADR10) ≤ ξ (4) (Contents of ADR10)-(Contents of ADR12) ≤ ξ (5) (Contents of ADR21)-(Contents of ADR20) ≤ ξ (6) (ADR20 (Contents of ADR22) ≤ ξ (7) where ADR10 is the address of parallel data in RAM65, ADR11 is ADR10 + 1 ADR12 is ADR10-1 ADR20 is the address of parallel data in RAM65 'ADR21 is ADR20 + 1 ADR22 ADR20-1 The gate is automatically generated by the CPU as shown in FIG. 7 before and after the picture edge satisfying the above two conditions as a mark obtained by the above procedure, and then the misregistration is performed by the equation (8). The quantity is obtained and used for controlling the printing section and the post-processing section. Misregistration amount = (contents of zero address of RAM65) -AD1 or (contents of zero address of RAM65 ')-AD2 (8) where AD1 is the encoder count number of the mark position extracted by the above procedure (RAM65 side), AD2 is the encoder count number of the mark position extracted by the above procedure (RAM65 'side) When the extracted mark signals corresponding to the left and right received signals are obtained at the RAM65 zero address and RAM65' zero address. The encoder count of is updated and stored for each cycle of the pattern. [Other Embodiments] Two light receiving elements having one light receiving surface may be used instead of the two-divided light receiving elements in the above embodiments. In the above embodiment, an example in which two light receiving portions are arranged in the left-right direction of the web and the registration mark is automatically extracted has been described. In this case, however, the inconvenience as shown in FIG. 12 occurs. That is, when the edge 121 in FIG. 12 (a) is detected by the method shown in the above embodiment, the edge 121 is detected by the light receiving signal of the light receiving surface 11 and the light receiving signal of the light receiving surface 12.
Is recognized as an edge parallel to the horizontal direction of the web, and satisfies one of the conditions as a registration mark. Then, for example, when trying to obtain the register shift amount using the light receiving signal of the light receiving surface 12, there is no problem if the mark 120 shifts in the direction of the broken line in FIG. 12 (a) due to the meandering of the web. When the broken lines in FIG. 12 (b) are displaced in the direction shown by the broken lines, the light receiving surface 12 detects an edge 11 which is not parallel to the horizontal direction of the web, and it is recognized that the vertical displacement has occurred. Will end up. Therefore, as shown in FIG. 13, it is preferable to arrange three light receiving portions in the left-right direction of the web and automatically extract the registration mark. In this case, first, from the received light signal of the light receiving surface 111 and the received light signal of the light receiving surface 112, it is checked whether the edge 121 is parallel to the horizontal direction of the web, and then, the light receiving signal of the light receiving surface 112 and the light receiving surface 113 are received. Similarly, from the signal, it is checked whether the edges 121 are parallel. In both cases, the edge 121 satisfies the condition as the registration mark only when it is determined that they are parallel to each other, and thereafter, the misregistration amount is obtained by the light reception signal of the light receiving surface 112 in the middle. To According to this method, as shown in FIG. 12 (b), the pattern including the edge 122 which is not parallel to the horizontal direction of the web is not extracted as the registration mark and the edge shown in FIG.
It is possible to extract only edges such as 123 that are composed only of parts parallel to the left and right of the web.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the most conceptualized configuration of an apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing a light receiving surface configuration of a light receiving element used in an embodiment of the present invention. , FIG. 3 is an explanatory view of a mark signal detection circuit combined with the light receiving element of FIG. 2, and FIG.
FIG. 5 is a waveform diagram showing detection signals of various marks by the light receiving element of FIG. 2, FIGS. 5 and 6 are explanatory views of an example of the mark detection head according to the present invention, and FIG. 7 is FIGS. FIG. 8 is a circuit diagram showing a mark detection circuit in combination with the light receiving elements shown in FIGS. 5 and 6, and FIG. 9 is a diagram illustrating FIG. Flowchart showing the mark detection operation by the circuit of
FIG. 10 is an explanatory view of a conventional detection method for detecting a registration mark by one mark detector, FIG. 11 is a view for explaining inconvenience in the conventional detection method, and FIGS. 12 and 13 are the present invention. FIG. 8 is a diagram for explaining a description related to another embodiment of the present invention. 10 ... Light receiving element, 11, 12 ... Light receiving element, 15 ... Current-voltage conversion circuit, 31 ... LED array, 32 ... Lens, 90 ...
Mark detector, 91 ... One-round pattern, 93 ... Slice level, 94 ... Binary signal of picture signal 92, 95 ... Binary signal
Rise of 94, 96 ... gate.

Claims (1)

(57) [Claims] A mark automatic extraction device for a printed matter for automatically extracting a registering picture edge including a register mark from a printed picture in order to match a printing register, which has a detection means and an extraction means, wherein the detection means is At least one light receiving element in which at least two light receiving elements are arranged along the direction perpendicular to the printed material transfer direction is arranged in the direction perpendicular to the printed material transfer direction, and a light receiving signal obtained from each of these light receiving elements The extracting means registers the picture edges extending in the direction perpendicular to the transfer direction of the printed matter based on the received light signal, and the picture edges having a predetermined distance or more in the transfer direction of the adjoining picture edges. An automatic mark extraction device for printed matter, characterized by extracting as a picture pattern edge. 2. The extraction means has a multiplexer for inputting a light reception signal output from the light reception element of the detection means and a selection signal for selecting the light reception element, and selectively outputting the light reception signal output from the selected light reception element. The automatic mark extraction device for printed matter according to claim 1.