JPH0458388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that compares the state of a printed matter being printed in-line with a standard state in a printing press and sets temporary reference data for a printed matter inspection device that detects abnormalities in the printed matter. .

Conventionally, the mainstream method for inspecting printed matter has been offline and relying on human vision. This stems from the fact that each piece of printed matter has a different pattern, and because inspection items for printed matter have been thought to involve subtle differences that require reliance on human vision. On the other hand, in response to the desire to evaluate printed matter while it is being printed, attempts have been made to use strobe lighting that is synchronized with the printing speed and to use mirrors that rotate synchronously at high speed to judge printed matter that is being printed as a still image. It was done. but,
These methods were not systems that could be called inspection machines in that they relied on human vision for inspection. In addition, attempts have been made to print color patches at the same time as the patterns on the printed matter and inspect the color patches, thereby allowing the inspection of the printed matter to be performed on behalf of the user. However, with this method, if printing defects (oil drips, stains, etc.) occur in the pattern area, they will be overlooked, and the inspection machine cannot be said to perform its function satisfactorily.

On the other hand, recently, patent application No. 1051 of 1982 or
A system has been proposed that inspects printed matter inline using a licensor, as seen in the "printed matter inspection device" proposed in No. 220515 and the like.

The outline of this system will be explained based on FIG. A strip of printing paper 2 is fed from a roll of paper 1 attached to the feeder of the printing machine, and is printed in four colors (yellow, red, indigo, black) in the printing section 1.
After printing is performed, the paper is transported to a dryer and a folding machine (not shown). In order to inspect the printing condition after the front and back sides are printed in four colors, the printed matter inspection device imports pattern information from the licensor of the detection section 4 to the processing circuit 6 while timing the sampling with a rotary encoder 5 attached to the printing section. , perform judgment work. As a result, if it is determined that the printing condition is abnormal, it becomes possible to take measures such as alarms, markings, rejects, etc.

According to such a system, the entire pattern of a printed matter can be automatically inspected in-line, so it does not have the above-mentioned drawbacks and can be expected to have excellent effects as an inspection machine.

Here, the image information inputted from the detection section 4 plays two roles within the processing circuit 6: reference information and inspection information. The reference information is image information of the pattern of the printed matter at the time when the operator judges that the printing is normal, and this image information is stored in the reference information memory and used as a reference for inspection. On the other hand, inspection information is information that is input from the detection unit 4 after the reference information is stored in the memory, and is compared (difference, differentiation, etc.) with the reference information to ensure that the test exceeds a predetermined tolerance range. By determining whether the printed material is good or bad by determining whether or not the printed material is good or not, it becomes possible to inspect the printed material in-line.

As a result, it is understood that in this system, inspection is impossible before the reference information is input, that is, during the transition from the start of printing to normal printing.

In actual printing, a large amount of defective printed matter is generated during the transition from the start of printing to the normal printing state.In particular, rotary printing machines have a large loss of printing paper, so at what point after printing has started is it possible to print normally? There is a desire to automatically determine whether the transition has been made. It is clear that the printed matter inspection apparatus of the invention is completely ineffective in meeting this demand, and a solution to this problem has been desired.

The present invention has been made to solve this problem, and its purpose is to provide a standard information setting device that supplies standard information for inspection to a printed matter inspection apparatus so that printed matter can be inspected immediately after printing starts. Our goal is to provide the following.

A feature of the present invention is that provisional reference information to be supplied to a print inspection device is created from pattern information of a proof print.

Here, proof prints are printed to check the finished state of the print during actual printing work and to obtain approval from the person who ordered the print, and usually the order from the orderer is printed in the red. There are many cases of writing.

For this reason, the standard information setting device of the present invention prepares a plurality of proof prints in advance, and prepares a spare proof print that will not be given to the orderer, that is, a proof print that does not have red or other red pattern information written on it. It is necessary to do so.

Furthermore, a characteristic of proof prints is that they are often printed in units different from those used in printing on an actual printing machine. This is due to the difference in size (printing area) between the printing machine for proof printing and the actual printing machine, and the fact that for printed matter such as books and magazines, the destinations for submitting proof printing for advertisements and body text are different.

The present invention has been made in consideration of the differences between such proof printed matter and actual printed matter, and the present invention will be explained in detail below with reference to FIGS. 2 to 4.

In FIG. 2, reference numeral 7 denotes a proof print, which is set on a pedestal 16. The pedestal 7 is provided with positioning means such as a contact line or a register pin for setting the proof print at a fixed position in consideration of signal acquisition by the CCD camera 9 located above the pedestal 7.

Reference numeral 8 denotes a light source for illuminating the proof print 7, and in this example, rod-shaped light sources (fluorescent lamps, etc.) are arranged at four locations around the proof print 7 to reduce unevenness in illuminance.

As the CCD camera 9, it is desirable to use a CCD area sensor having 488 x 380 pixel elements in terms of input speed and simplification of the mechanism. How to move and scan the entire area,
Alternatively, there is no problem as long as the method has the same effect, such as a method using an image pickup tube.

Note that such a measurement system is desirably placed in a dark room to block the influence of external disturbances, that is, external light.

After the image information taken in from the CCD camera 9 is digitized by the A/D converter 10,
Transferred to CPU 11.

The CPU 11 calculates image information and controls the operation of the entire device, which will be described later, according to a built-in program.

Reference numeral 12 denotes an external memory, which uses a fixed disk, a floppy disk, or the like, and stores image information transferred from the CCD camera 9 and image information after calculation.

The CPU 11 also has a CRT display 1
3 is connected to an input board 14, which reproduces the captured image information on the CRT display 13 and gives instructions from the input board 14 to layout the image.

Further, 15 is a floppy disk drive device for writing the results (temporary reference information) calculated by the CPU 11 onto the floppy disk 17, and the floppy disk 17 on which the temporary reference information is written is a printed matter inspection device. and read into the reference memory of the print inspection device.

Next, the functions of such a device will be explained based mainly on FIGS. 3 and 4.

FIG. 4 shows a flowchart of the arithmetic processing program in the CPU 11. The device of the present invention functions based on such a program. First, the CPU 11 gives a command to read the image information of the proof print to the CCD camera 9, and the CCD
Based on this command, the camera 9 captures the image information of the proof print set on the stand 7 as image information IS (step S ₁ ). The image information IS is digitized by the A/D converter 10, sent to the CPU 11, and temporarily stored in the external memory 12.

In the CPU 11, first, for this image information,
Light intensity correction is performed in the input system (step S ₂ ).

The light amount correction in the input system is based on the fact that the image information IS includes illumination unevenness or sensitivity unevenness of each element of the CCD camera 9, etc.
This is done for the purpose of removing these.

The correction formula for light intensity correction in the input system is IS' = G _MN (IS) IS': Image information after light intensity correction IS: Image information before light intensity correction G _MN : Light intensity correction coefficient at pixel position (MN) expressed.

In the present invention, for the layout work of the proof print, which will be described later, unless the image information is adjusted to the same level by correcting the amount of light, the information level of each pixel of the proof print will differ as a result of positional movement. This process has an important meaning.

Next, the image information after the light amount correction is fitted into the layout position (step _S3 ).

In other words, the read image information is in units of separate proof prints, so the CRT display 1
3, while using the input board 14, insert the image information into the same position as the layout of the actual printed matter to be inspected.

To explain using an example, as shown in Fig. 3, in a case where 8 pages of A4 size are laid out on the A-horizontal print 18, the proof prints are 4 pages A, 3 pages B, If one page is divided into C, the image information is also A,
B and C are each in an independent state and are input separately.

On the other hand, in print inspection equipment,
Since the printed matter 18 in which the information of A, B, and C is finally laid out is to be inspected, the display 13 and input board 14 are used to divide the inspection area and non-inspection area, position movement, and rotation correction. After doing the fitting work including etc., A, B, C
It is necessary to create image information to be transferred by combining each piece of image information into one location.

Such light amount correction and fitting into the layout position are performed for each proof printed matter.

Once all the proof prints have been inserted and the layout is the same as the print to be inspected (step _S4 ), use the CRT display 13 and input board 14 again to correct the layout, such as adjusting the overall position. (step _S5 ), and further determines the effective range as a pattern by specifying an area size or setting a size for each printing machine in advance and specifying a number (step _S6 ). This means that basic temporary reference information has been created.

Next, inspection standards are set for the image information whose layout has been completed (step _S7 ).

This process is especially necessary when the proof print differs in some respects from the final print. That is, there are cases in which the orderer wishes to make partial corrections to the proof printed matter due to its nature, but due to delivery deadlines, etc., the actual printing is carried out without creating a proof printed matter with that portion corrected again. In this case, by setting loose inspection standards (increasing the tolerance) for a portion of the proof print (for example, changing the color of text, etc.), even input image information that is slightly different from the final print can be corrected to a certain extent. inspection becomes possible.

Furthermore, the temporary reference information set in this way needs to be corrected in light intensity based on the detection pixel position of the illumination light source on the print inspection device side and the light source 8 on the print inspection device standard information setting device side (step
_S8 ). The correction formula for light amount correction is: ISN′=g _MN (ISN) ISN′; Temporary reference information after light amount correction ISN; Temporary reference information before light amount correction g _MN ; Light amount correction coefficient at pixel position (MN) It is expressed as

The provisional reference information processed as above is
The data is recorded on the floppy disk 17 by the floppy disk drive device 15. (Step S ₉ )
Print inspection equipment is equipped with a floppy disk drive for reading, which is connected to the reference information memory, and temporary reference information is
Based on the signal from the DMA interrupt circuit, the data is transferred from the floppy disk to the reference information memory and stored.

The print inspection device that receives the temporary standard information,
At the beginning of printing, this provisional reference information is compared with the inspection information detected from the printed material to inspect the print quality.

Although the present invention has the configuration and functions as described above, it is not limited to the above embodiments in any way.

For example, we have already mentioned that it is necessary to set loose inspection standards for the parts of the proof print that have been corrected, but since the proof print is strictly speaking a print that is different from the print that should be inspected, it is necessary to set a relaxed inspection standard. Compared to testing based on information, it is often better to perform testing using temporary reference information with a rough overall tolerance. For this reason, data representing rough inspection standards may be simultaneously recorded on a floppy disk and delivered to the print inspection device.

Further, there is no problem even if the temporary reference information is coarser than the pixel size in the regular inspection, and in this case, it is sufficient to make a plurality of pixels of the print inspection device correspond to the same data of the temporary reference information.

Further, the recording medium is not limited to a floppy disk, and other recording media may be used without any problem, and it may be possible to make it online by wiring.

As described above, according to the standard information setting device for print inspection according to the present invention, it is possible to perform inspection by the print inspection device from the start of printing to normal printing, which was impossible in the past. Therefore, it is possible to easily determine the point at which normal printing will start, reducing the workload of printing press operators such as monitoring duties, and stabilizing the quality standards of printed materials. Through early detection and feedback, it is possible to minimize the number of defective prints, which makes it possible to reduce the cost of materials such as printing paper and printing ink.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a state in which a printed matter inspection device to which the present invention is applied is attached to a rotary printing press.
FIG. 2 is an explanatory diagram showing one embodiment of the input device for inspecting printed matter of the present invention, FIG. 3 is an explanatory diagram showing the positional relationship between a proof printed matter and an actual printed matter, and FIG.
The figure is a flowchart of processing in the CPU. 4...Detection unit, 6...Processing circuit, 7...Calibration printout,
9... CCD camera, 11... CPU, 13... Display, 15... Floppy disk drive device,
17...Floppy disk, 18...Printed matter.

Claims (1)

[Claims] 1. An input means for inputting picture information of a proof print as image information in pixel units, and a signal for each proof print input from the input means to be inserted into the same position as the layout of the actual print. 1. A reference information setting device for a print inspection device, comprising: a converter for converting the temporary reference information into temporary reference information for the print inspection device; and a transmission device for transmitting the temporary reference information to the print inspection device.