JPH06246906A - Inspecting device for printed matter - Google Patents

Abstract

PURPOSE:To accurately inspect respective ink density levels by reading the pattern of printed matter and converting three kinds of the image data stored in a present value memory to hues and chromas to compare them with the corresponding judge levels. CONSTITUTION:An inspection processing part 10 transmits the start pulse and scanning pulse based on the timing signal from a rotary encoder 5 detecting the running state of printed matter to an image detection part 1 and receives RGB color image signals on the basis of those pulses from the image detection part 1. After the color image signals are stored in respective RGB memories, those color image signals are stored in the respective present value memories of HSI by an PGB-HSI conversion part 15 and the subtraction with the respective reference value memories of already stored HSI is performed and the result is compared with a judge level to judge quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a pattern on a printed matter in a printing machine, and more particularly to an apparatus for color-separating a color printed matter to accurately inspect each ink density level.

[0002]

2. Description of the Related Art The quality inspection of printed materials has long relied on manpower. In other words, after printing using a roll of paper, if it is a printed matter that is rolled up and conveyed to the next step, the strobe emits light in synchronism with the running speed of the printed matter to perform a visual inspection, or after printing, it is discharged in a sheet or signature state. If it is a printed matter, the printed matter is taken out as necessary and visually inspected. In recent years, this has been automated. For example, there is a printed matter inspection device as shown in Japanese Patent Publication No. 1-47823, Japanese Patent Application Laid-Open No. 62-11152, and Japanese Patent Application Laid-Open No. 2-71123. You can do it.

As the color image detecting section, conventionally, in addition to the technique disclosed in the above publication, the optical system and line sensor shown in FIGS. 9 and 10 are used.

FIG. 9 is a top view of an optical system of an image detecting section having three black and white line sensors corresponding to three filters and a black and white line sensor. The pattern on the printed matter is taken into the image detecting section by the lens 66, divided by the two beam splitters (half mirrors) 67, and R
Filter 61, G filter 62, B filter 63
It is an optical system of an image detection unit that forms an image on each line sensor 60 via the and is photoelectrically converted by each light receiving element 65.

FIG. 10 is a top view of a line sensor with a color filter. R filter, G filter, B
It is a line sensor with a color filter in which filters are alternately arranged on the front surface of each light receiving element.

[0006]

In the conventional printed matter inspection apparatus, the R filter, G
The image of the design on the printed matter is input through the filter and the B filter, and the RGB color system or its complementary color YM
Since the input image data was expressed in the C color system and the inspection was performed, it was difficult to determine pass / fail based on the mutual correlation of RGB, and the detection performance was increased even though the amount of information increased to 3 times that of monochrome input. Did not improve much. Further, it was not possible to accurately inspect the print color of intermediate density such as yellow.

The present invention has been made in view of the above points, and an object thereof is to provide an apparatus for inspecting a color pattern on a printed matter.

[0008]

As an apparatus of the present invention, a timing signal generating section for generating a timing signal for reading a pattern of a printed matter, and a timing from the timing signal generating section for optically monitoring a paper surface condition of the printed matter. An image detection unit having a plurality of light receiving elements each having three types of color filters arranged on the front surface for reading the pattern of the printed matter according to the signal, and image data detected by the light receiving elements in the detection unit for each color filter. The first current value memory to be stored and the three types of image data stored in the first current value memory are H (hue: hue), S (saturation: saturation), I (lightness: inten).
a second current value memory corresponding to H, S, and I for storing the image data converted by the conversion unit, and the reference image data detected by the image detection unit. The reference value memory stored after conversion by the conversion unit, the reference image data stored in the reference value memory, and the second
Of the inspection image data stored in the present value memory, a determination level setting unit for setting the determination level corresponding to H, S, I for the quality determination, and the setting from this determination level setting unit. Inspection of a printed matter, comprising: a determination level storage unit that stores the determined determination level; and a comparison unit that outputs a result of comparing the subtraction value and the determination level set in the determination level storage unit. A device is provided.

[0009]

As the apparatus of the present invention, the pattern of the printed matter is read in accordance with the timing signal from the timing signal generating section by using the image detecting section provided with a plurality of light receiving elements each having three kinds of color filters arranged on the front surface. This image data is stored in the first current value memory for each color filter,
The three types of image data stored in the first current value memory are set to H (hue: hue), S (saturation: saturation).
conversion) to I (brightness: intensity) and stored in the second current value memory corresponding to H, S, and I. H, S, I corresponding to the reference image data stored in the reference value memory and the inspection image data stored in the second current value memory, the result of subtraction, and H set in the determination level storage unit, The printed matter is inspected by comparing the determination levels corresponding to S and I.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of an image detecting section relating to a printed matter inspection apparatus of the present invention. The image detection unit 1 uses the lens 3 to color-code the pattern on the printed matter.
An image is formed on the CD line sensor 2. According to the start pulse and the scanning pulse from the inspection processing unit 10, the image is photoelectrically converted by the line sensor 2 and subjected to signal processing as RGB color signals, and then transmitted to the inspection processing unit 10.

The pattern on the printed matter is imaged on the color CCD line sensor 2 through the lens 3 in the image detecting section 1. A schematic view and a top view of the line sensor 2 are shown in FIG.
Shown in. The outline is a package-like shape of an IC, and a detection window 47 with a glass for protecting the line sensor 46.
have. Further, the line sensor 46 is a set of three rows, and there are 1024 light receiving elements 45 in one row, and the front surface thereof has the R filter 4 in the first row over the longitudinal direction.
A G filter 42 is arranged in the first and second columns, and a B filter 43 is arranged in the third column. And R in the first row
The light receiving element row with the filter 41, the second light receiving element row with the G filter 42, and the third light receiving element row with the B filter 43 are photoelectrically converted by a start pulse from the outside, and the light receiving element is lengthened by a scanning pulse. Images sequentially driven in the directions and formed on the line sensor 2 are sequentially output. Here, the start pulse and the scan pulse from the outside are common to the R, G, and B light receiving element arrays. In addition, YM which is a complementary color of the RGB filter
A C filter may be used.

As shown in FIG. 1, the start pulse and the scan pulse are transmitted from the inspection processing unit 10 to the image detection unit 1 which optically monitors the paper surface condition of the printed matter based on the timing signal output from the rotary encoder 5. The rotary encoder 5 is provided as a timing signal generator in a printing unit (not shown), and detects the traveling state of the printed matter in synchronization with the rotation of the plate cylinder of the printing machine. The rotary encoder 5 outputs a predetermined number of pulses such as 2000 pulses per revolution of the plate cylinder at regular intervals, and further outputs one pulse for each revolution of the plate cylinder. The former is called A phase and the latter is called Z phase. These are combined into a timing signal, and A
A start pulse is generated from the phase and a pulse indicating the head of the pattern of the printed matter is generated from the Z phase. As another installation method, two rollers may be arranged with the surface of the printed matter sandwiched therebetween, and the rotary encoder 5 that rotates in synchronization with the rotation may be connected to either one of the rollers.

The inspection processing unit 10 outputs a start pulse and a scanning clock based on a timing signal from the rotary encoder 5 which detects the traveling state of the printed matter. The image of the print pattern formed on the color CCD line sensor 2 through the lens 3 of the image detection unit 1 is photoelectrically converted according to the start pulse, and is output from the line sensor 2 to the amplifier 6 as a color image signal according to the scanning pulse. To do. The light receiving element row with the R filter 41 in the first row,
The RGB color image signals photoelectrically converted from the light receiving element row with the G filter 42 in the second row and the light receiving element row with the B filter 43 in the third row are respectively R signal, G signal, and B signal.
Call it a signal. The R signal, the G signal, and the B signal are amplified to the required voltage levels by the corresponding amplifiers 6, and the A / D
An analog signal is converted into a digital signal through the converter 7, a parallel signal is converted into a serial signal through the P / S converter 8, and the serial signal is transmitted to the inspection processing unit 10. Since it is converted into a serial signal after being converted into a digital signal, S / N
The ratio is good and the number of signal lines for transmission is small.

Here, the A / D converter 7 and the following may be housed in the inspection processing section 10, but it is not preferable because the signal level is lowered in the transmission of the analog signal or the noise from the outside is affected. . Further, since there is an advantage that the transmission time is shortened, the P / S converter 8 may be omitted and the parallel signal may be transmitted, but the number of transmission lines is increased, which is complicated and troublesome. Further, the P / S converter 8 may be subjected to electrical-optical conversion and transmitted using an optical cable, or data may be compressed after the A / D converter 7 by a method such as run length coding or Huffman coding. You may go and send. In these cases, there is an advantage that the transmission time is shortened.

FIG. 2 is a block diagram showing an embodiment of an inspection processing section relating to the printed matter inspection apparatus of the present invention. The inspection processing unit 10 transmits a start pulse and a scanning pulse based on a timing signal from the rotary encoder 5 that has detected the traveling state of the printed matter to the image detection unit 1, and based on these pulses, the image detection unit 1 outputs an RGB color image. Receive the signal. Then, after storing them in RGB memories, these color image signals are recorded in RGB-HS.
The I conversion unit 15 stores each in the current value memory of the HSI,
Subtract with the already stored HSI reference value memory,
The result is compared with the determination level to make a pass / fail determination.

The timing signal from the rotary encoder 5 which detects the running state of the printed matter is input to the driving circuit 4 of the color CCD line sensor, and the driving circuit 4 is based on this timing signal.
To transmit a start pulse and a scan pulse to the image detection unit 1. The start pulse is formed based on the A-phase pulse of the rotary encoder 5, and the scanning pulse is formed by the crystal oscillator 23 provided in the drive circuit 4. Image detector 1
Forms an image on a printed matter on the color CCD line sensor 2 through the lens 3, photoelectrically converts it, and extracts it as an RGB color image signal.
Are transmitted to the inspection processing unit 10 as three types of serial signals. The three types of RGB serial signals transmitted are S /
An R memory 12, a G memory 13, which are converted from a serial signal into a parallel signal through the P converter 9 and correspond to RGB,
It is stored in the B memory 14. Each of these memories is a 1-megabyte memory of 1024 × 1024 × 8 bits, and has 0 to 1023 row addresses and 0 to 1023.
Is a memory that can be expressed in 256 gradations from 0 to 255, and the gradation of the stored image is 8 bits.

At this time, the start pulse from the drive circuit 4 and the timing signal from the rotary encoder 5 are given to the address control unit 22, and based on the given signals, the address control unit 22 determines the deviation of the light receiving element row in each memory. By controlling the storage start address in association with each other, the RGB color image signals can correspond to the respective R memories 12 and G.
It is stored in the memory 13 and the B memory 14. That is, the position of the image detected from the light receiving element row with the R filter 41 in the first row of the line sensor 2, the position of the image detected from the light receiving element row with the G filter 42 in the second row, and the third row The position of the image detected from the light receiving element array with the B filter 43 is the position of the pattern on the printed material at the start of detection because the start pulse and the scanning pulse are common, and the length of the light receiving element array in the running direction of the printed material. It deviates by the minute. The value of this misalignment is used as the offset value of the memory address,
The address stored in each RGB memory is shifted to RG
The deviation of the detection start position of the B color image signal is corrected. As a result, the image of the same pattern on the printed matter is stored as an image signal through the RGB filters in the areas designated by the addresses of the R memory, the G memory, and the B memory.

This will be described with reference to FIGS. 5 and 6. First, FIG. 5 shows a case where the image detection unit 1 inputs an image of a pattern on the printed matter 50. In the color CCD line sensor 2, three rows of light receiving element rows are simultaneously scanned according to the start pulse and the scanning pulse from the driving circuit 4 of the CCD line sensor in accordance with the arrow 54 indicating the scanning direction, and the pattern on the printed matter 50 is monitored. The light receiving element row with the R filter 41 in the first row monitors the line 51 on the printed matter 50, the light receiving element row with the G filter 42 in the second row monitors the line 52 on the printed matter 50, and the third line The light receiving element row with the B filter 43 of the row monitors the line 53 on the printed matter 50. That is, each light receiving element row of the color CCD line sensor 2 is in the traveling direction of the printed matter at the same time.
Lines deviated by the length of the light receiving element array in the running direction of the printed matter are monitored. Therefore, as described above with reference to FIG. 2, the address control unit 22 corrects the deviation of the length of the light receiving element array by the length in the traveling direction of the printed matter as an offset value for starting image recording of the image memory corresponding to each light receiving element array. .

Next, FIG. 6 shows the image detecting section 1 described with reference to FIG.
The RGB color image signal input from the inspection processing unit 1
The case of storing in the RGB image memory of 0 is shown. The RGB color image signals are transmitted from the image detection unit 1 to the inspection processing unit 10 as parallel signals and stored in the image memories of the R memory 12, G memory 13, and B memory 14, respectively, and the address control unit 22 controls the image memories. Control the row and column addressing of. Address control unit 2
2 comprises a row address generator 24 of the image memory, a row address R memory offset section 25, a row address B memory offset section 26, and a column address generator 27.

The row address generator 24 receives a Z-phase signal from the rotary encoder 5 and a start pulse from the drive circuit 4 to generate a row address signal.
The G memory uses this row address signal as it is. R
The memory uses the R address of the row address in order to correct the deviation of the length of the light receiving element row with the G filter and the light receiving element row with the R filter in the image detection unit 1 by the length in the traveling direction of the printed matter as the R memory offset value. A row address signal is generated through the offset unit 25 for. The B memory is the image detection unit 1
In order to correct the deviation of the length of the light receiving element array with G filter and the light receiving element array with B filter by the length in the traveling direction of the printed matter as the offset value for B memory, the offset unit for B memory 26 of the row address is used. Generate a row address signal. Next, the column address generator 27 receives the scan pulse and the start pulse from the drive circuit 4 and generates a column address signal. This column address signal is common to the RGB image memories. This allows R memory, G memory,
In the area designated by each address of the B memory, the image of the pattern on the same printed matter is stored as a different image signal through the RGB filters.

Although the color CCD line sensor 2 is used as the image detection unit 1 used together with the address control unit 22, three black and white CCD line sensors are used as the image detection unit used together with the address control unit 22. It may be used as a detection unit for monitoring a pattern on a different printed matter through different color filters, or different color filters may be used for three multi-head type detection units having a plurality of photodiodes arranged in the width direction. It may be used as a detection unit that monitors patterns on different printed materials.

Returning to the explanation of FIG. 2, RGB is used as the offset value of the memory address in this way.
R memory 1 as a first current value memory by shifting the address stored in each memory
2. After storing in G memory 13 and B memory 14, RGB
The HSI conversion unit 15 converts these three types of image data into H (hue: hue), S (saturation: saturation), I (brightness: inten) according to a constant conversion formula.
status).

Next, an example of RGB-HSI conversion will be described. The relationship between the image data R, G, B and I is defined by the following mathematical formula. However, the range of R, G, B, S, and I is [0, 1], and H has a value of [0, 2π].

[0024]

## EQU1 ## I = max (R, G, B)

Here, max is a function that gives the maximum value.

Next, i, r, g and b are defined by the following mathematical expressions.

[0027]

## EQU2 ## i = min (R, G, B) r = (IR) / (Ii) g = (IG) / (Ii) b = (IB) / (I -I)

Here, min is a function that gives the minimum value.

Next, S and H are defined by the following mathematical expressions.

[0030]

## EQU00003 ## S = (I-i) / I When R = I H = (b-g) .pi. / 3 When G = I H = (2 + r-b) .pi. / 3 When B = I H = (4 + g−r) π / 3

When I = i, strictly speaking, H and S are defined by the following mathematical expressions.

[0032]

## EQU4 ## H = undefined, S = 0

However, in terms of processing, the following values are converted.

[0034]

[Equation 5] H = 0, S = 0

Returning to the explanation of FIG. 2, the image data converted by the RGB-HSI converter 15 is stored in the second current value memory 16 corresponding to H, S, and I.

Next, the reference value memory 17 will be described.
Before the inspection of the printed matter is started, the pattern on the printed matter which the operator judges to be non-defective is used as the reference image data, and is detected by the image detection unit 1 to perform the various processes described above. Then, it is stored in an RGB image memory as a first current value memory while following the address control section 22, and this RGB color image signal is converted into an HSI color image signal by the conversion section 15, and H, S , I are stored in the second current value memory 16 and then stored in the reference value memory 17 corresponding to H, S, and I. It is also possible to manually press a reference value input switch (not shown) during the inspection to update the image data stored in the reference value memory 17. If the image at the time of updating is a non-defective item, a program for automatically updating once for 100 images may be provided to update the image data stored in the reference value memory 17.

In order to determine whether the printed matter is a good product or a defective product, the subtraction unit 18 subtracts the reference image data stored in the reference value memory and the inspection image data stored in the second current value memory. That is, H obtained for each pixel of the inspection image data,
The S, I data is subtracted from the H, S, I data obtained for each pixel of the reference image data corresponding to the pixel. In order to determine whether or not this result is an acceptable level as a non-defective item, the determination level corresponding to H, S, and I of the reference image data stored in the reference value memory 17 is set to the determination level setting unit 1.
9 is used to set the decision level memory 20 for each pixel.
That is, a set of H, S, and I, which is an upper limit and a lower limit that are acceptable as non-defective products, is set as a determination level for each pixel of the reference image. Based on this, the subtraction result is compared with the judgment level set in the judgment level memory in the comparison unit 21, and if the subtraction result is larger than the upper limit of the judgment level, it is judged as a defective product, and if it is smaller, further judgment is made. Compared with the lower limit of the level, if it is smaller than the lower limit, it is determined as a defective product, and if it is larger, it is determined as a good product. That is, if the subtraction result is within the upper and lower limits, it is determined as a good product, and if not, it is determined as a defective product.
In this embodiment, an upper limit and a lower limit of 1 are set for each pixel based on the reference image.
Although a set of H, S, and I is provided, depending on the pixel, the upper limit needs to be set larger than the upper limit of other pixels, or the lower limit needs to be set smaller, and conversely the upper limit of other pixels is set. This is because it is necessary to set it to be smaller than the upper limit of or to set the lower limit to be larger.

The subtraction method here may be comparison for each pixel obtained by dividing the image, or may be the sum of pixels within a predetermined range such as a rectangle, a square or the same straight line, or the same pattern. May be arranged next to each other, the comparison may be made with the same part of the pattern. Further, the storage method of the determination level memory may be such that a determination level corresponding to HSI is provided for each pixel, or the entire image may be divided into several and HSI may be provided for each to make a pass / fail determination for each divided image. One set of HSI may be provided for the entire image to determine pass / fail. Of course, the absolute value of the subtraction result may be taken, and the judgment level may be uniformly set instead of the upper and lower limits.

Although not shown in FIG. 2, a halogen lamp is used as a light source for illuminating a pattern on the surface of the printed matter in the embodiment, but a tungsten light source or a xenon light source may be used. Alternatively, an instantaneous light source such as a strobe may be used to intermittently monitor a necessary place.

FIG. 3 shows the main elements shown in FIGS. 1 and 2 while the printed matter 50 is taken up from the paper feeding section 30 of the gravure printing machine through each printing unit 31 and to the winding section (not shown). It shows the situation of installing.

In the installation state diagram of FIG. 3, a winding 33 of a blank paper or a transparent film, which is a base material for the printed matter 50, is set in the paper feeding section 30. From this winding, the blank paper or the transparent film is sent to the printing unit 31 via the guide roller 34, is supplied between the plate cylinder 36 and the impression cylinder 37, and is printed to become a printed matter 50. Here, the printing plate cylinder 3 for receiving the ink supply from the ink pan 35 that stores the ink
The ink is transferred to the white paper or the transparent film by 6 and the impression cylinder 37 that sandwiches and presses the white paper or the transparent film together with the plate cylinder to print. After that, the printed matter 50 is dried by the dryer 38 located above the printing unit 31 and supplied to the next printing unit to print the next color. 1
After each color is printed, the printing in the final printing unit 32 is completed, and all colors are printed, the printed matter 50 is inspected by the inspection device. That is, the timing signal corresponding to the traveling of the printed matter 50 is taken out by the rotary encoder 5 which generates the timing signal for reading the pattern of the printed matter in association with the rotation of the plate cylinder of the final printing unit 32. Next, the paper surface of the printed matter on the roller is uniformly illuminated by the light source 28 arranged in the vicinity of the image detecting section 1 for detecting the image data of the picture on the printed matter, and the picture on the printed matter surface is image-detected by the image detecting section 1 according to the timing signal. Is read, and the inspection processing unit 10 determines whether the image data is good or bad.

As another embodiment using this inspection apparatus, as a defective data input section, in combination with a winding material processing step management apparatus and a terminal apparatus used therefor according to the invention disclosed in Japanese Patent Application No. 2-301424. You may use. When comprehensively handled by the host computer using this defect data etc., it is possible to check quality information, production information, operation information in relation to other printing machines and processing machines in the post process and automatically fail in the post process. The part can be pulled out.

7 and 8 will be described. There are some small defects in printing. In the case of gravure printing, there are defects such as doctor streaks that occur in long streaks with a width of around 0.1 mm, and in the case of offset printing, defects that are approximately circular with a diameter of around 0.1 mm called Hicky. Sometimes occurs. However, such a fine defect cannot be detected by using only one image detection unit 1. In other words, since the line sensor used in the image detection unit 1 is composed of 1024 light receiving elements for one row, the defect detection of about 1 millimeter is the limit for a printed matter with a width of 1 meter. Therefore, as shown in FIG. 7 and FIG.
Image detection unit 1 for reducing the viewing field per pixel
It is possible to detect small defects by arranging about 10 of them and inspecting them in parallel. In addition, one line of the line sensor is the light receiving element 1
It uses 024, but one column has 250
The same is possible by using 0 or 5000.

An image detecting section 80 is provided so as to face the printed matter 50. The detection unit 80 is provided with a plurality of image detection units and a light source-related component that uniformly illuminates the pattern on the printed matter. The image detection unit is provided with 10 units facing the printed matter so that the pattern on the printed matter 50 can be monitored over the entire width of the printed matter and in the direction substantially perpendicular to the traveling direction of the printed matter, from the image detection section 1A to the image detection section 1J. ing. Regarding the light source, the light source 82 is installed in the lamp house 81, and the light from the light source is passed through the optical fiber 83 and the light guide 84.
Supply to one end of. The light guide 84 has a reflection surface formed on the entire surface inside the light guide, and the light incident from one end is reflected by the reflection surface inside the light guide and exits from a slit 89 provided so as to irradiate the print material. Irradiate evenly. Two such light guides 84,
The ten image detection units are arranged in parallel with each other in a direction substantially perpendicular to the traveling direction of the printed matter. If the detection areas of the 10 image detection units are set so as to overlap each other, no defect will be missed.

In this way, the images on the printed matter, which are uniformly irradiated by the light source, are subjected to image detection by 10 image detection units installed in the detection unit 80, and the image described in FIG. The signal processing is performed and the image signals of the 10 image detection units are parallelly processed by the signal transmission circuit 85 to the comprehensive inspection processing unit 86.
Send to. The processing unit 86 has a signal receiving circuit 87, which receives the image signals of the ten image detecting units from the signal transmitting circuit 85 in parallel, and receives these image signals from the inspection processing unit 10A corresponding to each image detecting unit. Send by 10J.
Then, as described with reference to FIG. 2, the image inspection of the pattern on the printed matter is performed in each inspection processing unit, and if there is at least one defect determination result in each inspection processing unit, the comprehensive inspection processing unit 86.
The result of the determination that the defect is more defective is output.

[0046]

According to the present invention, since the image data input by the HSI color system is expressed and the inspection is performed, it is easy to set the pass / fail judgment level of the inspection. Further, it has become possible to accurately inspect the print color of intermediate density such as yellow. Further, since three color filters are arranged on the entire surface of the light receiving element array in a direction orthogonal to the printed material traveling direction and these are stored in one line sensor, the corresponding light receiving elements have the same pattern. It is easy to align the pixels so that they can be monitored, and they are relatively unaffected by mechanical vibration or the like. Moreover, there is no need for a complicated mechanism to prevent vibration,
The mechanism such as the image detection unit can be simplified. Further, it becomes possible to inspect a fine print pattern.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an image detection unit of an inspection device according to the present invention.

FIG. 2 is a diagram showing a configuration of an embodiment of an inspection processing unit of the inspection device according to the present invention.

FIG. 3 is a diagram showing an installation situation in a printing machine in the embodiment of FIGS. 1 and 2;

FIG. 4 is a diagram showing an appearance of a line sensor in the embodiment of FIG.

FIG. 5 is a diagram showing an image pickup state of a printed matter of the image detection unit in the embodiment of FIG.

FIG. 6 is a diagram showing an address controller related to the embodiment of FIG. 2;

FIG. 7 is a diagram showing another embodiment of FIGS. 1 and 2.

FIG. 8 is a diagram showing a state where the image detection unit in the embodiment of FIG. 7 is viewed from the printed matter side.

FIG. 9 is a diagram showing a first conventional example.

FIG. 10 is a diagram showing a second conventional example.

[Explanation of symbols]

 1 Image Detection Section 2 Color CCD Line Sensor 3 Lens 4 Drive Circuit 5 Rotary Encoder 6 Amplifier 7 A / D Converter 8 Parallel / Serial Converter 10 Inspection Processing Section 15 RGB-HSI Conversion Section 16 Current Value Memory 17 Reference Value Memory 18 Subtraction unit 19 Judgment level setting unit 20 Judgment level memory 21 Comparison unit 22 Address control unit 50 Printed matter

Claims (1)

[Claims] 1. A memory having a memory capable of storing image data read from a design of a printed matter at a predetermined time, image data read from a non-defective printed matter is reference image data, and image data read from an inspected printed matter is inspection image data. age,
In a printed matter inspection device of a method of judging whether printing is good or bad based on a comparison between the reference image data and the inspection image data, a timing signal generation unit for generating a timing signal for reading a pattern of the printed matter, and a paper surface state of the printed matter are optically detected. Image detecting section provided with a plurality of light receiving elements, each of which is provided with three kinds of color filters on the front surface, in order to monitor the image in accordance with the timing signal from the timing signal generating section, and to read the pattern of the printed matter. A first current value memory for storing the image data detected by the light receiving element for each color filter, and three types of image data stored in the first current value memory are H (hue), S (saturation). ), I (lightness), and a conversion unit for converting the image data converted by this conversion unit to H (hue), S (saturation), and I (lightness). A second current value memory, a reference value memory that stores the reference image data detected by the image detection unit after conversion by the conversion unit, reference image data stored in the reference value memory, and a second current value memory. A subtraction unit that subtracts the inspection image data stored in the value memory, a determination level setting unit that sets the determination level for the quality judgment, and a determination level storage that stores the determination level set by this determination level setting unit An apparatus for inspecting a printed matter, comprising: a unit; and a comparison unit that outputs a result of comparing the subtraction value with the determination level set in the determination level storage unit.