JPH0654940B2 - Automatic image inspection device - Google Patents

Description

The present invention relates to an automatic image inspection apparatus for inspecting the quality of an image reproduced by, for example, a facsimile machine, a printing machine, or a copying machine.

"Conventional technology" In the office, various information devices output image information such as characters and images. A typical example of this is a copying machine for copying a document. A copying machine forms an electrostatic latent image on a photosensitive drum, reads image information using an image device such as a CCD, develops using a developing device, or uses a recording head such as a thermal head. The image is reproduced on paper.

When designing such information devices or shipping these information devices from the factory, inspection of reproduced images is performed. Such inspections are roughly classified into the following two types.

(I) Inspection of whether or not the information device normally operates according to a predetermined procedure and reproduces an image.

(Ii) Inspection of whether or not the quality of the reproduced image is acceptable in the market or within the specifications specified at the time of designing the device.

For example, in the case of a copying machine, the inspection item includes the position of the image on the copied sheet, the density of the image on the original, the resolution, and the like. The inspector makes full use of the scale, magnifying lens or measuring device, or visually inspects to make sure that the processes of the copier are operating normally, and there is no error in reading the image or transferring the toner image. Whether or not it is determined.

In the case of a copying machine, the latter inspection is also performed by the inspector. That is, the degree of the image is determined by the inspector directly comparing the image copied on the sheet with the sample.

Since the inspector is the main body of the above conventional inspection,
There were the following problems.

(I) When the inspector is different, the measured value or the inspection result changes.

(Ii) Even in the same inspector, the measurement value or the inspection result changed due to the familiarity of the inspection or the psychological influence of the previously inspected object.

(Iii) The measured values or test results also changed depending on the physical and mental fatigue of the inspector.

In order to avoid such a defect, an image inspection apparatus that automatically inspects has been proposed (Japanese Patent Laid-Open No. 59-1034).
64 and JP-A-59-103465).

In this image inspection apparatus, a table for positioning and placing an inspection object having an image is prepared. The object to be inspected is set on this table, and the detection section is arranged facing this. Then, the detection data output from this detection unit is supplied to the data processing unit, and the position of the image based on the detection data,
Digitize density and resolution.

"Problem to be solved by the invention" However, in this proposed image inspection apparatus, the detection unit sequentially detects some predetermined patterns,
Only stylized inspections can be done. For example, it is assumed that only the density inspection is required for a certain information device to be inspected, and the resolution inspection is required for other information devices in many places of the inspection object. In the proposed image inspection apparatus, uniform inspection is performed on all the inspection objects, so that the former information equipment is wastefully inspected and wastes inspection time. Moreover, in the latter information device, there is a possibility that the inspection location may be insufficient.

Of course, the latter inspection can be satisfied by incorporating a program that performs many inspections at many places on the inspection object, but such an image inspection apparatus requires a simple inspection. There is a problem that a more inefficient inspection is performed on the inspection object.

Therefore, an object of the present invention is to provide an image automatic inspection apparatus which is an automated apparatus and which can freely set inspection contents according to an inspection object.

“Means for Solving Problems” In the present invention, (a) a predetermined chart in which an inspection pattern to be inspected and a position detection pattern for clarifying the position thereof are arranged is obtained by copying. An inspecting object accommodating means capable of stacking a plurality of the sheet-shaped inspected objects, and (b) an inspecting object feeding means for sequentially sending the inspecting objects one by one from the inspecting object accommodating means in accordance with the progress of the inspection. ,
(C) A mounting table capable of holding one by one on the surface of the inspected objects sent by the inspected object feeding means, and (d) the position of the position detection pattern and the inspection pattern for each chart. And (e) an inspection pattern selection unit that selects a pattern whose optical density is to be measured from a plurality of types of inspection patterns according to the inspection item. ) Optical density measuring means for measuring optical density, (g) position detecting pattern detecting means for detecting a position detecting pattern on the inspection object held on the mounting table, and (h) position storing means On the mounting table of the inspection pattern selected by the inspection pattern selecting means from the relationship between the position of the position detecting pattern stored in the table and this position detected by the position detecting pattern detecting means. And (b) moving means for moving the optical density measuring means to face the position on the mounting table calculated by the inspection pattern position calculating means, and (u) optical density measuring The automatic image inspection apparatus is provided with a discharging means for removing the object to be inspected, which has been measured by the means, from the mounting table and discharging it to a predetermined position. Then, when the inspected object whose chart for inspection is changed according to the inspection item is placed on the mounting table, the inspected pattern is searched for, and the optical density measuring unit arranged opposite to this inspects the inspected pattern. The optical density is detected.

Of course, even if the chart is not changed, it is possible to set inspection items and omit unnecessary inspections.

[Examples] The present invention will be described in detail below with reference to Examples.

Outline of Apparatus FIG. 1 shows an appearance of an automatic image inspection apparatus according to an embodiment of the present invention. This automatic image inspection apparatus is composed of an inspection unit 1, a computer unit 2 and a printer unit 3. Of these, the inspection unit 1 is a unit that continuously inspects the copy paper 4 as the inspection object. The inspection unit 1 includes a supply tray 5 and a discharge tray 6. When the copier is inspected, a desired chart is set on the copier, and the copy paper 4 thus obtained is stacked on the supply tray 5 as shown. The copy papers 4 are fed one by one to the cylindrical chart holding unit 8 by the feed roller 7. The surface of the chart holding portion 8 is covered with an insulating film, and the copy sheet 4 is electrostatically adsorbed to this surface by a charging operation by an electrostatic charge supply device (not shown). In this state, the image inspection of the copy paper 4 as the inspection object is performed.

The copy paper 4 that has been inspected is peeled from the chart holding unit 8 by a peeling mechanism described later. The copy paper 4 after peeling is sequentially discharged to the discharge tray 6.

An operation display panel 9 is arranged in the inspection unit 1,
Here, a power switch 11, a moving key 12 used for manually specifying the pattern to be inspected, and a display 13 for displaying density data as a measurement result are arranged.

The computer unit 2 can be configured by a commercially available computer, and performs specification of inspection items, processing of data such as concentration data, and various displays. This part includes a keyboard 15 as an input means, a CRT 16 as a display means,
A disk drive device 17 for driving a floppy disk is provided, and a CPU (central processing unit) for data processing is installed inside.

The printer section 3 is a section for outputting inspection results and the like, and a dot printer is used in this embodiment.

FIG. 2 shows the outline of the inspection unit of this automatic image inspection apparatus. The shaft 21 that rotates the feed roller 7 of the inspection unit 1 receives the driving force from the feed roller drive motor 23 via the chain 22. The supply tray 5 is provided with a force that moves upward by the excitation of a solenoid (not shown), and the surface of the uppermost layer of the copy sheet 4 as the inspection object comes into contact with the feed roller 21 during the excitation. When the feed roller 21 rotates by a predetermined amount in this state, only one copy sheet 4 of the uppermost layer is fed out. Prior to this feeding, the chart holding portion 8 has its surface uniformly charged by a charging mechanism (not shown). As a result, the copy paper 4 sent out is electrostatically adsorbed to the chart holding unit 8. The rotation of the cylindrical chart holder 8 in the circumferential direction (Y-axis direction) is performed by the driving force of the chart holder driving motor 26 connected to the speed reducer 25.

In the present embodiment, the chart holder 8 has an outer diameter of 162.
77 mm, the step angle of the chart holding unit drive motor 26 was 1.8 degrees, and the speed reduction ratio of the speed reducer 25 was 1/256. As a result, the chart holding unit drive motor 26 becomes 1
By being step-driven, the surface of the chart holding unit 8 moves by 10 μm in the Y-axis direction. The control of the rotational position of the chart holding unit 8, that is, the position control in the Y-axis direction is performed by using the point where the notch 27 provided at the end of the cylinder is detected by the photo sensor 28 as a reference point.

A ball screw 32 rotated by an X-axis stepping motor 31 is arranged above the chart holding unit 8 such that its axis is parallel to the rotation axis of the cylindrical chart holding unit 8. The Y-axis direction moving hole 34 of the optical head mounting block 33 is screwed into the ball screw 32. Therefore, when the X-axis stepping motor 31 rotates, the X-axis stepping motor 31 is guided by the two guide bars 35 and 36 arranged in parallel with the ball screw 32 to move in the X-axis direction.

In this embodiment, the pitch of the ball screw 32 is 5 mm. Set the step angle of the X-axis stepping motor 31 to 0.7
With the configuration of two degrees, the optical head mounting block 33 moves in the X-axis direction by 10 μm in one step of driving. Two limit switches 37 and 38 are arranged in the X-axis direction to limit the moving range of the optical head mounting block 33.

The optical head mounting block 33 is mounted with a density detecting section 41 described below. A magnifying eyepiece lens 42 is also attached to the density detecting unit 41, so that the position of the image captured by the objective lens 43 can be confirmed during focus adjustment and particularly during manual operation.

FIG. 3 shows the optical structure of the optical head.

The concentration detector 41 includes a tungsten lamp 51 for illumination. The light emitted from the tungsten lamp 51 is condensed by the illumination lens 52, and the measurement site 53 of the chart holding unit 8 is illuminated. The reflected light from the measurement site 53 is collected by the objective lens 43 and split into two directions by a prism 54 equipped with a semitransparent mirror (beam splitter).

One of the branched lights is reflected by a mirror 55, passes through a measurement visual field adjusting mechanism 56, is corrected in wavelength component by a color correction filter 57, and is incident on a photomultiplier tube 58. Here, the measurement visual field adjusting mechanism 56 has an aperture plate 59 and a visual field lens 61 arranged in the optical path.

The opening plate 59 is a plate having a rectangular opening as shown in FIG. In the 50 μm × 2500 μm opening area, the image of the measurement site on the copy sheet is magnified 5 times and formed. On the chart, that is, in this embodiment, the long piece on the copy paper 4 is 500 μm,
A light beam reflected from a rectangular region (FIG. 4) having a short side of 10 μm is incident on the photomultiplier tube 58 through the opening. The opening plate 59 can set the longitudinal direction of the opening at an arbitrary angle by the opening plate rotating solenoid 62.

The other light split by the prism 54 has its traveling direction changed by the roof prism 64 and is formed as an erect image on the observation screen 65. The image of the measurement site 53 thus formed can be magnified and observed by the magnifying eyepiece lens 42.

Circuit Configuration of Device (Principle Configuration of Device) Prior to a specific description of the device, the principle configuration of the circuit will be described.

Next, FIG. 5 shows an outline of the circuit configuration of the automatic image inspection apparatus. This apparatus is provided with an external signal input means 72 for instructing a desired inspection item. The measurement control means 73 is adapted to set the position, type and inspection processing procedure of the pattern to be inspected according to the inspection item represented by the external signal input means 72. The pattern information storage means 74 stores the inspection pattern in the inspection object, and the processing procedure storage means 75 stores the inspection processing procedure for the inspection pattern. Measuring means 7
Reference numeral 6 scans the surface to be inspected under the control of the measurement control means 73 to detect the image density. The arithmetic processing means 78 is a processing procedure instructed by the measurement control means 73, and uses the measuring means 76.
The data obtained from is processed. The inspection result thus obtained is output by the output means 83. The output unit 83 is typically the printer unit 3 shown in FIG. 1, but the inspection result can also be displayed on the CRT screen of the computer unit 2.

The operation of the automatic image inspection apparatus will be described in more detail. In the automatic image inspection apparatus, the type and the inspection item of the inspection object are coded by the external signal input means 72 at the time of inspection. The chart code 84 for specifying the chart copied to the object to be inspected and the inspection item code 85 representing the inspection item are sent to the measurement control means 73. The measurement control means 73 sends the chart code 84 to the pattern information storage means 74. Pattern information storage means 7
Reference numeral 4 denotes a pattern code 86 representing an inspected pattern included in the chart represented by the chart code 84 and a representative point position 8 representing a representative position of the inspected pattern.
7 is output. Of these, the pattern code 86 is sent to the processing procedure storage means 75 together with the inspection item code 85,
The image density detection format 88 corresponding to the inspection item and the pattern to be inspected and the arithmetic processing code 89 representing the arithmetic processing procedure are read into the measurement control means 73.

At this stage, the kind of the pattern to be inspected necessary for the inspection, the position information of the position of the pattern on the copy paper, and the result corresponding to the image density detecting method and the inspection item for the pattern are arithmetically processed. Information about the method will be set in the measurement control means 73 in coded form.

Of these pieces of information, the representative point position 87 representing the coordinates of the position where the pattern exists and the image density detection format 8
8 is sent to the measuring means 76. The measuring means 76 moves to the representative point position 87 designated by the measurement control means 73, and detects the image density to be measured according to the image density detection format 88. The detection result is output to the arithmetic processing means 78 as the density data string 91. An end signal 92 is added to the end of the density data sequence 91 to instruct the start of arithmetic processing.

When the arithmetic processing means 78 receives the end signal 92, the arithmetic processing code 89 supplied from the measurement control means 73 before that.
Based on, the arithmetic processing routine corresponding to this is selected. Then, this arithmetic processing routine is loaded into the internal arithmetic processing routine memory area. The above-mentioned density data string 91 is stored in the density data string memory area of the arithmetic processing means 78. The arithmetic processing means 78 processes the density data sequence 91 by the routine loaded in the arithmetic processing routine memory area, and supplies the result according to the inspection item as the inspection result 93 to the output means 83. The output means 83 will output this content.

The image density detection and the density data calculation processing operation described above are sequentially performed on all the inspection patterns preset in the measurement control unit 73. The arithmetic processing means 78 performs arithmetic processing on individual patterns and also statistical processing of arithmetic processing results corresponding to all the set inspection patterns. In this way, the desired inspection result for the inspection object can be obtained.

(Structure of External Signal Input Means) Next, the structure of the external signal input means will be described with reference to FIG.

The external signal input means 72 comprises a coding means 101. Each chart 102 and inspection item 103 input by the operator are coded by this coding means 101. Upon receiving the coded information, the code type discrimination means 104 separates the coded information into a chart code and an inspection item code. Then, it is output as the chart code 84 and the inspection item code 85 via the code control unit 105.

(Structure of Pattern Information Storage Means) FIG. 7 shows the structure of the pattern information storage means. The pattern information storage means 74 supplies the chart code 84 to the pattern information storage position searching means 107. The pattern information storage position searching means 107 searches the position of the pattern to be inspected and sends it to the pattern information storage unit 108 as a pointer 109.

FIG. 8 shows the contents of the pattern information storage section. The pattern information storage unit 108 stores, as data, all the pattern codes to be inspected in the corresponding chart using the chart code as a key and the representative point positions of the patterns represented by these pattern codes. . In this figure, for example, for the chart code "XXX", three pattern codes a,
a and b are prepared. This means that two types of patterns specified by the pattern codes a and b are displayed in the chart specified by this chart code "XXX", and the coordinates of a total of three patterns are representative. It is as shown in the dot position.

Here, the pattern represented by the pattern code a is, for example, the Electrophotographic Society test chart "No. 1-".
This is a resolution measurement pattern (not shown) in R 1975 ″. In this test chart, this pattern is arranged in the upper left and lower right parts. Also, the pattern represented by the pattern code b is this electron. It is a pattern for density measurement in a photo society test chart.
In this test chart, various concentration samples are displayed in a row below the test chart to form a concentration measurement pattern.

The pattern information output means 110 is the pattern information storage unit 1.
The contents stored in 08 are read from the position indicated by the pointer 109 output by the pattern information storage position searching means 107. The read content is the pointer 109
All pattern codes for one chart code indicated by and their representative point positions. The combination of the pattern code 86 and the representative point position 87 corresponding thereto is sequentially read out by the control of the measurement control means 73 shown in FIG.

(Structure of Processing Procedure Storage Means) Next, the contents of the processing procedure storage means 75 are shown in FIG.

The inspection item code 85 and the pattern code 86 are supplied to the processing procedure storage means 75. Of these, the inspection item code 85 is the inspection item code detecting means 11
2 and the pattern code 86 is detected by the pattern detecting means 113. The detection result of the inspection item code detection means 112 is output to the processing code storage means 115 as the first pointer 114, and the detection result of the pattern detection means 113 is also output to the processing code storage means 116 as the second pointer 115.

FIG. 10 shows the contents of the processing code storage means. The processing code storage means 116 stores (i) calculation processing code, (ii) pattern code, and (iii) image density detection code for each inspection item code.
The inspection item code for specifying the inspection item is designated by the first pointer 114 output from the inspection item code detecting means 112. Then, the arithmetic processing code in the inspection item code is selected by the second pointer 115 output from the pattern detecting means 113.
In the example shown in FIG. 10, for the pattern specified by the pattern code "a", the image density detection code "a"
It can be seen that the image density detection specified by and the calculation processing specified by the calculation processing code "A" are performed. The code contents designated by the two pointers 114 and 115 are
It is temporarily stored in the storage area in the processing code storage means 116.

Returning to FIG. 9, the explanation will be continued. Inspection procedure search means 11
7 reads out the image density detection code 118 stored in the processing code storage means 116. In the example of FIG. 10 described above, the image density detection code 118 is “A”. Then, based on this, the third pointer 119 as address information is output to the inspection procedure storage means 121.

FIG. 11 shows the contents of the inspection procedure storage means. The image density detection format is stored in the inspection procedure storage means 121 for each image density detection code. There are a plurality of sets of image density detection formats, each of which is stored in block units. The contents of these block units are, for example, (i) measurement start position, (ii) direction, (ii
i) interval, (iv) total score, and (v) slit direction.

Here, (i) the measurement start position is shown as a position as a pair representative point. The representative point is indicated by the reference coordinates for each pattern, as described above, whereas the representative point is the difference between the coordinate value of the start position and the representative point coordinate value when the pattern is scanned. The (ii) direction is the scanning direction, and there are two types, the X-axis direction and the Y-axis direction. (Ii
i) Interval is the sampling interval for density detection, and (iv) Total score is the total number of sampled data. (V) The slit direction means the direction of the opening of the opening plate 59 shown in FIG. In this embodiment, the opening is set parallel to the X-axis or parallel to the Y-axis rotated by 90 degrees.

The third pointer 119 identifies the image density detection code. In the example shown in FIG. 11, the image density detection code "A" is selected. The first code output means 122 reads the image density detection format 88 selected by the third pointer 119 and supplies it to the measuring means 76 under the control of the measurement control means 73 shown in FIG. On the other hand, the second code output means 123 reads out the arithmetic processing code 89 from the processing code storage means 116 and similarly supplies it to the arithmetic processing means 78 under the control of the measurement control means 73.

(Structure of Measuring Means) Next, FIG. 12 shows the contents of the measuring means.

The measuring means 75 can be roughly classified into (i) an image density detecting section, (ii) a detection aperture control section, and (iii) a moving section.
It can be divided into two parts. The measurement output terminal 75 moves on an object to be inspected (copy paper 4 on which the chart is copied in this embodiment) based on the image density detection format 88 supplied from the measurement control means 73, and in a predetermined format. The image density will be detected. That is, the image density detection format 88 (see FIG. 11) supplied from the measurement control unit 73 is supplied to the data sampling control unit 131, and based on the format 88 decoded here, the image density detection unit and the detection aperture control unit. ,
The moving part will be controlled by it.

By the way, the data sampling control unit 131 uses the data 133 obtained from the drive control unit 132 to detect the light receiving unit 1.
Knowing 33 currently existing locations. Then, the data sampling control unit 131 obtains the amount of movement of the light receiving unit 133 by comparison with the measurement start position obtained from the image density detection format 88. The data 134 regarding the obtained movement amount and the like is sent to the drive control unit 132.

The drive control unit 132 obtains the X-axis direction movement amount and the Y-axis direction movement amount based on the data 134, and outputs the X-axis direction drive signal 135 and the Y-axis direction drive signal 136 having the corresponding pulse numbers. X-axis direction drive signal 135
Is supplied to the X-axis stepping motor 31, and the Y-axis direction drive signal 136 is supplied to the chart holding unit drive motor 26 (also see FIG. 2) which is also a stepping motor.

As described above, the X-axis stepping motor 31 moves the density detector 41 (FIG. 2) in the X-axis direction.
Further, the chart holding unit drive motor 26 drives the drum-shaped chart holding unit 8 to rotate in the Y-axis direction, and the light receiving means 133 including the photomultiplier tube 58 and the like moves to a desired measurement position.

Next, the data sampling control unit 131 decodes the image density detection direction, the sampling interval, the total number of sampling points, and the slit direction. Then, first, the opening direction is compared with the current opening direction, and the angle signal 138 representing the comparison result with the instructed angle is output. Angle signal 138
Is supplied to the angle signal generator 139. The angle signal generator 139 supplies the control signal 141 to the aperture plate rotating solenoid 62 (see FIG. 3) to rotate the aperture plate 61 by a desired angle.

When the setting of the light receiving unit 133 is completed as described above,
The data sampling control unit 131 sets the total score obtained from the image density detection format 88 in a counter (not shown) in the control unit. Then, the image density detection direction and the sampling interval are output to the drive control unit 132 as data 134 and set.

The drive control unit 132 moves the density detection unit 41 or the chart holding unit 8 by a predetermined amount according to the instructed detection direction.

By the way, the detection output 14 output from the light receiving means 133
3 is amplified by an amplifier 144 in the image density detecting section, and its output 145 is logarithmically converted by a logarithmic converter 146. The converted output 147 is supplied to the A / D converter 148. A / D
The converter 148 has an A / D signal 151 from the A / D signal generator 149 for designating the time at which the A / D converter is operated.
Are being supplied. A / D signal generator 14
9 is A supplied from the data sampling control unit 131
The A / D signal 151 is generated by the / D start signal 152, and the output of a counter (not shown) in the data sampling control unit 131 is used as the A / D start signal 152.

That is, the count value corresponding to the measurement start position is preset in this counter.
The count value increases with the start of movement of 33. When the count value of the counter reaches the preset value, A / D
The start signal 152 will be output. When the A / D conversion is completed, the A / D signal generator 149 outputs the end signal 153.
Is output. Upon receiving the end signal 153, the data sampling control unit 131 manages the above-mentioned counter to instruct the drive control unit 132 to move the light receiving unit 133, and when necessary, starts the next A / D at a predetermined timing. The signal 152 will be output. In this way
It is possible to manage the sampling interval of concentration data.

On the other hand, when A / D conversion is instructed by the A / D signal 151, the A / D converter 148 converts the converted output 147 from analog to digital. The converted density data 154 is
It is sequentially stored in the image density buffer 155. The stored density data 154 is supplied to the arithmetic processing means 78 as the density data string 91, and the arithmetic processing is performed.

When the sampling of the density data progresses and the built-in counter counts a certain value as the final value, the data sampling control unit 131 outputs the end signal 156 to the measurement control unit 73. Upon receiving the end signal 156, the measurement control unit 73 supplies the data for the next block to the data sampling control unit 131 as the image density detection format 88. In this way, the concentration data is collected for each part to be measured.

(Structure of Arithmetic Processing Unit) FIG. 13 shows the structure of the arithmetic processing unit. The arithmetic processing means includes an arithmetic control unit 161. The arithmetic processing section 89 is supplied with the arithmetic processing code 89 from the measurement control means. The arithmetic processing code 89 is a code representing an arithmetic processing procedure. The arithmetic control unit 161 decodes the arithmetic processing code 89 and supplies the result as the arithmetic processing code 162 to the arithmetic processing address searching means 163.

The arithmetic processing address searching unit 163 searches the arithmetic processing storage unit 164 using the arithmetic processing code 162.
The arithmetic processing storage unit 164 stores arithmetic processing data groups necessary for various inspections. The arithmetic processing address search means 163 moves the pointer 165 to the start address of the corresponding memory area by the search, and then the arithmetic control unit 1
The end signal 166 is sent to 61. After receiving the end signal 166, the arithmetic control unit 161 generates a start signal 167,
Supply to the loader / starter 168.

When the loader / starter 168 receives the activation signal 167, it generates load signals 169 and 171. Then, (i) a series of arithmetic processing contents 172 indicated by the pointer 165 in the arithmetic processing storage unit 164, and (ii) working the density data string 91 stored in the image density buffer 155 (see FIG. 12) of the measuring means. Load in area 174. After the loading is completed, the loader / starter 168 supplies a start signal 175 to the working area 174, activates it, and transfers control to the working area 174 itself.

Along with this, the working area 174 has a concentration data string 91.
Then, the desired arithmetic processing is executed for. The result is stored in the operation result output buffer 177 as the operation result 176. The output means 83 shown in FIG. 5 inputs this stored content as an inspection result 93 and visualizes it.

Flow of Density Inspection Operation FIG. 14 shows the flow of the inspection operation by the image automatic inspection apparatus. In the flow chart, a portion surrounded by a broken line 181 is a portion for obtaining the pattern information about the corresponding chart from the chart code input from the outside and reading it into the main storage unit (not shown) in the measurement control means 73.

First, when the automatic image inspection apparatus is activated, a request message is displayed on the screen of the CRT 16 of the computer section 2 shown in FIG. 1 to input the type of the chart to be inspected by the chart code CC (step ), The inspection operator waits for input of the chart code CC from the keyboard 15. When a chart code is input and read (step), a CPU (central processing unit) (not shown) in the measurement control means drives the disk drive unit 17 to obtain pattern information about the corresponding chart, and the floppy disk. Open the chart information file stored in (step).

FIG. 15 shows the contents of the chart information file. The chart information file is composed of an index table and a pattern information storage unit. In the index table, the chart code CC _i and the pattern information storage address ADP _i are stored as a pair. Here, the pattern information storage address ADP _i is
The address of the corresponding pattern information in the pattern information storage unit. For example, if the chart code representing the chart to be inspected is CC ₁ , the pattern information storage address is ADP ₁ . Therefore, looking at the location of the address ADP _{1 in} the pattern information storage unit, this chart code shows four pattern codes PC ₁₁ ,
It can be seen that it includes PC ₁₂ , PC ₁₃ , and PC ₁₄ . As an example, the pattern represented by the pattern code PC ₁₁ has three coordinates (X ₁₁ , Y ₁₁ ), (X ₁₂ ,
It can be seen that they are present at the respective positions of Y ₁₂ ), (X ₁₃ , Y ₁₃ ).

First, the index table is read into the work area of the main memory described above (step), and the corresponding pattern information storage address ADP _i is obtained using the input chart code CC as a search element (step). Then, a series of pattern information starting from the address ADP _i of the pattern information storage unit is read and read into the pattern information table of the main storage unit (step).

FIG. 16 shows an example of the contents of the pattern information table. In the pattern information table, the respective pattern codes of the chart to be measured and their existing representative point positions are represented. For example, in this example, since there are two patterns represented by the pattern code PC ₁ on the same chart, their representative point positions (X ₁₁ , Y ₁₁ ) and (X ₁₂ , Y ₁₂ ) are shown on the table, respectively. Has been done.

When the pattern information table for the chart to be inspected is created as described above, the chart information file on the floppy disk is closed (step).

A portion surrounded by a broken line 182 is a portion for obtaining a processing procedure from the inspection item code externally input and the above-mentioned pattern information and creating a measurement control table in the main memory. The operation of this part will be described below.

When the chart type is entered in the previous work, CRT16
This time, a request message is displayed to enter the inspection item by code (step), and the inspection operator waits for input of the inspection item code INS _i from the keyboard 15. The inspection item code INS _i is a code for specifying an inspection item such as resolution and density. If there is only one type of inspection item, inspection item code IN
Although S _{i is} also one type, if there are a plurality of inspection items, a plurality of inspection item codes INS _i must be input. Therefore, one inspection item code I from the keyboard 15
After the NS _i is read (step), if the request end message is not input (step; N), other inspection item codes INS _i can be read repeatedly.

When the input of the inspection item code INS _i is completed, the CPU drives the disk drive device 17 to open the processing procedure information file stored in the floppy disk in order to obtain the processing procedure information for the corresponding inspection item (step ).

FIG. 17 shows the contents of the information processing procedure file.

The information processing procedure file includes a processing procedure code table and a density detection format storage unit. In the processing procedure code table, (i) inspection item, (ii) pattern code, (iii) operation processing code, and (i
v) Four types of information of the density detection format storage address are stored as a set. Here, the arithmetic processing code cl _j is a code representing the arithmetic processing corresponding to the inspection item code ins _j , and the pattern code pc _j is used when inspecting the inspection item indicated by the inspection item code ins _j. Is a code that represents a pattern. The density detection format storage address adf _j is a code representing the density detection format for inspecting the corresponding inspection item with the above-mentioned pattern.

The density detection format storage unit stores the density detection format mform _j from the storage address corresponding to each density detection format storage address adf _j .

The CPU first searches the processing procedure code table for a column having an inspection item code ins _j that matches the keyed-in inspection item code INS _i (step). continue,
It is searched whether or not the pattern code PC _k that matches the pattern code pc _j in the matched column exists in the pattern information table shown in FIG. 16 (step). If the number of columns in the pattern table is N, the search is repeated up to this number N (step). If they do not match, the pointer j indicating the search column of the processing procedure code table is advanced to the next column, and the above search is repeated (step).

If they match, the operation processing code cl _j and the density detection format storage address adf _j are read from that column of the matched processing procedure code table (step), and a series of density detection formats MFORM _i (starting from this address). = Mform _j ) is read (step). Then, the representative point position (X, Y) _in of the corresponding pattern is read from the corresponding column of the pattern information table (step).

The inspection item code INS _i , the operation processing code CL _j (= cl _j ), the representative point position (X, Y) _in, and the density detection format MFORM _{i obtained as} described above are written in the measurement control table of the main memory ( Step). First
FIG. 8 shows the structure of this measurement control table.

The above operation is repeated for the number L of the inspection item codes INS _i keyed in (step), the measurement control table shown in FIG. 18 is created, and then the floppy disk file is closed (step).

Next, in FIG. 14, a portion surrounded by a broken line 183 is a portion for detecting the density of the measured portion on the copy sheet 4 according to the measurement control table, and a portion surrounded by a broken line 184 is the measurement control table and the density detection result. It is a part that obtains the result for the inspection item by calculation processing from and outputs it to the outside. Both portions surrounded by the broken lines 183 and 184 are repeated one by one for the previous inspection item on the measurement control table, and are repeated by the number of copy sheets 4 input prior to the inspection work. That is, if a plurality of copy sheets 4 on which the same chart is copied are set in advance on the supply tray 5 shown in FIG. 1, the inspection of each inspection item will be performed for these.

Now, the work flow will be described from the part surrounded by the broken line 183.

Upon completion of the step, a request message is displayed on the screen of the CRT 16 to enter the number NS of sheets to be inspected (copy sheet 4 in which the chart is copied in this embodiment) (step), and the inspection operator uses the keyboard 15
It waits until the number NS is input. As described above, the inspection operator normally inputs the number of copy sheets 4 set on the supply tray 5 from the keyboard 15.

When the device receives a key input (step), the inspection operation is started. First, the pointer (PP) indicating the current work column of the measurement control table shown in FIG. 18 is initialized (step), and the copy paper replacement subroutine is called in the copy paper 4 loading mode (step).

When the copy paper 4 is sent out from the supply tray 5 and electrostatically adsorbed by the chart holding unit 8 and its mounting is completed,
The representative point position (X, Y) _pp and the density detection format MFORM _{pp in the} column indicated by the pointer of the measurement control table are read (step). Then, a density detection subroutine for detecting the density of the pattern to be inspected is called (step).

When the density detection of the corresponding pattern is completed, the arithmetic processing code of the measurement control table is read (step). At the same time, an arithmetic processing subroutine of the same name is loaded / run from the floppy disk, and arithmetic processing is started for the density detection result in the output storage section (step).

In this way, when the calculation process for the target inspection item is completed, the result is sequentially output by the printer 3 (step). After this, the pointer is advanced to the next column (+1) of the measurement control table shown in FIG. 18 (step).

Until the pointer goes beyond the last column of the measurement control table, the density detection, the calculation process, and the printer output are repeated according to the contents of each column of this table (step).

When the pointer goes beyond the last column of this table, the number NS of copy sheets 4 to be inspected is decremented by 1 (step). If the number NS is 1 or more (step), it means that the copy paper 4 to be measured still remains in the supply tray 5. So in this case,
The copy paper replacement subroutine is called in the copy paper 4 replacement mode. Then, after the next copy sheet 4 is attached to the chart holding unit 8, the pointer of the measurement control table is initialized (step), and the inspection of the next copy sheet is started.

The above measurement operation is repeated and the number of copy sheets 4 NS
Is subtracted by 1 (step) as a result, the number of sheets NS
Becomes 0, the copy paper replacement subroutine is called in the copy paper 4 discharge mode (step), and after the final copy paper 4 is discharged to the discharge tray 6, the entire operation is completed.

Positioning with respect to each measurement site The flow of measurement has been described above. Next, positioning with respect to each pattern on the copy sheet 4 will be described.

In order to measure an image from a copy paper on which the chart is copied, the objective lens 43 of the optical head must correctly grasp the target measurement site. By the way, if the density detection unit 41 side is unilaterally set to a predetermined coordinate position, the desired position on the copy sheet 4 is ± 5.
An error of about mm occurs. This is due to the following reasons.

(I) Misalignment that occurs when copying a chart with a copying machine.

This includes not only the alignment error (registration deviation) between the copy paper 4 and the photosensitive drum of the copying machine, the setting error of the magnification, but also when the copy paper 4 is conveyed inside the copying machine. The error due to the occurrence of skew (rotation) is included.

(Ii) Misalignment when set on the chart holding unit 8.

This is a deviation that occurs when the copy paper 4 delivered from the supply tray 5 is set in the chart holding unit 8, and an error in the setting of the supply tray 5 or a positional alignment deviation when the copy paper 4 is delivered is applicable. To do.

In this embodiment, the target position can be reached with an accuracy of ± 0.5 mm. For this purpose, a chart 191 used in the automatic image inspection apparatus as shown in FIG.
For example, the position detection patterns 192-1
94 were placed. These position detection patterns 192 to
The coordinates of 194 are grasped by the type of chart on the image automatic inspection device side. These patterns on the chart 1
The coordinate values of 92 to 194 will be referred to as real coordinate values, and these will be represented by (X ₁ , Y ₁ , X ₂ , Y ₂ , X ₃ , Y ₃ ).

The apparatus scans the copy paper 4 around the actual coordinate values (X ₁ , Y ₁ , X ₂ , Y ₂ , X ₃ , Y ₃ ) and detects the change in the density of the image by scanning them. The position on the copy paper 4 is detected. These position detection patterns 19 on the copy paper 4
The coordinate values of 2-194 are (x ₁ , y ₁ , x ₂ , y ₂ ,
x ₃ , y ₃ ). Both coordinate systems (X, Y), (x, y)
The actual position (X ₀ , Y ₀ ) corresponding to the coordinate (x ₀ , y ₀ ) of the pattern to be measured on the copy paper 4 is calculated by assembling the relational expression of
₀ , Y ₀ ) is used to cause the density detection unit 41 to reach the target image portion.

The position detection pattern does not need to be arranged at three places on the copy sheet, and by arranging the position detection pattern at two places, the copy sheet 4
It is possible to grasp the rotation and displacement of the. Further, by arranging more points, it is possible to grasp the elongation of each portion of the copy sheet 4 and the like, and it is possible to further improve the accuracy of reaching the measurement site.

In the embodiment described above, the image density is detected by setting a fine window having a width of 10 μm on the copy paper as the inspection object. Therefore, the density data equivalent to that when the image inspection is performed by human eyes is performed. Can be obtained. Therefore, depending on the data processing, there is an advantage that a delicate inspection result (operation of a sensory value) equivalent to that inspected by human eyes is possible.

[Effects of the Invention] As described above, according to the present invention, the supply means for supplying the inspection object to the mounting table is provided, and the inspection object supplying means sequentially sends the inspection object to the mounting table one by one. Depending on the contents of the inspection, the inspection of a plurality of sheets can be performed automatically, and the labor for the inspection can be significantly reduced. Further, since the inspection pattern can be selected according to the measurement content, efficient inspection becomes possible. Further, in the present invention, the position of the position detection pattern and the positional relationship between the inspection patterns are stored in advance in the position storage means for each chart, and the position of the inspection pattern on the inspection object held on the mounting table is stored. The position detection pattern is detected by the position detection pattern detection unit, and the inspection pattern selection unit is selected from the relationship between the position of the position detection pattern stored in the position storage unit and the position detected by the position detection pattern detection unit. It was decided to calculate the position on the mounting table of the inspection pattern selected by. Since the optical density measuring means is moved so as to face the calculated position on the mounting table, it is possible to measure the optical density with high accuracy at an accurate position.

[Brief description of drawings]

The drawings are for explaining an automatic image inspection apparatus according to an embodiment of the present invention, in which FIG. 1 is a perspective view of the automatic image inspection apparatus, and FIG.
FIG. 3 is an arrangement explanatory view showing the arrangement of optical parts of the optical head, FIG. 4 is an explanatory view showing the size of an area as a unit of measurement on the copy paper, and FIG. 5 is a circuit configuration of the image automatic inspection apparatus. FIG. 6 is a block diagram showing the outline, FIG. 6 is a block diagram showing the configuration of the external signal input means, FIG. 7 is a block diagram showing the configuration of the pattern information storage means, and FIG. 8 is an explanatory diagram showing the configuration of the pattern information storage section. FIG. 9 is a block diagram showing the configuration of the processing procedure storage means, FIG. 10 is a block diagram showing the configuration of the processing code storage means, FIG. 11 is a block diagram showing the configuration of the inspection procedure storage means, and FIG. FIG. 13 is a block diagram showing the configuration of the measuring means, FIG. 13 is a block diagram showing the configuration of the arithmetic processing means, FIG. 14 is a flowchart showing the flow of the inspection operation by the automatic image inspection apparatus, and FIG. 15 is the configuration of the chart information file. Explanation to show FIG. 16 is an explanatory view showing the structure of a pattern information table, FIG. 17 is an explanatory view showing the structure of an information processing procedure file, FIG. 18 is an explanatory view showing the structure of a measurement control table, and FIG. 19 is position detection. FIG. 6 is a plan view of a chart showing the locations where the use patterns are arranged. 1 ... inspection unit, 2 ... computer unit, 3 ... printer unit, 4 ... copy paper (inspection object), 5 ... supply tray, 7 ... feed roller, 8 ... chart holding unit (mounting table) ), 15 ... keyboard, 16 ... CRT, 17 ... disk drive device, 41 ... density detector, 43 ... objective lens, 51 ... tungsten lamp, 58 ... photomultiplier tube, 59 ... opening Plate, 62 ... Opening plate rotating solenoid, 72 ... External signal input means, 73 ... Measurement control means, 74 ... Pattern information storage means, 75 ... Processing procedure storage means, 76 ... Measuring means, 78 ... Computation processing means, 83 ... Output means, 191, ... Chart, 192-194 ... Position detection pattern.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Yoshizawa 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Business Office (72) Inventor Kenichi Segawa 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Business In-house (56) Reference JP-A-59-103464 (JP, A)

Claims (1)

[Claims] 1. A plurality of sheet-shaped inspected objects obtained by copying a predetermined chart in which an inspection pattern to be inspected and a position detection pattern for clarifying its position are copied. Possible inspecting object accommodating means, inspecting object feeding means for sequentially sending out the inspecting objects one by one from the inspecting object accommodating means, and these inspected objects sent out by the inspecting object feeding means A mounting table capable of holding objects one by one on the surface instead of each other, a position storage unit that stores in advance the positions of the position detection patterns and the positional relationship between the inspection patterns for each chart, and inspection items. Inspection pattern selecting means for selecting a pattern whose optical density is to be measured from among a plurality of types of inspection patterns, optical density measuring means for measuring optical density, and Position detecting pattern detecting means for detecting the position detecting pattern on the inspection object held above, the position of the position detecting pattern stored in the position storing means and the position detecting pattern detecting means Inspection pattern position calculating means for calculating the position on the mounting table of the inspection pattern selected by the inspection pattern selecting means from the relationship with this position detected by the inspection pattern position calculating means. A moving means for moving the optical density measuring means so as to face the position on the table, and a discharging means for removing the object to be inspected, which has been measured by the optical density measuring means, from the table and discharging it to a predetermined position. An image automatic inspection apparatus characterized by being provided.