JPS62299712A - Detecting device for mounting position - Google Patents

Abstract

PURPOSE:To accurately detect a measurement position mounted on a holding means and to perform high-accuracy position measurement by setting at least two standard measurement positions on a body to be measured corresponding to the measurement positions. CONSTITUTION:A measurement control means 73 sets the position and kind of a pattern to be inspected and an inspection processing procedure according to inspection items from an external signal input means 72. Then, a pattern information from an external signal input means 72. Then, a pattern information storage means 74 stores a pattern to be inspected in the body to be inspected and a processing procedure storage means 75 stores the inspection processing procedure for the pattern to be inspected. Then, a measuring means 76 scans the surface of the object of inspection under the control of a measurement control means 73 and detects image density. Then, an arithmetic processing means 78 processes data obtained from the measuring means 76 by a processing procedure indicated by the measurement control means 73 and displays the inspection result on a printer part or CRT screen of a computer part. Consequently, the measurement positions are accurately detected and the high-accuracy measurement is performed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention "Field of Industrial Application" The present invention is used, for example, in an image inspection device for inspecting the quality of images reproduced by facsimile machines, printing machines, or copying machines. The present invention relates to an optical density measuring device for image inspection.

"Prior Art" In offices, various information devices output graphic information such as text and images. A typical example of this is a copying machine that copies originals. A copying machine forms an electrostatic latent image on a photosensitive drum, reads image information using an image sensor such as a CCD, and develops the image using a developing device, or uses a recording head such as a thermal head. Images are reproduced on paper.

When designing such information devices or shipping these information devices from factories, reproduced images are inspected. There are two types of such tests:

(i) Inspection of whether the information equipment operates normally according to predetermined procedures and reproduces images.

(ii) Checking whether the quality of the reproduced image is within the market acceptable range or the specifications established when the equipment was designed.

For example, in the case of a copying machine, the inspection items include the position of the image relative to the copied paper, the density of the image relative to the original, and the resolution. The inspector uses a scale, a magnifying lens, a measuring device, or visually inspects to check whether each process of the copier is working properly, and to check if there are any errors in I@ reading or the transfer position of the toner image. Determine whether or not there are any.

In the case of copying machines, the latter inspection is also performed by an inspector. That is, the quality of the image is determined by the inspector directly comparing the image copied on the paper with the sample.

　　　.

In conventional inspections as described above, the inspector is the main person, so
There were the following problems.

(i) Measured values or test results changed when different testers were used.

(ii) Even for the same tester, the measured values or test results changed due to familiarity with the test or the psychological influence of the test subject tested previously.

(iii) Measured values or test results also changed due to physical or mental fatigue of the examiner.

In order to avoid such drawbacks, an image inspection device that automatically performs inspection has been proposed (Japanese Patent Application Laid-Open No. 1034-1989).
No. 5 and Japanese Patent Application Laid-open No. 10346/1983).

This image inspection apparatus is provided with a table on which an object to be inspected having an image is positioned and placed. The object to be inspected is set on this table, and the detection section is placed facing it. Then, the detection data output from this detection section is supplied to a data processing section, and the position, density, and resolution of the image are digitized based on the detection data.

FIG. 17 shows a table on which an object to be inspected is placed in this proposed apparatus.

An L-shaped guide 201 is arranged on this table so that the end of the object to be inspected, such as copy paper, can be positioned. Suction holes 203 are arranged in a grid pattern on the entire surface of the table 202. Each suction hole 2
03 is connected to a vacuum pump (not shown).

In this ysw, after the end face of the object to be inspected is placed along the guide 201, the vacuum pump is activated and the object to be inspected is suctioned and fixed onto the table 202 by its suction pressure. In this state, image inspection is started.

``Problems to be Solved by the Invention'' However, with this proposed image inspection apparatus, for example, when paper on which a chart has been copied (hereinafter referred to as copy paper) is used as the inspection object, it is difficult to position the part to be measured. This resulted in inaccuracies, and in some cases, the entire optical density measurement work was wasted.

This will be explained specifically. 18th! ! + represents an example of a chart for checking the copy status.

This subchapter) 204 has a pattern 205 for resolution inspection.
Patterns 206 representing various shadings for testing optical density and the like are arranged. When this chart 204 is set on a platen (not shown) of a copying machine and a copy is made, the position where the image is copied on each copy sheet may be shifted to a considerable extent depending on the copying machine. Also, for example, if the copy magnification is not set accurately, the pattern 205
．． The position of 206 is out of order.

'[Figure 19 is a slightly exaggerated representation of copy paper with such an error. Even if this copy paper 207 is fixed with its end face along the guide 201 as shown in FIG. In some cases, inspection of the area may be necessary. For example, even if positioning is performed for a pattern for resolution measurement consisting of parallel lines of different orders, if the copy paper 207 is set relatively tilted, the angle at which this pattern is scanned will be tilted. There was also the problem that the determined resolution contained errors.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a placement position detection device that accurately detects a measurement location placed on a holding means and enables highly accurate measurement.

[Means for Solving Problems J] In the present invention, at least two standard measurement points corresponding to the measurement points are arranged on the object to be measured, which is placed on the holding means. And the placement position detection device has
A storage means that stores a standard measurement point with respect to the planned placement position of the object to be inspected, a position measurement device that measures the existing position of the standard measurement point, and a calculation device that calculates the amount of deviation from the measured existing position with respect to the planned existing position. and place it. This amount of deviation makes it clear the positional relationship between the object to be inspected and the inspection device, and this amount of deviation can be used to accurately reach each inspection location.

"Example" The present invention will be described in detail below with reference to Examples.

1. Overview of the Apparatus FIG. 1 shows the external appearance of an optical density measuring apparatus for image inspection equipped with the placement position detecting apparatus of this embodiment. This optical density measurement apparatus for image inspection is composed of an inspection section 11, a computer section 2, and a printer section 3.

Of these, the inspection section 1 is a section that continuously inspects copy paper 4 as an object to be inspected. The inspection section 1 includes a supply tray 5 and a discharge tray 6.

When inspecting a copying machine, a desired chart is inserted into the copying machine, and the resulting copy sheets 4 are stacked on a supply tray 5 as shown.

The copy sheets 4 are fed into a cylindrical chart holder 8 one by one by a feed roller 7. The surface of the chart holder 8 is covered with an insulating film, and the copy paper 4 is electrostatically attracted to this surface by a charging operation by an electrostatic charge supply device (not shown). In this state, an image inspection of the copy paper 4 as the object to be inspected is performed. At this time, a placement position detection device, which will be described later, detects the location of the standard measurement location, based on which the location of the inspection location is predicted, and the desired image inspection is performed at that location.

The copy paper 4 that has been inspected is peeled off from the chart holder 8 by a peeling mechanism that will be described later. The peeled copy sheets 4 are sequentially discharged onto the discharge tray 6.

An operation display panel 9 is arranged in this inspection section 1.
Disposed here are a power switch 11, a movement key 12 used when manually specifying the pattern of the object to be inspected, and a display 13 for displaying concentration data as a measurement result.

The computer section 2 can be configured by a commercially available computer, and performs identification 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,
It is equipped with a disk drive device 17 etc. for driving a floppy disk, and a CPU (central processing unit) etc. for data processing is mounted inside.

The printer section 3 is a section that outputs test results and the like, and in this embodiment a dot printer is used.

FIG. 2 shows an outline of the inspection section of this optical density measuring device for image inspection. The feed roller 7 of this inspection section 1
A shaft 21 that rotates receives driving force from a feed roller drive motor 23 via a chain 22. The supply tray 5 is adapted to be given a force to move upward by the excitation of a solenoid (not shown), and at the time of this excitation, the top layer surface of the copy paper 4 as the object to be inspected comes into contact with the feed roller 21. When the feed roller 21 rotates by a predetermined amount in this state, only one sheet of copy paper 4 in the uppermost layer is fed out. Prior to this feeding, the surface of the chart holder 8 is uniformly charged by a charging mechanism (not shown).

As a result, the fed-out copy paper 4 is electrostatically attracted to the chart holding section 8. The rotation of the cylindrical chart holder 8 in the circumferential direction (Y-axis direction) is performed by the driving force of a chart holder drive motor 26 connected to a decelerator 25 .

In this embodiment, the outer diameter of the chart holder 8 is 162 mm in diameter.
77 mm, the step angle of the chart holder drive motor 26 is 1.8 degrees, and the reduction ratio of the reducer 25 is 1/256.
And so. As a result, the chart holder drive motor 26 is driven one step, and the surface of the chart holder 8 is moved by 10 μm in the Y-axis direction. Control of the rotational position of the chart holder 8, that is, the position control in the Y-axis direction, is performed using a point detected by the photosensor 23 in a notch 27 provided at the end of the cylinder as a reference point.

A ball screw 32 rotated by an X-axis stepping motor 31 is arranged above the chart holder B8 so that its axis is parallel to the rotation axis of the cylindrical chart holder 8. The Y-axis movement hole 34 of the optical head mounting block 33 is threadedly engaged with the ball stopper IJ, -32. Therefore, when the X-axis stepping motor 31 rotates, it moves in the X-axis direction while being guided by two guide bars 35 and 36 arranged parallel to the balls IJ and -32.

In this example, the pitch of ball stop IJ: L-32 is 5.
It is mm. By setting the step angle of the X-axis stepping motor 31 to 0.72 degrees, the optical head mounting block 33 is moved by 10 μm in the X-axis direction by driving one step. Two limit switches 37.
38 is arranged to limit the movement range of the optical head mounting block 33.

A density detection section 41, which will be described next, is attached to the optical head attachment block 33. A magnifying eyepiece lens 42 is also attached to the concentration detection fi 41, and the position of the image captured by the objective lens 43 can be checked during focus adjustment and especially during manual operation.

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

The concentration detection section 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 chart holder B8
The measurement site 53 is illuminated. The reflected light from the measurement site 53 is collected by an objective lens 43 and split into two directions by a prism 54 equipped with a semi-transparent mirror (beam splitter).

One of the branched lights is reflected by a mirror 55, passes through a measurement field of view adjustment mechanism 56, has its wavelength component corrected by a color correction filter 57, and enters a photomultiplier tube 58. Here, the measurement field of view adjustment mechanism 56 has an aperture v in the optical path.
i59 and a field lens 61 are arranged.

The aperture plate 59 is a slope with a rectangular opening as shown in FIG. In this opening area of 50 μm x 2500 μm, an image of the measurement site on the copy paper is magnified five times and formed. A light beam reflected from a rectangular area (FIG. 4) with a long side of 500 μm and a short side of 10 μm on the chart, that is, in this embodiment, on the copy paper 4, passes through this opening and enters the photomultiplier tube 58 described above. will be done. The longitudinal direction of the opening of the aperture plate 59 can be set at an arbitrary angle by an aperture plate rotation solenoid 62.

The other light branched by the prism 54 has its traveling direction changed by the roof-shaped prism 64, and forms an erect image on the observation screen 65.

The image of the measurement site 53 thus formed can be enlarged and observed using the magnifying eyepiece 42.

Circuit Configuration of Optical Density Measuring Apparatus for Image Inspection (Principle Configuration of the Apparatus) Regarding the optical density measuring apparatus for image inspection using a placement position detection device, the fundamental configuration of the circuit will first be explained.

The following FIG. 5 shows an outline of the circuit configuration of the optical density measuring device for image inspection. This device is equipped with an external signal manual means 72 for instructing desired inspection items. The measurement control means 73 is configured to set the position and type of the pattern to be inspected and the inspection processing procedure according to the inspection item indicated by the external signal manual means 72. The pattern information storage means 74 stores the pattern to be inspected in the object to be inspected, and the processing procedure storage half-receiver 75 stores the inspection processing procedure for the pattern to be inspected. The measurement means 76 scans the surface of the object to be inspected under the control of the measurement control means 73 and detects the image density. The arithmetic processing means 78 performs arithmetic processing on the data obtained from the measuring means 76 according to a processing procedure instructed by the measurement control means 73. As a result, the results of the i-inquired test are outputted by the output means 83. The output means 83 is typically the printer section 3 shown in FIG. 1, but the test results can also be displayed on the CRT screen of the computer section 2.

The operation of this optical density measuring device for image inspection will be explained in more detail. In the optical density measuring device for image inspection, the type of the object to be inspected and the inspection items are determined by an external signal manual means 7 during the inspection.
Coded by 2.

A chart code 84 for identifying the chart copied to the object to be inspected and an 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. The pattern information storage means 74 stores chart information.
A pattern code 86 representing the pattern to be inspected included in the chart represented by the code 84 and a representative point position 87 representing a representative position of the pattern to be inspected are output.

Of these, pattern code 86 is test item code 85.
The image density detection format 88 corresponding to the inspection item and pattern to be inspected and the arithmetic processing code 89 representing the arithmetic processing procedure are also sent to the processing procedure storage means 75 and read into the measurement control means 73.

At this stage, ■ the type of pattern to be inspected required for inspection, ■
Positional information on where the pattern exists on the copy paper, information on (1) an image density detection method for that pattern, and (2) information about a method for calculating and processing the results corresponding to the inspection items are stored in a code in the measurement control means 73. It will be set in a formatted state.

Among 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 measuring means 76.

The measuring means 76 moves to the representative point position 87 instructed by the measurement controlling means 73, and reads the image density detection format 8.
8, the image density to be measured is detected. The detection result is outputted to the arithmetic processing means 78 as a concentration data string 91. At the end of the concentration data string 91, an end signal 9
2 is added to instruct the start of arithmetic processing.

Upon receiving the end signal 92, the arithmetic processing means 78 executes the arithmetic processing code 89 previously supplied from the measurement control means 73.
Based on this, the corresponding calculation processing routine is selected. This arithmetic processing routine is then loaded into the internal arithmetic processing routine memory area. In the arithmetic processing means 78, the density data string 91 described above is stored in a density data string memory area. The arithmetic processing means 78 processes this concentration data string 91 using the routine loaded into the arithmetic processing routine memory area, and outputs the results according to the test items as the test results 9.
3 and is supplied to the output means 83.

The output means 83 will output this content.

The image density detection and density data arithmetic processing operations described above are sequentially performed for all patterns to be inspected that are preset in the measurement control means 73.

The arithmetic processing means 78 not only performs arithmetic processing on each pattern, but also performs statistical processing of the arithmetic processing results corresponding to all set patterns to be inspected. In this way, the desired test results for the object to be tested will be obtained.

(Configuration of external signal manual means) Next, the configuration of the external signal manual means will be explained using FIG. 6.

The external signal input means 72 includes encoding means 101 . The chart salt 102 and test items 103 manually entered by the operator are encoded by this encoding means 101. When the code type discrimination means 104 receives the coded information, it separates it into a chart code and a test item code. Then, it is output as a chart code 84 and a test 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 retrieval means 107. The pattern information storage position search means 107 searches for the position of the pattern to be inspected, and searches the pattern information storage B1.
08 as a pointer 109.

FIG. 8 shows the contents of the pattern information storage section. The pattern information storage unit 108 stores as data the pattern codes of all the objects to be inspected in the corresponding chart using the chart code as a key, and the representative point positions of the respective patterns represented by these pattern codes. . In this figure, for example, for chart code "XXX", there are three pattern codes a1
aSb is available. This applies to the chart specified by this chart code XXX'' with pattern code aS.
This means that two types of patterns specified by b are displayed, and the coordinates of the three patterns in total are as shown in the representative point 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) for "R1975".This pattern is placed in the upper left and lower right parts of this test chart.In addition, pattern code b
The pattern represented by is a pattern for density measurement in this electrophotographic society test chart.

In this test chart, various density samples are displayed in a row at the bottom, forming a pattern for density measurement.

The pattern information output means 110 includes the pattern information storage section 1
08 is read out from the position indicated by the pointer 109 output by the pattern information storage position search means 107. The read content is the pointer 109
All pattern codes and their representative point positions for one chart code indicated by . The pattern code 86 and its corresponding combination of representative point positions 87 are sequentially read out under the control of the measurement control means 73 shown in FIG. 5 and sent into the measurement control means 73.

(Configuration of processing procedure storage means) Next, the contents of the processing procedure storage means 75 are shown in FIG.

The processing procedure storage means 75 is supplied with an inspection item code 85 and a pattern code 86. Among these, the inspection item code 85 is detected by the inspection item code detection means 11.
2, and the pattern code 86 is detected by the pattern detection means 113. The detection result of the inspection item code detection means 112 is outputted as a first pointer 114 to the processing code storage means 115, and the detection result of the pattern detection means 113 is outputted as the pointer 115 of the rod 2 to the processing code storage means 116.

FIG. 10 shows the contents of the processing code storage means. The processing code storage child actor 116 stores (1) an arithmetic processing code, (11) a pattern code, and (iii) an image density detection code for each inspection item code. The first pointer 114 output from the above-mentioned test item code detection means 112 specifies the test item code for specifying the test item. Then, the second pointer 115 output from the pattern detection means 113 selects the arithmetic processing code in that inspection item code. In the example shown in FIG. 10, the pattern code “a
It can be seen that for the pattern specified by ``, image density detection specified by image density detection code A'' and calculation processing specified by calculation processing code A'' are performed.The code specified by the two pointers 114 and 115 is performed. The contents are temporarily stored in a storage area within 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 (layer degree 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 “i”. Based on this, the third pointer 119 as address information is stored in the inspection procedure storage means 121.
Output for.

FIG. 11 shows the contents of the inspection procedure storage means. The inspection procedure storage means 121 stores image density detection formats for each image density detection code. There are multiple 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, (11) direction, (
iii) interval, (iv) &e number of sunspots (V) in the slit direction.

Here, (i) the measurement start position is shown as a relative representative point. As described above, the representative point is indicated by the coordinates that serve as a reference for each pattern, whereas the counter representative point is the difference between the coordinate value of the starting position and the coordinate value of the representative point when scanning the pattern.

(ii) The direction is the direction of scanning, and there are two types of directions: the X-axis direction and the Y-axis direction. (iii) Interval is the sampling interval for concentration detection, and (iv)
The total score is the total number of sampled data. (
v) The slit direction refers to the direction of the opening of the aperture plate 59 shown in FIG. In this example, is the opening parallel to the χ axis?
It is set parallel to the Y axis rotated 90 degrees.

The third pointer 119 specifies the image density detection code. In the example shown in FIG. The selected image density detection format 88 is read out and supplied to the measurement means 76 under the control of the measurement control means 73 shown in FIG. The arithmetic processing code 89 is read out from the arithmetic processing means 78 and similarly supplied to the arithmetic processing means 78 under the control of the measurement control means 73.

(Configuration of measurement means) The following FIG. 12 shows the contents of the measuring means.

The measuring means 75 can be roughly divided into three parts: (1) an image density detection section, (II) a detection aperture control section, and (iii) a moving section. Measurement output terminal 75
Now, based on the image density detection format 88 supplied from the measurement control means 73, the object to be inspected (in this embodiment, the copy paper 4 on which the chart has been copied) is moved, and the image density is detected in a predetermined format. I will do it. That is, the image density detection format 88 (see FIG. 11) supplied from the measurement control means 73 is supplied to the data sampling control section 131, and based on the format 88 decoded here, the image density detection section and the detection aperture control section , and the moving part will be controlled accordingly.

By the way, the data sampling control section 131 controls the light receiving means 1 based on the data 133 obtained from the drive control section 132.
The current location of 33 is known. Therefore, the data sampling system W8'E131 determines the amount by which the light receiving means 133 should be moved by comparing it with the measurement start position obtained from the image density detection format 88. Data 134 regarding the determined movement amount etc. is sent to the drive control section 132.

The drive control unit 132 determines the amount of movement in the X-axis direction and the amount of movement in the Y-axis direction based on the data 134, and outputs an X-axis direction drive signal 135 and an X-axis direction drive signal 136 having the corresponding number of pulses. The X-axis direction drive signal 135 is supplied to the X-axis stepping motor 31, and the X-axis direction drive signal 136 is supplied to the chart holder drive motor 26 (both shown in FIG. 2) which also serves as a stepping motor.

As already explained, the concentration detection section 41 (FIG. 12) is moved in the X-axis direction by the X-axis stepping moke 31. Further, the drum-shaped chart holder 8 is rotated in the Y-axis direction by the drive of the chart holder drive motor 26, and the light receiving means 133 consisting of the photomultiplier tube 58 and the like is moved to a desired measurement position.

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

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

The drive control section 132 moves the concentration detection section 41 or the chart holding section 8 by a predetermined amount in accordance with 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 detection section, and its output 145 is logarithmically converted by a logarithmic converter 146. Conversion output 147 is provided to A/D converter 148. A/D
The converter 148 receives an A/D signal 151 from the A/D signal generator B149 for specifying the time at which the A/D conversion is performed.
is being supplied. A/D signal signal generating section 149 - A supplied from the data sampling control section 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 section 131 is used as the A/D start signal 152.

That is, this counter is preset with a count value corresponding to the measurement start position, and the light receiving means 1
As 33 begins to move, the count increases. When the count value of the counter reaches the preset value, the A/D
A start signal 152 will be output. When the A/D conversion is completed, the A/D signal generation section 149 completion signal 153
Output. When the data sampling control section 131 receives the end signal 153, it manages the above-mentioned counter and instructs the drive control section 132 to move the light receiving means 133, and if necessary, starts the next A/D at a predetermined timing. A D start signal 152 will be output. In this way,
It becomes 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 conversion output 147 from analog to digital. The density data 154 after conversion is
The images are sequentially stored in the image density buffer 155. The stored concentration data 154 is supplied to the arithmetic processing means 78 as a concentration data string 91, and is subjected to arithmetic processing.

Now, when the sampling of the concentration data progresses and the built-in counter counts a certain value as the final value, the data sampling control section 131 outputs an end signal 156 to the measurement control means 73.

When the measurement control means 73 receives this end signal 156,
Data regarding the next block is supplied to the data sampling control section 131 as an image density detection format 88. In this way, concentration data is collected for each part to be measured.

(Configuration of arithmetic processing means) FIG. 13 shows the configuration of the arithmetic processing means. The calculation processing means includes a calculation control section 161. The calculation control section 161 receives the calculation processing code 8 from the measurement control means.
9 is supplied. The arithmetic processing code 89 is a code representing the arithmetic processing procedure. The arithmetic control unit 161 decodes the arithmetic processing code 89 and supplies the result as an arithmetic processing code 162 to the arithmetic processing address search means 163.

The arithmetic processing address search means 163 uses this arithmetic processing code 162 to search the arithmetic processing storage section 164.

The arithmetic processing storage unit 164 stores arithmetic processing data groups necessary for various tests. When the arithmetic processing address search means 163 moves the pointer 165 to the start address of the corresponding memory area by searching,
A termination signal 166 is sent to 61. Arithmetic control II 61
After receiving the termination signal 166 , the start signal 167 is generated and supplied to the loader starter 168 .

When loader starter 168 receives activation signal 167, it generates load signal 169.171.

(1) Pointer 1 in the arithmetic processing storage unit 164
A series of arithmetic processing contents 172 indicated by 65 and (II) a density data string 91 stored in the image density buffer 155 (see FIG. 12) of the measuring means are transferred to the working area 17.
Load into 4. After loading, loader starter 16
8 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 contains the concentration data string 91.
The desired arithmetic processing is performed on the data. The result is stored in the calculation result output buffer 177 as the calculation result 176. The output means 83 shown in FIG. 5 manually outputs this stored content as an inspection result 93 and visualizes it.

Details of Placement Position Detection Apparatus In this optical density measurement apparatus for image inspection, the copy paper 4 is first held in the chart holding section 8, and after its position is determined, the density of each pattern is measured. Therefore,
Next, the positioning with respect to the copy paper 4 will be explained, and then the density measurement work for each pattern will be explained.

(Positioning for each measurement site) In order to measure an image from the copy paper on which the chart has been copied, the objective lens 43 of the optical head must correctly capture 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 paper 4 is ±5
An error of about mm occurs. This is due to the following reasons.

(1) Misalignment that occurs when a chart is copied using a copying machine.

As already explained, this includes errors in positioning (registration misalignment) between the copy paper 4 and the photosensitive drum of the copying machine, and errors in setting the magnification. Contains errors caused by skew (rotation) during transportation.

(1j) Misalignment of the positions set in the chart holder 8.

This is a deviation that occurs when the copy paper 4 sent out from the supply tray 5 is set in the chart holding unit 8, and is caused by an error in the setting of the supply tray 5 or a misalignment in position alignment when the copy paper 4 is sent out. do.

In this embodiment, the target position can be reached with an accuracy of ±0.5 mm. For this purpose, position detection patterns 192 and 193 are arranged at two locations, for example, on a chart 191 used in an optical density measuring device for image inspection, as shown in FIG. 14 as an example. The coordinates of these position detection patterns 192 and 193 are grasped for each type of chart by the optical density measuring device for image inspection. The coordinates of these patterns 192.193 on the chart are (X+
, Vl, X2, Y2).

The device calculates these coordinates (X+, Vl, X2,
3'2) is used to scan the surrounding copy paper 4, and by detecting the density change of the image (image), the position on the copy paper 4 on the apparatus side is detected. The coordinate values are (X, , Y, , X2,
Y2). By assembling the relational expressions of both coordinate systems (x, y), (x, y), the actual position (Xo, Y) corresponding to the coordinates (xo, yo) of the pattern to be measured is determined.
o) is calculated, and using this coordinate value (Xo, Yo), the density detection unit 41 is caused to reach the target image area.

(Coordinate correction using two standard measurement points) Figure 15 shows
This is intended to explain the principle of coordinate correction that enables desired positioning using two standard measurement points. In this figure, the y-axis and the Y-axis are coordinates on the placement position detection device, and these will be referred to as absolute coordinates. The y-axis and the y-axis are coordinates on the chart, and will be referred to as chart coordinates. Furthermore, the X' axis and the y' axis are coordinates on the copy paper as the object to be inspected, and these will be referred to as the coordinates of the object to be inspected.

Assuming that the chart is copied at a copying magnification of m, the coordinates of the object to be inspected (x', y') and the chart coordinates (x, y) have the relationship expressed by the following equation (1).

x' = mX y' = mY ...... (1) Absolute coordinates (X
, Y) is the inclination of the inspected object coordinates (xL, y/), and the origin of the inspected object coordinates on the absolute coordinates is (DX, DY).

Generally, any point (xt', yl
') and the corresponding absolute coordinates (XI, Yl
), then the two have the following relationship.

X, =x, 'cosθ−y, 'sin
θ+DXY, ==x, 'sin θ-'/
l' COSθ+DY Therefore, the absolute coordinates corresponding to any point (xl, 3/+) in chart coordinates are (X
, ,Y,''), the relationship between the two is expressed by the following equation (2).

X, =m (x, cos θ−y, sin θ
)+DXY, =m (x, sin θ−y,
cos θ)+DY (2) This equation (2) can also be expressed as follows.

Xl = (()++ -DX) cosθ+
(Yl −DY)sin θ)/m'/+ =
C(Yl-DY) cosθ-(XI
D Is required.

mS sin θ, cos θ, DX, DY Therefore, the 14th
As shown in the figure, there are two position detection patterns 192.
Coordinates on the chart of 193 (XI r 'II%
X213'2) as a clue, the absolute coordinates on the device side (
Xl, Yl, X2, Y2) are detected.

Using this result, five parameters are determined as follows.

(Left below) However, U+ =X+ (X2'+Y2'-XIXz-V+Y
2) 10X2 (XI"L"-XI>h-31+3h)"L
(XIV2-X2Yl)-Yz(X+3h-XzY+
) However, αx = L (x2"Q*"XIL2-y1y2)"
Y2(XI"yl" XIX2-3!+Vz)-Xl
(XIY2-L2VI)”X2(XIY2-X2Yl)
Therefore, by using these five parameters, based on the stored data about the desired inspection position (XI, yl) on the chart, its position (Xi, xt'') on the copy paper 4 on the placement position detection device can be determined. can be found.

FIG. 16 shows this procedure.

When the copy paper 4 is automatically set in the chart holder 8 shown in FIG. 1, the coordinates of the position detection patterns 192 and 193 shown in FIG. The detection unit 41 moves. Then, reading scanning is performed with some margin, and the position of this position detection pattern is measured. When this is finished, 2
Position measurement is also performed for the second position detection pattern (step 2 in FIG. 16). The data sampling control unit 131 in the compiler unit 2 calculates the five parameters described above based on this (step ■).
. After this, the coordinates of the representative point position and the coordinate values of the opposite representative point are called for one of the patterns to be inspected (
Step ■).

By adding the coordinates of the representative point to the coordinates of the representative point position, the coordinates of that point on the chart can be determined.

These chart coordinates are converted into absolute coordinates using the five parameters determined previously (step 2). After this,
The concentration detection unit 41 is moved to the representative point serving as the measurement start point (step 2). Measurement is started in this state (step ■). Specifically, the aperture plate 59 is oriented in a predetermined direction, the optical head is relatively moved in the X-axis direction or the Y-axis direction, and images are sampled. Measurement results are shown on CRT
16 and the display 13 as necessary (step ■).

When the measurement for one pattern is completed, it is determined whether a pattern to be measured exists (step 2). When the next measurement is performed on the same copy paper 4, its coordinates are read out (step 2) and the same operations as described above are performed. In this way, density measurements are performed for each requested pattern.

When all measurements are completed for one copy paper 4 (no copy paper), this copy paper 4 is discharged to the output tray 6 and the next copy paper is sent out from the supply tray 5. In this manner, when copy paper 4 remains as a measurement target (step ■; Yes), the position of the standard measurement point is first determined for the newly set copy paper 4 (step ■), and then Measurements for each pattern are performed by the above-described operations (steps ① to ②). When the measurement work has been completed for all of the copy sheets 4 scheduled for measurement (step 2; N), all inspections have been completed.

"Modification" Above, we have explained the method of measuring two predetermined points to arrive at the predicted position, but it is also possible to measure three points and arrive at the desired position based on the results. be.

FIG. 17 shows an example of the arrangement of position detection patterns in this case. According to this three-point measurement method, 3
By measuring the three position detection patterns 211 to 213, the amount of expansion and contraction of the object to be inspected in the X-axis direction and the Y-axis direction can also be determined, thereby making it possible to reach the target point more accurately. Furthermore, by measuring four or more points, it is possible to approximately calculate the local expansion and contraction of the object to be inspected, and it is possible to reach the target point with even higher accuracy.

Next, for reference, six parameters obtained by measuring three points are shown. However, m8 here is the magnification of the inspected object in the X-axis direction with respect to the chart, and is m.

is the magnification of the object to be inspected relative to the chart in the Y-axis direction.

(XI)h' ”-(yl-Y3-1, αs = L(X3"y3'-XIX3 M+!/3)"
X3(X+'jL"-XIX3-Y+Vs)"L(XI
Ys-X3Y+)-L(X+!/3X3Y+) However, a4 = Y, (x, 2+y, 2-)(, x3-y, y
3)+Y3(XI"Y+"-XIx3-Y+!/5)-
Xl (XIV3-X3Vl)"X3 (XIY3-X
dl) Although the present invention has been described above in detail in connection with an optical density measuring device in the embodiments and modifications, it goes without saying that the present invention can be widely applied to other general positioning applications.

"Effects of the Invention" As described above, according to the present invention, it is possible to accurately calculate the amount of deviation of the object to be inspected, and by increasing the number of measurement points, various quantities such as expansion and contraction and distortion of the object to be inspected can also be measured. It becomes possible to do so. Furthermore, by performing coordinate transformation based on the determined amount of deviation, it is possible to position the patient accurately at the target position.

[Brief explanation of drawings]

1 to 16 are for explaining one embodiment of the present invention, of which FIG. 1 is a perspective view of an automatic image inspection device;
Fig. 2 is a schematic configuration diagram showing the main parts of the inspection section, Fig. 3 is an explanatory layout diagram showing the arrangement of optical components of the optical head, and Fig. 4 shows the size of the area that is the measurement unit on copy paper. 5 is a block diagram showing the outline of the circuit configuration of the automatic image inspection device, FIG. 6 is a block diagram showing the configuration of the external signal manual means, and FIG. 7 is a block diagram showing the configuration of the pattern information storage means. , FIG. 8 is an explanatory diagram showing the structure of the pattern information storage section, FIG. 9 is a block diagram showing the structure of the processing procedure storage means, FIG. 1O is a block diagram showing the structure of the processing code storage means, and FIG. 11 is a block diagram showing the structure of the processing code storage means. FIG. 12 is a block diagram showing the structure of the test procedure storage means, FIG. 12 is a block diagram showing the structure of the measuring means, FIG. 13 is a block diagram showing the structure of the arithmetic processing means, and FIG. 14 is a plan view showing the main parts of the chart. , FIG. 15 is an explanatory diagram showing the principle of coordinate correction, FIG. 16 is a flowchart to explain position detection and the measurement work involved, and FIG. 17 is a plan view showing a table of a conventionally proposed device. , FIG. 18 is a plan view showing the measurement part of the chart, and FIG.
It is a top view which shows the example which copied the chart shown in the figure. 1... Inspection section, 2... Computer section, 3... Printer section, 4... Copy paper (object to be inspected), 8...・
・Chart holder, 26...Chart holder drive motor, 31...
...X-axis stepping motor, 41 ... Concentration detection section, 131 ... Data sampling control section, 132
... Drive control section, 133 ... Light receiving means. Applicant: Fuji Xerox Co., Ltd. Agent

Claims (1)

[Scope of Claims] 1. A holding means, an object to be inspected having at least two standard measurement points placed on the holding means, and the existence of a standard measurement point for the planned placement position of the object to be inspected. A mounting position characterized by comprising means for storing a planned position, a position measuring means for measuring the existing position of a standard measurement point, and a calculation means for calculating the amount of deviation from the measured existing position with respect to the expected existing position. Detection device. 2. A holding means, an object to be inspected having an inspection point and at least two measurement points placed on the holding means;
Means for storing the expected position of the standard measurement point relative to the planned placement position of the object to be inspected, position measuring means for measuring the position of the standard measurement point, and calculating the amount of deviation from the measured position to the expected position. 1. A placement position detection device comprising: calculation means for calculating the amount of deviation; and position prediction means for predicting the location of the inspection point relative to the scheduled placement position from the calculated amount of deviation.