JP2005115732A - Image correction device and image correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve the problem that an inspection image is largely distorted by not only assembling precision of an inspecting jig but also an influence of error amount of image sticking parts in the case that an inspection object is made larger than a scan length by making a device high-speed, small-scale, or the like. <P>SOLUTION: An image correction device has; a line sensor 1 for photographing an inspection object 9; an X axis driving means 104 for carrying the line sensor 1 in parallel with an S-axis direction being the scanning direction in the line direction of the line sensor 1; a Y axis table driving means 8 for moving a table having the inspection object 9 placed thereon; and a memory 109 for recording and synthesizing image data obtained by photographing the inspection object 9 with the line sensor 1 and the error amount is detected from image data obtained by synthesizing strip-shaped image data obtained by the line sensor 1, on the memory 109 and corrected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an image correction apparatus and an image correction method. More specifically, the present invention relates to an apparatus that performs an inspection using a line sensor that scans an inspection target and outputs an image signal, an image position error due to assembly accuracy, an image pasting position error due to a reciprocating operation of a conveyance unit, The present invention relates to a technique for measuring and correcting a scanning width error or the like.

FIG. 24 shows an outline of an image correction apparatus that performs inspection using a line sensor that scans a conventional inspection object and outputs an image signal.
In FIG. 24, the line sensor 1 for scanning the inspection object, and the line sensor 1 on the inspection object,
A motor 5, which is a means for conveying in the Y-axis direction, a ball screw 6, and guide rails 7a and 7b for guiding the conveyance table 8 are provided. Since the scanning width of the line sensor 1 is imaged in a measurement region larger than the inspection object as shown in FIG. 24, the image can be corrected simply and easily. However, when the inspection object is larger than the measurement range, in other words, when the scanning width of the line sensor 1 is smaller than the inspection object width, not only the image position error due to the assembly accuracy but also the image bonding position due to the reciprocating operation of the conveying means. Various errors such as errors and line sensor scanning width errors greatly affect the measurement image.

Patent Document 1 discloses that a correction reference sample is read, a correction image is obtained, correction data is obtained based on the correction image, an inspection object is then imaged, and correction is performed based on the correction data. .

Further, Patent Document 2 stores correction values corresponding to a plurality of predetermined positions of a position detection unit that detects a position coordinate value of a driving unit of the line sensor and a display unit of an image signal from the line sensor. An image input device for correcting data coordinate values is described.
JP 2000-121337 A Japanese Patent Laid-Open No. 10-311705

When the inspection object is sufficiently smaller than the measurement range, the influence of the error is not a factor that greatly affects the bonded image and the measurement accuracy. However, due to the high speed of the device and the narrowing of the measurement range due to the miniaturization of the device, the inspection object may be larger than the scanning width,
The influence of the error amount in the image pasting portion causes a large distortion in the inspection image, and the measurement accuracy is greatly deteriorated. In addition, not only the assembly accuracy but also the influence of aging of various members due to the use of the image correction apparatus affects the inspection accuracy, so various error amounts must be corrected.

The present invention solves the above-described conventional problems, and performs measurement and correction of an image position error due to assembly, an image pasting position error due to a reciprocating operation of a conveying unit, a scanning width error of a line sensor, and the like with high accuracy. An object of the present invention is to provide an image correction apparatus and an image correction method that can be obtained by photographing an inspection target.

In order to solve the above problems, an image correction apparatus according to the present invention includes a line sensor that captures an inspection target and outputs an image signal, a scanning direction in a line direction of the line sensor is an S-axis direction, and the S-axis direction is X-axis drive means for transporting in parallel, Y-axis table drive means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction, and image data obtained by imaging the inspection object by the line sensor And a memory for recording and synthesizing
The X-axis drive means and the Y-axis drive from image data obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory. It is characterized by detecting the deviation of the orthogonality of the means.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Parallelism between the S-axis and the X-axis from image data obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the operation width in the S-axis direction of the line sensor on the memory. It is characterized by detecting the deviation of the difference.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. The transport amount of the Y-axis direction transport means is corrected according to the error amount.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. Then, the image storage position in the Y-axis direction in the memory is corrected according to the error amount.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Pasting an image in the X-axis direction of the scanning width of the line sensor obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory An error amount of the alignment position is detected, and the conveyance amount of the X-axis direction conveyance unit is corrected according to the error amount.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Pasting an image in the X-axis direction of the scanning width of the line sensor obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory An error amount of the alignment position is detected, and the image storage position in the X-axis direction in the memory is corrected according to the error amount.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. In addition, the error amount of the image pasting position in the X-axis direction of the scanning width of the line sensor is detected, and the X-axis direction and the Y-axis are detected according to the detected error amounts in the Y-axis direction and the X-axis direction, respectively. The conveyance amount of the direction conveyance means is corrected.

The image correction apparatus according to the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and the scanning direction of the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. In addition, the error amount of the image pasting position in the X-axis direction of the scanning width of the line sensor is detected, and the X-axis to the memory is determined according to the detected error amounts in the Y-axis direction and the X-axis direction. The image storage position in the direction and the Y-axis direction is corrected.

The image correction method of the present invention includes a line sensor that shoots an inspection target and outputs an image signal, and a scanning direction in the line direction of the line sensor is an S-axis direction, and is conveyed in parallel with the S-axis direction. Recording and synthesizing image data obtained by imaging the inspection object by the line sensor and the Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction perpendicular to the X-axis direction. Memory and
The inspection object is scanned with the predetermined scanning width of the line sensor, and when scanning of one line is completed, the line sensor is moved in the Y-axis direction by a distance corresponding to a predetermined resolution by the Y-axis table moving means. The X-axis is obtained from the inspection image data obtained by synthesizing on the memory strip-like image data obtained by repeating this operation for the number of lines corresponding to a predetermined distance in the Y-axis direction. It is characterized in that a mounting deviation in the orthogonality between the driving means and the Y-axis table driving means is detected.

As described above, according to the image correction apparatus and the image correction method of the present invention, when an image position error due to assembly accuracy, an image pasting position error due to a reciprocating operation of the conveying unit, a scanning width error of the line sensor, or the like occurs. However, these errors and the like can be detected and corrected using synthesized image inspection data, and high-precision assembly adjustment can be performed.

Hereinafter, when the inspection object is larger than the scanning width of the line sensor, the image correction apparatus and the image correction method of the present invention are used to measure various errors generated in the inspection image and the correction methods thereof. Will be described in detail.

FIG. 1 is a diagram schematically illustrating the overall configuration of an image correction apparatus according to the present invention, and FIG. 2 is a diagram for illustrating an outline of a line sensor unit. 1 and 2, the overall operation of the image processing apparatus of the present invention will be described.
First, the movement of the line sensor 1 and the Y-axis table 8 to the inspection start position will be described.
(1) A scan start command signal 1) is sent from the CPU 100 to the drive system controller 101.
(2) When a signal from the CPU 100 enters the drive system control unit 101, a drive signal 2) to the inspection start position is transmitted to the X-axis drive unit 104 and the inspection via the X-axis correction unit 102 and the Y-axis correction unit 103. It is sent to the Y-axis table drive unit 105 that conveys the conveyance table 8 on which the object is placed.
(3) Next, drive signals output from the X-axis drive unit 104 and the Y-axis table drive unit 105
In accordance with 3), the line sensor 1 and the Y-axis table 8 are passed through the X-axis drive means and the Y-axis transport means.
Is moved to a predetermined inspection start position. The X conveying means moves the line sensor 1 over the inspection object 9 to X
The motor 2 and the ball screw 3 are transported in the axial direction, and guide rails 4a and 4b guide the line sensor 1. The Y-axis transport means is composed of the motor 5, the ball screw 6, and the transport tables 7a and 7b.

Next, the flow of the inspection signal will be described.
(4) After the line sensor 1 moves to the inspection start position, a command signal 4) for starting scanning of the line sensor 1 from the CPU 100 is sent to the sensor I / F board 106.
(5) When a signal from the CPU 100 enters the sensor I / F board 106, a scan start signal 5) is sent to the line sensor 1, and scanning of the inspection object 9 is started.
As shown in FIG. 2, the line sensor 1 includes a scanning optical system including a light source 30, a polygon mirror 31, and a scanning lens 32, a light receiving optical system including a condenser lens 33 and a position detection element 34. In FIG. 2, the scanning operation is performed by deflecting the light beam from the light source (laser) 30 by the polygon mirror 31 and irradiating the measurement target surface of the inspection target 9 via the scanning lens 32 with the scanning light. Reflected light from the measurement object is passed through the condenser lens 33 and the position detection element 34.
To obtain an image signal of the inspection object 9.
An inspection image is acquired at a resolution of 1500 points within the scanning width of 30 mm of the line sensor 1, that is, 20 μm. Of course, the resolution can be changed by changing the number of 1500 points.
A desired resolution is obtained. When the scanning of 30 mm per line is completed, the resolution is 20 μm.
A drive signal is sent to the Y-axis stage moving means for m minutes, and after the movement in the Y-axis direction, the next one line is scanned. By repeating this, scanning with a width of 30 mm is performed, and a strip-like image with a width of 30 mm is taken.
(6) When photographing of the strip image is completed, the scanning end signal 6) is sent from the line sensor 1 to the sensor I / F.
Sent to the board 106.
(7) When a scanning end signal from the line sensor 1 is input to the sensor I / F board 106, the CPU
A scan end signal is sent to 100, an X-axis drive signal is sent to the drive system control unit 101, and a signal is sent to the X-axis drive unit 104 via the X-axis correction unit 102.
(8) When an X-axis drive signal is input to the X-axis drive unit 104, a drive signal 8) is sent to the X-axis drive means,
The line sensor 1 moves 30 mm in the X axis direction. After the line sensor 1 moves 30 mm in the X-axis direction, a series of operations from (4) are repeated. In this way, a strip-shaped image signal having a width of 30 mm is obtained on the entire surface to be inspected.

Next, the flow of image data will be described.
(9) The data 9) captured by the line sensor 1 is sent to the sensor I / F board 106.
(10) The input data 9) is stored on the image memory 107 as image data 10) from the sensor I / F board 106.
(11) The data stored on the image memory 107 is output as image data 11) to the correction unit 108, and the corrected image data is combined on the inspection image via the correction unit 108.
At this time, in consideration of the directionality of the image data stored on the image memory 107, the image data are combined, and a composite image (inspection image) is formed in the inspection memory 109. The CPU 100 calculates an error amount using the synthesized inspection image, and stores the calculated error amount in the correction unit 108 as a correction value. Then, the bonding position error amount in the X-axis direction and Y-axis direction of the strip-shaped image is read as a correction value by the correction unit 108, and the storage address on the inspection memory 109 is corrected and stored using this correction value. Of course, the image memory 107 and the correction unit 10
8. It is also possible to adopt a configuration in which the inspection memory 109 is integrated.
(12) The inspection image data 12) formed in the inspection memory 109 is sent to the CPU 100 for inspection.
The scan operation to be inspected and the storage of the captured image on the image memory 107 are performed in conjunction with each other.

FIG. 2 is a diagram for explaining the configuration of the line sensor 1. As described above, the light beam from the light source (laser) 30 is deflected by the polygon mirror 31 and scanned on the measurement target surface via the scanning lens 32. Irradiate light. Then, the reflected light from the measurement object 9 is condensed on the position detection element 34 via the condenser lens 33. When the measurement object 9 has a difference in height, in the configuration of the line sensor of the present invention, the position of the light beam entering the position detection element 34 differs if the height of the measurement object is different. Can also be done.

The flow of imaging of an inspection target, storage of image data, synthesis of image data, calculation of correction values, and the like will be described with reference to the drawings, taking examples.

It is assumed that the strip-like images are six composite images “1” to “6”. (No. 1 to 6 drawings are displayed although the number display is different from the drawings.)
To facilitate understanding, in FIG. 3, the inspection object 9 is the alphabet “A” and the size is 18
A case of 0 mm × 200 mm will be described. Specifically, the X-axis and Y-axis resolution is 20 μm.
m, the X-axis inspection target area is 180 mm, the Y-axis inspection target area is 200 mm, and the inspection start position is the upper left of the drawing. When the movement to the inspection start position is completed by the scan start command signal from the CPU 100, the scan width is 30 mm (1500 dots at a resolution of 20 μm).
200mm in the Y-axis direction while scanning on the inspection object 9 (10,0 at a resolution of 20 μm)
00 line) is conveyed and a strip-shaped image “1” is taken. When shooting of the strip-shaped image “1” by 200 mm transport is completed, the line sensor 1 is transported by 30 mm in the X-axis direction, and the inspection target 9 is scanned with a scanning width of 30 mm, while the strip-shaped image “1” is captured. The strip-shaped image “2” is photographed while moving in the reverse direction. This operation is repeated until the strip-like image “6” is photographed and stored in the image memory 107. In the image memory 107, the strip images “1” to “6” are stored in series as shown in FIG. That is, the address value of the X axis of one strip-shaped image data having a width of 30 mm is 0 to 1500, the address value of the Y axis is 0 to 10,000, and 6 sheets are stored in series. The address value is 60,000. Then, the strip-shaped image stored in the image memory 107 is set to have an X-axis address value of 0 to 9,000 and a Y-axis address value of 0 to 10,000 in the inspection memory 109 as shown in FIG. Synthesized.

Since the resolution is 20 μm, the image memory 107 from the inspection area in the X-axis direction and the Y-axis direction is used.
Six strip images for 1500 dots in the upper X-axis direction and 10,000 lines in the Y-axis direction are stored. The image data stored on the image memory 107 is synthesized on the inspection memory 109 to create an inspection image. However, if the image data is simply pasted, the following problems occur.

In other words, image synthesis is performed on the inspection memory 109, but if the images are pasted at the address 0 on the image memory 107, the Y-axis direction is taken in a reciprocating motion, so that the amount of movement in the Y-axis direction is 200 mm. Due to the influence of the movement amount error, FIG.
As shown in FIG. 4, the inspection image has a level difference (Y-axis direction bonding error Ey) in the Y-axis direction. Also in the X-axis direction, an inspection image in which a step (X-axis direction bonding error) has occurred with respect to the actual inspection target image as shown in FIG. 8 due to the influence of the movement amount error with respect to the scanning width of 30 mm. Become.

In order to correct a level difference caused by photographing and synthesizing the strip-shaped image of the inspection object 9, a bonding position error between adjacent strip-shaped images is determined from the inspection image in the inspection memory 109 by C.
Calculate with PU100. The calculated value is stored as a correction amount in the correction units 102 and 103 disposed between the drive system control unit 101, the X-axis drive unit 104, and the Y-axis drive unit 103, and using this correction value, the drive system The drive signal from the control unit is corrected and sent to the X-axis drive unit 104 and the Y-axis table drive unit 105 to correct the movement amount (X-axis direction movement amount) and the Y-axis table movement amount of the line sensor 1.

In addition, the correction amount calculated by the CPU 100 from the inspection image synthesized in the inspection memory 109 is
The data is stored in the correction unit 108 arranged between the image memory 107 and the inspection memory 109, and the inspection memory 1
By correcting the storage position (address) of the image data stored in 09, the bonding position error can be corrected. FIG. 7 corrects the bonding position in the Y-axis direction, and FIG. 9 corrects the bonding position in the X-axis direction.

The correction of the Y-axis direction bonding error will be specifically described with reference to FIGS. The strip shape stored in the inspection memory 109 is pasted with the Y-axis direction pasting error Ey in FIG. 6 from (1500, 10,000) to (1500, 10,000-Ey) as the start address of the image data “2”. . In the same manner, the strip images are pasted together to create a composite image shown in FIG.

In the correction of the composite image having the X-axis direction combining error shown in FIG. 8, the head address stored is also corrected, and the composite image shown in FIG.

  Next, the image correction apparatus of the present invention will be described using a grid-like inspection pattern.

FIG. 10 is a schematic diagram of the image correction apparatus according to the first embodiment of the present invention. In FIG.
A line sensor 1 for photographing the inspection object 9 and outputting an image signal; a motor 2 and a ball screw 3 as means for conveying the line sensor 1 in the X-axis direction on the inspection object 9; a guide rail 4a for guiding the sensor; 4b, a conveyance table 8 for fixing the inspection object 9, a motor 5 as a means for conveying the conveyance table 8 in the Y-axis direction, a ball screw 6, and guide rails 7a and 7b for guiding the conveyance table 8. .

An example of the inspection object 9 in this embodiment is shown in FIG. FIG. 11 shows a pattern 11 in the X-axis direction.
And a Y-axis direction pattern 12, which is a grid-like inspection pattern 10, and a pattern 1
FIG. 12 shows an example of an inspection pattern in which the right angle of the crossing angle between 1 and the pattern 12 is accurately formed and can be applied to a pattern having a regular pattern.

FIG. 13 is a schematic diagram of the formation of an inspection image by image pasting according to the present embodiment. In FIG. 13, a strip-shaped image 13 is obtained by scanning in the S-axis direction by the line sensor 1 of the image correction apparatus of the present embodiment shown in FIG. 10 and by reciprocating conveyance in the Y-axis direction by the conveying means 5, 6, 7a, 7b. Take a picture. Since the scanning width of the line sensor 1 is a predetermined length W, when photographing an inspection object larger than the scanning width W, after the photographing of the strip-shaped image 13 is finished, the conveying means 2, 3, 4a, By 4b, the line sensor 1 is conveyed in the X-axis direction by the scanning width W, and another region to be inspected is imaged. This is repeated over the entire measurement area, the coordinate axes of the X and Y conveying means are detected by the position detecting means, and the photographed images of the inspection images are combined and combined to form the inspection image.

  The line sensor 1 used has a width of 30 mm, the inspection object is 330 mm × 250 mm, and the line sensor has a 1500-point detection source and a resolution of 20 μm. The scanning of 1500 points in the line sensor is scanning in the S-axis direction, and after scanning in the S-axis direction, after moving a predetermined distance in the Y-axis direction, scanning for the next one line is performed. In addition, a strip-shaped image is taken by repeating the number of lines corresponding to a predetermined distance (in this example, 250 mm). Further, the desired resolution can be obtained up to 20 μm by setting the detection points of the line sensor to an appropriate number other than 1500 points.

FIGS. 14A and 14B show the influence on the scanning line and the photographed image when a deviation occurs in the angular relationship between the X axis and the Y axis due to the assembly of the image correction apparatus according to the present embodiment. Similarly, FIGS. 15A and 15B show the influence on the scanning line and the photographed image when an error occurs in the angular relationship between the X axis and the S axis by assembling the apparatus.

FIG. 14A is a schematic diagram of the influence on the scanning line 14 when an error occurs in the angular relationship between the X axis and the Y axis. In the apparatus according to the present invention shown in FIG. 3, when the movement axis of the X-axis and the Y-axis is not perpendicular but is set to have an error α in the angle relationship, the scanning line 14 is set to the angle-related error α. It shows that it tilts.

That is, when the scanning line is tilted downward by an angle α, the inspection image synthesized by laminating the strip-shaped images 13 is synthesized by being corrected upward, and thus synthesized by tilting upward by the angle α. An inspection image is obtained.

FIG. 14B shows that when an error α occurs in the angular relationship between the X-axis and the Y-axis, the scanning line 14 is inclined by the error α, and the inspection image synthesized by pasting the strip-shaped images 13 is pasted. It shows that the angle α is inclined by an error α relative to the Y axis, which is the reference axis.

FIG. 15A is a schematic diagram of the influence on the scanning line when an error β occurs in the angular relationship between the X axis and the S axis. In the apparatus according to the present invention shown in FIG. 10, when an error β occurs in the angular relationship between the X axis and the S axis by assembling the apparatus, the scanning line 14 is tilted by the angular error β.

FIG. 15B shows that when an error occurs in the angular relationship between the X axis and the S axis, the scanning line 14 is inclined by the error β, and the inspection image synthesized by the joining of the strip-shaped images 13 is the joining reference. This shows that the angle β is tilted with respect to the Y axis, which is the axis, by an error β in the angular relationship between the X axis and the S axis. This is a case where the S-axis that is the scanning axis of the line sensor 1 is not parallel to the X movement axis by the conveying means of the line sensor 1 in the X-axis direction but is inclined at an angle β. Line sensor 1 is β upward
The image data of 1500 points is obtained by tilting the image data, but the image data is stored in the image memory 107, but is recorded in the image memory 107 in a one-dimensional manner. As shown in FIG. 15B, the output data obtained as a result of the synthesis is strip-shaped inspection image data downward. Therefore, the S-axis of the line sensor 1 can be aligned with the X movement axis of the line sensor 1 by detecting the inclination angle β.

The perpendicularity of the X-axis and Y-axis movement axes of the X-axis and Y-axis line sensor 1 of the image correction apparatus shown in Embodiment 1 of the present invention is measured by photographing the inspection object shown in FIG. The edge position of the inspection object is measured from the inspection image shown. In FIG. 16, the inclination angle of the X axis is the pattern 1 in the X axis direction.
Focusing on 1, the Y-axis coordinate value of the edge position is extracted for each strip-shaped image 13. That is, both ends of the width in the Y-axis direction of the pattern to be inspected in the X-axis direction, that is, the Y position of the edge are detected. That is,
For each scan of one line (30 mm) in the S-axis direction, the Y position of the edge of the pattern in the X-axis direction to be inspected is detected, and a representative value for each strip is extracted. At this time, the more extracted data, the better the measurement accuracy. Using the representative value aX extracted for each strip image 13, for example, it can be calculated from the slope of the linear function obtained from the representative value calculated by the linear equation by the least square method. The inclination angle γ can be calculated from γ = tan−1 (aX).

Similarly, in FIG. 17, the inclination angle of the Y axis pays attention to the pattern 12 in the Y axis direction, and extracts the X axis coordinate value of the edge position. That is, both ends of the X-axis direction width of the pattern to be inspected, that is, the X position of the edge are detected. In other words, the X position of the edge of the pattern in the Y-axis direction to be inspected is detected for each scan of one line (30 mm) in the S-axis direction, and a representative value for each strip is extracted. At this time, the greater the number of extractions, the better the measurement accuracy. Using the extracted representative value, for example, it can be calculated from the slope aY of the linear function obtained from the representative value calculated by a linear equation by the least square method. At this time, the inclination angle δ is calculated by the equation δ = tan−1 (aY).

  As described above, the perpendicularity between the X axis and the Y axis can be easily calculated from the inclination angles of the X axis and the Y axis.

Next, a method for measuring the tilt angle between the X axis and the S axis will be described. The parallelism between the X axis and the S axis is measured by photographing the inspection object shown in FIG. 11 and measuring the edge position of the inspection object from the inspection image obtained by synthesizing the strip-shaped image shown in FIG. In FIG. 18, the inclination angle of the S-axis focuses on the pattern 11 in the X-axis direction, and Y-axis coordinate values are extracted at a plurality of positions for each strip-shaped image 13. Inclination of characteristic equations 17a, 17b, 17c, 17d, 17e, and 17f approximated by a linear function for each strip-shaped image 13 from the extracted coordinate values (X, Y) at, for example, the least square method It can be calculated from aSi and can be calculated from the average value of the inclination angles εi. At this time, the inclination angle εi is εi
= Tan-1 (aSi). Here, i is i = a, b, c, d, e, f.
The parallelism between the X axis and the S axis can be easily calculated from the inclination angles of the X axis and the S axis.
Also, the inspection object of the XY pattern in FIG. 11 is photographed, and the inspection image in FIG.
By measuring both the straightness of the Y-axis and the parallelism of the X-axis and the S-axis, and processing them simultaneously, a quick correction can be performed.

In this way, by calculating the perpendicularity of the X axis and the Y axis and the parallelism of the X axis and the S axis, and performing assembly adjustment of the image correction apparatus shown in FIG. 10, high-accuracy apparatus assembly can be realized. High-accuracy inspection image synthesis can be realized, and high-accuracy inspection using an image correction apparatus can be realized. Further, by calibrating the X-axis, Y-axis, and S-axis not only at the time of assembly adjustment but every predetermined time, it is possible to provide a highly accurate image correction apparatus and image correction method.

In the present embodiment, in FIG. 19, an inspection object having patterns 18 arranged at predetermined intervals in the Y-axis direction is used as the inspection object. Similarly to the synthesis of the inspection image described with reference to FIG. 13 in the first embodiment, while scanning the inspection object with the scanning width W, the scanning length L is conveyed in the Y-axis direction, and a strip-shaped image is taken. After the photographing is completed, the image is conveyed in the X-axis direction by the scanning width W, and measurement is performed in the same manner to obtain a composite image. At this time, when a conveyance amount error occurs in the Y-axis direction as shown in FIG. 20 (a), the inspection image synthesized by joining the strip-shaped images 13 is as shown in FIG.
As shown in (b), a bonding position error amount 19 is generated in the Y-axis direction.

In the correction method in this embodiment, the bonding position error amount 19 is calculated from the inspection image, and the command signal to the motor 5 which is the conveying means in the Y-axis direction is adjusted by the bonding position error amount 19. It corrects the axial transport position error and realizes highly accurate inspection.

In addition to the mechanical method of correcting the bonding position error amount 19 by adjusting the conveying means in the Y-axis direction, the bonding position error amount 19 is calculated from the inspection image, and the strip image data is stored in the memory. By correcting the storage position in the Y-axis direction according to the bonding position error amount 19, the conveyance position error in the Y-axis direction is corrected, and a high-precision inspection is realized. Then, not only when the image correction apparatus is assembled and adjusted, but also by periodically calibrating it, it is possible to guarantee a highly accurate inspection. It can also be realized by providing the image correction apparatus itself with a pattern to be inspected as an inspection target. Furthermore, by performing calibration every predetermined time as well as during assembly adjustment, a highly accurate image correction apparatus and image correction method can be provided.

In this embodiment, an inspection object having a pattern 20 arranged at a predetermined interval T in the X-axis direction is used as an inspection object in FIG. Similarly to the synthesis of the inspection image described in the first embodiment with reference to FIG. 6, while scanning the inspection object with the scanning width W, the scanning length L is conveyed in the Y-axis direction, and a strip-shaped image is taken. After the photographing is completed, the image is conveyed in the X-axis direction by the scanning width W, and measurement is performed in the same manner to obtain a composite image.

 At this time, as shown in FIGS. 22A and 22B, if a conveyance amount error in the X-axis direction or an error amount of the scanning width W of the line sensor 1 occurs, an inspection synthesized by pasting the strip-shaped images 13 together. As shown in FIG. 22C, the image generates a bonding position error in the X-axis direction. Thereby, the interval of the predetermined interval pattern in the X-axis direction in the inspection image expands and contracts. Due to this expansion and contraction, the actual shape of the inspection object is greatly displaced at the bonding position, and the inspection accuracy is deteriorated.

  The correction method in the present embodiment calculates the image expansion / contraction amount ΔT from the predetermined interval T from the inspection image, and corrects the command signal to the motor 2 that is the conveying means in the X-axis direction according to the image expansion / contraction amount ΔT. The image expansion and contraction is corrected to realize a highly accurate inspection.

  In addition to the mechanical method of correcting the image expansion / contraction amount by adjusting the conveying means in the X-axis direction, ΔT is calculated from the inspection image, and the image expansion / contraction amount is calculated from the inspection image by the X-axis to the memory of the strip-shaped image data By correcting the image storage amount in accordance with ΔT in the direction storage position, the conveyance position error in the X-axis direction is corrected, and high-precision inspection is realized. Then, not only when the image correction apparatus is assembled and adjusted, but also by periodically calibrating it, it is possible to guarantee a highly accurate inspection. It can also be realized by providing the image correction apparatus itself with a pattern to be inspected as an inspection target. Furthermore, a highly accurate image correction apparatus and image correction method can be provided by performing calibration not only at the time of assembly adjustment but also at regular intervals.

In the present embodiment, as shown in FIG. 23, an inspection object having a pattern arranged at predetermined intervals in the X-axis and Y-axis directions is used for the inspection object 9. Similarly to the synthesis of the inspection image described with reference to FIG. 13 in the first embodiment, while scanning the inspection object with the scanning width W, the scanning length L is conveyed in the Y-axis direction, and a strip-shaped image is taken. After the photographing is completed, the image is conveyed in the X-axis direction by the scanning width W, and measurement is performed in the same manner to obtain a composite image.

  At this time, as shown in FIGS. 20 (a), 22 (a), and 22 (b), if an error in the conveyance amount in the X-axis and Y-axis directions or an error in the scanning width W occurs, a factor that degrades the inspection accuracy. It becomes.

In this embodiment, the X-axis and Y-axis conveyance amount errors are measured using the inspection object shown in FIG. 23, and the X-axis and Y-axis conveyance unit errors are mechanically corrected. Realizes high-precision inspection.
In addition to the mechanical method of measuring the X-axis and Y-axis conveyance errors and adjusting and correcting the conveyance means, the X-axis direction storage position and the Y-axis direction storage position of the strip-shaped image data in the memory are set. By correcting, the conveyance position error in the X-axis and Y-axis directions is corrected, and high-precision inspection is realized. Then, not only when the image correction apparatus is assembled and adjusted, but also by periodically calibrating it, it is possible to guarantee a highly accurate inspection. It can also be realized by providing the image correction apparatus itself with a pattern to be inspected as an inspection target. Furthermore, a highly accurate image correction apparatus and image correction method can be provided by performing calibration not only at the time of assembly adjustment but also at regular intervals.

The image correction according to the present invention includes mechanical correction to the conveying means even when an image error due to assembly accuracy, an image pasting position error due to the reciprocating operation of the conveying means, a scanning width error of the line sensor, etc. By using electrical correction for correcting the storage position in the memory, highly accurate assembly adjustment can be realized, which is useful for adjustments such as appearance substrate inspection.

The figure which shows the whole structure of the image correction apparatus in the Example of this invention. The figure which shows the structure of the line sensor of the image correction apparatus in the Example of this invention. The figure which shows one example of the test object of the image correction apparatus in the Example of this invention The figure for demonstrating that the image data of test object is memorize | stored in series on an image memory with the image correction apparatus in the Example of this invention. The figure for demonstrating the state by which the image data of test object was synthesize | combined on the test | inspection memory with the image correction apparatus in the Example of this invention. The figure for demonstrating the image data synthesize | combined on the test | inspection memory before Y-axis direction bonding error correction with the image correction apparatus in the Example of this invention. The figure for demonstrating the image data synthesize | combined on the test | inspection memory after the Y-axis direction bonding error correction | amendment with the image correction apparatus in the Example of this invention. The figure for demonstrating the image data synthesize | combined on the test | inspection memory before X-axis direction bonding error correction | amendment with the image correction apparatus in the Example of this invention. The figure for demonstrating the image data synthesize | combined on the test | inspection memory after the X-axis direction bonding error correction | amendment with the image correction apparatus in the Example of this invention. 1 is a schematic diagram of an image correction apparatus according to a first embodiment of the present invention. Schematic of the inspection object of the image correction apparatus in Embodiment 1 of the present invention The figure which shows another test object example of the image correction apparatus in Example 1 of this invention. The figure for demonstrating formation of a test | inspection image by image bonding of the image correction apparatus of this invention The figure for demonstrating synthetic | combination image data when the error of the orthogonality of the X-axis and a Y-axis has generate | occur | produced with the image correction apparatus of this invention. The figure for demonstrating the composite image data when an angle error generate | occur | produces in the X-axis and the S-axis with the image correction apparatus of this invention Schematic for demonstrating the X-axis inclination angle measuring method with the image correction apparatus of this invention Schematic for demonstrating the Y-axis inclination angle measuring method with the image correction apparatus of this invention Schematic for demonstrating the S-axis inclination angle measuring method with the image correction apparatus of this invention Schematic diagram of an image correction apparatus in Embodiment 2 of the present invention The figure for demonstrating the Y-axis conveyance error amount with the image correction apparatus in Example 2 of this invention. Schematic diagram of an image correction apparatus in Embodiment 3 of the present invention The figure for demonstrating X-axis conveyance error amount with the image correction apparatus in Example 3 of this invention. Schematic of an image correction apparatus in Embodiment 4 of the present invention Schematic diagram of an image correction apparatus in a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Line sensor 2, 5 Motor 3, 6 Ball screw 4a, 4b, 7a, 7b Guide rail 8 Conveyance rail 9 Inspection object 10 Lattice-like inspection pattern 11 X-axis direction pattern 12 Y-axis direction pattern 13 Strip-shaped image 14 Scanning line 18 Inspection pattern arranged at a predetermined interval in the Y-axis direction 19 Y-axis direction bonding position shift 20 Inspection pattern arranged at a predetermined interval in the X-axis direction 100 CPU
DESCRIPTION OF SYMBOLS 101 Drive system control part 102 X-axis correction part 103 Y-axis correction part 104 X-axis drive part 105 Y-axis table drive part 106 Sensor I / F board 107 Image memory 108 Correction part 109 Inspection memory

Claims (20)

A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
The X-axis drive means and the Y-axis drive from image data obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory. An image correction apparatus for detecting a deviation in orthogonality of means.   The strip-shaped image data scans the inspection object with a predetermined scanning width of the line sensor, and when the scanning of one line is completed, the Y-axis table moving means moves the line sensor to a distance corresponding to a predetermined resolution. 2. The image correction apparatus according to claim 1, wherein the image correction apparatus is obtained by moving in the axial direction, scanning the next one line, and repeating this operation for the number of lines corresponding to a predetermined distance in the Y-axis direction. .   The image correction apparatus according to claim 2, wherein the inspection target for detecting the deviation of the orthogonality is an orthogonal lattice pattern.   The image correction apparatus according to claim 3, wherein an orthogonal lattice pattern to be inspected is incorporated.   A linear function obtained from a representative value of the Y coordinate value of the grid-like X direction pattern obtained in the inspection image for each strip shape of the strip image data, and obtained from the (X, Y) coordinate value of the representative value The image correction apparatus according to claim 3, wherein a deviation in the X-axis direction is detected by calculating an inclination of the image.   A representative value of the X coordinate value is obtained for each predetermined number of lines corresponding to a predetermined distance in the Y-axis direction of the grid-like Y-direction pattern obtained in the inspection image for each strip shape of the strip-shaped image data. 4. The image correction apparatus according to claim 3, wherein a deviation in the Y-axis direction is detected by calculating a slope of a linear function obtained from the (X, Y) coordinate value of the representative value. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Parallelism between the S-axis and the X-axis from image data obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the operation width in the S-axis direction of the line sensor on the memory. An image correction apparatus that detects a shift of the image.   The image correction apparatus according to claim 7, wherein the inspection target for detecting a deviation in parallelism between the S axis and the X axis is an orthogonal lattice pattern.   Y-axis coordinate values of a grid-like X direction pattern obtained in the inspection image for each strip shape of the strip image data are extracted at a plurality of positions, and from the (X, Y) coordinate values at the extracted positions. 9. The image correction apparatus according to claim 8, wherein a deviation in parallelism between the S-axis direction and the X-axis direction is detected by calculating an inclination of the obtained linear function.   The image correction apparatus according to claim 9, wherein a deviation in parallelism between the S-axis direction and the X-axis direction is detected from an average value of inclination obtained for each of the strip-shaped image data. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. An image correction apparatus that corrects the conveyance amount of the Y-axis direction conveyance unit according to the error amount. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. An image correction apparatus that corrects the image storage position in the Y-axis direction in the memory according to the error amount.   The image correction apparatus according to claim 11, wherein the inspection target has a pattern with a predetermined interval in the Y-axis direction. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Pasting an image in the X-axis direction of the scanning width of the line sensor obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory An image correction apparatus that detects an error amount of an alignment position and corrects the conveyance amount of the X-axis direction conveyance unit according to the error amount. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Pasting an image in the X-axis direction of the scanning width of the line sensor obtained by combining strip-shaped image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor on the memory An image correction apparatus that detects an error amount of the alignment position and corrects an image storage position in the X-axis direction in the memory according to the error amount.   The image correction apparatus according to claim 14, wherein the inspection target has a pattern with a predetermined interval in the X-axis direction. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. In addition, the error amount of the image pasting position in the X-axis direction of the scanning width of the line sensor is detected, and the X-axis direction and the Y-axis are detected according to the detected error amounts in the Y-axis direction and the X-axis direction, respectively. An image correction apparatus for correcting a conveyance amount of a direction conveyance unit. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
Detects the amount of error in the image pasting position in the Y-axis direction obtained by synthesizing on the memory strip-like image data obtained by imaging an inspection object larger than the scanning width in the S-axis direction of the line sensor. In addition, the error amount of the image pasting position in the X-axis direction of the scanning width of the line sensor is detected, and the X-axis to the memory is determined according to the detected error amounts in the Y-axis direction and the X-axis direction. Correction apparatus for correcting the image storage position in the direction and the Y-axis direction.   19. The image correction apparatus according to claim 17, wherein the inspection target includes a pattern having a predetermined interval in the Y-axis direction and a pattern having a predetermined interval in the X-axis direction. A line sensor that shoots an inspection target and outputs an image signal, a scanning direction in the line direction of the line sensor as an S-axis direction, and an X-axis driving unit that conveys the line sensor in parallel to the S-axis direction, and a right angle to the X-axis direction Y-axis table driving means for moving the table on which the inspection object is placed in the Y-axis direction which is the direction, and a memory for recording and synthesizing image data obtained by imaging the inspection object by the line sensor,
The inspection object is scanned with the predetermined scanning width of the line sensor, and when scanning of one line is completed, the line sensor is moved in the Y-axis direction by a distance corresponding to a predetermined resolution by the Y-axis table moving means. The X-axis is obtained from the inspection image data obtained by synthesizing on the memory strip-like image data obtained by repeating this operation for the number of lines corresponding to a predetermined distance in the Y-axis direction. An image correction method characterized by detecting a mounting deviation of orthogonality between a driving means and a Y-axis table driving means.

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