JP2002323454A - Method and apparatus for inspecting defects in specimen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for inspecting defects in a specimen. SOLUTION: The method is used for inspecting or measuring the specimen 2 using lighting with a two-dimensional and spatial pattern. In the method for inspecting the defects in the specimen 2, an image-pickup means 3 for separating colored pattern lighting from the wavelength constituent of light for picking up an image should be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to inspection of minute defects caused by local refraction abnormality of a transparent body by obtaining a reflection image or a transmission image using illumination having a periodic pattern, The present invention relates to a defect inspection method for a test object for inspecting an abnormal reflection defect due to local unevenness or the like, or measuring the surface shape of an object, and a defect inspection device for the test object used therefor.

[0002]

2. Description of the Related Art There has been proposed a defect inspection method for an object which irradiates a black and white periodic pattern and determines a defect using an obtained image in order to inspect the object and measure a surface shape and the like. I have. For example, in Japanese Patent Application Laid-Open No. 2000-18932, in order to inspect irregularities and the like, which are minute defects of glass and the like, a plurality of images are acquired using a periodic pattern illumination while moving the pattern to change the phase. There is disclosed a method of determining a defect by using the method. In addition, for example,
000-004338, JP-A-11-14327 and the like disclose an illumination grid pattern called a phase shift method by 1 /.
A method is disclosed in which an image is taken while being illuminated with a shift of four phases and the surface shape is measured by analyzing the image.
1-211443 discloses a technique for moving a measurement target for the same purpose. Further, Japanese Patent Application Laid-Open No. H11-14881
No. 3 discloses a method of acquiring a reflection image of stripe pattern illumination in order to measure the surface shape of glass or the like, and using a measurement result of the amount of expansion / contraction of the pitch.

[0003]

However, Japanese Patent Laid-Open Publication
In the methods described in Japanese Patent Application Laid-Open Nos. 0189332, 2000-004338, and 11-14327, it is necessary to move the pattern in order to acquire an image with the phase of the pattern illumination changed. For this reason, the measurement takes time, the apparatus for driving the pattern becomes complicated, and there are many restrictions in application.

Further, for example, Japanese Patent Application Laid-Open No. H11-212443
In the method described in (1), there are restrictions such as the need to move the measurement target and to take an image in synchronization with the movement.
In addition, there is a restriction that this method cannot be realized by a configuration using a line sensor.

[0005] For example, see Japanese Patent Application Laid-Open No. H11-148813.
In such a method as described above, it is necessary to reduce the stripe pitch in order to perform the measurement with high resolution in the horizontal direction. However, in order to measure a stripe with high reliability, it is necessary to use a stripe of a certain size or more, and to achieve high resolution, a plurality of measurements with a phase shift are required. These limits the speed of the measurement and the simplification of the apparatus.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and receives reflected light reflected from the surface of a test object or transmitted light transmitted through the test object. A defect inspection method for inspecting a defect of the test object using the image obtained by irradiating the test object with a plurality of lights having different color patterns having different colors; The reflected light or transmitted light obtained from the irradiation of light is received by an imaging unit capable of imaging separately for each wavelength component of light to obtain a plurality of images, and the defect information of the test object is obtained from the information of the images. Provided is a method for inspecting a defect of a test object, characterized in that it is obtained.

As a result, the obtained image for each wavelength component is an image due to the influence of only the light emitted from the illumination of the color portion corresponding to the wavelength component. For example, by changing the illumination color between the transmitted light and reflected light of the test object, images with multiple illumination patterns can be obtained simultaneously and independently, and when analyzing the characteristics of the image according to the illumination of each wavelength component. This eliminates the need for alignment between images. Further, effects such as vibrations are reduced, and the time required for imaging is further reduced, and effects such as simplification of equipment are obtained. Note that the coloring patterns having different colors do not include a simple light and dark pattern (black and white pattern) of an achromatic color.

In the present invention, it is preferable that a plurality of lights of which arbitrary wavelength components are shielded are radiated to the test object and received by imaging means having sensitivity only to the wavelength components. This makes it possible to simultaneously obtain an image with illumination having a pattern having a distribution of light and dark in one plane for an arbitrary wavelength component without affecting the image with illumination of other wavelength components, In addition to the above, it is possible to eliminate the influence of the time difference of the imaging when the image is generated, and to obtain the effect that the means for moving the illumination pattern or the like becomes unnecessary.

The imaging means having sensitivity only to the wavelength component of the light means that the imaging means has high sensitivity to the wavelength component of the light, has low sensitivity to the wavelength component of the other light, and converts the light of the wavelength component to the other component. And imaging means that can be distinguished from the light of the wavelength component.

Further, in the present invention, a plurality of lights each having a desired wavelength component blocked by a plurality of light blocking means are radiated to the object, and received by an image pickup means having sensitivity only to each of the wavelength components. Is preferred. This makes it possible to simultaneously and independently acquire images obtained by illumination having patterns with different light and dark distributions in one plane for each wavelength component, to remove the influence of a time difference of imaging when vibration or the like occurs, and to reduce the illumination. The effect that means such as moving the pattern becomes unnecessary is obtained.

Further, in the present invention, it is preferable that the plurality of light-shielding means is an array pattern of colors that are superposed with different phases. Accordingly, images of the test object under illumination conditions in which the phases of the periodic patterns are different can be simultaneously captured, and there is no need to move the illumination pattern in order to change the phase of the illumination pattern. Note that the colors that are superposed with different phases include not only the colors that are actually superimposed but also the colors that are the same as the colors that are consequently changed with different phases even if they are single colors.

Further, in the present invention, the plurality of lights are
It is an array pattern of colors in which complementary colors of R, G, and B are superimposed, and the imaging unit is preferably a color camera. As a result, there is no need to use a special member such as a filter for the imaging means, and an effect is obtained that a generally available device such as a color camera can be used. In addition,
The color obtained by superimposing the complementary colors of R, G, and B is the same as the color obtained by superimposing the complementary colors of R, G, and B, even if the color is actually superimposed. It contains a certain color.

[0013] In the present invention, the plurality of lights may include:
It is preferable to use a periodic array pattern of six colors in which periodic patterns of complementary colors of R, G, and B are shifted by ３ phase and superimposed. Thus, in all regions of the test object, images with bright-field illumination and dark-field illumination can be obtained with images under any of the phase conditions.

In the present invention, the obtained R, G, and B signals of the same pixel are compared, or the obtained R, G, and B images are compared, and the maximum value, the minimum value, or the maximum value or the minimum value is obtained. Preferably, an image of the difference is used. This makes it possible to obtain images by bright-field illumination and dark-field illumination in all areas of the test object, and to selectively detect a portion that becomes a dark point in a bright field and a bright point in a dark field. The effect that it becomes easy is obtained.

Further, in the present invention, a plurality of lights having a periodic colored jagged pattern are irradiated on the test object,
It is preferable to use R, G, and B line sensors for the imaging unit. As a result, the effect of reducing the sensitivity difference depending on the direction with respect to the linear defect can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a first embodiment of an inspection apparatus for implementing a defect inspection method for an object according to the present invention. The illumination from the light source 1 is reflected by the test object 2, input to the imaging unit 3 such as a camera, and the signal from the imaging unit 3 is sent to the arithmetic unit 4 and calculated.

The light source 1 includes a plurality of lights having a periodic stripe pattern of different colors, for example, R,
This is an illumination unit that can irradiate the test object with periodic pattern light such as G and B stripes. As the light source 1, R, G,
A white light source is arranged on the back surface of the semitransparent body of the stripe of B, a white light source is arranged on the back surface of the semitransparent body of the R, G, B and complementary colors of R, G, and B, or a linear light source. LEDs or arrays of LEDs can be used. That is,
Illumination from the light source 1 has a periodic pattern such as a stripe in which an array of different colors is arranged according to a wavelength selected by an imaging unit described later.

Although there is no particular limitation on the material of the test object 2, any of a transparent material, an opaque material, and a translucent material can be used. For example, a plate glass can be used. Imaging means 3
Is an image pickup unit that can select a wavelength by using an optical filter, a prism, or the like, and has an image pickup element having sensitivity to a wavelength in a desired phase region, so that a plurality of selected images can be obtained. The specific configuration of the imaging unit 3 is, for example, a plurality of optical filters and an imaging element (for example, a CCD).
(A sensor array), a combination of a plurality of optical filters and an image pickup tube, and a combination of an optical element such as a prism and an image pickup element for separating light by wavelength components.

Each image picked up by the image pickup means 3 is a reflection image of the same test surface, and is an image obtained by illuminating the periodic stripe pattern with a phase shift. Imaging means 3
Are sent to the arithmetic unit 4 and calculated.

The configuration shown in FIG. 1 is an embodiment of the reflection optical system when the test object 2 is an opaque object. When the test object 2 is a translucent object, the same effect can be obtained even if the method of the present invention is applied to the transmission optical system shown in FIG. FIG. 3 is a plan view of the configuration of FIG. 1 or FIG.

In the case of the configuration shown in FIG. 3, when a one-dimensional line sensor (for example, a color line camera) is used as the image pickup device of the image pickup means 3, the test object 2 is moved in the left-right direction. Two-dimensional information of the specimen 2 is obtained.
Also, the illumination from the light source 1 can cover the entire surface of the test object,
In the case where a two-dimensional sensor (for example, a CCD sensor array) is used as an image sensor of the image pickup means 3, the object 2
Can be obtained without moving the object.

In FIG. 3, reference numeral 6 denotes a line to be measured of the test object 2 when a one-dimensional line sensor is used as an image pickup device of the image pickup means 3. That is, the light of the periodic illumination pattern 7 such as a stripe pattern
Is reflected by the line to be measured and reaches the image pickup device of the image pickup means 3. In addition, the pattern of the stripe of the illumination is directed in the left-right direction as illustrated.

Next, with reference to FIGS. 4 to 7, an image pickup means and an illumination pattern for obtaining an image under stripe pattern illumination in which two stripes having opposite brightness are obtained will be described.

FIG. 4 is a graph showing the relationship between the wavelength of light and the imaging sensitivity of the imaging device used in the imaging means 3.
That is, it is a graph showing the relationship between the wavelength of light and the imaging sensitivity of an imaging device used for obtaining an image under stripe pattern illumination under two phase conditions. (A) and (B) in the figure
Represents the sensitivity of each of the two imaging elements used to the wavelength of light.

FIG. 5 is a graph showing the relationship between the light wavelength and the light transmittance of the colored striped translucent body used in the light source 1. That is, it shows an example of the transmittance with respect to the wavelength of light of a portion corresponding to a light-shielding filter that generates stripe pattern illumination under two phase conditions.

The color of the illumination pattern has a transmittance distribution as shown in FIG. 5A which blocks only the wavelength component having sensitivity to the imaging means A having the wavelength sensitivity as shown in FIG. This is created by superimposing a pattern having the transmittance distribution pattern as shown in FIG. 5B on the imaging means B of FIG. 4B.

FIG. 6 is a schematic diagram showing an example of stripe pattern illumination under two phase conditions. In FIG. 6, a portion a indicates illumination using a light-shielding filter having the characteristics of FIG.
The part b represents illumination using a light-blocking filter having the characteristics shown in FIG. The horizontal direction in FIG. 6 corresponds to the vertical direction of the stripe-shaped illumination pattern 7 in FIG.

FIG. 7 is a schematic diagram showing an image obtained when the illumination pattern of FIG. 6 is picked up by the image pickup device having the wavelength sensitivity of FIG. 4, and FIG. 7A is a schematic diagram showing the image pickup device of FIG. 4B shows an image taken by the image sensor shown in FIG. 4B, and FIG. In order to obtain these two images, for example, using a prism or a half mirror, an optical filter, or the like, a method is employed in which light rays reflected for each color component are separated to correspond to a plurality of sensors, and the light is reflected by an image sensor. .

In the image obtained by the image pickup means A, the portion a in FIG. 6 is dark because there is no light of a wavelength component having sensitivity due to the characteristics of FIG. Since there is light of the component, the light becomes bright, and an image as shown in FIG. 7A is obtained. On the other hand, in the imaging means B, the portion a is bright and the portion b is dark, and an image in which the brightness is reversed as shown in FIG. 7B is obtained.

Next, referring to FIGS. 8 to 11, an image pickup means and an illumination unit for obtaining an image under stripe pattern illumination of four different phases shifted by 1/4 phase according to the second embodiment. The pattern will be described.

FIG. 8 is a graph showing the relationship between the light wavelength and the imaging sensitivity of an imaging device used for obtaining an image under stripe pattern illumination under four phase conditions. That is, (C), (D), (E), and (F) represent the sensitivity of each of the four imaging elements used to each wavelength.

FIG. 10 is a graph showing the relationship between the light wavelength and the light transmittance of the colored striped translucent body under the four phase conditions used for the light source 1. That is, it shows the transmittance with respect to the wavelength of light of a portion corresponding to a light-shielding filter that generates an illumination pattern used for obtaining an image under stripe pattern illumination under four phase conditions.

FIG. 10C is a color filter having a transmittance distribution that blocks wavelengths sensitive to the image sensor of FIGS. 8C and 8F, and FIG. 8 (C) and 8 (D) are color filters having a transmittance distribution that shields wavelengths having sensitivity in the image sensor, and FIG. 8 (D) is FIG.
And (E) are color filters having a transmittance distribution that blocks wavelengths sensitive to the image sensor. (F) is a wavelength filter sensitive to the image sensor shown in (E) and (F) of FIG. This is a color filter having a transmittance distribution that blocks light.

FIG. 9 is a schematic diagram showing an example of stripe pattern illumination under four phase conditions. That is, c, d,
e and f are different colors. The horizontal direction in FIG. 9 corresponds to the vertical direction of the stripe-shaped illumination pattern 7 in FIG.

In the figure, the portion c is shown in FIG.
FIG. 8 shows illumination using a light-blocking filter having the following characteristics.
(C) and (F) are colors obtained by a filter having a transmittance distribution that blocks light having a wavelength sensitive to the imaging means. The part d is illumination using a light-blocking filter having the characteristic of FIG. 10D, and a filter having a transmittance distribution that blocks wavelengths sensitive to the imaging means of FIGS. 8C and 8D. Color. Part e is illumination using a light-blocking filter having the characteristic of FIG. 10E, and a filter having a transmittance distribution that blocks wavelengths sensitive to the imaging means of FIGS. 8D and 8E. Color. The portion f is illumination using a light-blocking filter having the characteristics of FIG. 10F, and a filter having a transmittance distribution that blocks wavelengths sensitive to the imaging means of FIGS. 8E and 8F. Color.

FIG. 11 is a schematic diagram showing an image obtained when the illumination pattern of FIG. 9 is picked up by the image sensor having the wavelength sensitivity of FIG. 8C, an image captured by the image sensor of FIG. 8C, (D) an image captured by the image sensor of FIG. 8D, and (E) of FIG. 8F illustrates an image captured by the image sensor, and FIG. 8F illustrates an image captured by the image sensor of FIG.

When the illumination having the color pattern shown in FIG. 9 is picked up by the image pickup means shown in FIG. 8, light having a wavelength which is sensitive to the image pickup means (D) and (E) is transmitted through the light source 1 in FIG. Therefore, in the images obtained in (D) and (E),
The light having a wavelength sensitive to the imaging means (C) and (F) is the light source 1
, The image obtained in (C) and (F) becomes dark.

The part d is the image pickup means (E) and (F).
, The image becomes dark in (C) and (D), the portion e becomes light in the imaging means (C) and (F), the image becomes dark in (D) and (E), and the portion f becomes imaged. By means (C) and (D),
(E) and (F) become dark. As a result, the image obtained by the imaging means (C) is obtained by a light and dark pattern as shown in FIG. 11C, and the image obtained by the imaging means (D) is obtained by (D) of FIG. 11 and the imaging means (E). The obtained image is an image of a light and dark pattern having a different phase as shown in FIG. 11F, and the image obtained by the imaging means (F) is as shown in FIG. 11F.

Next, referring to FIGS. 12, 13, and 14, a method of obtaining images by illumination in three different phase states using the color camera according to the third embodiment will be described. FIG. 12 is a schematic diagram showing illumination color patterns for obtaining images under different three-phase conditions with a color camera.
(L) indicates different colors. FIG. 13 shows an image obtained when this illumination is captured. (1) shows an R image, (2) shows a G image, and (3) shows a light and dark pattern of a B image.

In this method, pattern illumination in which six colors are arranged as shown in FIG. 12 in a width corresponding to one phase of the light-dark pattern is used. (G) is green, (H) is bluish green, which is a complementary color of red, (I) is blue, (J) is magenta, which is a complementary color of green, (K) is red, and (L) is a complementary color of blue. Composed of a certain yellow color.

(G) transmits only G component light corresponding to green, (H) transmits light other than R component corresponding to red,
(I) transmits only the B component light corresponding to blue,
(J) transmits light other than the G component corresponding to green,
(K) transmits only the R component light corresponding to red,
(L) transmits light other than the B component corresponding to blue. The arrangement of the pattern illumination in FIG. 12 is in the order of GHIJKL, but is in other order, for example, IHGLK.
Similar effects can be obtained even in the order of J.

When the pattern of FIG. 12 is picked up by a color camera, the R image has a light and dark pattern as shown in FIG. 13A, the G image has a light and dark pattern as shown in FIG. A light / dark pattern as in 3) is obtained, and the phase is 1/3.
Thus, a pattern image that is shifted each time is obtained.

FIG. 14 shows that a transparent film is colored by a color printer to form a pattern in which the color patterns shown in FIG. 12 are continuous, placed on a white diffused surface light source, imaged with a color camera, and imaged on the same line. It shows R, G, and B output signals of the camera, and rectangular signals having different phases from each other are obtained.

Hereinafter, a color pattern and a defect inspection method using a color camera according to the present invention will be described. The configuration uses a transmission optical system as shown in FIG.
A color line sensor camera having the arrangement shown in FIG. 12 is used as an image pickup means, and the jagged pattern shown in FIG. 15 and the same color scheme as in FIG. 12 is used as illumination.

In FIG. 15, the one-dot chain line at the center is
This is an illumination portion corresponding to the field of view of the line sensor. With respect to the color, the R, G, and B signals obtained by imaging by the imaging means are adjusted so as to be rectangular waves having respective phase shifts.
FIG. 16 shows a signal processing method for forming an inspection image using the respective signals of R, G, and B of the imaging means. R, G,
The offset and the gain are independently adjusted so that the upper and lower signals of each rectangular wave signal coincide with the obtained signal of B.

The signal of one line of R, G, B thus obtained is a rectangular signal having different phases of light and dark, as shown in FIG. Is a low signal when the background signal is at a high level, and a high signal when the background signal is at a low level. On the other hand, the light-shielding defect (light-shielding) is a low signal regardless of the level of the background signal.

FIG. 17B shows the signal of the line shown in FIG. 17A by the signal processing described in FIG.
It shows the result of calculating the maximum value, the minimum value, and the difference between the maximum value and the minimum value by comparing the R signal, the G signal, and the B signal at the same position. At any position on one line,
Since at least one of the R, G, and B signals is a high signal, the maximum value signal is high in an ordinary portion having no defect, etc., and a signal in a portion having a refractive error or a light blocking defect. Will be lower.

On the other hand, at any position on one line,
Since at least one of the R, G, and B signals is a low signal, the minimum value signal is low in a normal portion having no defect, and the signal in a portion having a defect of refractive error is high. .

The difference signal, which is the difference between the maximum value signal and the minimum value signal, has a constant value in an ordinary portion having no defect or the like, but when there is a signal change in either the maximum value signal or the minimum value signal. Means that if the signal is low and there is a signal change in both the maximum value signal and the minimum value signal, the signal change will be greater than that in which only one of the signals has changed, and the maximum value signal or the minimum value Higher sensitivity than detection by signal.

As a specific method of detection, when a difference signal falls below a certain threshold value, it is detected as a defect candidate, and a maximum value signal and a minimum value signal at the same place are respectively detected. It is possible to discriminate the type of the defect as compared with.

Further, a maximum value image, a minimum value image, and a difference image of the object to be inspected are created by changing the maximum value signal, the minimum value signal, and the difference signal of these lines with time while scanning the object. . The maximum value image obtained in this manner is an image composed of signals in a state where each pixel is in a bright field under jagged pattern illumination, and a defect of refraction abnormality and a light-shielding defect are detected as dark spots. On the other hand, the minimum value image is an image composed of signals in a state where each pixel is in a dark field, and the drawbacks of causing a refractive error and scattering are as follows.
Detected as a bright spot.

In the difference image, a defect that becomes a dark point in a bright field and a defect that becomes a bright point in a dark field can be simultaneously detected, and a refractive error defect that generates a signal in both a bright field and a dark field can be selectively detected with high sensitivity. Can be detected. By performing image processing such as two-dimensional differentiation processing on the difference image, it is possible to detect a defect candidate with higher sensitivity.

By comparing the signal at the same pixel of the defect candidate in the maximum value image, the minimum value image, or an image obtained by processing the image with respect to the defect candidate detected by the above method, the type of the defect, the defect, and the stain can be reduced. Can be distinguished.

For example, if the value of the obtained difference image or the value after image processing is smaller than the threshold value, a portion corresponding to the pixel is set as a defect candidate, and the maximum value of the defect candidate is determined. The value of the value image, the value of the minimum value image, or the value after image processing thereof is compared with each threshold value. After that, the type and strength of the defect are determined using the comparison result according to the purpose. For example, among the defect candidates, a signal whose signal in the minimum value image exceeds a threshold value can be discriminated as a defect of refraction abnormality, and a signal which does not exceed the threshold value is a light-shielding defect.

Further, since it is conceivable that a pixel where a signal is generated in the maximum value image and a pixel where a signal is generated in the minimum value image of the defect are shifted, a window larger than the size of the defect is provided around the defect candidate, and the window is provided. The minimum value of the maximum value image in the, the maximum value of the minimum value image is compared with the respective threshold value to discriminate the defect type,
Further stable discrimination becomes possible.

FIG. 18 shows a signal processing method capable of obtaining the same effect. Each image is composed of R, G, and B signals, and the maximum value image, the minimum value image, and the difference image are calculated by calculating the respective images. It is a method to ask. The calculation method of the maximum value image, the minimum value image, and the difference image is as shown in the flowchart of FIG.
This is performed by comparing the values of R, G, and B images for each pixel.

The obtained R, G, and B images have different light and dark phases as shown in FIG.
For example, a pattern image having a periodic pattern such as a stripe and causing a refractive error (refraction error) is a black point when the background is white, and a white point when the background is black. On the other hand, the light-shielding defect (light-shielding) is a black point regardless of the background black and white. In the same manner as described with reference to FIG. 17 shown in FIG. 20B, it is possible to discriminate a defect causing refraction abnormality and a light-shielding defect from the calculated difference image, maximum value image, and minimum value image. is there.

In this embodiment, a one-dimensional color line sensor of 2000 pixels is used, and the pixel resolution is 0.16 m.
Under the conditions of m, an aperture of F16, and a distance between the test glass and the illumination pattern of 150 mm, a jagged pattern having a color arrangement as shown in FIG. 15 in which the width of each color of the pattern is 2.3 mm was used. The transport speed of the test glass is 160 mm
/ Sec, and the time required to capture one line with the line sensor was set to 0.001 second.

Due to the strength of the signal in the difference image obtained by the signal processing in FIG. 16, all the bubbles having a minimum diameter of 0.1 mm or more among the samples used in the experiment adhere to the glass surface in a normal indoor environment. Detected without erroneous detection due to contamination.

Also, using the same apparatus, FIGS.
9, the same result as the signal processing of FIG. 16 was obtained. Further, when the signal processing shown in FIGS. 18 and 19 is performed on an image captured with the test glass stationary while using the same optical system and a two-dimensional color area camera, Similar results were obtained.

However, in this case, the obtained R, G, and B images are not stripes as shown in FIG. 20A, but each of the jagged patterns used for illumination has a width of three colors. Is obtained. Inspection methods using these techniques can be similarly performed in a reflection optical system if calibration is performed using colors after reflection.

[0062]

According to the present invention, a fine irregularity defect inspection or shape measurement using an image under illumination of a periodic pattern is performed.
It can be easily performed, and the speed of inspection or measurement can be increased and the performance can be improved. Further, the price can be reduced due to the simplification of the device, and the range of usable objects can be expanded. further,
This makes it possible to control and control the quality of the process in an area that has been difficult in the past.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram (front view) showing an outline of an embodiment of the present invention.
It is.

FIG. 2 is a conceptual diagram (front view) showing an outline of another embodiment of the present invention.

FIG. 3 is a conceptual diagram (plan view) showing an outline of an embodiment of the present invention.
It is.

FIG. 4 is a graph showing a relationship between a wavelength of light of an image sensor and an image pickup sensitivity.

FIG. 5 is a graph showing a relationship between a light wavelength and a light transmittance of a light shielding unit.

FIG. 6 is a schematic diagram illustrating an example of an illumination pattern used to obtain an image under stripe pattern illumination under two phase conditions.

7 is a schematic diagram illustrating an image obtained when the illumination pattern of FIG. 6 is imaged by the image sensor having the wavelength sensitivity of FIG. 4;

FIG. 8 is a schematic diagram illustrating an example of an imaging sensitivity according to a wavelength of light of an imaging device used to obtain an image under pattern illumination under four phase conditions.

FIG. 9 is a schematic diagram illustrating an example of an illumination pattern used to obtain an image under stripe pattern illumination under four phase conditions.

FIG. 10 is a graph showing the relationship between the light wavelength and the light transmittance of the light shielding means used when obtaining an image under pattern illumination under four phase conditions.

11 is a schematic diagram illustrating an image obtained when the illumination pattern of FIG. 9 is imaged by the image sensor having the wavelength sensitivity of FIG. 8;

FIG. 12 is a schematic diagram showing a color pattern of illumination for obtaining images under different three-phase conditions with a color camera.

13 is an image when the illumination of FIG. 12 is captured by a color camera, (1) is an R image, (2) is a G image,
(3) shows the light and dark pattern of the B image.

FIG. 14 is a graph showing signals obtained by imaging the illumination in which the pattern in FIG. 12 is continuous by an imaging device and dividing the components into R, G, and B components.

FIG. 15 is a schematic diagram showing a color pattern of illumination used in the inspection machine.

FIG. 16 is a schematic diagram of signal processing for obtaining an inspection image according to the embodiment of the present invention.

FIG. 17 is a schematic diagram for explaining a feature of a defect signal and a method of detecting and discriminating the defect in the embodiment of the present invention.

FIG. 18 is a schematic diagram of signal processing for obtaining an inspection image according to another embodiment of the present invention.

FIG. 19 is a schematic diagram of a calculation process for calculating a maximum value image, a minimum value image, and a difference image in the embodiment of the present invention.

FIG. 20 is a schematic diagram for explaining a feature of a defect on an image and a detection and discrimination method according to the embodiment of the present invention.

[Explanation of symbols]

 1: light source 2: subject 3: imaging means 4: arithmetic unit 5: subject (light transmitting body) 6: visual field by the imaging means 7: illumination pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/48 H04N 1/46 A F term (Reference) 2F065 AA49 BB24 FF04 FF42 GG07 GG14 GG23 HH05 HH16 HH17 JJ03 JJ26 LL21 LL46 QQ13 QQ17 QQ24 QQ29 2G051 AA32 AA42 AB07 CA03 CB01 CB02 CC07 CC15 DA06 EA08 EA11 EA12 EA14 5B047 AA11 AB04 BB02 BB04 BC07 BC12 BC14 CB21 5B00 5

Claims (9)

[Claims] 1. A defect of a test object which receives reflected light reflected from the surface of the test object or transmitted light transmitted through the test object and inspects the defect of the test object using an image obtained by receiving the light. In the inspection method, a plurality of lights having different color patterns are applied to the test object, and reflected light or transmitted light obtained from the plurality of light irradiations is separated for each wavelength component of light. A defect inspection method for an object, comprising: obtaining a plurality of images by receiving light by an imaging means capable of imaging the object; and obtaining defect information of the object from information of the images. 2. A defect inspection of a test object according to claim 1, wherein the test object is irradiated with a plurality of light beams of which arbitrary wavelength components are shielded, and is received by an image pickup means having sensitivity only to the wavelength component. Method. 3. An object is irradiated with a plurality of lights, each of which has an arbitrary wavelength component shielded by a plurality of light shielding means, and received by an imaging means having sensitivity only to each of the wavelength components. 4. The defect inspection method for a test object according to 1. 4. The defect inspection method for a test object according to claim 3, wherein the plurality of light-shielding means are arranged patterns of colors that are superposed with different phases. 5. The defect of the test object according to claim 3, wherein the plurality of lights have an array pattern of colors in which complementary colors of R, G, and B are superimposed, and the imaging unit is a color camera. Inspection methods. 6. A periodic array pattern of six colors obtained by superposing periodic patterns of complementary colors of R, G, and B with a shift of 1/3 phase on each other. The defect inspection method of the test object described in the above. 7. The obtained R, G, and B signals at the same pixel are compared, or the obtained R, G, and B images are compared, and an image having a maximum value, a minimum value, or a difference therebetween is determined. The defect inspection method for a test object according to claim 5 or 6, which is used. 8. The object is irradiated with a plurality of lights having a periodic colored jagged pattern, and R, G,
The defect inspection method for a test object according to claim 5, 6 or 7, wherein the line sensor B is used. 9. A light irradiating means for irradiating a plurality of lights having a color pattern with different colors to a test object, and a light wavelength reflecting light reflected from the test object surface or transmitted light transmitted through the test object. An apparatus for inspecting a defect of a test object, comprising: an imaging unit capable of separately capturing an image for each component to obtain a plurality of images; and a calculating device for calculating defect information of the test object from the plurality of pieces of image information.