Image inspection apparatus

Patent metadata

Field	Value
Publication number	US-10591285-B2
Application number	US-201815955732-A
Country	US
Kind code	B2
Filing date	Apr 18, 2018
Priority date	May 31, 2017
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

To make it possible to set a shift direction of phases of illuminance distributions of pattern lights to an appropriate direction and perform an inspection at high accuracy while improving setting flexibility of an illuminating section and an imaging section. A phase shift direction of pattern light irradiated from a pattern light illuminating section is determined according to moving direction information concerning a moving direction of an inspection target object with respect to an array direction of light receiving elements and positional relation information concerning a positional relation between the light receiving elements and the pattern light illuminating section.

First claim

What is claimed is:

1. An image inspection apparatus that inspects a defect of an inspection target object using an image obtained by imaging the inspection target object moving in one direction,
the image inspection apparatus comprising:
a pattern light illuminating section for irradiating pattern light having a periodic illuminance distribution on the inspection target object;
an imaging section configured to be capable of being set independently from the pattern light illuminating section and including a line camera that includes a plurality of image receiving elements arrayed in a line shape and is capable of being set such that an array direction of the light receiving elements is a direction orthogonal to the moving direction of the inspection target object;
a control section configured to control the pattern light illuminating section and the imaging section to generate a plurality of pattern lights, phases of illuminance distributions of which are shifted in the array direction of the light receiving elements, and a plurality of pattern lights shifted in the moving direction of the inspection target object, sequentially irradiate the pattern lights on the inspection target object, image the inspection target object at timings when the pattern lights are irradiated, and obtain a plurality of luminance images;
an image generating section configured to generate, on the basis of a deflectometry principle, phase data of a surface of the inspection target object from the plurality of luminance images captured by the imaging section and generate, on the basis of the phase data, an image for inspection indicating a shape of the inspection target object; and
an information acquiring section configured to acquire moving direction information concerning the moving direction of the inspection target object with respect to the array direction of the light receiving elements of the line camera and positional relation information concerning a positional relation between the light receiving elements of the line camera and the pattern light illuminating section, wherein
the control section is configured to determine, according to the moving direction information and the positional relation information acquired by the information acquiring section, a phase shift direction of the pattern lights irradiated by the pattern light illuminating section so that a proper direction is acquired to obtain the phase data based on the deflectometry principle.

2. The image inspection apparatus according to claim 1 , wherein the positional relation information includes a positional relation of reflected light reception in which the light receiving elements receive the pattern lights irradiated from the pattern light illuminating section and reflected on the inspection target object and a positional relation of transmitted light reception in which the light receiving elements receive the pattern lights irradiated from the pattern light illuminating section and transmitted through the inspection target object.

3. The image inspection apparatus according to claim 1 , wherein, when a direction orthogonal to the array direction of the light receiving elements when viewed from a light reception side of the line camera is set as an up-down direction of the line camera, the moving direction information includes the up-down direction of the line camera and the moving direction of the inspection target object.

4. The image inspection apparatus according to claim 1 , wherein
the information acquiring section is configured to control, during setting of the image inspection apparatus performed before the image inspection apparatus is operated, the pattern light illuminating section and the imaging section to generate a first image obtained by imaging an irradiation surface on which first pattern light having a periodic illuminance distribution in one direction is irradiated and a second image obtained by imaging an irradiation surface on which second pattern light having a periodic illuminance distribution in a direction orthogonal to the one direction is irradiated, and
the information acquiring section is configured to analyze the first image and the second image to thereby acquire positional relation information concerning a positional relation between the light receiving elements of the line camera and the pattern light illuminating section.

5. The image inspection apparatus according to claim 1 , wherein the control section is configured to control the pattern light illuminating section and the imaging section to generate a plurality of pattern lights, phases of illuminance distributions of which are shifted in both directions of the array direction of the light receiving elements and the moving direction of the inspection target object, and sequentially irradiate the pattern lights on the inspection target object and, every time the pattern light is irradiated, image the inspection target object to generate a plurality of luminance images.

6. An image inspection apparatus that inspects a defect of an inspection target object using an image obtained by imaging the inspection target object moving in one direction,
the image inspection apparatus comprising:
a pattern light illuminating section for irradiating pattern light having a periodic illuminance distribution on the inspection target object;
an imaging section configured to be capable of being set independently from the pattern light illuminating section and including a line camera that includes a plurality of image receiving elements arrayed in a line shape and is capable of being set such that an array direction of the light receiving elements is a direction orthogonal to the moving direction of the inspection target object;
a control section configured to control the pattern light illuminating section and the imaging section to generate a plurality of pattern lights, phases of illuminance distributions of which are shifted in the array direction of the light receiving elements and the moving direction of the inspection target object, sequentially irradiate the pattern lights on the inspection target object, image the inspection target object at timings when the pattern lights are irradiated, and obtain a plurality of luminance images;
an image generating section configured to generate, on the basis of a deflectometry principle, phase data of a surface of the inspection target object from the plurality of luminance images captured by the imaging section and generate, on the basis of the phase data, an image for inspection indicating a shape of the inspection target object; and
an information acquiring section configured to acquire moving direction information concerning the moving direction of the inspection target object with respect to the array direction of the light receiving elements of the line camera and positional relation information concerning a positional relation between the light receiving elements of the line camera and the pattern light illuminating section, wherein
the image generating section is configured to generate, according to the moving direction information and the positional relation information acquired by the information acquiring section, the image for inspection related to the shape of the inspection target object.

Assignees

• Keyence Co Ltd

Inventors

• Ando Daisuke

Classifications

• G06T2207/30108

  Industrial image inspection · CPC title

• G01N21/55

  Specular reflectivity · CPC title

• G01N21/8806

  Specially adapted optical and illumination features · CPC title

• G01B11/2527 Primary

  with phase change by in-plane movement of the patern · CPC title

• G01N2021/8829

  Shadow projection or structured background, e.g. for deflectometry · CPC title