Surface inspection system

Patent metadata

Field	Value
Publication number	US-2023419471-A1
Application number	US-202318215739-A
Country	US
Kind code	A1
Filing date	Jun 28, 2023
Priority date	Jun 28, 2022
Publication date	Dec 28, 2023
Grant date	—

Abstract

A surface inspection system for capturing surface defects of a surface to be checked, includes a camera system, an illumination system including one or more light sources, and an evaluation system. The evaluation system evaluates a brightness and/or color distribution of the surface to be checked in at least one image captured by the camera system and captures surface defects of the surface to be checked as local deviations in the brightness and/or color. The evaluation system is configured to assess a local deviation in the brightness and/or color as a surface defect when the local deviation appears brighter in at least one first subregion and darker in at least one second subregion than a surface region surrounding the local deviation, and/or different colors are dominant in different subregions.

First claim

What is claimed is:

1 . A surface inspection system for detecting surface defects of a surface to be checked, the surface inspection system comprising:
a camera system; an illumination system; and an evaluation system, wherein the evaluation system evaluates a brightness and/or color distribution of the surface to be checked in at least one image captured by the camera system and determines surface defects of the surface to be checked as local deviations in the brightness and/or color, and wherein the evaluation system determines that a local deviation in the brightness and/or color is a surface defect when the local deviation appears brighter in at least one first subregion and darker in at least one second subregion than a surface region surrounding the local deviation, and/or when different colors are dominant in different subregions.

2 . The surface inspection system as claimed in claim 1 , wherein the illumination system includes one or more light sources,
wherein the evaluation system evaluates a brightness and/or color distribution of the surface to be checked in at least one image captured by the camera system and determines surface defects of the surface to be checked as local deviations in the brightness and/or color, wherein the camera system includes at least two cameras which completely or partly image the surface to be checked, and wherein the cameras and one or more light sources of the illumination system are arranged with respect to one another in such a way that the directional reflections of the light source or light sources for each camera appear at different locations of the check field of the surface inspection system.

3 . The surface inspection system as claimed in claim 1 , wherein the camera system and the illumination system are arranged with respect to one another such that, alongside at least one first region of the check field in which directional reflections of a light source of the illumination system appear, at least one second region without directional reflections of the light source remains in the recording of the camera, and
wherein the evaluation system evaluates the recording in the second region.

4 . The surface inspection system as claimed in claim 1 , wherein for each camera of the camera system, alongside a first region of the check field in which directional reflections of a light source appear, a second region of the check field without directional reflections of the light source remains,
wherein the second region for each color channel, and for all the cameras taken together, constitutes at least 40% of the area of the check field, or at least 60% of the area of the check field, and/or wherein the second regions over all the color channels and cameras cover the entire check field.

5 . The surface inspection system as claimed in claim 1 , wherein the evaluation system evaluates a plurality of recordings of the surface to be checked, which differ with regard to the position of the camera used to record them with respect to the surface to be checked,
wherein the evaluation system typically assesses a local deviation in the brightness and/or color which is contained in a plurality of recordings as a surface defect if the local deviation in at least one recording appears brighter in at least one first subregion and darker in at least one second subregion than a surface region surrounding the local deviation and/or has different subregions in which different colors are dominant.

6 . The surface inspection system as claimed in claim 1 , wherein the illumination system includes at least two spatially separate regions, and
wherein the two regions have different colors and/or are arranged on opposite sides of the surface inspection system.

7 . The surface inspection system as claimed in claim 1 , wherein the illumination system or its spatially separate regions is/are realized in rod-shaped or ring-shaped fashion and/or contain(s) one or more areally emitting light sources which emit nondirectionally into a large angular range.

8 . The surface inspection system as claimed in claim 1 , wherein the illumination system has at least two spatially separate and different-colored regions and the camera system includes at least one color camera having at least two color channels,
wherein the brightness distribution generated by the spatially separate, different-colored regions of the illumination device is recorded simultaneously and independently of one another over the different color channels of the camera and/or is evaluated by the evaluation system, and/or wherein the evaluation system assesses a local deviation in the brightness as a surface defect if the local deviation appears brighter or darker in at least one first subregion in a first color channel and in at least one second subregion in a second color channel than a surface region surrounding the local deviation.

9 . The surface inspection system as claimed in claim 1 , wherein the simultaneous image recording of all the cameras of the camera system is sufficient for fully inspecting the check field, and/or
wherein the surface inspection system has an extent that is not larger than 1.5 times the extent of the check field, relative to the basic area of the surface inspection system in a plane parallel to the check field.

10 . The surface inspection system as claimed in claim 1 , wherein a plurality of regions of the illumination system are arranged rotated by an angle with respect to one another relative to the check field,
wherein two regions of the illumination system are arranged in a manner rotated by 90° with respect to one another relative to the check field, and wherein the regions of the illumination system extend in rod-shaped fashion along an edge of the surface inspection system.

11 . The surface inspection system as claimed in claim 1 , wherein the cameras of the camera system are situated within an area enclosed by regions of the illumination system, and
wherein the regions of the illumination system extend in rod-shaped fashion along an edge of the surface inspection system.

12 . The surface inspection system as claimed in claim 1 , further comprising:
a kinematic unit configured to move the surface inspection system relative to the surface to be checked; and a controller, wherein the kinematic unit is controlled along a defined path by the controller.

13 . The surface inspection system as claimed in claim 1 , wherein the checking is effected during a relative movement of the surface inspection system with respect to the surface to be checked.

14 . The surface inspection system as claimed in claim 1 , wherein the surface inspection system forms a structural unit with a 3D measurement system with a stripe projection system, and
wherein a camera of the 3D measurement system is surrounded by cameras of the camera system and/or regions of the illumination system of the surface inspection system.

15 . A method for detecting surface defects of a surface to be checked with a surface inspection system including a camera system and an illumination system, the method comprising:
generating, by the illumination system, together with reflection and scattering properties of the surface to be checked, a brightness and/or color distribution in which surface defects become visible as local deviations in the brightness and/or color, said distribution being detected by the camera system; determining a local deviation in the brightness and/or color to be a surface defect when the local deviation appears brighter in at least one first subregion and darker in at least one secon

Assignees

• Zeiss Carl Industrielle Messtechnik Gmbh

Inventors

• Schleith Christian
• Dieball Stefan
• Pontai Béla

Classifications

• G06T7/0004 Primary

  Industrial image inspection · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• G06T2207/30108

  Industrial image inspection · CPC title

• H04N23/695

  Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects · CPC title

• G06T2207/10024

  Color image · CPC title