EP0452905A1
Expired / Lapsed
EP
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Method and apparatus for inspecting surface pattern of object
Assignee: Hitachi Ltd
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Filing: 1991-04-17
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Granted: —
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Expires: 2011-04-17
Abstract
Abstract A method and an apparatus for inspecting a three-dimensional surface shape and pattern of an object (1) under inspection by images of the surface of the object, said images being formed by reflected light rays from the object illuminated by lights. The surface of the object is illuminated by first (3) and second lights (4) provided on the inspected surface side of the object and at different heights from the object, images of the reflected light rays from the surface of the object illuminated by the first and second lights (3,4) are acquired by an imaging unit (5), a first image of the surface of the object illuminated by the first light and a second image of the surface of the object illuminated by the second light, both acquired by the imaging unit, are input separately, brightness values at the same pixel points of the first and the second images are subjected to a division process to obtain a value, and by using this value as the brightness value of the pixel, a third image is formed which is used for quality evaluation.
Inventors
- 👤 Yuji Takagi
- 👤 Seiji Hata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 05:05
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/8806; G01N21/95; G01N21/956; G01N21/95684; G01N21/17; G01N2021/1765; G01N2021/177; G01N2021/1776; G01N2021/178; G01N2021/1785; G01N21/8851; G01N2021/8887; G01N2021/95638; G01N2021/95653
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
160 words
An apparatus for inspecting a surface shape and pattern of an object, comprising: first and second lighting means (3, 4), provided on the inspected surface side of an object and at different heights from the object, for illuminating the surface of the object; imaging means (5) for acquiring images of lights reflected from the surface of the object illuminated by the first and second lighting means; input means (16) for accepting a first image of the surface of the object illuminated by the first lighting means (3) and a second image of the surface of the object illuminated by the second lighting means (4), said first and second images being captured by said imaging means (5); and means (19, 20) for performing a division process using brightness values at the same pixel points of the first and second images accepted by the input unit (16) and forming a third image by using a value (DVDPIC) derived from said division process.
Claim 2
Dependent Claim
27 words
An apparatus according to Claim 1, wherein each of said first and second lighting means (3, 4) comprises means for emitting light rays with multiple different wavelengths.
Claim 3
Dependent Claim
56 words
An apparatus according to Claim 1, further comprising means (7) for classifying brightness values at each pixel of a third image formed by said third image forming means (19, 20), assigning different colors to the respective classes and displaying each pixel of said third image in a color according to the brightness value at the pixel.
Claim 4
Dependent Claim
64 words
An apparatus according to Claim 1, wherein there is further provided light on/off control means (21, 26) for turning on and off said first and second lighting means (3, 4) alternately, and wherein said input means (16) comprises means for alternately accepting the first and second images captured by said imaging means (5) in synchronism with on/off control by said light on/off control means.
Claim 5
Dependent Claim
53 words
An apparatus according to Claim 1, wherein frequency bands of the illumination light of said first and second lighting means (3, 4) are different first and second frequency bands, and wherein said imaging means includes image pick-up means (30a, 30b) for separately acquiring reflected light rays of said first and second frequency bands.
Claim 6
Dependent Claim
26 words
An apparatus according to Claim 1, wherein said apparatus is adapted to inspect the condition of solder joints of parts mounted on a printed circuit board.
Claim 7
Independent Claim
151 words
A method of inspecting a surface shape and pattern on the surface of an object, comprising the steps of: providing first and second lighting means (3, 4) on the inspected surface side of an object and at different heights from the object for illuminating the surface of the object; acquiring images of reflected light rays from the surface of the object illuminated by said first and second lighting means; separately inputting a first image of the surface of the object illuminated by the first lighting means (3) and a second image of the surface of the object illuminated by the second lighting means (4); and forming a third image by using a value derived from the division process as the brightness value of a given pixel, said third image being obtained by performing a division process between brightness values of at the same pixel points of the first and second images.
Claim 8
Dependent Claim
30 words
A method according to Claim 7, further comprising the step of causing the first and the second lighting means (3, 4) to respectively emit light rays with multiple different wavelengths.
Claim 9
Dependent Claim
62 words
A method according to Claim 7, further comprising the steps of classifying a brightness value at each pixel of said third image formed by the step of forming said third image into a plurality of ranges, assigning different colors to the respective classes and displaying each pixel of said third image in a color according to the brightness value at the pixel.
Claim 10
Dependent Claim
33 words
A method according to Claim 7, further comprising the steps of alternately turning on and off the first and second lighting means (3, 4) and alternately inputting the first and second images acquired.
Claim 11
Dependent Claim
58 words
A method according to Claim 7, further comprising the step of separating frequency bands of the illumination light by the first and second lighting means (3, 4) into different first and second frequency bands, wherein said image acquiring step comprises a step of separately acquiring images of the reflected light rays of said first and second frequency bands.
Claim 12
Dependent Claim
26 words
A method according to Claim 7, wherein said method is adapted to inspect the condition of solder joints of parts mounted on a printed circuit board.
References Cited (Backward Citations)
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