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Patent Searching and Data

Document Type and Number:
Japanese Patent JP01189549
Kind Code:

PURPOSE: To enable the detection of a defect of glass with high resolution and at a high speed, by a method wherein a light from a light source provided linearly is projected into the glass through a slit.

CONSTITUTION: Glass 2 is irradiated by a light of a light source, e.g. a halogen lamp 7, through a slit 6. In the case when a defect exist inside or one the surface of the glass 2, a normal part thereof is bright and a defect part is dark when the light is applied to the glass 2. The intensity of the light therefrom is sensed by a one- dimensional camera 1, converted into an electric signal and transmitted to a prepara tory processing element 11. The glass 2 is carried at a prescribed speed by a carrying device 5 driven by a motor 3, and an information on the position of the glass 2 is detected by a rotary encoder 4 fitted to a driving system and sent likewise to the preparatory processing element 11. In the preparatory processing element 11, a video signal from the camera 1 is transformed into one-dimensional binary-coded data and further it is subjected to run-length coding and transmitted to an after processing element 12. In the after processing element 12, one-dimensional signal is converted into a two-dimensional signal on the basis of the run-length data and a position signal from a carrying control element 10, and thereafter the dimensions of the defect part are calculated to determine the quality of the glass 2.

Tani, Hideto
Kobayashi, Shinji
Application Number:
Publication Date:
July 28, 1989
Filing Date:
January 26, 1988
Export Citation:
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International Classes:
G01N21/88; G01N21/896; G01N21/958; (IPC1-7): G01N21/88