Title:
METHOD AND DEVICE FOR INSPECTING SHEET OF DRIED LAVER
Document Type and Number:
Japanese Patent JP2678411
Kind Code:
B2
Abstract:
PURPOSE: To judge the quality of sheets of dried laver to be inspected by inspecting in advance several sheets of reference dried laver which are identified as defectless and obtaining a reference value by adding a fixed value to the mean value of the signal levels of reflected light rays.
CONSTITUTION: A camera 5 scans a sheet of dried laver which is identified as defectless and reads reflected light signals for a fixed period of time and an integration circuit 39 integrates the signals through an analog switch 38 at every scanning line. An A/D conversion circuit 40 converts the integrated signals into digital values and an arithmetic circuit 41 calculates the optimum threshold (reference value) by summing and averaging the digital values of each scanning line from the downstream side edge to the upstream side edge of the sheet and a memory 42 stores the reference value. A comparator circuit 44 inputs the set reference value through a D/A conversion circuit 43. Therefore, the signals of sheets of dried laver to be inspected are supplied to the comparator circuit 44 while the sheets are carried and the circuit 44 compares the signals with the reference signal. When any one of the signal levels from a sheet to be inspected exceeds thc reference value, the sheet is judged as a defective sheet and, when the signal levels front the entire area of the sheet do not reach the reference value, the sheet is judged as a defectless sheet.
Inventors:
Ryoichi Hamada
Hiroshi Suzuki
Hiroshi Suzuki
Application Number:
JP27607491A
Publication Date:
November 17, 1997
Filing Date:
July 26, 1991
Export Citation:
Assignee:
Nikka Densoku Co., Ltd.
International Classes:
G01N21/89; G01N21/88; G01N21/892; G01N21/93; (IPC1-7): G01N21/89
Domestic Patent References:
| JP2253142A | ||||
| JP240542A | ||||
| JP2129535A | ||||
| JP388654A |