Assembled PCB visual inspection machine using image processor with DSP

Author

Hata, Seiji ; Hagimae, Kinuyo ; Hibi, Susumu ; Gunji, Takeo

Author_Institution

Hitachi Ltd., Ibaraki, Japan

fYear

1989

fDate

6-10 Nov 1989

Firstpage

572

Abstract

To automate the visual inspection of assembled printed circuit boards (PCBs), a visual inspection machine was developed. The machine detects a variety of defects of assembled PCBs, such as missing parts, polarity errors, improper names of ICs, and improper insertion of leads. To achieve this variety of functions, a microprogrammable image signal processor, the DSP-i, has been introduced into the machine. A character recognition algorithm called the multistep similarity vector comparison method is used in the processor. This method enables the inspection machine to recognize IC names reliably without the learning of various patterns of characters from many manufacturers. The operation speed of the DSP-i is about 20 times faster than that of a general 16-b microcomputer

Keywords

computer vision; computerised picture processing; inspection; printed circuit manufacture; DSP-i; IC name recognition; assembled PCB visual inspection machine; character recognition algorithm; lead improper insertion; microprogrammable image signal processor; missing parts; multistep similarity vector comparison method; polarity errors; Assembly; Character recognition; Inspection; Machine learning; Manufacturing; Microcomputers; Pattern recognition; Printed circuits; Signal processing; Signal processing algorithms;

fLanguage

English

Publisher

ieee

Conference_Titel

Industrial Electronics Society, 1989. IECON '89., 15th Annual Conference of IEEE

Conference_Location

Philadelphia, PA

Type

conf

DOI

10.1109/IECON.1989.69695

Filename

69695