Patent · US Expired

Image processing apparatus

US5351316A · kind A · utility

3Cited by
6References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 23, 1993
Grant dateSep 27, 1994
Priority date
Expiry dateAug 23, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/026
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The present invention provides an image processing apparatus capable of forming a sharp image of a detection mark formed in a plane. The image processing apparatus comprises a camera unit (1) comprising a lens system (12) and a photodetecting device (13) inclined at a predetermined angle to the optical axis (L') of the lens system. The camera unit (1) is disposed with the optical axis (L') of the lens system (12) inclined at a predetermined angle to a perpendicular line (L) to the plane including the detection mark so that the difference in length between respective sections of light paths between diametrically opposite portions of the detection mark and the lens system is canceled by the difference in length between respective sections of the same light paths between the lens system and the photodetecting device.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.