Title:
FOCUS DETECTOR
Document Type and Number:
Japanese Patent JPH03196008
Kind Code:
A
Abstract:
PURPOSE:To effectively prevent the generation of intersected light rays so that focus detection is made with high accuracy by providing light absorbing means or light reflecting means between the secondary imaging lenses of a pair of the secondary imaging lenses. CONSTITUTION:A pair of the secondary imaging lenses 34-1 are formed by integrally molding lens parts 34-1a, 34-1b having a lens effect of acryl, etc. together with a substrate 20 in such a manner that a hollow groove is formed between the two secondary imaging lenses. The inside surfaces 36-a, 36-b of the hollow grooves are so set as to have a light absorbing effect or light reflecting effect. The intersected light 45-1a is absorbed or reflected by the surface 36-b and is thereby prevented from being made incident on a photodetector array 35-1a and from being made incident on other photodetector arrays as well. The focus detection with the high accuracy is possible in this way even in plural measuring regions.
Inventors:
OMURA YUSUKE
Application Number:
JP33687689A
Publication Date:
August 27, 1991
Filing Date:
December 26, 1989
Export Citation:
Assignee:
CANON KK
International Classes:
G03B13/36; G02B7/34; (IPC1-7): G02B7/34; G03B13/36
Attorney, Agent or Firm:
Takanashi Yukio