Patent ID: 6278108
Filing Date: 2001-08-21
Classification: G02B

Abstract:
A synchronous light detector for an optical scanning apparatus in which a light beam is deflected by light-deflecting means, thus deflected light beam is focused like a spot by an imaging lens onto a surface to be scanned, and said surface is scanned with said spot; said synchronous light detector attaining an optical scanning start timing by detecting as synchronous light the light beam deflected by said light-deflecting means toward an optical scanning area;said synchronous light detector comprising:a light-receiving device for receiving said light beam as said synchronous light by way of said imaging lens; anda cylindrical lens disposed between said imaging lens and said light-receiving device;said cylindrical lens being disposed so as to have a generator direction thereof parallel to a scanning direction of said light beam;a light-receiving surface of said light-receiving device being disposed at a position shifted from a paraxial image point by a predetermined distance in an optical axis direction of said light-receiving device within a plane orthogonal to the scanning direction of said light beam when a deflecting point of said light beam caused by said light-deflecting means is taken as an object point.