The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 12, 2003
Filed:
Oct. 25, 2002
Seizo Suzuki, Kanagawa, JP;
Magane Aoki, Kanagawa, JP;
Hiromichi Atsuumi, Kanagawa, JP;
Kohji Sakai, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A light source emitting a light flux; a coupling optical system couples the light flux from the light source to a subsequent optical system by transforming it into a parallel light flux, an approximately convergent light flux or an approximately divergent light flux; a light deflector reflects the light flux from the coupling optical system with a deflection reflective surface, and deflects it; a scanning and imaging optical system condenses the deflected light flux from the light deflector onto a surface to be scanned as a beam spot; and a correcting optical system is provided for self correcting shift of focal position of the beam spot on the surface to be scanned occurring due to environmental change or the like. The correcting optical system comprises at least one pair of a resin-made lens having an anamorphic surface having a negative power in each of main scanning direction and sub-scanning direction and a glass-made lens having an anamorphic surface having a positive power at least in sub-scanning direction, and is disposed between the coupling optical system and deflection reflective surface.