US 2004/0105132 A1 · Imaging optical system and image reading apparatus using the same

Abstract

To obtain an original reading imaging optical system, with which a carriage integral type scanning system can be readily realized in an original reading system such as a digital copier for which high-speed performance and high resolution are required, and an image reading apparatus using the same. According to the present invention, by crossing optical paths in a reflection optical system, the more compact imaging optical system capable of coping with decentering error can be attained. Further, by crossing the optical paths on an object side from a diaphragm, the still more compact imaging optical system can be attained. As a result, the original reading imaging optical system of the carriage integral type scanning system and the image reading apparatus using the same can be provided.

Claims8

Dependent claims

An imaging optical system for imaging on a predetermined surface information in a region having a length (A) in a long side direction and a length (B) in a short side direction which satisfy a relation of A/B>10, comprising:

a diaphragm;
a first set of a plurality of curved reflection surfaces arranged on an object surface side from the diaphragm;
and
a second set of a plurality of curved reflection surfaces arranged on an image surface side from the diaphragm,
wherein an optical path of a light beam passing through a center of the diaphragm and a center of an image obtained through the imaging is deflected by the reflection surfaces within a surface substantially perpendicular to the long side of the region to undergo crossing at least once.

2 more elements

Dependencies are inferred from the claim text.

Imaging optical system and image reading apparatus using the same

Life of this patent

Imaging optical system and image reading apparatus using the same

Life of this patent

Abstract

Claims8