Method and apparatus for reading image using a line image sensor

Abstract

A method for reading optical image information using a line image sensor is disclosed which comprises the steps of reading in the optical image information at a spatial frequency in the reading in the sub-scanning direction adapted to be higher than the spatial frequency in the reading in the main scanning direction and converting the read optical image information into an electric signal and outputting the electric signal to the outside. Also disclosed is an apparatus for reading optical image information according to the above method, and which comprises feed means for feeding a medium with the optical image information represented thereon in the sub-scanning direction so that the line image sensor may read the optical image information in the sub-scanning direction, control means for controlling the feed means so that the spatial frequency in the reading in the sub-scanning direction may become higher than the spatial frequency in the reading in the main scanning direction, and line density conversion means for converting an electric signal output from the line image sensor upon its reading the optical image information so that the line density in the sub-scanning direction and the line density in the main scanning direction may concur.

Dependencies are inferred from the claim text.