Patent · US Expired

Image reading apparatus

US6163414A · kind A · utility

188Cited by
4References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 13, 1998
Grant dateDec 19, 2000
Priority date
Expiry dateOct 13, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B26/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An image reading apparatus includes: illuminating means for illuminating an original with light; a lens forming an image of reflected light from the original, the lens having a resolution characteristic in which a resolution in a vertical scanning direction in an image-reading wavelength region at a field angle in a vicinity of an end of the original is lower than a minimum resolution in an image-reading wavelength region at a field angle on an inner side of the vicinity-of the end of the original; light shielding means for shielding part of the reflected light such that a pupil diameter in the vertical scanning direction in the reflected light from the vicinity of the end of the original is reduced; and photoelectrically converting means for converting the reflected light partly shielded by the light shielding means and undergone image formation by the lens into an electrical signal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.