Title:
EXPOSING DEVICE
Document Type and Number:
Japanese Patent JPS5844461
Kind Code:
A
Abstract:
PURPOSE: To reduce the size and weight of an exposing device without occurrence of sinking by using a Fresnel lens at least for an intermediate plate lens among three plate lenses.
CONSTITUTION: Plate lenses 1, 4 and 1 are stacked in order to form a layer, and are fitted in grooves 2a of a housing 2 made of aluminum, or zinc, etc. Some of the plate lenses 4 are Fresnel lenses 4a. Consequently, the lens is reduced in thickness and the extent of contraction is less, so a prescribed radius of curvature is obtained without a serious influence of sinking.
Inventors:
EBARA SHIYOUICHI
SUGASAWA ISAMU
ITOU HIDENORI
JIYOUDAI YASUHIRO
NAKAGAWA NOBUHIKO
SUGASAWA ISAMU
ITOU HIDENORI
JIYOUDAI YASUHIRO
NAKAGAWA NOBUHIKO
Application Number:
JP14249381A
Publication Date:
March 15, 1983
Filing Date:
September 11, 1981
Export Citation:
Assignee:
RICOH KK
International Classes:
G03B27/50; G03G15/04; (IPC1-7): G03B27/32
Attorney, Agent or Firm:
Tamio Nishiwaki