Title:
PROJECTION OPTICAL DEVICE
Document Type and Number:
Japanese Patent JPH05107503
Kind Code:
A
Abstract:
PURPOSE:To obtain an projection optical device which obtains a projection image having no irregularity in the quantity of light at all times by correcting the irregularity in the quantity of light on a screen surface at the time of low magnifications when the power variation ratio of the projection optical device is large. CONSTITUTION:Luminous flux emitted by a light source means 1 passes through a lighting optical system 20 to illuminate an image 5, which is projected on the surface of a screen 10 through a projection lens 6. This projection optical device uses the projection lens 6 which is made different in NA(numerical aperture) on the side of the screen 10 corresponding to the projection magnifications of the image projected on the surface of the screen 10.
Inventors:
ISHIBE YOSHIHIRO
Application Number:
JP29844691A
Publication Date:
April 30, 1993
Filing Date:
October 16, 1991
Export Citation:
Assignee:
CANON KK
International Classes:
G02B27/18; G03B21/00; G03B21/20; (IPC1-7): G02B27/18; G03B21/00
Attorney, Agent or Firm:
Takanashi Yukio