Imaging optical system
AssigneeMinolta Co., Ltd.
InventorsAkira Sato, Soh Ohzawa, Katsuhiro Takamoto
Life of this patent
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Abstract
An imaging optical system transmits a primary image. The optical system does not form an intermediate image. The primary image is projected on a screen as a secondary image. The optical system has a projection optical system and a reflection optical system. An optical axis of the reflection optical system forms an angle other than 90.degree. with respect to a screen-side image surface.
Claims6
An imaging optical system for transmitting a primary image to form an enlarged or reduced secondary image without forming an intermediate image in the middle of optical paths, comprising:
- a projection optical system;
- and
- a reflection optical system having a positive power and disposed in such a way that its optical axis forms an angle other than a right angle with respect to a enlargement-side image surface,
- wherein all principal rays between said reflection optical system and said enlargement-side image surface form a uniform angle with respect to the enlargement-side image surface and a base ray incident on a reflection surface of said reflection optical system forms an angle of 90.degree. or less with respect to a base ray reflected by the reflection optical system.
An image projection device, comprising:
- an image providing means for providing a primary image;
- a screen on which a secondary image is projected;
- a projection optical system;
- and
- a reflection optical system having a positive power and disposed in such a way that its optical axis forms an angle other than a right angle with respect to the screen,
- wherein all principal rays between said reflection optical system and said screen form a uniform angle with respect to the screen and a base ray incident on a reflection surface of said reflection optical system forms an angle of 90.degree. or less with respect to a base ray reflected by the reflection optical system.
An image reading apparatus, comprising:
- an image providing surface for providing a primary image;
- an image projection surface for projecting a secondary image on;
- a reflection optical system having a positive power and disposed in such a way that its optical axis forms an angle other than a right angle with respect to the image providing surface;
- and
- a projection optical system,
- wherein all principal rays between said reflection optical system and said image providing surface form a uniform angle with respect to the image providing surface and a base ray incident on a reflection surface of said reflection optical system forms an angle of 90.degree. or less with respect to a base ray reflected by the reflection optical system.
Dependencies are inferred from the claim text.