EP0537731A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Projection optical apparatus with adjustable diaphragm
Assignee: Canon Inc
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Filing: 1992-10-15
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Granted: —
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Expires: 2012-10-15
Abstract
Abstract A projection optical apparatus comprises an illuminating device (1,20) for illuminating an image (5), and a projecting device (6) for projecting the image illuminated by the illuminating device onto a screen. In the projection optical apparatus, the projecting device has a numerical aperture (NA) on a side of the screen changed depending upon a projection magnification of the image onto the screen.
Inventors
- 👤 Yoshihiro c/o Canon Kabushiki Kaisha Ishibe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:50
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/20; G02; G02B; G02B27/00; G02B27/18
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
54 words
A projection optical apparatus comprising: illuminating means for illuminating an image; and projecting means for projecting the image illuminated by said illuminating means onto a predetermined plane; wherein said projecting means has an NA on a side of said predetermined plane changed depending upon a projection magnification of said image onto said predetermined plane.
Claim 2
Dependent Claim
32 words
A projection optical apparatus according to Claim 1, further comprising light amount correction means disposed in an optical path between a light source portion of said illuminating means and said predetermined plane.
Claim 3
Dependent Claim
62 words
An image projection method comprising: a step of illuminating an image by illuminating means; a step of projecting by projecting means the image illuminated by said illuminating means onto a predetermined plane; and a step of changing an NA of said projecting means on a side of said predetermined plane depending upon a projection magnification of said image onto said predetermined plane.
References Cited (Backward Citations)
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