Patent US1009616A successfully refreshed from Google Patents.
Patent US4289377A successfully refreshed from Google Patents.
US4289377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projecting apparatus
Assignee: Canon Inc
•
Filing: 1979-03-23
•
Granted: 1981-09-15
•
Expires: 1999-03-23
Abstract
Abstract In a projecting apparatus which focuses the image of an object on an intermediate mirror through a lens array and finally projects the reflected image onto a projection plane again through said lens array, a polarizing beam splitter is provided between the object plane and the lens array to reduce the light loss and to compactize the apparatus.
Inventors
- 👤 Yoshiya Matsui
- 👤 Setsuo Minami
- 👤 Noritaka Mochizuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:09
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; G; G03; G03B; G03B21/00; G03B27/00; G03B27/32; G03B27/52; G03B27/522; G03B27/525; G03B27/526; G03B27/527; G03B27/528
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
118 words
A projecting apparatus comprising: an array of rod-shaped lenses for forming the image of an object, each of said lenses having only two lens surfaces and an axial length larger than the effective diameter thereof: a plane mirror positioned in the vicinity of the intermediate image plane of said array of rod-shaped lenses, wherein the principal ray of light rays incident on said mirror is traced by the principal ray of light rays reflected by said plane mirror; a polarizing beam splitter positioned obliquely to the optical axis of said lens array and being disposed between the object and the lens array; and optical means for changing the polarizing direction of the light to a direction perpendicular thereto.
Claim 2
Dependent Claim
118 words
A projecting apparatus comprising: an array of rod-shaped lenses for forming the image of an object, each of said lenses having only two lens surfaces and an axial length larger than the effective diameter thereof: a plane mirror positioned in the vicinity of the intermediate image plane of said array of rod-shaped lenses, wherein the principal ray of light rays incident on said mirror is traced by the principal ray of light rays reflected by said plane mirror; a polarizing beam splitter positioned obliquely to the optical axis of said lens array and being disposed between the object and the lens array; and optical means for changing the polarizing direction of the light to a direction perpendicular thereto.
Claim 3
Dependent Claim
19 words
A projecting apparatus according to the claim 1, wherein said optical means comprising a polarizer and a 1/4-wavelength plate.
Claim 4
Dependent Claim
30 words
A projecting apparatus according to the claim 1, wherein the axial length of each rod-shaped lens is within a range of 2 to 60 times of the effective diameter thereof.
Claim 5
Dependent Claim
190 words
A projecting apparatus according to claim 1, wherein each rod-shaped lens satisfies the following characteristics: ##EQU5## wherein K 1 =0.9 and K 2 =1.1 r 1 : radius of curvature of the first face, facing the object, of the rod-shaped lens; r 2 : radius of curvature of the second face, at the image field side, of said rod-shaped lens; d' 1 : axial thickness, or the distance between the first and second faces of said rod-shaped lens; n' 1 : principal refractive index, i.e. the refractive index for the design wavelength, of the material constituting said rod-shaped lens; φ.sub. : effective diameter of said rod-shaped lens; φ 0 : dimension of the object; φ 2 : dimension of the intermediate image formed by said rod-shaped lens; S 1 : distance from the first fact of the rod-shaped lens to the object; S' 2 : distance from the second face of the rod-shaped lens to the intermediate image; β 1 : lateral magnification of the intermediate image with respect to the object (≡-|φ 2 /φ 1 |); and Fe: effective F number at the object side of said rod-shaped lens.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |