Patent EP0434041A1 successfully refreshed from Google Patents.
EP0434041A1
Expired / Lapsed
EP
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Polarized illuminazing device
Assignee: Canon Inc
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Filing: 1990-12-19
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Granted: —
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Expires: 2010-12-19
Abstract
Abstract An image display apparatus has a radiation source, generator for generating an image by modulating a polarized light beam and directing device for directing a light beam from the radiation source toward the generator. The directing device has a conversion optical system for converting the beam from the radiation source into the polarized light beam. The conversion optical system has a polarizing beam splitter for splitting the beam from the radiation source into a first and second beams. In the conversion optical system, a 1/4 wavelength plate and a mirror are arranged so that the plane of polarization of the first beam is rotated to generate a third beam with the plane of polarization same as that of the second beam. The third beam is directed toward the generator through the polarizing beam splitter while the second beam is also directed toward the generator.
Inventors
- 👤 Hideaki Mitsutake
- 👤 Nobuo Minoura
- 👤 Kazumi Kimura
- 👤 Katsumi Kurematsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:47
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3167; G; G02; G02B; G02B27/00; G02B27/28; G02B27/283; H04N9/3102; H04N9/3105; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/133536; G02F1/13355; G02F1/1336; G02F1/13362
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
150 words
An image display apparatus comprising: a radiation source; a generator for generating an image by modulating a polarized beam; and directing means for directing a beam from said radiation source to said generator; wherein said directing means has a conversion optical system for converting the beam from said radiation source into said polarized beam; and said conversion optical system includes a polarizing beam splitter for splitting the beam from said radiation source into a first beam and a second beam of mutually orthogonal planes of polarization; and an arrangement of a 1/4 wavelength plate and a mirror for rotating the plane of polarization of said first beam to generate a third beam of a plane of polarization same as that of said second beam; and is adapted to direct said third beam to said generator through said polarizing beam splitter and also to direct said second beam to said generator.
Claim 2
Dependent Claim
34 words
An apparatus according to claim 1, wherein said directing means has a collimeter for converting the beam from said radiation source into a substantially parallel beam, which is introduced into said conversion optical system.
Claim 3
Dependent Claim
46 words
An apparatus according to claim 1 or 2, wherein said polarizing beam splitter is adapted to generate said first beam by reflecting the S-polarized component of the beam from said radiation source and to generate said second beam by transmitting the P-polarized component of said beam.
Claim 4
Dependent Claim
38 words
An apparatus according to claim 3, wherein said conversion optical system is to constructed as to direct said second beam to a predetermined direction and has an auxiliary mirror for reflecting said third beam to said predetermined direction.
Claim 5
Dependent Claim
38 words
An apparatus according to claim 3, wherein said conversion optical system is so constructed as to direct said third beam to a predetermined direction and has an auxiliary mirror for reflecting said second beam to said predetermined direction.
Claim 6
Dependent Claim
27 words
An apparatus according to claim 2, wherein said conversion optical system has an optical filter for compensating the unevenness in intensity between said second and third beams.
Claim 7
Dependent Claim
47 words
An apparatus according to claim 6, wherein said conversion optical system is so constructed as to direct said second beam to a predetermined direction and has an auxiliary mirror for reflecting said third beam to said predetermined direction, and said mirror is provided with said optical filter.
Claim 8
Dependent Claim
47 words
An apparatus according to claim 6, wherein said conversion optical system is so constructed as to direct said third beam to a predetermined direction and has an auxiliary mirror for reflecting said second beam to said predetermined direction, and said mirror is provided with said optical filter.
Claim 9
Dependent Claim
15 words
An apparatus according to claim 6, wherein said mirror is provided with said optical filter.
Claim 10
Dependent Claim
20 words
An apparatus according to claim 6, wherein said optical filter is provided between said polarizing beam splitter and said arrangement.
Claim 11
Independent Claim
18 words
An apparatus according to any of claims 6 to 10, wherein said optical filter has a multi-layered structure.
Claim 12
Dependent Claim
27 words
An apparatus according to claim 2 wherein said conversion optical system has a color filter for compensating the unevenness in color between said second and third beams.
Claim 13
Independent Claim
24 words
An apparatus according to any of claims 1 to 12, further comprising a projection optical system for projecting said image onto a predetermined plane.
Claim 14
Dependent Claim
168 words
An image display apparatus comprising: a radiation source; a generator for generating an image by modulating a polarized beam; and directing means for directing the beam from said radiation source to said generator; wherein said directing means has a collimator for substantially collimating the beam from said radiation source; and a conversion optical system for converting thus collimated beam into said polarized beam, and said conversion optical system includes a polarizing beam splitter provided with a splitting plane, inclined to the optical axis of said collimeter, for splitting said collimated beam by transmitting the P-polarized beam thereof and reflecting the S-polarized beam thereof; an arrangement of a 1/4 wavelength plate and a mirror for rotating the plane of polarization of said S-polarized beam to generate a polarized beam with a plane of polarization same as that of said P-polarized beam and directing said polarized beam to a predetermined direction through said polarizing beam splitter; and an auxiliary mirror for reflectively deflecting said P-polarized beam to said predetermined direction.
Claim 15
Dependent Claim
29 words
An apparatus according to claim 14, wherein said conversion optical system has an optical filter for compensating the unevenness in intensity between said P-polarized beam and said polarized beam.
Claim 16
Dependent Claim
18 words
An apparatus according to claim 15, wherein the mirror of said arrangement is provided with said optical filter.
Claim 17
Dependent Claim
16 words
An apparatus according to claim 15, wherein said auxiliary mirror is provided with said optical filter.
Claim 18
Dependent Claim
20 words
An apparatus according to claim 15, wherein said optical filter is provided between said polarizing beam splitter and said arrangement.
Claim 19
Dependent Claim
29 words
An apparatus according to claim 14, wherein said conversion optical system has a color filter for compensating the unevenness in color between said P-polarized beam and said polarized beam.
Claim 20
Independent Claim
24 words
An apparatus according to any of claims 14 to 19, further comprising a projection optical system for projecting said image onto a predetermined plane.
Claim 21
Dependent Claim
190 words
An image display apparatus comprising: a radiation source; a generator for generating an image by modulating a polarized beam; and directing means for directing the beam from said radiation source to said generator; wherein said directing means has a collimator for substantially collimating the beam from said radiation source; and a conversion optical system for converting thus collimated beam into said polarized beam; and said conversion optical system includes a first polarizing beam splitter provided with a splitting plane, inclined to the optical axis of said collimator, for splitting said collimated beam by transmitting the P-polarized beam thereof and reflecting the S-polarized beam thereof into a predetermined direction; a second polarizing beam splitter provided with a splitting plane inclined to the optical axis of said collimator; and an arrangement of a 1/4 wavelength plate and a mirror for receiving said P-polarized beam through said second polarizing beam splitter, rotating the plane of polarization of said P-polarized beam to generate a polarized beam having a plane of polarization same as that of said S-polarized beam, and causing said second polarizing beam splitter to reflect said polarized beam into said predetermined direction.
Claim 22
Dependent Claim
174 words
An image display apparatus comprising: a radiation source; a generator for generating an image by modulating a polarized beam; and directing means for directing the beam from said radiation source to said generator; wherein said directing means has a collimator for substantially collimating the beam from said radiation source; and a conversion optical system for converting thus collimated beam into said polarized beam; and said conversion optical system includes a polarizing beam splitter provided with a splitting plane, inclined to the optical axis of said collimator, for splitting said collimated beam by transmitting the P-polarized beam thereof to a predetermined direction and reflecting the S-polarized beam thereof; an arrangement of a 1/4 wavelength plate and a mirror for rotating the plane of polarization of said S-polarized beam to generate a polarized beam having a plane of polarization same as that of said P-polarized beam and directing said polarized beam to said polarizing beam splitter; and an auxiliary mirror receiving said polarized beam through said polarizing beam splitter and reflecting it to said predetermined direction.
References Cited (Backward Citations)
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