Patent EP0344810A2 successfully refreshed from Google Patents.
EP0344810A2
Expired / Lapsed
EP
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Display apparatus
Assignee: Canon Inc
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Filing: 1989-06-02
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Granted: —
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Expires: 2009-06-02
Abstract
Abstract A display apparatus comprises a display, a first diffraction grating for diffracting light from the display, and a second diffraction grating for diffracting diffracted light from the first diffraction grating, so that a half-wavelength-width of the first diffraction grating is set to be larger than that of the second diffraction grating.
Inventors
- 👤 Tetsuro Kuwayama
- 👤 Naosato Taniguchi
- 👤 Yoko Yoshinaga
- 👤 Nobuo Kushibiki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:05
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/01; G02B27/0101; G02B27/0103; G02B2027/0109; G02B2027/0112; G02B2027/0116; G02B2027/0118
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
49 words
A display apparatus comprising: a display; a first diffraction grating for diffracting light from said display; and a second diffraction grating for diffracting diffracted light from said first diffraction grating, a half-wavelength-width of said first diffraction grating being set to be larger than that of said second diffraction grating.
Claim 2
Dependent Claim
49 words
A display apparatus comprising: a display; a first diffraction grating for diffracting light from said display; and a second diffraction grating for diffracting diffracted light from said first diffraction grating, a half-wavelength-width of said first diffraction grating being set to be larger than that of said second diffraction grating.
Claim 3
Dependent Claim
23 words
An apparatus according to claim 1, wherein said first diffraction grating reflects and diffracts light from said display toward said second diffraction grating.
Claim 4
Dependent Claim
13 words
An apparatus according to claim 2,wherein said first diffraction grating comprises a hologram.
Claim 5
Dependent Claim
15 words
An apparatus according to claim 2, wherein said first diffraction grating comprises a relief grating.
Claim 6
Dependent Claim
14 words
An apparatus according to claim 1, wherein said second diffraction grating comprises a hologram.
Claim 7
Dependent Claim
21 words
An apparatus according to claim 5, wherein said first diffraction grating exhibits color dispersion opposite to that caused by said hologram.
Claim 8
Dependent Claim
33 words
An apparatus according to claim 1, wherein an optical path length between said display and said first diffraction grating is set to be smaller than that between said first and second diffraction gratings.
Claim 9
Dependent Claim
26 words
An apparatus according to claim 7, wherein a size of said second diffraction grating is set to be larger than that of said first diffraction grating.
Claim 10
Dependent Claim
36 words
An apparatus according to claim 8, wherein said second diffraction grating reflects and diffracts the diffracted light from said first diffraction grating toward a pupil and allows other light components to pass therethrough toward said pupil.
Claim 11
Dependent Claim
15 words
An apparatus according to claim 9, wherein said second diffraction grating comprises a volume-type hologram.
Claim 12
Dependent Claim
81 words
A display apparatus comprising: a display; a diffraction grating for diffracting light from said display toward a pupil; and optical means, arranged in an optical path between said display and said diffraction grating, for directing the light from said display toward said diffraction grating, said optical means causing the light to exhibit color dispersion for correcting color dispersion caused by said diffraction grating, and a half-wavelength-width of said optical means being set to be larger than that of said diffraction grating.
Claim 13
Dependent Claim
81 words
A display apparatus comprising: a display; a diffraction grating for diffracting light from said display toward a pupil; and optical means, arranged in an optical path between said display and said diffraction grating, for directing the light from said display toward said diffraction grating, said optical means causing the light to exhibit color dispersion for correcting color dispersion caused by said diffraction grating, and a half-wavelength-width of said optical means being set to be larger than that of said diffraction grating.
Claim 14
Dependent Claim
13 words
An apparatus according to claim 11, wherein said optical means comprises a hologram.
Claim 15
Dependent Claim
15 words
An apparatus according to claim 11, wherein said optical means comprises a relief diffraction grating.
Claim 16
Dependent Claim
13 words
An apparatus according to claim 11, wherein said diffraction grating comprises a hologram.
Claim 17
Dependent Claim
23 words
An apparatus according to claim 11, wherein light-receiving surfaces of said diffraction grating and said optical means are arranged in a non-parallel state.
Claim 18
Dependent Claim
58 words
A display apparatus comprising: a display; a first diffraction grating having a smaller full-width at half maximum than that of light emitted from said display; and a second diffraction grating for diffracting the light emitted from said display toward said first diffraction grating, said second diffraction grating having a larger half-wavelength-width than that of said first diffraction grating.
Claim 19
Dependent Claim
58 words
A display apparatus comprising: a display; a first diffraction grating having a smaller full-width at half maximum than that of light emitted from said display; and a second diffraction grating for diffracting the light emitted from said display toward said first diffraction grating, said second diffraction grating having a larger half-wavelength-width than that of said first diffraction grating.
Claim 20
Dependent Claim
19 words
An apparatus according to claim 16, said second diffraction grating corrects color dispersion caused by said first diffraction grating.
Claim 21
Dependent Claim
18 words
An apparatus according to claim 17, wherein each of said first and second diffraction gratings comprises a hologram.
Claim 22
Dependent Claim
24 words
An apparatus according to claim 17, wherein said first diffraction grating comprises a hologram, and said second diffraction grating comprises a relief diffraction grating.
Claim 23
Dependent Claim
33 words
An apparatus according to claim 17, wherein an optical path length between said display and said second diffraction grating is set to be smaller than that between said first and second diffraction gratings.
Claim 24
Dependent Claim
36 words
An apparatus according to claim 20, wherein said first diffraction grating reflects and diffracts the diffracted light from said second diffraction grating toward a pupil and allows other light components to pass therethrough toward said pupil.
Claim 25
Dependent Claim
26 words
An apparatus according to claim 21, wherein a size of said first diffraction grating is set to be larger than that of said second diffraction grating.
Claim 26
Dependent Claim
70 words
A head-up display apparatus comprising: a display; a hologram for reflecting and diffracting light from said display toward a pupil and allowing other light components to pass therethrough toward said pupil; and a diffraction grating, arranged in an optical path between said display and said hologram, for reflecting and diffracting the light from said display toward said hologram, said diffraction grating having a larger half-wavelength-width than that of said hologram.
Claim 27
Dependent Claim
70 words
A head-up display apparatus comprising: a display; a hologram for reflecting and diffracting light from said display toward a pupil and allowing other light components to pass therethrough toward said pupil; and a diffraction grating, arranged in an optical path between said display and said hologram, for reflecting and diffracting the light from said display toward said hologram, said diffraction grating having a larger half-wavelength-width than that of said hologram.
Claim 28
Dependent Claim
13 words
An apparatus according to claim 23, wherein said hologram has a refracting power.
Claim 29
Dependent Claim
13 words
An apparatus according to claim 24, wherein said hologram comprises a volume-type hologram
Claim 30
Dependent Claim
14 words
An apparatus according to claim 25, wherein said diffraction grating comprises a relief grating.
Claim 31
Dependent Claim
43 words
An apparatus according to claim 26, wherein said relief grating is formed on a surface of a transparent plate opposite to a surface thereof on a light-incidence side, and a refractive index of said plate is set to be not less than 1.3.
Claim 32
Dependent Claim
14 words
An apparatus according to claim 23, wherein said diffraction grating comprises a volume-type hologram.
Claim 33
Dependent Claim
17 words
An apparatus according to claim 23, wherein said diffraction grating corrects color dispersion caused by said hologram.
Claim 34
Dependent Claim
32 words
An apparatus according to claim 29, wherein an optical path length between said display and said diffraction grating is set to be smaller than that between said diffraction grating and said hologram.
Claim 35
Dependent Claim
23 words
An apparatus according to claim 31, wherein a size of said hologram is set to be larger than that of said diffraction grating.
Claim 36
Dependent Claim
48 words
An apparatus according to claim 23, wherein a half-wavelength-width of said diffraction grating is larger than a sum of a half-wavelength-width of said hologram and a variation width of a center wavelength of light incident on a pupil, which varies in accordance with a displacement of said pupil.
Claim 37
Dependent Claim
19 words
An apparatus according to claim 23, wherein said hologram is provided to a front window glass of a vehicle.
References Cited (Backward Citations)
No citation records indexed.
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