US5748377A
Expired / Lapsed
US
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Headup display
Assignee: Fujitsu Ltd
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Filing: 1996-06-20
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Granted: 1998-05-05
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Expires: 2016-06-20
Abstract
Abstract A headup display including a light emission-type display source, a concave mirror having an spherical reflecting surface and located so as to reflect light emitted from the display source, and a reflection-type hologram located so as to reflect the light reflected on the concave mirror toward an observer in a mobile unit. The concave mirror is configured so that its lateral focal length contributing to lateral enlargement of a displayed image is shorter than its longitudinal focal length contributing to longitudinal enlargement of the displayed image. The reflection-type hologram is configured so that its longitudinal focal length contributing to longitudinal enlargement of the displayed image is shorter than its lateral focal length contributing to lateral enlargement of the displayed image.
Inventors
- 👤 Tsuyoshi Matsumoto
- 👤 Yoshihiro Mizuno
- 👤 Keiichi Omata
- 👤 Shin Eguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:59
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/01; G02B27/0101; G02B27/0103
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
A headup display comprising: a light emission-type display source; a first concave mirror located so as to reflect light emitted from said display source, said first concave mirror having an aspherical reflecting surface, said first concave mirror having a lateral focal length contributing to lateral enlargement of a displayed image and a longitudinal focal length contributing to longitudinal enlargement of said displayed image, said lateral focal length being shorter than said longitudinal focal length; and a combiner located so as to reflect the light reflected on said first concave mirror toward an observer in a mobile unit, said combiner having a longitudinal focal length contributing to longitudinal enlargement of said displayed image and a lateral focal length contributing to lateral enlargement of said displayed image, said longitudinal focal length of said combiner being shorter than said lateral focal length of said combiner.
Claim 2
Dependent Claim
142 words
A headup display comprising: a light emission-type display source; a first concave mirror located so as to reflect light emitted from said display source, said first concave mirror having an aspherical reflecting surface, said first concave mirror having a lateral focal length contributing to lateral enlargement of a displayed image and a longitudinal focal length contributing to longitudinal enlargement of said displayed image, said lateral focal length being shorter than said longitudinal focal length; and a combiner located so as to reflect the light reflected on said first concave mirror toward an observer in a mobile unit, said combiner having a longitudinal focal length contributing to longitudinal enlargement of said displayed image and a lateral focal length contributing to lateral enlargement of said displayed image, said longitudinal focal length of said combiner being shorter than said lateral focal length of said combiner.
Claim 3
Dependent Claim
14 words
A headup display according to claim 1, wherein said combiner comprises a reflection-type hologram.
Claim 4
Dependent Claim
39 words
A headup display according to claim 2, wherein said reflection-type hologram has a laterally elongated, rectangular shape, and spatial frequency at laterally opposite ends of said hologram is substantially equal to that at longitudinally opposite ends of said hologram.
Claim 5
Dependent Claim
21 words
A headup display according to claim 1, wherein said aspherical reflecting surface of said first concave mirror is a cylindrical surface.
Claim 6
Dependent Claim
21 words
A headup display according to claim 1, wherein said aspherical reflecting surface of said first concave mirror is a toroidal surface.
Claim 7
Dependent Claim
20 words
A headup display according to claim 1, wherein said combiner comprises a semitransparent concave mirror having an aspherical reflecting surface.
Claim 8
Dependent Claim
30 words
A headup display according to claim 1, further comprising a second concave mirror located so as to reflect the light emitted from said display source toward said first concave mirror.
Claim 9
Dependent Claim
29 words
A headup display according to claim 1, further comprising a plane mirror located so as to reflect the light emitted from said display source toward said first concave mirror.
Claim 10
Dependent Claim
20 words
A headup display according to claim 1, wherein said display source is a monitor screen of a car navigation system.
Claim 11
Dependent Claim
137 words
An image projecting device comprising: a light emission-type display source;. light condensing means located so as to condense light emitted from said display source, said light condensing means having a lateral focal length contributing to lateral enlargement of a displayed image and a longitudinal focal length contributing to longitudinal enlargement of said displayed image, said lateral focal length being shorter than said longitudinal focal length; and a diffraction means located so as to diffract a light condensed by said light condensing means toward an observer in a mobile unit, said diffraction means having a longitudinal focal length contributing to longitudinal enlargement of said displayed image and a lateral focal length contributing to lateral enlargement of said displayed image, said longitudinal focal length of said diffraction means being shorter than said lateral focal length of said diffraction means.
Claim 12
Dependent Claim
137 words
An image projecting device comprising: a light emission-type display source;. light condensing means located so as to condense light emitted from said display source, said light condensing means having a lateral focal length contributing to lateral enlargement of a displayed image and a longitudinal focal length contributing to longitudinal enlargement of said displayed image, said lateral focal length being shorter than said longitudinal focal length; and a diffraction means located so as to diffract a light condensed by said light condensing means toward an observer in a mobile unit, said diffraction means having a longitudinal focal length contributing to longitudinal enlargement of said displayed image and a lateral focal length contributing to lateral enlargement of said displayed image, said longitudinal focal length of said diffraction means being shorter than said lateral focal length of said diffraction means.
Claim 13
Dependent Claim
15 words
An image projecting device according to claim 10, wherein said diffraction means comprises a hologram.
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) | 2001-05-04 | 2001-11-03 | 2002-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-04 | 2005-11-03 | 2006-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-04 | 2009-11-03 | 2010-05-05 | $7700.00 | Window Closed / Lapsed |