Patent US3913872A successfully refreshed from Google Patents.
US3913872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light tunnel for uniformly illuminating an object
Assignee: Bell and Howell Co
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Filing: 1973-01-18
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Granted: 1975-10-21
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Expires: 1993-01-18
Abstract
Abstract A light tunnel for unidirectionally and totally illuminating an object located perpendicular to the long dimension adjacent the exit aperture of the tunnel. In one embodiment, certain portions of the inner surfaces of the light tunnel are coated with a light absorbing coating which absorbs all higher order light rays, while allowing all lower order light rays to pass without interference to the aperture at the tunnel exit. In a further embodiment, the angle at which the light enters the tunnel through an entrance aperture is varied to maintain uniform exit aperture illumination. In still another embodiment, a coating of light-absorbing material adjacent the entrance aperture of the light tunnel permits only light entering the tunnel within a predetermined angular range to pass through the tunnel to the exit aperture.
Inventors
- 👤 Paul Egon Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:31
CPC Classifications
F; F21; F21V; F21V11/00; G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0096; G02B6/24; G02B6/241; G02B6/243; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/542
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
98 words
A device for illuminating an elongated area of an object disposed at an illumination station whereby the integral of light in every plane parallel to the short dimension of the area is the same, comprising: a source of light; a light tunnel having an entrance aperture disposed proximate said light source and an exit aperture whereby a portion of the light emitted by said source passes through said light tunnel from said entrance aperture to said exit aperture, wherein the distance between said light source and any point on said entrance aperture is determined by the following formula:
Claim 2
Independent Claim
98 words
A device for illuminating an elongated area of an object disposed at an illumination station whereby the integral of light in every plane parallel to the short dimension of the area is the same, comprising: a source of light; a light tunnel having an entrance aperture disposed proximate said light source and an exit aperture whereby a portion of the light emitted by said source passes through said light tunnel from said entrance aperture to said exit aperture, wherein the distance between said light source and any point on said entrance aperture is determined by the following formula:
Claim 3
Independent Claim
192 words
A device for illuminating an elongated area of an object disposed at an illumination station whereby the integral of light in every plane parallel to the short dimension of the area is the same, comprising: a source of light; a light tunnel having an entrance aperture disposed proximate said light source and an exit aperture whereby a portion of the light emitted by said source passes through said light tunnel from said entrance aperture to said exit aperture; the object being illuminated disposed at the illuminating station adjacent said exit aperture; said light tunnel including means for providing a substantially equal degree of illuminance from said light source to all portions of said exit aperture; said light tunnel includes a pair of parallel plates separated by two side plates; said side plates extending substantially in a line from said light source to the extremities of said exit aperture; a light absorbing coating on the inside surfaces of said parallel plates of said light tunnel; said coating extending from said entrance aperture a specified distance measured from said light source toward said exit aperture whereby said distance is determined by the following formula:
Claim 4
Independent Claim
192 words
A device for illuminating an elongated area of an object disposed at an illumination station whereby the integral of light in every plane parallel to the short dimension of the area is the same, comprising: a source of light; a light tunnel having an entrance aperture disposed proximate said light source and an exit aperture whereby a portion of the light emitted by said source passes through said light tunnel from said entrance aperture to said exit aperture; the object being illuminated disposed at the illuminating station adjacent said exit aperture; said light tunnel including means for providing a substantially equal degree of illuminance from said light source to all portions of said exit aperture; said light tunnel includes a pair of parallel plates separated by two side plates; said side plates extending substantially in a line from said light source to the extremities of said exit aperture; a light absorbing coating on the inside surfaces of said parallel plates of said light tunnel; said coating extending from said entrance aperture a specified distance measured from said light source toward said exit aperture whereby said distance is determined by the following formula:
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |