Patent US5400378A successfully refreshed from Google Patents.
Patent US5638220A successfully refreshed from Google Patents.
US5638220A
Expired / Lapsed
US
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Device for producing ring-shaped laser spot
Assignee: Topcon Corp
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Filing: 1995-06-21
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Granted: 1997-06-10
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Expires: 2015-06-21
Abstract
Abstract The present invention relates to a projector using laser light, and more particularly to a ring-shaped laser spot capable of forming a projected image having a ring-shaped projected image formed from a diffraction fringe, by interposing a diaphragm between a collimator lens and a target. The collimator lens transmits laser light emitted from a laser light source to the target to form a first projected image on the target. The diaphragm shapes the laser light transmitted through the collimator lens to form a ring-shaped second projected image as a diffraction fringe on the target.
Inventors
- 👤 Fumio Ohtomo
- 👤 Hiroo Sugai
- 👤 Youhei Ogawa
- 👤 Yoshiyuki Enomoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:32
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/09; G02B27/0927; G02B27/0938; G02B27/0988; G02B27/58
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
131 words
A device for producing a ring-shaped laser beam spot comprising: a laser light source for emitting laser light; a light transmitting means which includes a collimator lens for transmitting said laser light emitted from said laser light source to a target to form a first projected image on said target; and a diaphragm member formed between said light transmitting means and said target for forming a ring-shaped second projected image as a diffraction fringe on said target, wherein said device satisfies one of the following conditions: D<(f/r)×λ or (r/λ)<(f/D)=F.sub.no, where D is the aperture of said collimator lens, f is the focal length of said collimator lens, r is the size of said laser light source, λ is the wavelength of said laser light source and F no stands for F-number.
Claim 2
Independent Claim
131 words
A device for producing a ring-shaped laser beam spot comprising: a laser light source for emitting laser light; a light transmitting means which includes a collimator lens for transmitting said laser light emitted from said laser light source to a target to form a first projected image on said target; and a diaphragm member formed between said light transmitting means and said target for forming a ring-shaped second projected image as a diffraction fringe on said target, wherein said device satisfies one of the following conditions: D<(f/r)×λ or (r/λ)<(f/D)=F.sub.no, where D is the aperture of said collimator lens, f is the focal length of said collimator lens, r is the size of said laser light source, λ is the wavelength of said laser light source and F no stands for F-number.
Claim 3
Dependent Claim
42 words
A device for producing a ring-shaped laser beam spot according to claim 1 which satisfies the following condition: R≦(1.5 to 2.0)×R', where R is the divergence of said first projected image and R' is the divergence of said ring-shaped second projected image.
Claim 4
Dependent Claim
25 words
A device for producing a ring-shaped laser beam spot according to claim 1 or 2, wherein an apodization filter is added to said diaphragm member.
References Cited (Backward Citations)
US3990786A
Cited
USRE32988E
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-09 | 2000-12-09 | 2001-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-09 | 2004-12-09 | 2005-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-09 | 2008-12-09 | 2009-06-10 | $7700.00 | Window Closed / Lapsed |