US4576435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Endoscope including a reflector related by an inequality for uniform light distribution
Assignee: Olympus Corp
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Filing: 1983-07-14
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Granted: 1986-03-18
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Expires: 2003-07-14
Abstract
Abstract A light transmitting device includes a light guide formed by a bundle of optical fibres. Light from a light source is passed through a condenser lens to impinge upon the incident end face of the light guide for transmission to the exiting end face thereof. A pipe-shaped reflector is disposed between the condenser lens and the light guide for achieving a uniform distribution of light intensity across the incident end face of the light guide.
Inventors
- 👤 Kimihiko Nishioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:08
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4298; G02B6/26; G02B6/28; G02B6/2804; G02B6/2808; G02B6/4296; G02B6/241; G02B6/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
157 words
A light transmitting device comprising: a light guide formed by a bundle of optical fibres, a light source, a condenser lens disposed between the source and an incident end of the light guide, and a pipe-shaped reflector disosed between the condenser lens and the incident end of the light guide such that light from said light source passes through the condenser lens, through the pipe-shaped reflector and then through the light guide, the pipe-shaped reflector satisfying the following inequality: (-S+(d/n)) tan α>a where S representa a distance from the incident face of the pipe-shaped reflector to a point which is conjugate to the source with respect to the condenser lens, d the length of the reflector, n the refractive index of a portion of the reflector which allows the passage of light therethrough, a the radius of the portion of the reflector and α the minimum numerical aperture of a light flux which impinges upon the reflector.
Claim 2
Dependent Claim
157 words
A light transmitting device comprising: a light guide formed by a bundle of optical fibres, a light source, a condenser lens disposed between the source and an incident end of the light guide, and a pipe-shaped reflector disosed between the condenser lens and the incident end of the light guide such that light from said light source passes through the condenser lens, through the pipe-shaped reflector and then through the light guide, the pipe-shaped reflector satisfying the following inequality: (-S+(d/n)) tan α>a where S representa a distance from the incident face of the pipe-shaped reflector to a point which is conjugate to the source with respect to the condenser lens, d the length of the reflector, n the refractive index of a portion of the reflector which allows the passage of light therethrough, a the radius of the portion of the reflector and α the minimum numerical aperture of a light flux which impinges upon the reflector.
Claim 3
Dependent Claim
55 words
A light transmitting device according to claim 1 in which the pipe-shaped reflector is chosen so that a≦a where a represents the radius of the portion of the reflector which allows the passage of light therethrough and a represents the radius of a portion of the light guide which allows the passage of light therethrough.
Claim 4
Dependent Claim
69 words
A light transmitting device according to claim 1 in which representing the total amount of light which impinges upon the light guide through the pipe-shaped reflector by E and the total amount of light which impinges upon the light guide in the absence of the reflector by E, the reflector is constructed such that a light loss due to the presence of the reflector satisfies the following relationship: ##EQU8##
Claim 5
Dependent Claim
70 words
A light transmitting device according to claim 1 in which the pipe-shaped reflector is formed by a single fibre comprising a solid cylindrical core and a cladding thereon with a boundary surface therebetween, light from the source which impinges upon the reflector being subject to a reflection at the boundary surface between the core and the cladding, whereby light exiting from the reflector has a uniform distribution of light intensity.
Claim 6
Dependent Claim
55 words
A light transmitting device according to claim 4 in which the single fibre is constructed to satisfy the following relationship: ##EQU9## where n, n 1 , n 2 and n 3 represent the refractive index of the core and the cladding of the single fibre and the core and the cladding of the light guide.
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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |