US4830485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coded aperture light detector for three dimensional camera
Assignee: General Electric Co
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Filing: 1987-11-23
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Granted: 1989-05-16
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Expires: 2007-11-23
Abstract
Abstract High speed readout is achieved in a triangulation ranger by a coded aperture light detector which provides a direct digital representation of a range or height position. A light spot reflected from the surface is optically spread into a line segment so it can be shared among a number of light detection channels. The line of light falls on a coded aperture in front of a segmented fiber optic bundle and the light transmitted by each channel is led to a separate photomultiplier or solid state detector. Every coded channel is constructed to give one bit of the digital address of the range position, and a reference light value is obtained from another channel. Background and secondary reflections may be filtered out by focusing light scattered from the surface to a spot and passing it through a slit aperture oriented in the plane of triangulation before being spread to a line segment.
Inventors
- 👤 Carl M. Penney
- 👤 Nelson R. Corby, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:04
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/46; G01S17/48; G01B; G01B11/00; G01B11/02; G01B11/026; G01S7/00; G01S7/48; G01S7/481; G01S7/4816
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
A triangulation ranging system comprising: means to project onto a coded aperture light detecting means a line segment of light whose position along a coded aperture is related to range to an object surface; said light detecting means having a plurality of coded channels which transmit light to separate detectors and said coded aperture at the front of said channels providing a digital representation of the position of said line segment; wherein each coded channel ha a row of opaque and clear cells and said light detecting mean also has a clear reference light value channel, the number N of channels to yield a resolution of R range points being given by N=1+log 2 R; and said channels are comprised of noncoherent fiber optic bundles, a patterned mask in front of said bundles serving as said coded aperture.
Claim 2
Dependent Claim
138 words
A triangulation ranging system comprising: means to project onto a coded aperture light detecting means a line segment of light whose position along a coded aperture is related to range to an object surface; said light detecting means having a plurality of coded channels which transmit light to separate detectors and said coded aperture at the front of said channels providing a digital representation of the position of said line segment; wherein each coded channel ha a row of opaque and clear cells and said light detecting mean also has a clear reference light value channel, the number N of channels to yield a resolution of R range points being given by N=1+log 2 R; and said channels are comprised of noncoherent fiber optic bundles, a patterned mask in front of said bundles serving as said coded aperture.
Claim 3
Dependent Claim
149 words
An improved triangulation ranging system comprising: means to project a light beam onto a surface of an object; an optical system to spread a spot of light scattered from said surface into a line segment that is incident on all channels of a coded aperture light detector at a position therealong related to range to said surface; said coded aperture light detector comprised of a plurality of binary coded channels and a clear reference channel which are each formed of a noncoherent fiber optic bundle and transmit light to separate photodetectors, and a patterned mask in front of ends of said fiber optic bundles to serve as a coded aperture and block and pass light; said coded channels each contributing one bit of a digital address of a range position and said reference channel providing a reference light value against which light passing through said coded channels is compared.
Claim 4
Dependent Claim
149 words
An improved triangulation ranging system comprising: means to project a light beam onto a surface of an object; an optical system to spread a spot of light scattered from said surface into a line segment that is incident on all channels of a coded aperture light detector at a position therealong related to range to said surface; said coded aperture light detector comprised of a plurality of binary coded channels and a clear reference channel which are each formed of a noncoherent fiber optic bundle and transmit light to separate photodetectors, and a patterned mask in front of ends of said fiber optic bundles to serve as a coded aperture and block and pass light; said coded channels each contributing one bit of a digital address of a range position and said reference channel providing a reference light value against which light passing through said coded channels is compared.
Claim 5
Dependent Claim
11 words
The ranging system of claim 2 wherein said photodetectors are photomultipliers.
Claim 6
Dependent Claim
63 words
The ranging system of claim 2 further including means to filter out background and secondary reflections of light that may interface with a correct measurement of range, comprised of a lens to focus the spot of light scattered from said surface into a second light spot that passes through a slit aperture before being spread by said optical system into said line segment.
Claim 7
Dependent Claim
18 words
The ranging system of claim 4 wherein said optical system is a combination of spherical and cylindrical lenses.
Claim 8
Dependent Claim
21 words
The ranging system of claim 4 wherein said optical system is a combination of spherical lenses and a cylindrical lenticular plate.
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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) | 1992-05-15 | 1992-11-14 | 1993-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-15 | 1996-11-14 | 1997-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-15 | 2000-11-14 | 2001-05-16 | $7700.00 | Window Closed / Lapsed |