Patent US3775735A successfully refreshed from Google Patents.
US3775735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for scanning an underwater area
Assignee: United States Department of the Navy
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Filing: 1972-05-01
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Granted: 1973-11-27
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Expires: 1992-05-01
Abstract
Abstract The apparatus of this invention is designed to be generally operated from either a towed or self-propelled underwater vehicle. A nearly collimated beam of light from a rotating cylinder traces a narrow strip of the target area during each rotation. The strip is substantially perpendicular to the direction of travel of the apparatus. During subsequent rotations, a series of parallel strips are traced on the target area. The speed of rotation and corresponding raster scan on the display monitor is synchronized to the forward speed of the vehicle to which the apparatus is attached. The instantaneous field of view of the receiving optics is stopped down so that only the light from a small area at the center of the intersection of the collimated source beam and the target area is viewed. The size of this area corresponds to the minimum resolution element of the device. The location of the field stop of the receiving optics is a function of the viewing range, and is adjusted accordingly. The automatic gain control on the output signal from the photomultiplier tube compensates for the varying propagation losses due to varying path lengths in the mapping geometry. The intensity displayed at a particular spot on the video monitor or stored at a given location on the video tape is therefore a map of the optical reflectivity of the corresponding spot on the surface of the target area.
Inventors
- 👤 C Funk
- 👤 I Lemaire
- 👤 J Sutton
- 👤 F Marrone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:37
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/16; G02B23/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
239 words
An apparatus for linearly scanning, point by point, a target area, generally underwater, comprising: a housing, having an interior cylindrical wall, the cylindrical surface defining an axis, the housing having two slots through it perpendicular to the axis of the wall; a rotating, cylindrical scanning assembly, disposed within the cylindrical wall of the housing, comprising: a driven cylinder disposed within the housing, the cylinder being truncated at each end at approximately 45* to a plane through the axis of the cylinder, so that in this plane the cross section is trapezoidal; two transparent, right, cylindrical prisms, truncated at approximately 45*, having the same diameter and the same axis of rotation as the driven cyliNder, each prism bonded by at least part of its elliptical face to the corresponding surface at each end of the driven cylinder; and a pair of lenses, one mounted to each prism at the cylindrical surface thereof so that they rotate with the prisms, the principal axis of each of the lenses being convergent toward each other so that the axes may be made to intersect, through the slots in the housing, at some point in said plane, the point of intersection coinciding with the point of the target being scanned; and driving means for rotating the scanning assembly, and therefore the lenses, thereby scanning a line of the target area at a time, the line being substantially perpendicular to the axis of the cylinder.
Claim 2
Independent Claim
239 words
An apparatus for linearly scanning, point by point, a target area, generally underwater, comprising: a housing, having an interior cylindrical wall, the cylindrical surface defining an axis, the housing having two slots through it perpendicular to the axis of the wall; a rotating, cylindrical scanning assembly, disposed within the cylindrical wall of the housing, comprising: a driven cylinder disposed within the housing, the cylinder being truncated at each end at approximately 45* to a plane through the axis of the cylinder, so that in this plane the cross section is trapezoidal; two transparent, right, cylindrical prisms, truncated at approximately 45*, having the same diameter and the same axis of rotation as the driven cyliNder, each prism bonded by at least part of its elliptical face to the corresponding surface at each end of the driven cylinder; and a pair of lenses, one mounted to each prism at the cylindrical surface thereof so that they rotate with the prisms, the principal axis of each of the lenses being convergent toward each other so that the axes may be made to intersect, through the slots in the housing, at some point in said plane, the point of intersection coinciding with the point of the target being scanned; and driving means for rotating the scanning assembly, and therefore the lenses, thereby scanning a line of the target area at a time, the line being substantially perpendicular to the axis of the cylinder.
Claim 3
Dependent Claim
79 words
The apparatus according to claim 1, further comprising: a light source, for generating a beam of light along the axis of, and toward the internally reflecting surface of, one of the prisms, thereby projecting a beam of light through one of the lenses and onto the point being scanned; and a photodetector, adapted to receive a beam of light reflected from the scanned point, which is first received by the other lens and then passes through the other prism.
Claim 4
Dependent Claim
57 words
The apparatus according to claim 2, further comprising: an automatic gain control circuit, whose input is connected to the output of the photodetector, to compensate for the variations in the received light intensity due to the varying length of the scanning and received beams of light at different parts of the line of the target being scanned.
Claim 5
Dependent Claim
33 words
The apparatus according to claim 3, further comprising: a video tape recorder, whose input is connected to the output of the automatic gain control circuit, for recording the target area on video tape.
Claim 6
Dependent Claim
29 words
The apparatus according to claim 4, further comprising: a power supply, to furnish energy for the driving means, light source, automatic gain control circuit, and the video tape recorder.
Claim 7
Dependent Claim
33 words
The apparatus according to claim 5, wherein the housing is adapted for mounting to a moving vehicle, a line of the target area being scanned at a time as the vehicle moves forward.
Claim 8
Dependent Claim
51 words
The apparatus according to claim 5, further comprising: a stepper motor for incrementally tilting the prisms in a direction substantially at right angles to the scanning lines, an increment being equal to the distance between two adjacent scanning lines, permitting scanning of an area to be accomplished from a stationary platform.
Claim 9
Dependent Claim
37 words
The apparatus according to claim 1, wherein the rotation is less than 360*, so that the scanning assembly oscillates back and forth, the included angle of oscillation being sufficient to encompass the width of the target area.
Claim 10
Dependent Claim
35 words
The apparatus according to claim 8, wherein the driving means for rotating the scanning assembly comprises: a stepper motor, which causes the oscillation to progress in small incremental steps, rather than in one continuous oscillation.
Claim 11
Independent Claim
365 words
An apparatus for linearly scanning, point by point, a target area, generally underwater,comprising: a housing, having an interior cylindrical wall, the cylindrical surface defining an axis, the wall having two slots through it perpendicular to the axis of the wall; a rotating, cylindrical scanning assembly, disposed within the cylindrical wall of the housing, comprising: a driven cylinder disposed within the housing, the cylinder being truncated at each end at approximately 45* to a plane through the axis of the cylinder, so that in this plane the cross section is trapezoidal; a pair of mirrors, one attached to each end of the cylinder; a pair of lenses mounted to the cylinder in a manner so that they rotate with the cylinder, the principal axis of each of the lenses being convergent toward each other so that the axes may be made to intersect, through the slots in the housing, at some point in said plane, the point of intersection coinciding with the point of the target being scanned; driving means fOr rotating the scanning assembly, and therefore the lenses, thereby scanning a line of the target area at a time, the line being substantially perpendicular to the axis of the cylinder; a light source, for generating a beam of light along the axis of, and toward the reflecting surface of, one of the mirrors thereby projecting a beam of light through one of the lenses and onto the point being scanned; and a photodetector, adapted to receive a beam of light reflected from the scanned point, which is first received by the other lens and then passes through the other mirror; an automatic gain control circuit, whose input is connected to the output of the photodetector, to compensate for the variations in the received light intensity due to the varying length of the scanning and received beams of light at different parts of the line of the target being scanned; a video display, including a cathode-ray tube, whose input is connected to the output of the automatic gain control circuit, for displaying the target area; and a power supply, to furnish energy for the driving means, light source, automatic gain control circuit, and the video display.
Claim 12
Independent Claim
365 words
An apparatus for linearly scanning, point by point, a target area, generally underwater,comprising: a housing, having an interior cylindrical wall, the cylindrical surface defining an axis, the wall having two slots through it perpendicular to the axis of the wall; a rotating, cylindrical scanning assembly, disposed within the cylindrical wall of the housing, comprising: a driven cylinder disposed within the housing, the cylinder being truncated at each end at approximately 45* to a plane through the axis of the cylinder, so that in this plane the cross section is trapezoidal; a pair of mirrors, one attached to each end of the cylinder; a pair of lenses mounted to the cylinder in a manner so that they rotate with the cylinder, the principal axis of each of the lenses being convergent toward each other so that the axes may be made to intersect, through the slots in the housing, at some point in said plane, the point of intersection coinciding with the point of the target being scanned; driving means fOr rotating the scanning assembly, and therefore the lenses, thereby scanning a line of the target area at a time, the line being substantially perpendicular to the axis of the cylinder; a light source, for generating a beam of light along the axis of, and toward the reflecting surface of, one of the mirrors thereby projecting a beam of light through one of the lenses and onto the point being scanned; and a photodetector, adapted to receive a beam of light reflected from the scanned point, which is first received by the other lens and then passes through the other mirror; an automatic gain control circuit, whose input is connected to the output of the photodetector, to compensate for the variations in the received light intensity due to the varying length of the scanning and received beams of light at different parts of the line of the target being scanned; a video display, including a cathode-ray tube, whose input is connected to the output of the automatic gain control circuit, for displaying the target area; and a power supply, to furnish energy for the driving means, light source, automatic gain control circuit, and the video display.
References Cited (Backward Citations)
US3533697A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |