Patent EP0719527A1 successfully refreshed from Google Patents.
US3717772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear bidirectional scanning system
Assignee: MIDLAND CAPITAL CORP
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Filing: 1971-09-03
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Granted: 1973-02-20
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Expires: 1991-09-03
Abstract
Abstract A constant scan rate bidirectional infrared scanning system. A low momentum oscillatory scanning mirror is servo controlled to provide bidirectional linear frame scanning which results in a doubling of display intensity and reduction of flicker awareness. The sensitivity of the scanning system to vibration is reduced and the scan rate made readily available without loss of linearity or the other advantages of bidirectional scanning.
Inventors
- 👤 G Engman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:39
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/02; H04N3/08; H04N3/09
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
269 words
A system for linear, bidirectional scanning of radiation within a field of view comprising: means for receiving radiation from said field of view and for redirecting said received radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means for rotation about an axis; torquing means operative in response to a drive signal to torque said redirecting means about its axis of rotation in an angular direction depending upon one of two opposite characteristics of said drive signal, thereby to cause said redirecting means to scan through an angle of said field of view; means for detecting the rotation of said redirecting means and for generating a rate signal representative of the rotational rate of said redirecting means; means operative in response to rotation of said redirecting means for providing a positional signal representative of the relative angular position of said redirecting means about its axis of rotation; and means for generating a scan signal having first and second oppositely and linearly varying characteristics which sequentially alternate; said characteristics representing angular position of said redirecting means; means for combining and amplifying said scan signal and said positional signal to provide an error signal representing the difference between the instantaneous position of said redirecting means the position thereof represented by the characteristics of said scan signal; means for combining said error signal and said rate signal to produce said drive signal; and means for applying said drive signal to said torquing means, thereby to cause bidirectional, linear rotation of said redirecting means in correspondence with said first and second characteristics of said scan signal.
Claim 2
Independent Claim
269 words
A system for linear, bidirectional scanning of radiation within a field of view comprising: means for receiving radiation from said field of view and for redirecting said received radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means for rotation about an axis; torquing means operative in response to a drive signal to torque said redirecting means about its axis of rotation in an angular direction depending upon one of two opposite characteristics of said drive signal, thereby to cause said redirecting means to scan through an angle of said field of view; means for detecting the rotation of said redirecting means and for generating a rate signal representative of the rotational rate of said redirecting means; means operative in response to rotation of said redirecting means for providing a positional signal representative of the relative angular position of said redirecting means about its axis of rotation; and means for generating a scan signal having first and second oppositely and linearly varying characteristics which sequentially alternate; said characteristics representing angular position of said redirecting means; means for combining and amplifying said scan signal and said positional signal to provide an error signal representing the difference between the instantaneous position of said redirecting means the position thereof represented by the characteristics of said scan signal; means for combining said error signal and said rate signal to produce said drive signal; and means for applying said drive signal to said torquing means, thereby to cause bidirectional, linear rotation of said redirecting means in correspondence with said first and second characteristics of said scan signal.
Claim 3
Independent Claim
269 words
A system for linear, bidirectional scanning of radiation within a field of view comprising: means for receiving radiation from said field of view and for redirecting said received radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means for rotation about an axis; torquing means operative in response to a drive signal to torque said redirecting means about its axis of rotation in an angular direction depending upon one of two opposite characteristics of said drive signal, thereby to cause said redirecting means to scan through an angle of said field of view; means for detecting the rotation of said redirecting means and for generating a rate signal representative of the rotational rate of said redirecting means; means operative in response to rotation of said redirecting means for providing a positional signal representative of the relative angular position of said redirecting means about its axis of rotation; and means for generating a scan signal having first and second oppositely and linearly varying characteristics which sequentially alternate; said characteristics representing angular position of said redirecting means; means for combining and amplifying said scan signal and said positional signal to provide an error signal representing the difference between the instantaneous position of said redirecting means the position thereof represented by the characteristics of said scan signal; means for combining said error signal and said rate signal to produce said drive signal; and means for applying said drive signal to said torquing means, thereby to cause bidirectional, linear rotation of said redirecting means in correspondence with said first and second characteristics of said scan signal.
Claim 4
Independent Claim
269 words
A system for linear, bidirectional scanning of radiation within a field of view comprising: means for receiving radiation from said field of view and for redirecting said received radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means for rotation about an axis; torquing means operative in response to a drive signal to torque said redirecting means about its axis of rotation in an angular direction depending upon one of two opposite characteristics of said drive signal, thereby to cause said redirecting means to scan through an angle of said field of view; means for detecting the rotation of said redirecting means and for generating a rate signal representative of the rotational rate of said redirecting means; means operative in response to rotation of said redirecting means for providing a positional signal representative of the relative angular position of said redirecting means about its axis of rotation; and means for generating a scan signal having first and second oppositely and linearly varying characteristics which sequentially alternate; said characteristics representing angular position of said redirecting means; means for combining and amplifying said scan signal and said positional signal to provide an error signal representing the difference between the instantaneous position of said redirecting means the position thereof represented by the characteristics of said scan signal; means for combining said error signal and said rate signal to produce said drive signal; and means for applying said drive signal to said torquing means, thereby to cause bidirectional, linear rotation of said redirecting means in correspondence with said first and second characteristics of said scan signal.
Claim 5
Dependent Claim
44 words
The linear, bidirectional scanning system of claim 1 wherein said positional signal is produced by: a photodetector operating in response to incident illumination; and means for varyingly occluding the illumination incident on said photodetector in correspondence with the angular position of said redirecting means.
Claim 6
Dependent Claim
70 words
The linear, bidirectional scanning system of claim 2 wherein: said means for varyingly occluding radiation incident on said photodetector includes a low inertia vane rotating with said redirecting means in the path of illumination incident on said photodetector; anD said vane is adapted to operate in association with said photodetector to produce a positional signal and resulting drive signal that restores said shaft to its operating range when perturbed therefrom.
Claim 7
Dependent Claim
32 words
The linear, bidirectional scanning system of claim 1 further including means for varying the rate of variation of said scan signal, thereby to vary the bidirectional rotational rate of said redirecting means.
Claim 8
Dependent Claim
92 words
The linear, bidirectional scanning system of claim 4 further including: line scanning means for scanning radiation from said field of view through an angle orthogonal to the angle of scan of said redirecting means and operative in association therewith to scan a plurality of times for each scan of said redirecting means; and means for synchronizing the alternation of said first and second characteristics of said scan signal to the scanning of said line scanning means to commence generation of each of said characteristics with a scan of said line scanning means.
Claim 9
Dependent Claim
89 words
The linear, bidirectional scanning system of claim 5 further including: a radiation detector for receiving radiation from said redirecting means and said line scanning means and operative in response thereto to provide an electrical signal representative of the magnitude of received radiation; means for displaying radiation received by said detector in response to said detector signal and scanning of said redirecting means and line scanning means; and means for inhibiting display of said detected radiation during predetermined portions of the scan of redirecting means near the rotational limits thereof.
Claim 10
Dependent Claim
40 words
The linear, bidirectional scanning system of claim 1 wherein: said torquing means is a DC motor; said means for developing said damping signal is a rate tachometer; and said means for generating said scan signal is a triangle wave oscillator.
Claim 11
Dependent Claim
60 words
The linear, bidirectional scanning system of claim 7 wherein: said triangle wave oscillator includes: a square wave generator; and means for developing a signal which is the integral of the square wave signal from said square wave oscillator; and said combining means for producing said drive signal further includes means for differencing said square wave signal and said rate signal.
Claim 12
Independent Claim
166 words
A system for linear bidirectional scanning of radiation within a field of view comprising: means responsive to radiation from said field of view for redirecting said radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means to permit variation in the angular orientation of said redirecting means; means for generating a scan signal having first and second alternating portions of oppositely and linearly varying characteristics; means for detecting rotation of said redirecting means to provide a rotation representing signal; means for combining said scan signal and said rotation representing signal to provide a drive signal; means for bidirectionally torquing said redirecting means in response to said drive signal to cause linear, constant rate variation in the angular orientation thereof in response to said first and second portions of said scan signal; said torquing means thereby providing damped, rapid momentum reversal in the rate of variation of the angular orientation of said redirecting means in response to said drive signal.
Claim 13
Independent Claim
166 words
A system for linear bidirectional scanning of radiation within a field of view comprising: means responsive to radiation from said field of view for redirecting said radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means to permit variation in the angular orientation of said redirecting means; means for generating a scan signal having first and second alternating portions of oppositely and linearly varying characteristics; means for detecting rotation of said redirecting means to provide a rotation representing signal; means for combining said scan signal and said rotation representing signal to provide a drive signal; means for bidirectionally torquing said redirecting means in response to said drive signal to cause linear, constant rate variation in the angular orientation thereof in response to said first and second portions of said scan signal; said torquing means thereby providing damped, rapid momentum reversal in the rate of variation of the angular orientation of said redirecting means in response to said drive signal.
Claim 14
Dependent Claim
73 words
The system for linear bidirectional scanning of radiation of claim 9 wherein said means for providing a rotation representing signal includes means for altering the characteristic of said rotation representing signal when said redirecting means exceeds predetermined rotational limits to provide in said drive signal a characteristic which causes said torquing means to return said redirecting means to the range of variation between said rotational limits when said redirecting means is displaced therefrom.
Claim 15
Independent Claim
142 words
A system for linear, bidirectional scanning of radiation withIn a field of view comprising: means responsive to radiation from said field of view for redirecting said radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means to permit variation in the angular orientation of said redirecting means; means for generating a square wave; means for generating a scan signal in response to said square wave as an integration thereof having first and second alternating portions of oppositely and linearly varying characteristics; means for sensing rotational rate and position of said redirecting means to provide a rotation representing signal; means for combining said scan signal, said square wave signal, and said rotation representing signal to provide a highly damped drive signal; and means for applying torque to said redirecting means in response to said drive signal.
Claim 16
Independent Claim
142 words
A system for linear, bidirectional scanning of radiation withIn a field of view comprising: means responsive to radiation from said field of view for redirecting said radiation in accordance with an angular orientation of said redirecting means; means for supporting said redirecting means to permit variation in the angular orientation of said redirecting means; means for generating a square wave; means for generating a scan signal in response to said square wave as an integration thereof having first and second alternating portions of oppositely and linearly varying characteristics; means for sensing rotational rate and position of said redirecting means to provide a rotation representing signal; means for combining said scan signal, said square wave signal, and said rotation representing signal to provide a highly damped drive signal; and means for applying torque to said redirecting means in response to said drive signal.
Claim 17
Dependent Claim
61 words
The system for linear, bidirectional scanning of radiation of claim 11 wherein said combining means includes: means for producing an error signal as an amplified difference between said scan signal and said sensed position; and means for producing as said drive signal an amplified combination of said error signal with the difference between said square wave signal and said sensed rate.
Claim 18
Dependent Claim
40 words
The system for linear, bidirectional scanning of radiation of claim 11 wherein said integrating means includes means operative to respond directly at its output to a predetermined polarity transition in said square wave thereby to produce a sawtooth wave output.
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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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |