Patent US4409475A successfully refreshed from Google Patents.
US4409475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spatial frequency filter
Assignee: Visidyne Inc
•
Filing: 1981-07-29
•
Granted: 1983-10-11
•
Expires: 2001-07-29
Abstract
Abstract A spatial frequency filter including: an optical system having detector means and means for projecting onto the detector means an image of an object area; and means for operating the optical system alternately in a first mode to develop a first system transfer function and a second mode to develop a second system transfer function which is matched to the first system transfer function in low spatial frequencies and divergent therefrom in high spatial frequencies, for imposing on the detector means a first representation of the image in the first mode and a second representation of the image in the second mode, thereby providing a fluctuating elemental image output from each element of the detector means which derives from a high spatial frequency object; and also including means for limiting the wavelength range of input radiation to the detector means.
Inventors
- 👤 Theodore F. Zehnpfennig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:19
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
121 words
A spatial frequency filter comprising: an optical system having detector means and means for projecting onto said detector means an image of an object area; and means for gyrating said optical system alternately at least in a first mode to develop a first system transfer function and a second mode to develop a second system transfer function which is matched to said first system transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object.
Claim 2
Dependent Claim
121 words
A spatial frequency filter comprising: an optical system having detector means and means for projecting onto said detector means an image of an object area; and means for gyrating said optical system alternately at least in a first mode to develop a first system transfer function and a second mode to develop a second system transfer function which is matched to said first system transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object.
Claim 3
Dependent Claim
22 words
The spatial frequency filter of claim 1 in which said means for gyrating said means for projecting relative to said detector means.
Claim 4
Dependent Claim
20 words
The spatial frequency filter of claim 1 further including means for sensing fluctuations of the output of said detector means.
Claim 5
Dependent Claim
28 words
The spatial frequency filter of claim 3 in which said means for sensing includes means for subtracting the image in one mode from that in the other mode.
Claim 6
Dependent Claim
29 words
The spatial frequency filter of claim 3 in which said means for sensing includes a bandpass filter and a.c. coupling means interconnecting said bandpass filter and said detector means.
Claim 7
Dependent Claim
37 words
The spatial frequency filter of claim 5 in which said means for sensing includes a bandpass filter and wherein said bandpass filter is tuned to the temporal frequency of the alternation of said first and second modes.
Claim 8
Dependent Claim
41 words
The spatial frequency filter of claim 1 in which said optical system further includes an optical element in the optical path between said means for projecting and said detector means and said optical element is gyrated by said means for gyrating.
Claim 9
Dependent Claim
19 words
The spatial frequency filter of claim 1 in which said detector means is gyrated by said means for gyrating.
Claim 10
Dependent Claim
16 words
The spatial frequency filter of claim 1 in which said means for gyrating includes piezoelectric means.
Claim 11
Dependent Claim
57 words
The spatial frequency filter of claim 1 in which said means for gyrating includes means for driving said optical system to gyrate at at least a first radius for a first period of time in said first mode and to gyrate at at least a second radius for a second period of time in said second mode.
Claim 12
Dependent Claim
19 words
The spatial frequency filter of claim 1 in which at least one of said modes includes intermittent dwell periods.
Claim 13
Dependent Claim
125 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; and means for gyrating said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means which derives from a high spatial frequency object.
Claim 14
Dependent Claim
125 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; and means for gyrating said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means which derives from a high spatial frequency object.
Claim 15
Dependent Claim
138 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for gyrating said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for sensing fluctuations of the output of said detector means.
Claim 16
Dependent Claim
138 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for gyrating said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for sensing fluctuations of the output of said detector means.
Claim 17
Dependent Claim
133 words
A spatial frequency filter comprising: an optical system having detector means and means for projecting onto said detector means an image of an object area; means for operating said optical system alternately at least in a first mode to develop a first system transfer function and a second mode to develop a second system transfer function which is matched to said first system transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for limiting the wavelength of input radiation to said detector means.
Claim 18
Dependent Claim
133 words
A spatial frequency filter comprising: an optical system having detector means and means for projecting onto said detector means an image of an object area; means for operating said optical system alternately at least in a first mode to develop a first system transfer function and a second mode to develop a second system transfer function which is matched to said first system transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for limiting the wavelength of input radiation to said detector means.
Claim 19
Dependent Claim
23 words
The spatial frequency filter of claim 14 in which said means for operating moves said means for projecting relative to said detector means.
Claim 20
Dependent Claim
20 words
The spatial frequency filter of claim 14 further including means for sensing fluctuations of the output of said detector means.
Claim 21
Dependent Claim
28 words
The spatial frequency filter of claim 16 in which said means for sensing includes means for subtracting the image in one mode from that in the other mode.
Claim 22
Dependent Claim
29 words
The spatial frequency filter of claim 16 in which said means for sensing includes a bandpass filter and a.c. coupling means interconnecting said bandpass filter and said detector means.
Claim 23
Dependent Claim
36 words
The spatial frequency filter of claim 18 in which said means for sensing includes a bandpass filter and said bandpass filter is tuned to the temporal frequency of the alternation of said first and second modes.
Claim 24
Dependent Claim
41 words
The spatial frequency filter of claim 14 in which said optical system further includes an optical element in the optical path between said means for projecting and said detector means and said optical element is moved by said means for operating.
Claim 25
Dependent Claim
19 words
The spatial frequency filter of claim 14 in which said detector means is moved by said means for operating.
Claim 26
Dependent Claim
16 words
The spatial frequency filter of claim 14 in which said means for operating includes piezoelectric means.
Claim 27
Dependent Claim
57 words
The spatial frequency filter of claim 14 in which said means for operating includes means for driving said optical system to gyrate at at least a first radius for a first period of time in said first mode and to gyrate at at least a second radius for a second period of time in said second mode.
Claim 28
Dependent Claim
19 words
The spatial frequency filter of claim 14 in which at least one of said modes includes intermittent dwell periods.
Claim 29
Dependent Claim
139 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for moving said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for limiting the wavelength of input radiation to said detector means.
Claim 30
Dependent Claim
139 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for moving said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; and means for limiting the wavelength of input radiation to said detector means.
Claim 31
Dependent Claim
150 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for moving said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; means for sensing fluctuations of the output of said detector means; and means for limiting the wavelength of input radiation to said detector means.
Claim 32
Dependent Claim
150 words
A spatial frequency filter comprising: an optical system including detector means and means for projecting onto said detector means an image of an object area; means for moving said means for projecting relative to said detector means alternatively at least in a first mode to develop a first modulation transfer function and a second mode to develop a second modulation transfer function which is matched to said first modulation transfer function in low spatial frequencies for imposing on said detector means a first representation of the image in said first mode and a second representation of the image in said second mode for providing a fluctuating elemental image output from each element of said detector means, which image output derives from a high spatial frequency object; means for sensing fluctuations of the output of said detector means; and means for limiting the wavelength of input radiation to said detector means.
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) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |