US4951141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of determining the transmission function of a video camera
Assignee: Rohde and Schwarz GmbH and Co KG
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Filing: 1989-09-11
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Granted: 1990-08-21
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Expires: 2009-09-11
Abstract
Abstract For determining the transmission function of a video camera, a bar pattern is taken in which the width of the bars is selected to be sufficiently small so that their influence on the amplitude and phase response of the electric pulse that is produced upon scanning of a bar in the camera is negligible; the narrow electric pulses thus produced at the output of the video camera are selected and subjected to Discrete Fourier Transformation.
Inventors
- 👤 Walter Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:33
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A method of determining the transmission function of a video camera, comprising the steps of: scanning a bar pattern with the video camera to produce narrow electrical pulses, the width of the bars of the bar pattern selected to be sufficiently small so that its influence on the amplitude and phase response of an electrical pulse produced in the camera upon scanning of a bar is negligible; selecting the narrow electrical pulses thus produced at the output of the video camera; and performing a Discrete Fourier Transformation of the selected pulses.
Claim 2
Independent Claim
91 words
A method of determining the transmission function of a video camera, comprising the steps of: scanning a bar pattern with the video camera to produce narrow electrical pulses, the width of the bars of the bar pattern selected to be sufficiently small so that its influence on the amplitude and phase response of an electrical pulse produced in the camera upon scanning of a bar is negligible; selecting the narrow electrical pulses thus produced at the output of the video camera; and performing a Discrete Fourier Transformation of the selected pulses.
Claim 3
Dependent Claim
48 words
The method of claim 1, and further defined as: scanning bars of increasingly smaller width from the bar pattern so that the minimum bar width desired for Fourier transformation is selected by analysis of the amplitude of the electric pulses produced at the output of the video camera.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein: the distance between the bars of the bar pattern is selected to be sufficiently small so that the transient and decay characteristics of the pulses produced thereby do not influence each other.
Claim 5
Dependent Claim
42 words
The method of claim 1, and further comprising the step of: determining the amplitude response and/or the frequency response of the video camera with a processor from the complex transmission function obtained by Discrete Fourier Transformation after conversion to magnitude and phase.
Claim 6
Dependent Claim
21 words
The method of claim 4, comprising the step of: differentiating the phase response in a processor to provide the group delay.
Claim 7
Dependent Claim
31 words
The method of claim 1, wherein: the bar pattern comprises at least one vertical black bar on a white background and/or at least one vertical white bar on a black background.
Claim 8
Dependent Claim
24 words
The method of claim 1, wherein: the bar pattern comprises at least one bar whose width increases to wedge shape in the vertical direction.
Claim 9
Dependent Claim
15 words
The method of claim 1, wherein: the bar pattern comprises at least one oblique bar.
Claim 10
Dependent Claim
29 words
The method of claim 1, comprising the step of: forming the mean value from successively produced pulses of black bars and pulses of white bars after discrete Fourier analysis.
Claim 11
Dependent Claim
24 words
The method of claim 1, comprising the step of: forming a mean value from a plurality of successively produced pulses before Discrete Fourier transformation.
Claim 12
Dependent Claim
24 words
The method of claim 1, comprising the step of: forming a mean value from a plurality of successively produced pulses after Discrete Fourier Transformation.
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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) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |