US4691241A
Expired / Lapsed
US
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Method and system for compensating for a shading phenomenon
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1984-11-15
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Granted: 1987-09-01
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Expires: 2004-11-15
Abstract
Abstract An image signal of the input and/or the output side is (are) multiplied by a shading compensation signal obtained from the output signal of a low-pass filter employed in a PLL circuit or a greating signal multiplying means.
Inventors
- 👤 Kunio Tomohisa
- 👤 Kiyoshi Maeda
- 👤 Masamichi Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:17
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/19; H04N1/191; H04N1/192; H04N1/193; H04N1/047; H04N1/053; H04N1/40; H04N1/401; H04N25/00; H04N25/60; H04N25/63; H04N1/113; H04N1/1135; H04N1/12; H04N2201/00; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04712; H04N2201/04734; H04N2201/04744; Y; Y10; Y10S; Y10S331/00; Y10S331/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
86 words
A method for campensating for a shading phenomenon comprising the steps of: (a) obtaining a shading compensation signal by processing an output signal of a low-pass filter employed in a phase lock loop circuit for outputting signals in synchronism with a scanning speed of an input scanning beam polarized by a beam polarizing means; and (b) multiplying the shading compensation signal obtained in the step (a) by an image signal obtained by scanning an original with an input scanning beam polarized by the beam polarizing means.
Claim 2
Independent Claim
86 words
A method for campensating for a shading phenomenon comprising the steps of: (a) obtaining a shading compensation signal by processing an output signal of a low-pass filter employed in a phase lock loop circuit for outputting signals in synchronism with a scanning speed of an input scanning beam polarized by a beam polarizing means; and (b) multiplying the shading compensation signal obtained in the step (a) by an image signal obtained by scanning an original with an input scanning beam polarized by the beam polarizing means.
Claim 3
Dependent Claim
31 words
A method claimed in claim 1, in which the shading compensation signal is obtained by controlling a offset value and a amplitude produced by the output signal of the low-pass filter.
Claim 4
Independent Claim
87 words
A method for compensating for a shading phenomenon comprising the steps of: (a) obtaining a shading compensation signal by processing a output signal of a low-pass filter employed in a phase lock loop for outputting signals in synchronism with a recording speed of a recording beam for exposing a photosensitive material polarized by a beam polarizing means; and (b) multiplying the shading compensation signal obtained in the step (a) of this claim by a recording signal obtained by carrying out necessary processes on an input image signal.
Claim 5
Dependent Claim
31 words
A method claimed in claim 3, in which the shading compensation signal is obtained by controlling a offset value and a amplitude produced by the output signal of the low-pass filter.
Claim 6
Independent Claim
95 words
A system for compensating for a shading phenomenon comprising: (a) a signal processing means for processing a output signal of a low-pass filter employed in a phase lock loop and for outputting signals in synchronism with a scanning speed of an input scanning beam polarized by a beam polarizing means to obtain a shading compensation signal; and (b) a multiplication means for multiplying the shading compensation signal obtained in the step (a) of this claim by an image signal obtained by scanning an original with an input scanning beam polarized by the beam polarizing means.
Claim 7
Dependent Claim
37 words
A system claimed in claim 5, in which the signal processing means is operable for processing the output signal of the low-pass filter of the phase lock loop by varying an offset value and an amplitude thereof.
Claim 8
Dependent Claim
30 words
A system as recited in claim 5 wherein said signal processing means includes synchronizing means for outputting said signals in synchronism with the scanning speed of the input scanning beam.
Claim 9
Dependent Claim
34 words
A system as recited in claim 7 wherein said processing means includes amplitude control means for varying an offset value of the output signal of the low-pass filter and for varying an amplitude thereof.
Claim 10
Independent Claim
94 words
A system for compensating for a shading phenomenon comprising: (a) a signal processing means for processing an output signal of a low-pass filter employed in a phase lock loop and for outputting signals in synchronism with a recording speed of a recording beam for exposing a photosensitive material polarized by a beam polarizing means to obtain a shading compensation signal; and (b) A multiplying means for multiplying the shading compensation signal obtained in the step (a) of this claim by a recording signal obtained by carrying out necessary processes on an input image signal.
Claim 11
Dependent Claim
37 words
A system claimed in claim 9, in which the signal processing means is operable for processing the output signal of the low-pass filter of the phase lock lop by varying an offset value and an amplitude thereof.
Claim 12
Dependent Claim
29 words
A system as recited in claim 9 wherein said signal processing means includes synchronizing means for outputting said signals in synchronism with a recording speed of a recording beam.
Claim 13
Dependent Claim
34 words
A system as recited in claim 11 wherein said processing means includes amplitude control means for varying an offset value of the output signal of the low-pass filter and for varying an amplitude thereof.
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) | 1990-08-31 | 1991-03-02 | 1991-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-31 | 1995-03-02 | 1995-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-31 | 1999-03-02 | 1999-09-01 | $7700.00 | Window Closed / Lapsed |