Patent US4672682A successfully refreshed from Google Patents.
US4672682A
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Slice level deciding circuit
Assignee: Oki Electric Industry Co Ltd
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Filing: 1985-10-02
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Granted: 1987-06-09
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Expires: 2005-10-02
Abstract
Abstract A slice level deciding circuit includes a slice level generator for generating a variable slice level and a comparator for comparing a slice level generated from the generator with a picture image signal. An optimum slice level can be provided by operating, via an arithmetic circuit, a prescribed value on the same slice level as generated from the generator when an output from the comparator satisfies a prescribed slice level deciding condition. Accordingly, deterioration of a picture image quality can be prevented, which is caused by changes of a quantity of light due to variations of ambient temperature around the light source used for obtaining a picture image signal from the readout medium and noise produced upon reading portions on the readout medium where a quantity of light from the light source is reduced.
Inventors
- 👤 Seishiro Naruse
- 👤 Fumio Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:17
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/403
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
311 words
In an apparatus for reading out a picture image from a readout medium having ruled lines thereon in a dropout color by comparing in a comparison circuit a signal level of a picture image signal optically read from a readout medium and converted to an electrical signal, to a preselected slice level αV m , the improvement comprising a slice level selection circuit for selecting said preselected slice level αV m , said slice level selection circuit including: means for generating slice level signals of successively incrementally increased magnitudes V 1 , V 2 , . . . V n ; comparator means for successively comparing all values V of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium on which no pattern is written except the ruled lines, to the successively incrementally increased magnitudes V 1 , V 2 , . . . V n of slice level until all values V of said signal level are less than a magnitude V m among said incrementally increased magnitudes V 1 , V 2 , . . . V n ; an arithmetic circuit; means for inputting a signal indicative of said magnitude V m into said arithmetic circuit, said arithmetic circuit including means for multiplying said signal indicative of said magnitude V m by a constant value α, 0<α<1 to generate a signal indicative of said preselected slice level αV m ; and means for inputting to a memory and from said memory to said comparator means said signal indicative of said preselected slice level αV m , said comparator means including means for comparing values of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium to said preselected slice level αV m .
Claim 2
Dependent Claim
311 words
In an apparatus for reading out a picture image from a readout medium having ruled lines thereon in a dropout color by comparing in a comparison circuit a signal level of a picture image signal optically read from a readout medium and converted to an electrical signal, to a preselected slice level αV m , the improvement comprising a slice level selection circuit for selecting said preselected slice level αV m , said slice level selection circuit including: means for generating slice level signals of successively incrementally increased magnitudes V 1 , V 2 , . . . V n ; comparator means for successively comparing all values V of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium on which no pattern is written except the ruled lines, to the successively incrementally increased magnitudes V 1 , V 2 , . . . V n of slice level until all values V of said signal level are less than a magnitude V m among said incrementally increased magnitudes V 1 , V 2 , . . . V n ; an arithmetic circuit; means for inputting a signal indicative of said magnitude V m into said arithmetic circuit, said arithmetic circuit including means for multiplying said signal indicative of said magnitude V m by a constant value α, 0<α<1 to generate a signal indicative of said preselected slice level αV m ; and means for inputting to a memory and from said memory to said comparator means said signal indicative of said preselected slice level αV m , said comparator means including means for comparing values of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium to said preselected slice level αV m .
Claim 3
Dependent Claim
296 words
In an apparatus for reading out a picture image from a readout medium by comparing in a comparison circuit a signal level of a picture image signal optically read from a readout medium and converted to an electrical signal, to a preselected slice level αV m , the improvement comprising a slice level selection circuit for selecting said preselected slice level αV m , said slice level selection circuit including: means for generating slice level signals of successively incrementally increased magnitudes V 1 , V 2 , . . . V n ; comparator means for successively comparing all values V of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium, to the successively incrementally increased magnitudes V 1 , V 2 , . . . V n of slice level until all values V of said signal level are less than a magnitude V m among said incrementally increased magnitudes V 1 , V 2 , . . . V n ; an arithmetic circuit; means for inputting a signal indicative of said magnitude V m into said arithmetic circuit said arithmetic circuit said arithmetic circuit including means for multiplying said signal indicative of said magnitude V m by a constant value α, 0<α<1 to generate a signal indicative of said preselected slice level αV m ; and means for inputting to a memory and from said memory to said comparator means said signal indicative of said preselected slice level αV m , said comparator means including means for comparing values of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium to said preselected slice level αV m .
Claim 4
Dependent Claim
296 words
In an apparatus for reading out a picture image from a readout medium by comparing in a comparison circuit a signal level of a picture image signal optically read from a readout medium and converted to an electrical signal, to a preselected slice level αV m , the improvement comprising a slice level selection circuit for selecting said preselected slice level αV m , said slice level selection circuit including: means for generating slice level signals of successively incrementally increased magnitudes V 1 , V 2 , . . . V n ; comparator means for successively comparing all values V of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium, to the successively incrementally increased magnitudes V 1 , V 2 , . . . V n of slice level until all values V of said signal level are less than a magnitude V m among said incrementally increased magnitudes V 1 , V 2 , . . . V n ; an arithmetic circuit; means for inputting a signal indicative of said magnitude V m into said arithmetic circuit said arithmetic circuit said arithmetic circuit including means for multiplying said signal indicative of said magnitude V m by a constant value α, 0<α<1 to generate a signal indicative of said preselected slice level αV m ; and means for inputting to a memory and from said memory to said comparator means said signal indicative of said preselected slice level αV m , said comparator means including means for comparing values of the signal level of an electrical signal converted from a picture image signal optically read from the surface of a readout medium to said preselected slice level αV m .
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) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |