GB1289286A – – Google Patents
GB1289286A – – Google Patents
Info
Publication number
GB1289286A
GB1289286A
GB1289286DA
GB1289286A
GB 1289286 A
GB1289286 A
GB 1289286A
GB 1289286D A
GB1289286D A
GB 1289286DA
GB 1289286 A
GB1289286 A
GB 1289286A
Authority
GB
United Kingdom
Prior art keywords
level
video signal
clipper
clipping
black level
Prior art date
1969-03-21
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1969-03-21
Filing date
1970-03-13
Publication date
1972-09-13
1970-03-13
Application filed
filed
Critical
1972-09-13
Publication of GB1289286A
publication
Critical
patent/GB1289286A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
208000019300
CLIPPERS
Diseases
0.000
abstract
6
208000021930
chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids
Diseases
0.000
abstract
6
238000005070
sampling
Methods
0.000
abstract
1
Classifications
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
H04N5/00—Details of television systems
H04N5/14—Picture signal circuitry for video frequency region
H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
H04N5/165—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level to maintain the black level constant
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
H04N5/00—Details of television systems
H04N5/14—Picture signal circuitry for video frequency region
H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
H04N5/00—Details of television systems
H04N5/14—Picture signal circuitry for video frequency region
H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
H04N5/18—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level by means of «clamp» circuit operated by switching circuit
H04N5/185—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level by means of «clamp» circuit operated by switching circuit for the black level
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
H04N5/00—Details of television systems
H04N5/66—Transforming electric information into light information
Abstract
1289286 Television RCA CORPORATION 13 March 1970 [21 March 1969] 12100/70 Heading H4F To ensure that black level clipping and clamping are effected at the same signal level the black level clipper follows the clamping device and a feedback arrangement from the clipper to the clamping device is arranged to be responsive to the back level at which the video signal is clipped to produce a suitable control signal for application to the clamping device. As shown in Fig. 1 the video signal is passed via a voltage to current converting amplifier 12 to a black level clipper 13 the output of which is converted into a video signal voltage and applied to additional processing circuits such as a gamma correction circuit. The current level at which the signal is clipped is detected by a clipping level sensor 14 which transfers any excess of the video signal cut off by the clipper to a sampler 15. Sampler 15 is pulse controlled so that its output comprises a series of pulses representative of the difference between black level of the video signal during horizontal blanking or synchronizing intervals and the, reference level of the clipper. These pulses are integrated 16 into a continuous unidirectional current which is amplified 17 to produce a control signal representative of the excess of the video signal beyond the clipping level and applied to the input terminal 11 of the system to clamp the blanking intervals of the video signal at a level corresponding to the clipping level of clipper 13. A detailed transistorized circuit arrangement for this system is described in detail with respect to Fig. 2 (not shown), in which adjustment of the black level may be effected by adding differentially some of the sampling pulse applied to sampler 15 to the amplifier 12.
GB1289286D
1969-03-21
1970-03-13
Expired
GB1289286A
(en)
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
US80917869A
1969-03-21
1969-03-21
Publications (1)
Publication Number
Publication Date
GB1289286A
true
GB1289286A
(en)
1972-09-13
Family
ID=25200717
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB1289286D
Expired
GB1289286A
(en)
1969-03-21
1970-03-13
Country Status (4)
Country
Link
US
(1)
US3582545A
(en)
FR
(1)
FR2035161B1
(en)
GB
(1)
GB1289286A
(en)
NL
(1)
NL7004030A
(en)
Families Citing this family (5)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US4293874A
(en)
*
1980-02-04
1981-10-06
Zenith Radio Corporation
DC Restoration circuit for television receiver
US4730210A
(en)
*
1985-08-14
1988-03-08
Zenith Electronics Corporation
Wideband analog RGB video processor with negative feedback capability and black level control
US4688097A
(en)
*
1986-10-30
1987-08-18
Jerrold Electronics Corp.
D.C.-coupled video clamping circuit
US4802024A
(en)
*
1986-11-12
1989-01-31
Eastman Kodak Company
Video reproduction apparatus having automatic black and white calibration
US5390020A
(en)
*
1992-09-14
1995-02-14
Eastman Kodak Company
Video amplifier stabilization for CRT printing
Family Cites Families (6)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US2572179A
(en)
*
1949-05-24
1951-10-23
Philco Corp
Peak leveling circuit
US2850627A
(en)
*
1952-12-08
1958-09-02
Philco Corp
System for maintaining predetermined portions of a signal at a predetermined value
US2875332A
(en)
*
1953-12-01
1959-02-24
Rca Corp
Stabilized clipper and clamp circuits
GB932173A
(en)
*
1960-05-23
1963-07-24
Gen Precision Inc
Sub-miniature gyro
DE1172300B
(en)
*
1962-07-11
1964-06-18
Fernseh Gmbh
Method and circuit arrangement for transmitting a video signal
GB1027249A
(en)
*
1963-10-08
1966-04-27
Thorn Electronics Ltd
Improvements in voltage clamps
1969
1969-03-21
US
US809178A
patent/US3582545A/en
not_active
Expired – Lifetime
1970
1970-03-13
GB
GB1289286D
patent/GB1289286A/en
not_active
Expired
1970-03-20
NL
NL7004030A
patent/NL7004030A/xx
not_active
Application Discontinuation
1970-03-20
FR
FR7010111A
patent/FR2035161B1/fr
not_active
Expired
Also Published As
Publication number
Publication date
NL7004030A
(en)
1970-09-23
US3582545A
(en)
1971-06-01
FR2035161B1
(en)
1976-05-28
FR2035161A1
(en)
1970-12-18
DE2013217B2
(en)
1977-04-07
DE2013217A1
(en)
1970-10-01
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Legal Events
Date
Code
Title
Description
1973-01-24
PS
Patent sealed [section 19, patents act 1949]
1980-10-22
PCNP
Patent ceased through non-payment of renewal fee
