GB1049093A - Creation of Inventions and Patents with Artificial Intelligence

GB1049093A – Television video signal modifying apparatus
– Google Patents

GB1049093A – Television video signal modifying apparatus
– Google Patents
Television video signal modifying apparatus

Info

Publication number
GB1049093A

GB1049093A
GB27459/63A
GB2745963A
GB1049093A
GB 1049093 A
GB1049093 A
GB 1049093A
GB 27459/63 A
GB27459/63 A
GB 27459/63A
GB 2745963 A
GB2745963 A
GB 2745963A
GB 1049093 A
GB1049093 A
GB 1049093A
Authority
GB
United Kingdom
Prior art keywords
signal
level
curve
blanking
stage
Prior art date
1962-07-11
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
GB27459/63A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Philips GmbH

Original Assignee
Fernseh GmbH
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.)
1962-07-11
Filing date
1963-07-11
Publication date
1966-11-23

1963-07-11
Application filed by Fernseh GmbH
filed
Critical
Fernseh GmbH

1966-11-23
Publication of GB1049093A
publication
Critical
patent/GB1049093A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

Discuss

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

H04N5/18—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

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

Abstract

1,049,093. Television. FERNSEH G.m.b.H. July 11, 1963 [July 11, 1962], No. 27459/63. Heading H4F. A video signal Ia, Fig. 2, comprising picture components during the intervals t and blanking components during the intervals t1, is applied from terminal 1, Fig. 1, via transistor stages 7 and 15 to an output terminal 36 and has the peak level in one or the other direction (i.e. the level corresponding to the brightest or darkest picture area) held at a constant potential by a transistor clamp stage 26 which is rendered conductive by the inverted video signal IIa which is obtained from the collector of transistor 15 and applied to the base of transistor 26 via an emitter-follower stage 21. Where transistor 26 is a PNP type, the stage may be rendered conductive by the most negative extremity of signal IIa so that the peak level 2 corresponding to the brightest picture area in the original signal is held at a constant potential. The output signal is then as shown at IIIa with level 2 stabilized at potential p1. Where transistor 26 is an NPN type, the circuit functions to stabilize the level 4 corresponding to the darkest area so that the output is as shown at IVa with level 4 held at potential P. Emitterfollower 21 may be dispensed with, the signal which is applied to the base of transistor 26 being obtained directly from the collector of transistor 15, from transistor 7 or from a stage (not illustrated) which precedes stage 7. In a modified arrangement, Fig. 3 (not shown), for use where the signal level during blanking exceeds the peak level due to the darkest picture area, a gate stage is included in the signal path between transistor 15 and the clamp stage and is controlled by pulses coincident with the blanking intervals so as to substitute peak levels in the ” white ” direction. The clamp stage is an NPN type and thus responds to stabilize the peaks corresponding to the darkest picture area without interference by the blanking signals. The stabilized video signal may be applied to a limiter circuit, Fig. 5 (not shown), which may be operated to separate either the blanking (and any associated synchronizing) signals or picture signals with a lift or pedestal by which the darkest point exceeds the blanking level set by the clipping level. The stabilized signal may also be applied to a circuit Fig. 6 (not shown), which incorporates a gate stage which is opened only during the blanking interval and is connected to a capacitor. Depending upon the peak level which is stabilized the circuit functions to produce a control potential varying in accordance with the difference R1 (curve XI, Fig. 4) between the darkest picture point and the blanking level, or the difference R11 (curve XII, Fig. 4) between the brightest picture point and blanking level. In the first case the control potential may be employed to control the limiting potential of a clipper stage; in the second case the control potential may be employed for gain control or control of the characteristic of a non-linear amplifier. An application of the invention is illustrated in Fig. 7 where an original signal, curve V, Fig. 4, has its darkest picture point 46 stabilized at a reference level 60 by a circuit 51, which functions as described above in connection with Fig. 3 (not shown), and is then applied as the reference potential for a clamp circuit 92 which is controlled by pulses, curve XV, falling within the blanking interval and functions to stabilize the level of the original signal in a blanking amplifier 91. The resulting signal which is reblanked throughout the whole of the blanking interval, appears as shown in curve XIV with the darkest point 46 held a constant level P and is applied to limiter stage 95 to yield a final signal, curve X, in which the blanking level always differs from the darkest picture point by a fixed potential 55. A detailed transistor circuit for carrying out this application of the invention is described with reference to Fig. 8 (not shown). In another system, Fig. 9, the original signal, curve V, Fig. 4, is applied to a mixer stage where impulses, curve XVI, from a generator 121 are added to the signal to produce a composite signal as shown in curve XVII. This signal is then applied via non-linear amplifiers 122, 123 to a clamping stage 124 which stabilizes the signal level at a time during the injected impulses. The signal from amplifier 123 is also applied to a level stabilizing circuit as described above with reference to Fig. 3 (not shown) and is then applied to a circuit 126 which develops a control potential dependent on the difference R1, curve XVIII, between the stabilized darkest picture points 46 and the base of the blanking signals. The control potential controls the amplitude of the impulses from generator 121 in such manner that the tips of these have the same potential as the darkest picture points. Clamping stage 124 thus effectively stabilizes the level of the darkest picture points. Fig. 10 illustrates a further system in which a video signal, curve V, is blanked in a circuit 132 to yield a signal, curve XX, which is limited in a stage 135 to produce a final output signal as shown in curve X. The final signal is also applied to a stabilizing circuit as described above with reference to Fig. 3 (not shown) which feeds a circuit 135 which functions to produce a control signal proportional to the difference R1, curve XXI, between the stabilized darkest picture points and the blanking level. The control voltage is applied to limiter 133 to vary the limiting level so as to maintain constant the difference 55, curve X, between the darkest picture points and the blanking impulses. The original signal, curve V, may alternatively be applied directly to circuit 51 as indicated by the broken line connection.

GB27459/63A
1962-07-11
1963-07-11
Television video signal modifying apparatus

Expired

GB1049093A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

DEF37287A

DE1172300B
(en)

1962-07-11
1962-07-11

Method and circuit arrangement for transmitting a video signal

Publications (1)

Publication Number
Publication Date

GB1049093A
true

GB1049093A
(en)

1966-11-23

Family
ID=7096819
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB27459/63A
Expired

GB1049093A
(en)

1962-07-11
1963-07-11
Television video signal modifying apparatus

Country Status (4)

Country
Link

US
(1)

US3315033A
(en)

DE
(1)

DE1172300B
(en)

GB
(1)

GB1049093A
(en)

NL
(1)

NL295127A
(en)

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

FR2035161A1
(en)

1969-03-21
1970-12-18
Rca Corp

FR2469847A1
(en)

1979-08-17
1981-05-22
Sony Corp

VIDEO SIGNAL PROCESSING CIRCUIT

Families Citing this family (16)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US3389220A
(en)

1964-08-28
1968-06-18
Sarkes Tarzian
Television signal generating apparatus

NL6602675A
(en)

1966-03-02
1967-09-04

US3476875A
(en)

1967-03-03
1969-11-04
Bell Telephone Labor Inc
Digital clamping of pulse code modulated television signals

US3526710A
(en)

1967-03-30
1970-09-01
Gen Electric
Automatic black level control of television signals

US3597540A
(en)

1969-04-01
1971-08-03
Motorola Inc
Automatic brightness control responsive to black level of video signal

US3637921A
(en)

1970-01-09
1972-01-25
Zenith Radio Corp
Luminance amplifier with black level stabilization control

US3622694A
(en)

1970-03-12
1971-11-23
Gen Electric
Video signal processor for a light valve

US3977022A
(en)

1972-01-03
1976-08-24
Sunstein David E
Cathode-ray tube image presentation system of the indexing type and timing system useful therewith

US3811053A
(en)

1972-12-15
1974-05-14
Bell Telephone Labor Inc
Video clamping circuit with variable clamping level during blanking

US3813488A
(en)

1973-03-08
1974-05-28
Rca Corp
Video stripper

US3955047A
(en)

1974-04-16
1976-05-04
Rca Corporation
D.C. reinsertion in video amplifier

US3927255A
(en)

1974-05-01
1975-12-16
Rca Corp
Black level clamping circuit for a television signal processor

NL7700847A
(en)

1977-01-27
1978-07-31
Nemag Nv

GRIPPER OR THE LIKE.

JPS5553978A
(en)

1978-10-17
1980-04-19
Sony Corp
Automatic luminance adjusting device for television picture receiver

GB8923488D0
(en)

1989-10-18
1989-12-06
British Telecomm
Optical receiver

KR950007463B1
(en)

1992-11-27
1995-07-11
삼정전자 주식회사
Current sensing circuit of switching mode source voltage generating device

Family Cites Families (4)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US2636080A
(en)

1949-01-26
1953-04-21
Bell Telephone Labor Inc
Balanced diode clamper circuit for low-frequency restoration

US3013116A
(en)

1952-09-09
1961-12-12
Rca Corp
Signal correction circuits

FR1218764A
(en)

1958-04-05
1960-05-12
Fernseh Gmbh

Circuit for control by sampled fixed potential

DE1122985B
(en)

1958-11-15
1962-02-01
Felten & Guilleaume Gmbh

Circuit arrangement for obtaining antiphase clamping pulses from a video signal

1962

1962-07-11
DE
DEF37287A
patent/DE1172300B/en
active
Pending

1963

1963-07-10
NL
NL295127A
patent/NL295127A/xx
unknown

1963-07-10
US
US294085A
patent/US3315033A/en
not_active
Expired – Lifetime

1963-07-11
GB
GB27459/63A
patent/GB1049093A/en
not_active
Expired

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

FR2035161A1
(en)

1969-03-21
1970-12-18
Rca Corp

FR2469847A1
(en)

1979-08-17
1981-05-22
Sony Corp

VIDEO SIGNAL PROCESSING CIRCUIT

Also Published As

Publication number
Publication date

DE1172300B
(en)

1964-06-18

US3315033A
(en)

1967-04-18

NL295127A
(en)

1965-04-26

Contact information