GB1041726A

GB1041726A – Improvements in colour television systems using at least one frequency-modulated subcarrier
– Google Patents

GB1041726A – Improvements in colour television systems using at least one frequency-modulated subcarrier
– Google Patents
Improvements in colour television systems using at least one frequency-modulated subcarrier

Info

Publication number
GB1041726A

GB1041726A
GB24112/63A
GB2411263A
GB1041726A
GB 1041726 A
GB1041726 A
GB 1041726A
GB 24112/63 A
GB24112/63 A
GB 24112/63A
GB 2411263 A
GB2411263 A
GB 2411263A
GB 1041726 A
GB1041726 A
GB 1041726A
Authority
GB
United Kingdom
Prior art keywords
signal
filter
subcarrier
frequency
band
Prior art date
1962-06-18
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
GB24112/63A
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.)

CFT COMP FSE TELEVISION

Compagnie Francaise de Television SA

Original Assignee
CFT COMP FSE TELEVISION
Compagnie Francaise de Television SA
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.)
1962-06-18
Filing date
1963-06-17
Publication date
1966-09-07

1963-06-17
Application filed by CFT COMP FSE TELEVISION, Compagnie Francaise de Television SA
filed
Critical
CFT COMP FSE TELEVISION

1966-09-07
Publication of GB1041726A
publication
Critical
patent/GB1041726A/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

H04N11/00—Colour television systems

H04N11/06—Transmission systems characterised by the manner in which the individual colour picture signal components are combined

H04N11/18—Transmission systems characterised by the manner in which the individual colour picture signal components are combined using simultaneous and sequential signals, e.g. SECAM-system

G—PHYSICS

G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS

G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS

G09B29/00—Maps; Plans; Charts; Diagrams, e.g. route diagram

G09B29/10—Map spot or coordinate position indicators; Map reading aids

G09B29/102—Map spot or coordinate position indicators; Map reading aids using electrical means

Abstract

1,041,726. Colour television; frequency modulation systems. COMPAGNIE FRANCAISE DE TELEVISION. June 17, 1963 [June 18, 1962; June 10, 1963], No. 24112/63. Headings H3R and H4F. Relates to a colour television system of the type using a first wide band picture signal within the frequency band of which is located a subcarrier signal which is frequently modulated by a second picture signal and is concerned with improving the noise protection of the subcarrier signal in such a manner as not to disturb reception of the wide-band signal. In broad terms the noise protection is achieved by including in a receiver for the system a filter which is located in the subcarrier channel and has a characteristic as shown in Fig. 3(b) which emphasizes frequencies around the subcarrier frequency F 0 in relation to the side-band frequencies F 3 , F 4 . (F 1 -F 2 indicates the frequency deviation.) In addition, at the transmitter, in the channel for the second signal to the frequency modulator, there is provided a filter as shown in Fig. 2(a) which lowers the amplitude of the lower frequencies so as to increase the time that the subcarrier frequency is located within the range F1 1 -F1 2 of the receiver filter where substantial emphasis, and hence noise protection, is provided. For example, where the band-width fm of the second signal is 1 Mc/s., f in Fig. 2(a) may be made equal to 700 kc/s. and the ratio G 1 /G 0 approximately equal to 3. A filter, Fig. 2(b), having a characteristic complementary to Fig. 2(a) is provided following the frequency discriminator at the receiver, and a filter, Fig. 3(a), having a characteristic complementary to Fig. 3(b) is provided in the subcarrier channel at the transmitter. This latter filter is provided to compensate the phase distortion due to the corresponding receiver filter. Amplitude modulation imparted to the subcarrier at the transmitter by the use of the filter. Fig. 3(a), is removed by either a limiter following the filter, or an amplitude modulator preceding the filter which is connected in a feed-back circuit including an envelope detector connected to the output of the filter. The feed-back circuit may include a low-pass filter so as to be operative only for low frequency signals. The steps of amplitude suppression is an essential feature in preventing the disturbance of reception of the first picture signal by the subcarrier signal. The invention is described more particularly as applied to the ” SECAM ” (Registered Trade Mark) system where the first picture comprises a luminance signal and the second signal comprises red and blue colour difference signals alternating at line rate. Reference is made to 1,011,706 in connection with additional amplitude modulation of the subcarrier signal as a function of the level of the components of the luminance signal within the band common with the subcarrier signal. This may be effected by an amplitude modulator in the subcarrier channel, or, where amplitude suppression by feed-back is used as described above, the modulation signal may operate in a subtractor circuit in the feed-back path.

GB24112/63A
1962-06-18
1963-06-17
Improvements in colour television systems using at least one frequency-modulated subcarrier

Expired

GB1041726A
(en)

Applications Claiming Priority (2)

Application Number
Priority Date
Filing Date
Title

FR901089A

FR1338876A
(en)

1962-06-18
1962-06-18

Improvements to color television systems using at least one frequency modulated subcarrier

FR937521A

FR83827E
(en)

1962-06-18
1963-06-10

Improvements to color television systems using at least one frequency modulated subcarrier

Publications (1)

Publication Number
Publication Date

GB1041726A
true

GB1041726A
(en)

1966-09-07

Family
ID=26196208
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB24112/63A
Expired

GB1041726A
(en)

1962-06-18
1963-06-17
Improvements in colour television systems using at least one frequency-modulated subcarrier

Country Status (10)

Country
Link

US
(1)

US3365541A
(en)

BE
(1)

BE633733A
(en)

CH
(1)

CH420256A
(en)

DE
(1)

DE1196696B
(en)

DK
(1)

DK104688C
(en)

ES
(1)

ES289106A1
(en)

FR
(2)

FR1338876A
(en)

GB
(1)

GB1041726A
(en)

LU
(1)

LU43905A1
(en)

NL
(2)

NL141058C
(en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

FR87708E
(en)

*

1965-03-23
1966-07-22
Cft Comp Fse Television

Improvements to color television retransmission devices

FR1458292A
(en)

*

1965-07-30
1966-03-04
Cft Comp Fse Television

Improvements to the secam system

US4255758A
(en)

*

1979-04-05
1981-03-10
Rca Corporation
Self-adjusting bell filter circuit for use in SECAM coders

GB9027598D0
(en)

*

1990-12-20
1991-02-13
Indep Broadcasting Authority
Compatible non linear pre-emphasis for composite video signals

Family Cites Families (9)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US2285085A
(en)

*

1940-01-03
1942-06-02
Lorenz C Ag
Carrier frequency apparatus

NL110080C
(en)

*

1953-09-17

GB779457A
(en)

*

1954-07-28
1957-07-24
Emi Ltd
Improvements relating to colour television

NL200685A
(en)

*

1955-09-22

US3069679A
(en)

*

1959-04-22
1962-12-18
Westinghouse Electric Corp
Multiplex communication systems

NL268985A
(en)

*

1960-09-09

NL258345A
(en)

*

1960-11-24

GB985807A
(en)

*

1961-02-03
1965-03-10
Post Office
Angular modulation transmission systems

NL136339C
(en)

*

1961-09-22

0

BE
BE633733D
patent/BE633733A/xx
unknown

NL
NL294059D
patent/NL294059A/xx
unknown

1962

1962-06-18
FR
FR901089A
patent/FR1338876A/en
not_active
Expired

1963

1963-06-10
FR
FR937521A
patent/FR83827E/en
not_active
Expired

1963-06-14
LU
LU43905D
patent/LU43905A1/xx
unknown

1963-06-14
NL
NL294059A
patent/NL141058C/en
active

1963-06-15
DE
DEC30211A
patent/DE1196696B/en
active
Pending

1963-06-17
GB
GB24112/63A
patent/GB1041726A/en
not_active
Expired

1963-06-17
DK
DK286463AA
patent/DK104688C/en
active

1963-06-17
US
US288560A
patent/US3365541A/en
not_active
Expired – Lifetime

1963-06-17
ES
ES289106A
patent/ES289106A1/en
not_active
Expired

1963-06-18
CH
CH754863A
patent/CH420256A/en
unknown

Also Published As

Publication number
Publication date

NL141058C
(en)

1974-01-15

ES289106A1
(en)

1963-11-16

NL294059A
(en)

FR1338876A
(en)

1963-10-04

DK104688C
(en)

1966-06-20

CH420256A
(en)

1966-09-15

DE1196696B
(en)

1965-07-15

FR83827E
(en)

1964-10-23

US3365541A
(en)

1968-01-23

LU43905A1
(en)

1963-08-14

BE633733A
(en)

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