ES396900A1 - Videophone system - Google Patents

Videophone system

Info

Publication number
ES396900A1
ES396900A1 ES396900A ES396900A ES396900A1 ES 396900 A1 ES396900 A1 ES 396900A1 ES 396900 A ES396900 A ES 396900A ES 396900 A ES396900 A ES 396900A ES 396900 A1 ES396900 A1 ES 396900A1
Authority
ES
Spain
Prior art keywords
time reference
receiving end
field
pulse generator
video signals
Prior art date
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
ES396900A
Other languages
Spanish (es)
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Publication of ES396900A1 publication Critical patent/ES396900A1/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/14—Systems for two-way working
    • H04N7/141—Systems for two-way working between two video terminals, e.g. videophone
    • H04N7/147—Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H04N7/084—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the horizontal blanking interval only
    • H04N7/085—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the horizontal blanking interval only the inserted signal being digital
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H04N7/087—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the vertical blanking interval only
    • H04N7/088—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the vertical blanking interval only the inserted signal being digital
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/24—Systems for the transmission of television signals using pulse code modulation
    • H04N7/52—Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal
    • H04N7/54—Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal the signals being synchronous
    • H04N7/56—Synchronising systems therefor

Abstract

A video-telephone system comprising, at the transmitting end, means for generating synchronization and video signals and at the receiving end, a synchronizing circuit and means for processing and displaying the video signals, characterized in that the video signals are generated and transmitted in an analog form and at least the sync signals are generated and transmitted in a digital form, the system further comprising at the transmitting end a master time reference pulse generator for the generation of time reference pulses which they have a pulse repetition frequency such that the time reference master frequency can be derived from that at the receiving end, a coded word generator for generating at least one field coded word during part of the field recoil period, the timing circuit being arranged at the receiving end to synchronize the frequency of a time reference pulse generator located at the receiving end and being followed by a divider step that divides the pulses overall by said time reference pulse generator according to line, field and other frequencies optionally required, a synchronism verification circuit being arranged at the receiving end for verifying the instant of occurrence of the received field code word, detected by a code word detector and having a signal derived from the divider step, being connected to the minus a reset output of the verification circuit to a reset input of the splitter step for resetting said splitter step in such a way that phase equality is obtained between the detected encoded word and the component signal. (Machine-translation by Google Translate, not legally binding)
ES396900A 1970-11-13 1971-11-11 Videophone system Expired ES396900A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7016628A NL7016628A (en) 1970-11-13 1970-11-13

Publications (1)

Publication Number Publication Date
ES396900A1 true ES396900A1 (en) 1975-05-01

Family

ID=19811548

Family Applications (1)

Application Number Title Priority Date Filing Date
ES396900A Expired ES396900A1 (en) 1970-11-13 1971-11-11 Videophone system

Country Status (11)

Country Link
JP (1) JPS5227974B1 (en)
AU (1) AU3551771A (en)
CA (1) CA940244A (en)
CH (1) CH542560A (en)
DE (1) DE2152877C3 (en)
ES (1) ES396900A1 (en)
FR (1) FR2113933B1 (en)
GB (1) GB1321749A (en)
IT (1) IT942819B (en)
NL (1) NL7016628A (en)
SE (1) SE365691B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2389290A1 (en) * 1977-04-29 1978-11-24 Briand Marcel DEVICE FOR TRANSMISSION AND RECEPTION BY ANALOGUE LINES OF VIDEO-PHONE SIGNALS AND DIGITAL SIGNALS
FR2438401A1 (en) * 1978-10-05 1980-04-30 Thomson Csf METHOD FOR TRANSMITTING AN ANALOG AUDIO FREQUENCY SIGNAL DURING TELEVISION SIGNAL SYNCHRONIZATION INTERVALS AND DEVICE FOR CARRYING OUT SAID METHOD
FR2440669A1 (en) * 1978-10-31 1980-05-30 Thomson Brandt SYSTEM FOR BROADCASTING AUDIO-VISUAL TELEVISION SIGNALS SYNCHRONIZED BY A PILOT FREQUENCY AND METHOD FOR IMPLEMENTING SAME
IL58735A (en) * 1978-12-04 1982-01-31 Oak Industries Inc Subscription television coding system
EP0033306B1 (en) * 1980-01-22 1985-08-28 Paul Pierre Delogne Method and installation for transmitting television signals by means of a digital encoding of these signals
FR2524242B1 (en) * 1982-03-24 1986-02-07 Radiotechnique ENCRYPTION RECOGNITION CIRCUIT FOR TELEVISION BROADCASTING TRANSMISSION SYSTEM AND ENCRYPTED BROADCASTING TRANSMISSION SYSTEM INCLUDING SUCH A CIRCUIT
FR2524241A1 (en) * 1982-03-24 1983-09-30 Radiotechnique Receiver decoding control circuit for TV transmission system - uses phase locked loop and pseudo-random digital sequence generator to provide delay to line sync. signal
US4675722A (en) * 1982-12-02 1987-06-23 Independent Broadcasting Authority Apparatus for deriving synchronization signals for component television video signal reception
FR2552282B1 (en) * 1983-09-21 1990-07-13 Veillard Jacques METHOD AND DEVICE FOR CONSISTENT DEMODULATION OF DIGITALLY MODULATED CARRIER

Also Published As

Publication number Publication date
DE2152877B2 (en) 1978-01-19
IT942819B (en) 1973-04-02
CH542560A (en) 1973-09-30
AU465455B2 (en) 1975-09-25
DE2152877C3 (en) 1978-09-14
AU3551771A (en) 1973-05-17
SE365691B (en) 1974-03-25
FR2113933A1 (en) 1972-06-30
CA940244A (en) 1974-01-15
NL7016628A (en) 1972-05-16
JPS5227974B1 (en) 1977-07-23
DE2152877A1 (en) 1972-05-31
FR2113933B1 (en) 1977-03-18
GB1321749A (en) 1973-06-27

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