US1945626A - Television system - Google Patents

Television system Download PDF

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Publication number
US1945626A
US1945626A US244963A US24496328A US1945626A US 1945626 A US1945626 A US 1945626A US 244963 A US244963 A US 244963A US 24496328 A US24496328 A US 24496328A US 1945626 A US1945626 A US 1945626A
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US
United States
Prior art keywords
record
disc
coil
image
recording
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 - Lifetime
Application number
US244963A
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English (en)
Inventor
Baind John Logie
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.)
Baird Television Ltd
Original Assignee
Baird Television Ltd
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 Baird Television Ltd filed Critical Baird Television Ltd
Application granted granted Critical
Publication of US1945626A publication Critical patent/US1945626A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/78—Television signal recording using magnetic recording
    • H04N5/781—Television signal recording using magnetic recording on disks or drums
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/06—Systems for the simultaneous transmission of one television signal, i.e. both picture and sound, by more than one carrier
    • H04N7/063—Simultaneous transmission of separate parts of one picture
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/12—Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal

Definitions

  • 'Ihis invention relates 1:0 the transmission of signals for television and like purposes, and has for its object to provide an improved method of and apparatus for such transmission.
  • This invention accordingly comprises in a television system, the method of transmitting a plurality of individual signals consisting in recording them simultaneously or in concurrent groups on a record-element er elements and therea fter reading all the individual records in succession (for example, at a higher speed) by a device which is operatively connected to the transmitter.
  • the reading device may have associated with it means for wiping out the record which has just been read, so that a fresh record may be ma de immediately thereafter.
  • it consists in exp1oring simultaneously various sections cf a picture or view to be transmitted, recording the groups of signals corresponding to each section of the picture on a record element and traversing the record thus formed by a device which reads the record and transmits the signals to the receiving station.
  • a similar but reversed arrangement may be used at the receiving station, the signals being transmitted successively at, say, a high rate, and recorded on an element or group cf e1ements, such signals being thereafter read simultaneous- 1y in groups on different parts of the record.
  • This invention also covers certain details of the apparatus as hereinafter described.
  • FIGS 2 and 3 are diagrammatic representations of alternative forms of apparatus.
  • Figure 1 which illustrates diagrammatically a construction of apparatus in which magnetic recording is used, there is provided a series of discs 40, 41, 42 of. steel or other suitable magnetic material mounted on a. shaft 43 which is arranged to be rotated at any suitable speed.
  • the number of discs is equal to the number of sections in which the picture is explored, and one disc is appropriated to each section.
  • any suitable means adapted to explore several sections of an image simultaneously may be used for the purpose.
  • a plurality of separate exploring devices may be used, each positioned so as to scan one sectiononly cf the image.
  • an exploring device such as is shown in my copending application Serial N0. 244,964, fi1ed Jan. 6, 1928, in which a Single rotating disc is capable of' simultaneously exploring difierent sections of an image, may be utilized.
  • the signals derived from the light-sensitive or photoelectric cel1 for each section are applied respectively to magnetizing coi1s 44, 45 46, so as to make a corresponding record on each of the discs during its rotation.
  • Each of the discs also has associated with it a search-coil, indicated at 47, 48 and 49, this coi1 being so mounted that it can be rotated in the opposite direction to the disc at a higher speed. Conveniently, when three discs are used, the searchcoil will rotate at twice the speed of ehe disc.
  • Each search-coil has associated with it a wiping-out-coil energized by alternating current of a suitable frequency, and this coil is rotated immediately behind the search-coil so that after a record has been read it is erased, and the recordelement is 1eft ready to receive a new record; these wiping-out-coils are indicated ab 50, 51, 52.
  • the record on the disc 40 was erased immediately after it was read, and the coi1 44 impressed a new record thereon, the recording commencing immediately after the reading of the previous record commenced and continuing whilst; all three records on the discs 40, 41, 20 are being read and transmitted. Since the search-coils rotate at twice the speed of the discs, the disc 40 will have had a 11111 record impressed upon lt by the time the search-coil 49 has finished reading the disc 42 so that the cycle of operations cf reading ehe three discs in succession can be repeated.
  • the magnetizing cells are in operation practically continuously, and each search-coil is reading and transmitting a record for one revolution in three, so that the whole process of recording, reading and transmitting is a substantially continuous one, and the rate of transmission of the sei) of Signals constituting the complete picture (made up of the three sections) is three-times as great as it would be with a. single exploring and. transmitpting devlce.
  • FIG. 2 For example as is illustrated in Figure 2.
  • FIG. 2 there is a single disc 10 01 steel or other suitable magnetio material mounted on a. shaft 11 which is arranged to be rotated at any suitable speed.
  • the picture may be explored in three sections, and the exploring devioes are connected respectively to three magnetizing-coils 12, 13, 14, which are spaced apart around the periphery 01 the disc 10.
  • these coils are spaced 60 degrees apart around one-half 01 the disc.
  • the disc is rotated at such a speed that ehe exploration of each section (and therefore the exploration 01 the whole area) takes place whilst the disc is rotating through an angle of 60.
  • the reading of this record and its transmission to the receiving-station is effeoted by means 01 a reading-coil or search-coil 18 which is situated at any convenient position, for example, near the coil 12, so that as the record is formecl it passes under it.
  • the reading of ehe record 16 commences when the reference-radius 15 reaches the position 19, and continues whilst the disc is completing a halfrevolution, that is to say, until the reference-radius 15 reaches the position 20.
  • the magnetization of the disc in accordance with the various signals received from the exploring devices induces electrical impulses in the coil 18 which are amplified by any suitable device 21 and transmitted for example by an aerial 22 to the receiving station.
  • a demagnetizing 001123 supplied with alternating current at any suitable frequency, is preferably provided immediately behind 'che searchcoil 18 so as 110 wlpe out the -reoord a.s soon as it has been read and transmitted, thereby leaving the disc ready to receive another record.
  • a rotatable magnetic disc 25 is used, and there are mounted adjacent to it a plurality of magnetizing cells 26,. 2'7, 28, 29 four spacecl apart being illustrated.
  • Each o1 these coils is energized through a selenium cell or other light-sensitive body which is used in conjunction with an exploring device for exploring a s'edtion of the view o1 scene to be transmitted.
  • tl 1e view is divided. into four s'ections.
  • a reading-coil or search-coil 30 is so mounted that it can be rotated relatively to the disc, and in the example illusqrated it is rotated in the opposite direction to the disc, and a1; a higher speed, say four times that ofthe disc.
  • the search-coil 30 may also carry with ii a. wipingout coil 31 in the manner previously described.
  • the mode 01 operation of this apparatus will be as follows.
  • the radius 32 is in the position indicated the making of the record commenoes, and it continues whilst the disc turns through a quarter-revolution, that is to say, until the radius 32 occupies the position 33.
  • the'record will be complete, extending entirely around the circumference of the disc, and the whole of the view or picture will be recorded thereon.
  • the search-coil 30 is rotated in the direction indicated at a high speed, so as to read and transmit the record, and the speed is Conveniently such that the searchcoil makes one complete revolution during thetime in which the radius 32 turns from the position 33 120 the position 34.
  • this coil may be coupled to the output amplifier through two rotary switches 35, 36 whlch are provided over a part cf their circumference with a contact-strip, and which rotates in the same direction as the coi1 30 but at a slower rate.
  • Each contact-strip bridges a contact Irom the coil 30 and a contact to the output amplifier and by suitably selecting the relative rates oi movement cf the coil 30 and the switches, and the length of the contact-strips, the coil 30 is isolated during each alternative revolution.
  • a similar arrangement may be used for coupling the coi1s 26, 27, 28 and 29, to their respective lighflsensitive cel1s', the rotaryswitches being indicated by the character 37.
  • the signals may be used directly to control the variable light source which is ordinarily used in a television receivingstation, or apparatus similar to that above described may be used in the reverse manner, that is to say, a record is impressed upon it at a high speed, and this record is subsequently read in comcurrent sections by various devices, each of which controls its own source of light or equivalent device.
  • a method for the transmission of images consisting in exploring simultaneously individual luminous points in difierent portions of an image, recording simultaneously the explored individual lurninous points in the different portions cf the image, sending successively the recorded portions of the image, and reproducing simultaneously the individual luminous points in difierent portions of the image thus sent.
  • the method of television transmission which comprises scanm'ng simultaneously individual points in a plurality of different portions of an i1'nage, recording the 1ight variations from each portion separately, transmitting the separate recordings in succession, and reproducing simultaneously individual points in the separate transmitted recordings.
  • the method of television transmission which comprises scanning simultaneously a plurality of difierent portions of an image, transforming the light variations 013 each portion into electrical variations, recording the electrical variations for each portion separately, transmitting the separate recordings in succession, and reproducing simultaneously individual points in the separate transmitted recordings.
  • the method of television transmission which comprises scanning simultaneously a plurality' of different portions of an image, trans- Iorming the 1ight variations from each portion into electrical variations, recording magnetically theelectrical variations from each portion separate1y, transmitting the separate recordings in sucicession, and reproducing simultaneously individual points in the separate simultaneous recordings.
  • the method of transmitting television signals which comprises simultaneously scanning a plurality cf different sections of an image, recording magnetically the light variations from each section separately, transmitting the recording from each image separately, and. erasinz each recording after each transmlssion.
  • the method of transmitting television signals which comprises simultaneously scanning a plurality of difierent sections of an image, recording magnetically the l'1ght variations from each section separately, transmitting the recording from each image separately, erasing each recording after each transmission, and. again recording als before on the erased records.
  • the method cf reproducing an image, which comprises simultaneous1y scanning individual points in a plurality of difierent portions of an image, recording simultaneously the groups cf signals corresponding to each portion, reading the resulting records progressively and in succession, transmitting in succession the signals corresponding to each group,
  • an image which comprises simultaneously scanning individual points in a plurality cf difierent portions of an image, recording simultaneously, magnetically on metallic records, the groups of signals corresponding to each portion, reading the resulting records progressively and in succession, transmitting in succession the signals corresponding to each group and reproducing slmultaneously individual points in said different portions of the image.
  • the method o! re producing an image, which comprises simultaneously scanning individual points in a plurality of difierent portions of an image, recording simultaneously', magnetically on metallic records, the groups of signals corresponding to each portion, reading the resulting records progressively and in succession, erasing the recorded signals from each record following the reading thereof, transmitting in succession the signals corresponding to each group, and reproducing simultaneously individual points in said different portions of the image.
  • the method of reproducing an image which comprises simultaneously scanning individual points in a plurality 01 different portions cf an image, recording simultaneously, magnetically on metallic records, the groups of signals corresponding 130 each portion, reading the resu1ting records progressively and in succession, erasing the recorded signals ously individual points in said different portions 013 the image, and again scanning the image and recording as before the individual points in a plurality of different portions cf the image on the records, the recordings 01 which have been erased, and continuing to read the records, transmit the signals, and reproduce the image as before.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
  • Geophysics And Detection Of Objects (AREA)
US244963A 1927-01-26 1928-01-06 Television system Expired - Lifetime US1945626A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2327/27A GB292632A (en) 1927-01-26 1927-01-26 Improvements in or relating to the transmission of signals for television and like purposes

Publications (1)

Publication Number Publication Date
US1945626A true US1945626A (en) 1934-02-06

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Family Applications (1)

Application Number Title Priority Date Filing Date
US244963A Expired - Lifetime US1945626A (en) 1927-01-26 1928-01-06 Television system

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US (1) US1945626A (enrdf_load_stackoverflow)
DE (1) DE500722C (enrdf_load_stackoverflow)
GB (1) GB292632A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2434697A (en) * 1943-09-28 1948-01-20 Charles H Homrighous Time division multiplex telephone system
US2437027A (en) * 1943-01-12 1948-03-02 John H Homrighous Time division multiplex communication system
US2517265A (en) * 1947-07-18 1950-08-01 Wald George Multichannel television system
US2534842A (en) * 1947-10-10 1950-12-19 Panoramic Radio Corp Dual synchrometric system
US2690473A (en) * 1949-07-16 1954-09-28 Times Facsimile Corp Facsimile recording system and apparatus
US2698875A (en) * 1950-03-24 1955-01-04 Magnecord Inc Plural track magnetic recording and/or reproducing apparatus
US2773120A (en) * 1950-11-30 1956-12-04 Rca Corp Magnetic recording of high frequency signals
US2816157A (en) * 1954-09-20 1957-12-10 Technicolor Motion Picture Magnetic tape-to-film photographic system
US2826634A (en) * 1951-04-14 1958-03-11 Atkinson Method and means for magnetic reproduction of pictures
US2860179A (en) * 1953-11-25 1958-11-11 Servo Corp Of America Video-display devices
US3148242A (en) * 1956-10-19 1964-09-08 Lee A Collins Method of television transmission and reception
US3187314A (en) * 1959-09-01 1965-06-01 Frederic W Olmstead Electromagnetic resolver

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE877621C (de) * 1938-10-20 1953-05-26 Interessengemeinschaft Fuer Ru Verfahren zur UEbertragung bewegter Bilder
DE1016781B (de) * 1953-09-17 1957-10-03 Ulrich Fusban Dipl Ing Relaisstelle, insbesondere fuer Funksprechanlagen

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2437027A (en) * 1943-01-12 1948-03-02 John H Homrighous Time division multiplex communication system
US2434697A (en) * 1943-09-28 1948-01-20 Charles H Homrighous Time division multiplex telephone system
US2517265A (en) * 1947-07-18 1950-08-01 Wald George Multichannel television system
US2534842A (en) * 1947-10-10 1950-12-19 Panoramic Radio Corp Dual synchrometric system
US2690473A (en) * 1949-07-16 1954-09-28 Times Facsimile Corp Facsimile recording system and apparatus
US2698875A (en) * 1950-03-24 1955-01-04 Magnecord Inc Plural track magnetic recording and/or reproducing apparatus
US2773120A (en) * 1950-11-30 1956-12-04 Rca Corp Magnetic recording of high frequency signals
US2826634A (en) * 1951-04-14 1958-03-11 Atkinson Method and means for magnetic reproduction of pictures
US2860179A (en) * 1953-11-25 1958-11-11 Servo Corp Of America Video-display devices
US2816157A (en) * 1954-09-20 1957-12-10 Technicolor Motion Picture Magnetic tape-to-film photographic system
US3148242A (en) * 1956-10-19 1964-09-08 Lee A Collins Method of television transmission and reception
US3187314A (en) * 1959-09-01 1965-06-01 Frederic W Olmstead Electromagnetic resolver

Also Published As

Publication number Publication date
GB292632A (en) 1928-06-26
DE500722C (enrdf_load_stackoverflow)

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