FR2466158A1 - TERMINAL UNIT POWER SUPPLY DEVICE OF CABLE TELEVISION DIFFUSION DEVICE - Google Patents

Abstract

The invention relates to a device for cutting off the power supply to the terminal units of a device for broadcasting television by cable. THE CENTRAL PROGRAMS BROADCAST STATION PERIODICALLY EMITS DATA SIGNALS TO THE TERMINAL UNITS, POSSIBLY CONTAINING A POWER OFF MESSAGE ASSOCIATED WITH A UNIT ADDRESS. WHEN THE RECEIVED UNIT ADDRESS CONFLICTS WITH THE STORED ADDRESS, A TERMINAL UNIT DEVICE SHUT OFF THE POWER TO THE CORRESPONDING TELEVISION RECEIVER. THE INVENTION APPLIES IN PARTICULAR TO THE BROADCASTING OF TELEVISION IN HOTELS.

Description

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I

  The present invention relates to a device for

  community-based cable television and, more

  particularly, a device for

  intended for terminal units of the television set, capable of

  source of power for all television receivers

  the associated data, depending on a data signal

  trants applied to them by a central post.

  It is known that a device for broadcasting tele-

  cable vision is a means of extre-

  advantageously capable of broadcasting television programs on several channels by a cable, and

  simultaneously enabling bidirectional

  tional. In this case, the television receivers each associated with a terminal unit are controlled

  individually to receive the desired programs

  your. The terminal unit controls the tele-

associated vision.

  There are cases where the users of the receivers

  of television leave them running after

  grams are terminated, for one reason or another, or that people who are not authorized use

  machines. This is disadvantageous in

  identifies the energy saving and longevity of the devices. Since the interruption of the source

  individual television receivers

  is usually not done at the central station,

  but to the terminal units, the problem referred to

above is impossible to solve.

  For this reason, the object of the invention is to

  install a power cut-off device for the terminal units of a cable television set,

  able to cut positively and forcefully

  connection of the power source of the

  associated with the terminal units, in addition to

  putting a data signal that contains an instruction

  power source shutdown, from the central station of the unit to the terminal units,

  thus allowing the remote control of the receivers.

  Other features and advantages of the invention

  will be better understood from reading the description of

  following example of an embodiment and with reference to the accompanying drawings in which:

  Fig. 1 is a diagram of a set of distribu-

  cable television installed in a hotel and

  according to an example of the method according to the invention of

  particular channels in this set, FIG. 2 is a schematic diagram of the cable TV distribution device, FIGS. 3A to 30 are more detailed diagrams of a terminal unit of the cable television broadcast assembly,

  Fig. 4 is a plan view of the communication unit

terminal unit.

  In the embodiment to be described, a terminal unit comprising a television receiver is installed, for example, in each of the rooms of a hotel so that customers can watch

  different programs on the receivers. Communi-

  bilateral agreements can be established between

  TV receivers and a central post installed in the hotel. Fig. 1 schematically represents the interior of a hotel. A television receiver 3 forming part of a terminal unit is installed in each room 2 of the hotel 1. The television receivers 3 are connected by a cable 5 to a central station 4 which will hereinafter be called a "center" . Hotel 1 has a room

  6. A calculator 7 in this room 6 is

  connected to the center 4 by a data cable 8. A display unit 10 is provided on the facade 9 of the hotel and

  it is connected to the computer 7 by a data cable

  11. An antenna 12 is installed on the roof of

  the hotel to receive commercial broadcast signals

  television, and is connected to the center 4.

  In this set, guests in rooms 2 of the H8tel 1 can watch and listen to programs

  television by maneuvering the receivers 3. The

  television broadcast signals received by the antenna 12 are retransmitted by the cable 5 to the receivers 3

  and, in addition, programs that are established independently

  in the center 4 are also transmitted to the receivers 3. If any of the

  Television 3 is operated, these conditions of use

  are transmitted by the cable 5 towards the center 4.

  In other words, the time of use and the channel used

  are communicated via data cable 8 to

  caleulator 7 and y are stored therein. The times of use

  are added by the calculator 7 of

  that when the client leaves the hotel, he is

  charged for use, as shown by the unit of

  10 at the reception desk.

  my specials are produced for TV channels

  if we. In the event that these television channels are used

  When used by a customer, the periods of use of these channels are added so that the customer is also taxed for special programs when leaving the hotel. Fig. 2 represents in more detail the network of

  two-way data telecommunication of the mode of

  of fig. The center 4 comprises a source group 20 comprising a demodulator 21, an image disk reader 22, an image band reader 23 and a studio 24. The antenna 12 is connected to the demodulator 21. The center 4 further comprises a demodulation output section 25 comprising an intermediate frequency modulator circuit and a converter circuit 27. The output of the converter 27 is connected to the

  5. The latter is connected to a data transmitter

  28 and to a data receiver 29, which itself

  to a data analyzer 30. A portion of the output signal of the data analyzer 30 is applied, as an instruction signal, to the data transmitter

  28 while the other part is applied to the calculation

  7 by the data cable. The calculator 7 is

  connected to the display unit 10, for example an im-

  Primante. Branching units 31 are provided in

  specific points of the cable 5 and cables of

  32 from each branch unit 31 to the respective rooms 2 in the hotel. A unit

  terminal 35 is constituted by a tele-

  vision 3, a main unit 33 and a communication unit

  34. The connection cables 32 are connected

  to the main unit 33 in each chamber 2.

  The circuit of the terminal unit 35 is shown

  in fig. 3A. The main unit 33 comprises in

  a branch filter 36, a filter 37, a

  channel cooler 38 and a filter 39. The filter of

  branch 36 is connected to the branch cable 32.

  The output terminal of the filter 39 is connected to the

  television receiver 3. The service filter 36

  is further connected to a data receiver 40

  trants and to an outgoing data transmitter 41 which are both connected to a control circuit 42

Communication.

  The communication control circuit 42 includes

  a series-parallel converter 42-1 shown in FIG. 3B, which receives serial coded data

  g from the receiver of dongnes 40 and the conver-

  in a signal coded in parallel. The signal in

  The output generated by the converter 42-1 is stored

  se in a memory 42-2. The memory 42-2 also contains address codes corresponding to the respective rooms of the hotel. At the time of a query,

  an address signal provided by the center 4 is compa-

  d with the address stored in memory 42-2 and,

  if there is a coincidence, a reply is sent to the cen-

be 4.

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  An output of the memory 42-2 is connected to a decoder 42-3 of instruction signals whose function is to demodulate the instruction signal or other provided by the center 4 and stored in the memory 42-2. In the case of a message channel instruction from the center 4, the decoder 42-3 transmits a control signal k corresponding to the message channel to the tuning voltage generator 54 and, if the power supply is not applied to the television receiver 3 at this time, it controls a flip-flop circuit 42-4 which delivers a signal

  control c indicating the excitation of the relay of

  45. At this point, a function information

  The output of the power sensor 44 is supplied to a flip-flop circuit 42-5 and compared with the contents of the memory 42-2 to obtain a coincidence.

  with the control signal by which the relay of

45 is excited.

  A power cord 43 which is connected to a commercial power outlet is connected by a power sensor 44 and a power supply relay 45 to the television receiver 3. The power sensor 44 and the power supply relay 45 are connected to the circuit

42 of communication control.

  The control unit 34 has wne section 46 of

  channel button, answer buttons 47, an inter-

  power switch 48 and a message lamp 49 which

  are all connected to a function detection circuit 50

  which in turn is connected to circuit 42 of

aforementioned power control.

  The operation detection circuit 50 comprises

  a data transceiver 50-13 (n circuit board)

  eg 50-2 and a 50-3 key encoder, as shown in

Fig. 3C.

  When the channel button 46 is changed when the

  response muting 47 is closed or when the power switch 48 is closed information indicating the fact is provided to the key encoder 50-3 which delivers

  serial data output indicating the manual cor-

  noeuvré. These serial data are applied to the transmission

  data receiver-receiver 50-1 by which the signal of

  order has indicated the status of the 46 to 48 resellers

  is sent to the control circuit 42

  munication. Fig. 4 represents the upper part of the unit

  34. The central part of the communication unit

  Mande 34 is a channel array 51 consisting of blocks arranged in three rows and eight columns. of the

  line buttons 52 arranged vertically in a row.

  There are provided on the left of the channel table 51 and column buttons 53 arranged horizontally in a row are provided below the channel table 51. The row buttons 52 and the column buttons 53 are provided respectively for the blocks of the table. 51. In other words, section 46, supra

  channel buttons have buttons 52 and 53.

  Response buttons 47 arranged vertically in

  one row are provided to the right of the table of

  51. The message lamp 49 is provided above

  response buttons 47 and the power switch

  tation is below the answer buttons 47.

  The number of the line buttons 52 in the present example is equal to 8, the number of the column buttons 53 is equal to 3 and the number of the answer buttons is equal to 5.

  The embodiment of the invention described above

  above works in the way that will be explained above.

  after, successively for the different sections.

  With regard to the transmission of

  from Center 4, different TV programs

  are produced simultaneously in the group

  source 20 and the corresponding image signals are

  plicated at section 25 of modulation output. Television programs produced by the source group may be classified as a taxed program, as a program

  guidance and information, and in retransmission

  mission as described below. Eight channels

  are planned for each of these three types of programs.

  In other words, 24 channels are available.

  With regard to the taxed program, this program

  includes new film programs and

  special programs, that is, programs produced from the disc player 22 or the tape player 23, or direct broadcast programs produced

  in the studio 24. A user who has watched

  taxed grams is charged according to the number of times

  or how long he looked at them.

  With regard to the program of guidance and

  training, this program contains various guidance and information programs that are useful to the client of the hotel, for example those concerning

  hotel, city walks, telephone calls

  weather forecasts, traffic information and news. These programs are issued

  repetitively throughout the day.

  With regard to retransmission programs

  television broadcast signals received by 2466158 t

  antenna 12, after having been demodulated by the demodulator

  21, are applied to the modulation output section 25. In this operation, the programs broadcast by the local television stations are retransmitted as they are. In other words, the programs are strictly identical to those received by the receivers.

  normal television are broadcast.

  The television program image signal is applied by the source group to the modulation output section in which it is demodulated by the intermediate frequency modulator circuit 26. The purpose of assigning the modulated signal to a specified channel,

  its frequency is increased to a predetermined value

  in the converter 27 according to the frequency

  quence of the channel selected for him. The image signal thus assigned to the respective channel is retransmitted by the

cable 5.

  As described above, the signals of

  24-channel television program mage are trans-

  5. In addition to these 24 channels, there are information channels. These channels can be classified as follows according to their functions: (a) Broadcast Channels Total 24 Channels Channels Charged 8 Channels Channels Guided / Information 8 Channels Channels Retransmitted 8 Channels (b) Channel Procedure 1 Channel (c) Channel number of channels 1 channel (d) Special channels Total 4 channels Rental channels 2 channels Business channels 2 channels Thus, image signals of 30 channels in total

  are transmitted from module output section 25

  to television receivers 3. But each

2466158 '

8.

  terminal unit 35 can only select 24

  not the other 6 channels.

  With regard to the interrogation by the center 4, in the latter, the data transmitter 28 transmits data signals on the cable 5 at intervals

  predetermined, to define the conditions of use

  terminal units 35. Address numbers are assigned to these terminal units 35. The transmitter

  28 individually transmits signals of ex-

  traction at predetermined intervals to interrogate

  terminal units 35 with their

  particulars to detect the channel that is

  received at this time. In response to this interrogation signal

  tion, each terminal unit 35 responds to the center in

  indicating the channel that is received by the receiver at least

  the arrival of the interrogation signal. The addition

  taxes according to the duration of use

  and the calculation of additional fees for

  Special grams can be easily and quickly

  Dement. The data signals from the data transmitter 28 contain instruction signals for controlling the terminal units 35 so that the television receivers can be controlled at the same time.

  distance as described below.

  The operation of the television receiver 3

  or the reception of the image signal will now be de-

  crit. The television receiver 3 starts to function

  by the operation of the power switch

  48. The operation detection circuit 50 de-

  the operation of the power switch 48,

  producing a control signal a.-The signal of com-

  command a is applied to the control circuit 42 of com-

  munication which, in turn, applies to the food relay

  45 a control signal c of the power source

  tation. As a result, the power relay 45

  is excited to power the television receiver 3.

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  The power sensor 44 detects whether the power supply is applied correctly or incorrectly to the television receiver 3 by the power supply relay 45.

  from which it follows that a function information signal

  tioning is applied to the communication control circuit 42 by the power source 44; he is

  thus determined whether the television receiver 3 is

  properly or not fed by the maneuver of the in-

  48. For this operation, it is not necessary to maneuver any command on the

  television receiver. In other words, all the operations

  necessary for the television receiver 3 to receive the image signals are made on the control unit 34. For this purpose, the selector

  of channels of the television receiver 3 is adjusted

  The center 4 transmits the image signal via the cable 5, the branch units 31 and the bypass cable 32 to the main units 33. The image signal is applied by the branch filter 36 and the filter 37 to the channel converter 38 in the main unit 33. The frequency of the image signal is converted into the frequency of the particular channel by the converter of

  channels 38 and is applied to the television receiver

  3 by the filter 39. The image signal is reproduced

  from the television receiver on which the

gram can be watched.

  With regard to the selection of channels, a

  The desired level can be selected by pressing one of the line buttons 52 and one of the column buttons 53

  of the control boot 34 shown in FIG. 4.

  In other words, one of the blocks of the channel table 51 can be selected in this way. This maneuver corresponds to the operation of the channel button section 46, this operation being detected by the operation detection section which, accordingly, delivers

  the control signal a. The control signal a is

  connected to the communication control circuit 42 which, in turn, applies a channel signal to a tuning voltage generator circuit 54 so that a tuning voltage i corresponding to the selected channel is

  produced. The tuning voltage i is applied to the conver-

  channel weaver 38. The latter produces a signal of os-

  local cillation, the frequency of which corresponds to the

  tuning i, so that the frequency of the signal i-

  received mage is converted to that of the selected channel.

  The local oscillation frequency j of the converter of

  channels 38 is returned to the circuit 54 generating voltage.

  tuning, thus forming a locking loop

  phase to stabilize the frequency.

  As explained above, the receiver

  television 3 is activated by maneuvering the in-

  48. In this operation, whichever channel is selected by section 46

* channel button, the control circuit 42 of the

  nication feeds the tuning voltage generator 54 so that the B-1 guide and information channel

  be granted. After the agreement of channel B-1, the guide of

  use of the television distribution device is displayed, as well as the maneuvering instructions of the

  the control unit to receive different programs.

  flares, as shown in Table I. This allows people who are unfamiliar with the TV distribution system to easily understand

  how to maneuver and avoid improper operations

  ronées. After the operating instructions have been displayed with the B-1 channel, the line buttons 52 and the B and C column buttons (among the buttons

  column 53) are selectively manipulated to receive

  see the guidance and information programs as well

  than retransmission programs.

TABLE I

  HOW TO USE THIS TELEVISION? This receiver can be turned on as follows: first, operate the switch ...

LIST OF PROGRAMS OF THE DAY

1. 2. 3.

4.

5.

  Taxed programs may be received by

  button A in the column buttons 53.

  In combination with the row buttons 52, the

  grams charged with 8 channels can be received. Since customers can not know that the channels in column A are taxed, it is necessary to

  inform them that these programs are taxed, a-

  before they receive them. This is done by displaying the message "You will be taxed for the use of this channel", or similar, to avoid any problem that may arise when asked to pay to

reception for these programs.

  In other words, even if after the control instructions of the device have been introduced with the channel B-1, one of the taxed programs is selected by the operation of one of the row buttons 52 and the button A of the buttons column 53, the taxed program so selected can not be received immediately and a confirmation or caution message, shown in Table II, is displayed on the screen of the television receiver. This display is done by the channel of

2466158 1

  procedure. When the circuit 50 of function detection-

  transmission to the communication control circuit 42

  the control signal a representing the selection

  of a taxed program, the control circuit 42

  munication controls the voltage generator 54 to enable the converter to operate.

  channels 38 so that the procedure channel is received.

  When the receipt of the taxed program has been confirmed, a definite procedure is executed, that is, in this case, the customer intends to receive

  the taxed program. The procedure is for example the following

  : (a) When selecting a taxed channel, the display

  confirmation message appears on the reception screen.

  TV and the message lamp is on.

  (b) The message lamp is off.

  (c) Then, among the response switches 47, a specified switch is operated once or twice.

TABLE II

AT T AND I 0 N

  Programs are taxed and each channel

  has its own tax per use.

  1. 20 francs 5. 16 francs 2. 10 francs 6. 14 francs 3. 10 francs 7. 12 francs 4. 6 francs The procedure for receiving programs

is the following.

  With the operations mentioned above, the

  Customer's desire to receive the program may be

  confirmed and the taxed channel is made accessible to him. Au-

  in other words, the communication control circuit 42 determines the client's intention from the signal of

  data b from the generator 54 of voltage ac-

  cord and it applies to the channel converter 38 a predetermined tuning voltage corresponding to the channel of the taxed program. The taxed program can thus be received. If, when the present taxed program being received is replaced by another taxed program, the same procedure as that described above is carried out and it can be confirmed more positively than the

receipt of the program is taxed.

  With regard to the operation of the

  message, this channel is used to allow the

  particular information on the whole of the

  face or a particular part of the surface of the

  notch of the television receiver. For example, he can

  It is necessary to inform all customers of the

  rition of a fire. In this case, if a message such

  that of Table III appears on the screen, the

  hotels know by their TV receiver

a fire broke out.

TABLE III

FIRE!

  8th floor Evacuation by the right Direction

  For the transmission of this information, the

  28 of the data center 4 applies a data signal containing the message information to all

  main units 33. This data signal is

  plicated as data g, to the circuit 42 of

  communicating via the branch filter 36 and the data receiver 40 so that the communication control circuit 42 applies the control signal h to the tuning voltage generator 54; thus, a tuning voltage i corresponding to the frequency of the message channel is applied to the

  channel converter 38. As a result, a receiver

  television receiver that receives any channel is obliged to receive the message channel. In the case o

  the television receiver is not switched on, the cir-

  baked communication control 42 applies the control signal c to the power supply relay 45 so as to

  turn on the television receiver 3.

  Thus, the information shown in Table III is transmitted to customers by all

television.

  It is sometimes necessary to give a

  especially only an information message. For example, it may be necessary to inform a tourist of a tour package of a particular message as shown in Table IV. In this case, since the

  rooms 2 reserved for the tour package are

  The address numbers of the terminal units of the chambers and the data signal are transmitted by the data transmitter 28 of the center. It follows that

  only the terminal units 35 corresponding to the address numbers are forced on so that the information is

transmitted only to tourists

organized trip.

TABLE IV

  Organized tour Departure tomorrow 8 am Please press button (1) for acknowledgment of receipt. With regard to the response to the message channel, in the case such as that described above o all or part of the terminal units 35 is forced on

  for television receivers to receive the

  wise, it may be necessary to determine whether clients have received the information or not. For this purpose, the center 4 transmits to the terminal units 35 the signal

  of data containing the request for an answer.

  This data signal is applied by the receiver

  40 to the communication control circuit 42

  tion and the control circuit 42 is set to receive

  see an answer. In other words, the data signal

  b is applied to the function detection circuit 50

  to turn on the message lamp 49, so that the preparation for an answer has been completed

  while a message is displayed on the screen of the

  receiver; the specified 47 response buttons can be manipulated by the clients. The operation of the specified response button 47 is detected by the operation detection circuit 50 so that the data signal b is applied to the communication control circuit 42. When the reception of the information has been confined by the operation of the response button 47, the communication control circuit 42 provides the

  data signal f and the control signal e at 18

  data transmitter 41 which in turn delivers the data signal to the center 4. The data signal contains the particular address number to the terminal unit 35. These data signals are received by the receiver

  29 and their content is analyzed by the analysis of

  data lyser 30 so that the terminal units

  who carried out the confirmation of receipt operation

  information can be determined. The re-

  The results of the determination are applied by

  culator 7 to the display unit 10 on which they are displayed immediately, so that the units

  those who carried out the confiscation

  may be known easily.

  When the response knob 47 is operated, the cir-

  communication control cooker 42 applies the signal h to the tuning voltage generator 54 so that the tuning voltage i of the channel which has been received is

  applied to the channel converter 38, which it

  This channel is transferred to the one that has been received. Thus, the same television program can be received continuously, with the exception of

  period during which the information was transmitted.

  In the case where the television receiver 3 has been forced on in the manner described above, the power supply relay 45 is de-energized and stops the operation.

receiver operation 3.

  With regard to the reception of special channels, as described above, the programs of four special channels are issued by section 25 of

  modulation output. But these channels are not in-

  in the channel table 51 of FIG. 4 and, by

  therefore, they can not be received even in maneuver

  These channels can be received by a particular instruction from the data transmitter 28 of the center 4. In other words, data allowing the reception of a special channel are added to the data signals from the receiver. Since each terminal unit has its own address number, the data enabling reception of the special channel can be transmitted to the selected terminal units using the address numbers. Upon receipt of the special instruction, in Terminal Unit 35, the

  communication control circuit 42 applies the

  general to the tuning voltage generator 54 so

2466158 -

  that the particular channel can be received when a channel

  particular is selected by the maneuver of the

  46 channel button. In other words, when

  particular channel, for example the B-8 channel on the

  channel 51, which has been specified in advance is selected, the terminal unit 35 receives the program

  the special channel instead of the program which was originally

  assigned to channel B-8. Thus, in the communication control circuit 42 of the terminal unit 35 which has received the particular instruction, the generator 54

  tuning voltage is conmended, so that the

  TV receiver is tuned to the special channel frequency when channel B-8 is selected. By

  therefore, in a terminal 35 which can receive the

  nal, one of the television programs affected

  on the channel table 51 can not be received.

  Special channels include, for example,

  rented leases and business channels. The rented channels will be described. These are taxed channels that are rented at the time, for example to look in the rooms

  meetings of learned societies, reading meetings

  ture, wedding ceremonies and other meetings.

  In this case, the image signals from the television camera in the studio or in the meeting room are emitted to the modulation output section 25 in which their frequency is converted to that of a special channel, and the image signals processed in this way

  transmitted to the terminal units 35 in the rooms

  2 specified so that customers of these rooms

  can receive the special channel. When the rental time of the leased channel is exceeded, the transmitter of

  28 issues a special end-of-service instruction

  channel with the corresponding address number, so that the communication control circuit 42 is released from the reception of the special channel. The terminal units 35 can therefore no longer receive the leased channel. Business channels are used to give

  individually to Hotel Information Workers.

  instructions, eg the message shown in Table V. If, in this case, receivers

  other than those who are in

  2 clients are used, information or messages can be passed on to employees without benefit to anyone

these employees.

TABLE V

  INTRODUCTION TO THE TELEVISION SYSTEM

BY BIDIRECTIONAL CABLE

  1. Date: September 27, 1979 30 hours to 11:30 am 2. Location: First meeting room

  All directors must participate.

  For confirmation, press button 1

General direction.

  Regarding the response to the special channel,

  in the case described above o a separate instruction

  is issued to allow the terminal unit

  specified to receive a special channel, it is

  that it is necessary to receive a response from the

  of this unit, in relation to the special channel.

  For example, it is sometimes necessary to confirm

  sea whether or not employees of different sections

  have received an informational message. In this case, the

  Terminals 35 are interrogated by the data transmitter 28 to determine whether the response buttons 47 have been operated or not. The results are applied by the data receiver 29, the data analyzer

  and the calculator 7 at the display unit 10 and pea-

  therefore be known immediately. Table VI

  luster a case that requests an answer through the leased channel to a number of buyers in multiple rooms after a meeting in which new items in

  sale were presented. The intentions of the underwriters

  can be determined quickly.

TABLE VI

  Which stereophonic presentation is the best of those presented to you? Push a button of your choice 1. Vertical Stereo 2. Stereo Stereo 3. None TV Receiver Can Be Turned On

  by the feed interruption 48, in the manner described

  written above. If the customer leaves or goes to sleep without opening the power switch 48, the television receiver continues to operate. If, in this case,

  the receiver still works when all the

  are completed, this is undesirable in terms of energy consumption. Therefore, when

  all broadcasts are completed, a signal of

  containing a stop instruction is issued by

  the data transmitter 28 to all the terminating units

  35. This data signal is applied by the

  data receiver 40 to the control circuit 42

  munication. The latter analyzes these data and issues the

  power control signal c to the power relay

  45 to make him fall back. As a result, the supply of electrical energy to the television receivers is suspended. In other words, the receivers

are stopped by force.

  As explained above, when

  television broadcasts ceased, the sources of

  all receivers can be stopped

  simultaneously. But it is sometimes necessary to

  to turn on the power of some of the tele-

  vision during a broadcast because a person other than a customer can enter a free room or a room that is empty because the customer is out, and

  operate the receiver without permission to

  keep a taxed program. In order to avoid this, the

  data carrier 28 applies data signals con-

  holding the terminal unit addresses particular to the latter to interrupt the switches

  Power. Data signals intended for in-

  The power supply is produced periodically, that is to say at short intervals of time, for example a few tens of seconds or a few minutes. Therefore, in the end units of the empty chambers or chambers from which the client is output, the data signal is analyzed by the communication control circuit 42 in order to fall back

  periodically the power supply relay 45. The ter-

  35 is designed so that, even if the receiver

  TV 3 operates by maneuvering the

  comrautateur 48, the power supply is

  periodically. It is therefore impossible to use

  the receiver continuously. In other words, the use

  TV tuner is prohibited without permission or without paying taxes. In the case where a free room is occupied by a customer or when the customer returns to his room, the data signal from the data transmitter 28 is modified to eliminate the address number of the terminal unit 35 of the room, so that the television set 3

  it can be used normally.

  With regard to the summation of rental taxes, as described above,

  images are transmitted by center 4 to all

  terminal stations 35 so that television programs

  vision can be received by the devices.

  Terminal units 35 are detected by periodic interrogation by the data transmitter 28. More particularly, the communication control circuits 42 are individually controlled by the data signals containing the address numbers which are transmitted by the data transmitter 28 so that the conditions of use

  each terminal unit 35 at the time of the interrogation

  are detected. The conditions of use of

  the terminal unit 35 are relayed in the form of the

  data channel f to center 4, by the transmitter of

  41. This data signal is received by the

  29 and it is analyzed by the data analyzer 30, which results in that the conditions of use are stored in the computer 7. Therefore, the periods of use of each terminal unit 35 and the periods The use or the number of times taxed programs have been received can easily be added when necessary and displayed on the display unit 10 when the customer leaves the hotel 1. It can therefore be taxed without problems.

  for the use of the television receiver.

  The invention has been described in its application to a television distribution device in a hotel. But it is obvious that the invention is not

  not limited to this case. In other words, its technical concept

  can be applied to all kinds of premises, such as large apartments, large buildings and

  schools in which a certain number of

  TVs operate simultaneously.

  It is clear from the description given below

  above that, according to the invention, it is possible to

  forcing the power source according to an instruction from the central station when the television sets are operated on the side of the terminal units and left running for one reason or another. It is also possible to turn off the television receivers after a predetermined time (eg 10 seconds) from start-up

  periodically emitting from the center an

  truction of power supply to the central units

  trales (for example every 10 seconds).

  Of course, various modifications may be made by those skilled in the art to the process described and

  illustrated by way of non-limiting example without

shot from the scope of the invention.

Claims (2)

  1 - Cable television broadcasting device in which a central station is connected by cables to several terminal units, and various television programs are transmitted from the central station on the cables to television receivers associated with the units. terminals, characterized in that it comprises a data transmitter (28) provided   in said central station (4) and intended to emit a   of inbound data containing at least one   Power cutoff pull, a receiver (40)   incoming data provided for in each of those   end tees (2) and intended to receive said signal   incoming data, and a device (45) for   provided for in each of those units   terminals to cut off the power supply   said television receivers, said communication device   supply mutation reacting to a data signal   incoming receivers received by said receiver for decon-   to identify the power sources of these receivers of TV.   2 - Cable television broadcasting device   in which a central station is connected by means of   several terminal units in such a way that   television programs are transmitted by the central station on the cables to the terminal units, characterized in that it comprises a transmitter   (28) of incoming data provided for in that central   tral (4) and for periodically transmitting an incoming data signal containing at least one instruction   power supply and an address number of the-   said terminal unit (2), an incoming data receiver (40) provided in each of said terminal units for receiving said incoming data signal and a power cut-off device (45) provided in each of said terminal units, said   power supply responsive to said data   said receiver to cut off the source of   said television receivers when the address information contained in said data signal   Incoming coincides with his own address.