Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/63—Generation or supply of power specially adapted for television receivers

Definitions

• the present invention relates to a device for automatically stopping a TV receiver at the end of a mission.
• Devices of this kind are known: some are integrated into the TV receiver and are based on the detection of the video signal or of line or frame synchronization signals transmitted by the transmitter.
• the object of the present invention is to alleviate these drawbacks by the means claimed.
• the device according to the invention takes the in ⁇ formation necessary for the development of the order to stop the receiver, using an electromagnetic sensor consisting of a coil which is placed in the vicinity of the receiver TV and in which a voltage is induced coming from the variations of the magnetic field of the horizontal and vertical deflection coils with which the TV receivers are equipped.
• the signal thus picked up is then separated into two signals: those from the vertical deflection coil, the TRAME tops, and those from the horizontal deflection coil, the LINE tops.
• the electronic circuit contained in the device according to the invention calculates the correlation between these two signals and, if it does not conform to the correlation which one has during transmission, the stop order (possibly delayed) from the TV receiver is generated.
• the drawing shows, by way of example, an embodiment of the object of the invention and a variant.
• FIG. 1 is a block diagram of a device for stopping a TV receiver station applied to a 625 line / image transmission system.
• Fig. 2 is a perspective view of a variant of the device.
• Fig. 3 is a block diagram of a detail of the circuit of this variant.
• This device comprises a pick-up coil 1 housed in an adhesive box 2 placed in the vicinity of a TV receiver station 3, for example against the rear panel thereof.
• This coil 1 collects, by induction, the variations in magnetic fields produced by the deflection coils of this TV receiver.
• a circuit 4 filters and amplifies the low frequency component of the signal received at 1. The signal thus produced at 4 constitutes the RAME tcps.
• Circuit 4 is followed by a threshold device 5 which is in the high state in the absence of a signal and which oscillates at the FRAME frequency during the signal.
• flip-flop 6, of type 4013 is then set to zero.
• the output of the circuit 5 integrated by an integrating network 7 is low and the state of the flip-flop 6 depends on the value charged with each clock pulse.
• a counter 8, of the 4024 type cooperates with a flip-flop 9, of the 4013 type, in order to divide the frequency of the TRAME pulses by 40 and generate at each zero crossing a pulse charging the flip-flop 6 on the one hand and canceling a counter 10, type 4020, on the other hand.
• a circuit 11 filters, amplifies and shapes the high-frequency component of the signal picked up at 1.
• This same reset signal will at the frame FRAME 8 and at the flip-flop 6.
• Toggle 6 will only be activated if the TRAME counter 8 reaches count 40 within this interval, thus indicating that the ratio between LINE and IMAGE frequencies is 625 to * 0.32 per thousand.
• a similar arrangement could apply to the 525 lines per image system by wiring circuit 12 so that its output is high from count 10496 and circuit 13 so that counter 10 is reset to zero * as soon as it reaches .10505 .
• the output of flip-flop '6 will then be active when the ratio of the LINE and IMAGE frequencies is 525 to 0.38 per thousand.
• the output of the flip-flop 6 is connected to an integrator 14.
• a trigger 15, of the 40014 type goes high and that of an inverter 16 goes low, blocking triacs 37 to cut off one of the phases of the current supply socket of the receiver 3, the other phase being permanently connected to the mains current supply designated by 18.
• This device is reset by closing the ON / OFF button (not shown) on the TV receiver or, if it is closed, by opening it and then closing it again.
• a detector-trigger 19 then switches to the low level, generating a pulse saturating a transistor 20, charging the capacitor of the integrator 14, causing the trigger 15 to toggle and causing the triacs 17 to be driven via the inverter 16, said triacs establishing current in the switchable phase of the TV receiver's power socket 3.
• the tie sor ⁇ of flip-flop 6 high pass now has the charge of the capacitor of the integrator 14, this state is before mainte ⁇ ne until termination of the program.
• the looping of the trigger 15 on the base of the transistor 20 allows on the one hand, at the time of the establishment of the current on the socket of the receiver, to prolong the saturation pulse of the transistor 20 and, on the other hand, at the time by cutting the current on the receiver, inhibiting the pulse generated by the detector-trigger 19 and avoiding perpetual reset.
• a phase locked loop 21 enables LINE tops to be sent regularly to counter 10 even if, at the output of the filtering circuit 11, certain pulses - S -
• phase locked loop located at the output of the threshold device 5 could fulfill the same role with regard to FRAME pulses.
• the presence of these two phase locked loops gives the operator greater freedom in choosing the location of the sensor compared to that of the TV receiver.
• a manual switch 22 when in the open position, called “TEST”, cancels the constant of the integrator 14, which allows instantaneous display, using a control lamp for example, of the output of the flip-flop 6.
• This switch 22 is coupled with a switch 23 which, also in the "TEST" position, shunts the phase-locked loop 21, thus forcing a degraded operating mode of the device, which guides the operator in his search for a favorable location for the sensor.
• the housing 24 has, on its dorsal face, a male plug 26 intended to be inserted in, a wall outlet of the network and, on its anterior face , a socket 27 intended to receive the socket of a TV receiver station.
• the cable 25 is arranged to ache ⁇ mine the analog information received by the sensor 1, the state of the switch 22 and the supply current of the diode 23.
• the diagram in fig. 3 is an example of a diagram usable in the case of the device of FIG. 2.
• the elements taken up unchanged from the diagram in FIG. 1, or counterparts, are designated by the same reference numbers.
• the constitution of the device is described here at the same time as its operation:
• One of the two contact pads of the switch 22, designated by 22, is connected to the integrator 14 like the switch 22 of the diagram in FIG. 1.
• the second pad of the switch 22, designated by 22, is connected to the witness light-emitting diode 23.
• the latter, as well as the inverter 16,. are connected to the triacs 17 by means of a current switch 28.
• the switch occupies its "SEARCH” position, in which its pad 22 is connected at most, the constant of integrator time 14 is canceled. Consequently, according to the result of the measurement, developed at terminal Q of circuit 6, _ the control current of the triacs 17 comes either from the inverter 16, when the measurement is favorable, the diode 23 then goes out , or directly from pad 22.
• the TV receiver 3 remains permanently on. Detecting 'the favorable location of the housing 2 is greatly facilitated by the fact that the warning lamp, in this case the diode 23 is carried by the housing itself, which allows the operator to observe both this indicator light and the position of the housing. Once the latter in place, for example on the rear panel of the TV receiver, the operator brings the switch 22 to the "AUTO" position, activating the automatic stop device of the TV receiver. This gesture is also facilitated by the fact that the switch 22 is also mounted on the housing 2.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
• Details Of Television Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4226505

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (3)

• 1982
  • 1982-03-23 EP EP82900787A patent/EP0076267A1/de not_active Withdrawn
  • 1982-03-23 WO PCT/CH1982/000046 patent/WO1982003519A1/en not_active Application Discontinuation
  • 1982-03-24 IT IT8248080A patent/IT1210678B/it active
  • 1982-03-29 ES ES510896A patent/ES8304741A1/es not_active Expired

Non-Patent Citations (1)

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