CN1219077A - Signal scrambling method for cable television charging system - Google Patents

Abstract

The present invention belongs to the charging management method of cable television sytsem, and features that through changing the field strength entering television receiver periodically, the V-hold and H-hold are interfered, and the television program can not be viewed normally. The method is simple, low in cost and low in power consumption.

Description

Signal scrambling method for cable television charging system

A kind of signal scrambling method for cable television charging system belongs to cable television system toll administration using method.

Present cable TV is the TV signal that cable TV station receives satellite earth receiving station, through frequency mixer, cable or optical cable, amplifier, decoder, cross fluidic distributor, branch distributor is to the user, the cable TV signal that sends is logical, breaking can only be at whole residential building building, can not be at a certain user, therefore, if the individual user does not pay license fee in certain residential building, the also bad processing of cable TV station, the interests of sacrificing TV station send signal, the whole building of interests of sacrificing most of people does not send signal, in order to address this problem, the way that at present existing people sets about developing by scrambling makes the user who does not pay dues can not normally watch pay TV, method mainly is that TV station uses the scrambler scrambling when sending TV signal, the user is by descrambling taximeter descrambling, just can watch the TV of all scrambled channels in the time in predetermined rating.Disclosed on March 6th, 1996 as Chinese patent, name is called: pay TV message accounting scrambler and descrambling taximeter thereof, applicant: Sijia Electronic Technology Co., Nanjing, application number: 94242661, this pay TV message accounting scrambler and descrambling taximeter thereof, be provided with monolithic computer in it separately, scrambler also includes buffer, clamp circuit, scrambling forms circuit, the buffering output circuit, synchronizing separator circuit, the scrambling time sequential pulse forms circuit, communication interface, pulse modulator, hybrid circuit, the descrambling taximeter also includes tuner, processing circuitry of intermediate frequency, the buffering input circuit, clamp circuit, descrambling circuit, audio buffer, synchronizing separator circuit, the descrambling time sequential pulse forms circuit, video output, demodulator circuit, the radio station is carried out scrambling by scrambler to television channel, and the user just can watch all scrambled channels within the predetermined time by descrambling taximeter descrambling.And for example, the Chinese patent of University Of Tianjin's application, name is called: fee-monitoring and controlling system for wire television, application number: 93120654, the day for announcing: June 14 nineteen ninety-five, this fee-monitoring and controlling system for wire television, mainly comprise the microcomputer, modulator, blender, transmission circuit, signal distributor, decoder and the customer controller that are used for outputting data signals, decoder and customer controller are subjected to cable television system front end and control of microcomputer, can make the user's that do not pay dues cable TV signal circuit be in off state easily, thereby reach the purpose of paid service management.Above-mentioned two kinds of catv charge-management method and systems are a kind of to be the method that adopts the scrambling descrambling, a kind of is to adopt the method for turn-offing, all can reach the purpose that the user that do not pay dues is individually imposed sanctions upon, but it is complicated that the subject matter that exists is method, system, the cost height, the power consumption height has influenced itself promotional value.

Purpose of the present invention just is, overcomes the deficiencies in the prior art, provides a kind of simple in structure, and cost is low, and is low in energy consumption, convenient-to-running cable TV signal method for scrambling.

The objective of the invention is to realize in the following way:

This cable TV signal method for scrambling is characterized in that: by control the field intensity implementation cycle property variation that enters television receiver is realized to field synchronization or the synchronous interference of row television receiver normally being watched.

Purpose of the present invention also can realize in the following way:

Described scrambled signals makes the attenuation 〉=10db of radiofrequency signal.

Describedly the field intensity implementation cycle property variation that enters television receiver is realized field synchronization or the synchronous interference of row by control, cable TV station sends signal by management computer, by the intelligent controller in the intelligent branch distributor scrambling switch is controlled, the scrambling switch is controlled user's television receiver again.

Described scrambling switch can adopt two-stage or multistage, and when the back level control end of scrambling switch was implemented to disturb, the prime control end was implemented to turn-off simultaneously.

As everyone knows, television receiver is reduced to image with radiofrequency signal and need goes synchronously and field sync signal, if lose one of them or one of them be interfered, television receiver just can't normally be watched, the asynchronous meeting of row makes image perpendicular line occur, and an asynchronous meeting makes image band occur.Therefore as long as one of them synchronizing signal is implemented to disturb, can reach the user watched purpose of control, cable TV signal method for scrambling of the present invention, be exactly by pressing the method for some cycles change field intensity, promptly the scrambling switch is controlled by the intelligent controller in the intelligent branch distributor, make television receiver can not get the efficient synchronization signal and can't go back original image, reach the user watched purpose of control, therefore this method is very simple, system is simple, cost is low, and is low in energy consumption, and the user easily accepts.

Fig. 1 is a signal scrambling method for cable television charging system theory diagram of the present invention.

Fig. 2 is signal scrambling method for cable television charging system intelligence branch distributor circuit theory diagrams of the present invention;

Fig. 3 is a signal scrambling method for cable television charging system scrambling switching circuit theory diagram of the present invention;

Fig. 4 is a signal scrambling method for cable television charging system scrambling switching circuit schematic diagram of the present invention;

Fig. 5 is a signal scrambling method for cable television charging system scrambling switching circuit schematic diagram of the present invention;

Fig. 1-the 5th, signal scrambling method for cable television charging system of the present invention is implemented preferred plan, is described in further detail below in conjunction with the enforcement of accompanying drawing to signal scrambling method for cable television charging system of the present invention:

As shown in Figure 1, signal scrambling method for cable television charging system of the present invention, implement by cable television charging system, in order to realize this method, this system design has microcomputer as management host, its output control signal enters frequency mixer and the mixing of TV TV signal by modulator MC2831, the signal of frequency mixer output by optical cable or cable to line amplifier, decoder MC3372, cross fluidic distributor, arrive user's television receiver by intelligent branch distributor at last, signal scrambling method for cable television charging system of the present invention is, when the user normally pays dues, host monitor is normal, do not send interference signal, the user is TV reception normally, when main frame finds that by monitoring the user does not pay dues or pay dues deficiency, main frame is exported a control signal and is given intelligent branch distributor, the intelligent controller control scrambling switch of intelligence branch distributor changes the radiofrequency signal field intensity, and the row of television receiver or field are asynchronous, television image can not reduce, perpendicular line or band appear in screen, and the user can not normally teleview, and supervises as early as possible and pays dues.

Shown in Fig. 2-3: to television receiver, intelligent controller links to each other with the scrambling switch TV signal by the scrambling switch, when scrambling switch off-state, as long as make radiofrequency signal attenuation 〉=10db, therefore, be very easy to realize by electronic circuit, and cost is low, and is low in energy consumption.

R among Fig. 2 ₁～R ₇Resistance C ₁～C ₈Electric capacity BG ₁, BG ₂Transistor

IC ₁Integrated regulator, IC ₂, IC ₃Can heavily trigger monostable circuit, IC ₄Monolithic computer, IC ₅Be EEPROM, the scrambling switch adopts the radio-frequency (RF) switch element circuit of system support design.

As shown in Figure 2: demultiplexer comprises: L ₁, IC ₁, C ₁, C ₂, C ₃, C ₄

Amplifying circuit comprises BG ₁, BG ₂, R _1-4, C ₅

Shaping circuit comprises IC ₁, IC ₂, IC ₃, IC ₆, IC ₇, R ₅, R ₇, C ₆, C ₈

Intelligent controller comprises IC ₄, IC ₅

By the mixed signal that the prime controller sends, import through input, by L ₁, C ₁, IC ₁The demultiplexer of forming, radiofrequency signal wherein is because of L ₁The induction reactance effect can not pass through, by capacitor C ₂Be coupled to the input of branch distributor, distribute through branch distributor to export the scrambling switch to, deliver to user's television set by the scrambling switch.Control signal wherein owing to adopted the intermediate frequency transmission, can be passed through L ₁, C ₁The filter circuit of forming.Through transistor BG ₁, BG ₂Two-stage is sent by can heavily triggering the monostable integrated circuit (IC) after amplifying ₂The shaping circuit shaping of forming is reduced to modulation signal, by the monostable circuit IC that can heavily trigger ₂An end export monolithic computer IC to ₄Serial port, meanwhile by IC ₂Q end export to and can heavily trigger monostable circuit IC ₃, as long as there is IC in control signal ₃Q end output low level to single-chip microcomputer IC ₄P3.1 end, end is as detecting control signal, if control signal sends continuously, the P3.1 end keeps low level, single-chip microcomputer IC ₄To receive control signal continuously, finish if control signal sends, by the monostable circuit IC that can heavily trigger ₃Q end upset be high level, when P3.1 end during for high level, single-chip microcomputer IC ₄To enter dormant state, no longer receive control signal.

Single-chip microcomputer IC ₄The state of its reset terminal R is depended in control from the resting state to the accepting state.Before the control signal emission, at first send a wake-up signal by the prime controller, this signal connects through amplifying circuit, shaping circuit can heavily trigger monostable circuit IC ₃Q end, and by IC ₃Q end output high level.Via capacitor C ₈, resistance R ₇The delay circuit and the two not circuit IC that form ₆, IC ₇The shaping circuit of forming is at not circuit IC ₇Output output high level, make single-chip microcomputer IC ₄Reset (waking up) IC ₄Serial port RXD just can begin to receive control signal.As mentioned above, can heavily trigger monostable circuit IC if transmit control signal in succession ₃Q end will keep low level, thereby guarantee that the RXD end continues reception.Finish when control signal sends, P3.1 test side level by low change height after, single-chip microcomputer IC ₄To enter resting state, the RXD end no longer receives control signal, IC ₄After entering resting state, its operating current will be reduced to several milliamperes by tens milliamperes, thereby realize low-power consumption work.

Its effect of intelligent controller among Fig. 2 is to make the scrambling switch by the some cycles break-make, when field sync signal is implemented to disturb, its switching frequency all can be subjected to good effect in the 70-1000HZ scope, when switching frequency was high, the screen band was thin and close, when switching frequency hangs down, the screen band is thick and rare, under higher frequency, can form interference synchronously simultaneously to field synchronization and row, block picture appears in screen.

As shown in Figure 3: the scrambling switch that adopts in the signal scrambling method for cable television charging system of the present invention is a radio-frequency (RF) switch, can adopt two-stage or adopt Multistage Control, when the control end of radio-frequency (RF) switch and control end 2 add high level, radiofrequency signal is also interference-free, can all pass through, television receiver can normally be watched.When the needs scrambling is controlled, add low level (shutoff control level) at control end 1, the oscillator signal that is added in control end 2 this moment both can have been realized disturbing.

Fig. 4-the 5th, signal scrambling method for cable television charging system scrambling switching circuit schematic diagram of the present invention is a most preferred embodiment of the present invention, as shown in Figure 4: D ₁, D ₂Be two switching diodes, C ₉, C ₁₀Be coupling capacitance, R ₈, R ₉, R ₁₀Be biasing resistor, IC ₈For or the door, when control end is high level, D ₁Conducting, D ₂Also conducting though the other end of OR circuit also is added with oscillator signal at this moment, can not form interference to radiofrequency signal, can normally teleview; When control end is low level, D ₁End, radiofrequency signal is attenuated, D ₂With or the door IC ₈Added oscillation signal frequency is done periodically break-make, thereby forms the purpose to the TV signal scrambling.Because of D ₁End, can avoid the interference of oscillator signal to adjacent channel.

As shown in Figure 5: D ₃, D ₄Be two switching diodes, C ₁₁, C ₁₂Be coupling capacitance, R ₁₁, R ₁₂, R ₁₃Be biasing resistor, when control end 1 added high level, control end 2 added oscillator signal, D ₃, D ₄All be in conducting state, radiofrequency signal can be passed through, and can normally teleview; When control end 1 adds low level, D ₃End, radiofrequency signal is attenuated, and adds oscillator signal at control end 2, can realize the purpose to the TV signal scrambling.Simultaneously owing to D this moment ₃End, effectively avoided the interference of oscillator signal that control end 2 adds again adjacent channel.

Claims (4)

1, a kind of signal scrambling method for cable television charging system is characterized in that: by control the field intensity implementation cycle property variation that enters television receiver is realized to field synchronization or the synchronous interference of row television receiver normally being watched.

2, signal scrambling method for cable television charging system according to claim 1 is characterized in that described scrambled signals makes the attenuation 〉=10db of radiofrequency signal.

3, signal scrambling method for cable television charging system according to claim 1, it is characterized in that describedly the field intensity implementation cycle property variation that enters television receiver being realized field synchronization or the synchronous interference of row by control, cable TV station sends signal by management computer, by the intelligent controller in the intelligent branch distributor scrambling switch is controlled, the scrambling switch is controlled user's television receiver again.

4, signal scrambling method for cable television charging system according to claim 3 is characterized in that described scrambling switch, can adopt two-stage or multistage, and when the back level control end of scrambling switch was implemented to disturb, the prime control end was implemented to turn-off simultaneously.

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