JPS60171886A - Charging method - Google Patents

Abstract

PURPOSE:To read and display a charge data as required by receiving charge information in response to the content of a program in a form of digital signal at each prescribed time, and writing a charge data to a nonvolatile memory. CONSTITUTION:When a receiver 16 receives a satellite broadcast, an IDU19 amplifies and detects it and outputs a signal of base band. A data processing circuit 20 processes in the output and supplies it to a descrambler 21. The descrambler 21 switches inversion or non-inversion of the image and rearranges each bit of the digital sound signal and restores the result into the normal image and sound. Furthermore, a charge is commanded by a control signal superimposed on the video signal of the program in the data processing circuit 20 and recorded in a memory.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a billing method that can be used in a unidirectional signal transmission and reception system such as satellite broadcasting.

Conventional configuration and its problems In a unidirectional signal transmission/reception system such as satellite broadcasting, in order to operate the terminal receiver in the same way as when receiving a pay program on CATV, it is necessary for the viewer to pay for the viewing fee in a deferred manner. It is necessary to make the viewer pay, and if the payment is inadequate, it is necessary to make the viewer's terminal unable to receive reception.

These are implemented in pay television in interactive CATV systems.

However, in the case of the CATV system, a request for viewing pay TV is made to the transmitting side via uplink or telephone, so this cannot be used for a one-way system such as satellite broadcasting. Furthermore, when a large number of subscribers applied to the sending side all at once, the capacity of the telephone line was exceeded and the processing capacity of the receiving side of the sending side was exceeded.

An example of the configuration of such a conventional example is shown in FIG.

In the figure, reference numeral 1 is the central computer of the CATV station, which manages subscriber viewing fee payment status, specification of broadcast programs according to subscriber requests, and creation of control codes. The control code is added to a video signal from a studio or the like and sent out. 3A sends out a plurality of video signals from the CATV center 2 in line with, for example, a VHF midband at its head end. 3B is a buffer circuit that receives upstream signals from each terminal, and the head end 3A, the tuner/converter 4 on the CATV terminal side, and the buffer circuit 3B are connected by the same cable or another cable. A telephone line may be used instead of the cable from the /converter 4 to the buffer circuit 3B.

4 is a tuner or converter on the terminal side that converts a mid-band signal to one channel (or two channels) of VHF, and according to a command from the keypad 6, converts one channel of the mid-band CATV signal to VHF.
1 channel. Note that if the CATv signal is scrambled, it may be converted once to a baseband signal, descrambled, and then converted to an RF signal again and output as a VHF 1-channel signal.

Reference numeral 6 denotes a television receiver that receives a normal VHF band.

A viewer applies for a desired program (charged) to the center computer 1 by operating the keypad 6 or via the telephone. At the center 1, charges are set for each terminal, and if the terminal is scrambled, the decoding key code is sent in the order of the center computer 1 → CATV center 2 → head end 3 → converter/tuner 4. Then, this kill code is used to descramble the signal, reproduce the NTSC video signal of a normal image, convert it to one channel of VHF, and supply it to the television receiver 6. There are a large number of Qi-Qi/converters 4 to telephones 7, and a telephone office is interposed between the telephones 7 and the telephone interface 8. The telephone interface 8 is generally used by a human to listen to requests from each terminal and convert them into input form for the center computer 1. This is an example.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a billing method that can implement a pay television system in a unidirectional signal transmission system such as a satellite broadcasting system.

Structure of the Invention In the present invention, in a unidirectional television signal receiving device such as a satellite broadcasting system, billing information corresponding to the content of a program is received in the form of a digital signal at regular intervals, and this and the television program are The charge amount determination circuit in the receiving device determines the charge amount based on the amount of time the user listened to the video, writes charge data proportional to the amount into non-volatile memory, reads out the charge data in the memory as necessary, and displays it. The feature is that it is displayed on the device.

Also, when charge information for each terminal is sent from the TV program sending side, this charge information is transmitted to the non-volatile memory and compared with the charge information in the non-volatile memory, and the two are matched. The present invention is characterized in that a new key code sent from the sending side can be received in the memory only when the fee sent from the sending side is larger than the fee stored in the non-volatile memory.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
This will be explained in detail.

FIG. 2 shows an embodiment of the present invention. In the figure, 11 is a satellite broadcasting transmission center, which is called a DBS center. 12 is a large parabolic antenna that sends signals to a geostationary satellite 13. 13 is a geostationary satellite, which is a broadcasting satellite that relays signals sent from the ground and retransmits them to the ground. 14 is a receiving antenna installed on the ground. A low-noise converter 16 converts, for example, a 12 GHz band signal received by the antenna 14 into an IGHz band signal and transmits it to the receiver 16.

19 in the receiver 16 is an intermediate frequency demodulator (ID)
For example, if the IGHz band input is 400 MHz
It converts to the second F of z, amplifies it, detects it, and outputs a baseband signal. 2o is a data processing circuit that extracts the output digital signal, processes it, and supplies it to the descrambler 21.

Assume now that the video signal is scrambled using a method of synchronized shifting and randomly inverting the video components, and the audio is scrambled using a method of randomly changing the bit arrangement using digital audio. If the output of the IDU 19 is projected as it is on the CRT of the color television receiver 17, the brightness of the screen will be inverted and the horizontal and vertical synchronization cannot be achieved, so the screen will flow and the content will be unclear. Also, when the audio is heard from the mass beaker, it becomes noise.Therefore, the descrambler 21 switches between inverting and non-inverting the video according to the output of the data processing circuit 2o, and converts the audio digital signal. Reorders each bit to restore normal video and audio (
Descramble).

The A/N reproducing circuit 22 changes the DC level only during the horizontal retrace period during the output of the IDU 19, that is, the portion from t1 to t2 in FIG.
) and the parts t2 to t11 of the original video signal (the third
A) is reproduced, and the digital audio signal output from the descrambler 21 is converted into an analog audio signal.

The output of this A/V reproducing circuit 22 is converted to VH by an RF modulator 23.
By converting the signal into an appropriate F-band channel signal and supplying the output to the antenna input of a normal color television receiver 17, the scrambled video and audio can be viewed in their normal, descrambled state.

If you want to watch such scrambled video and audio back to normal images and sounds, you often have to pay a fee. If there is a charge, the charge is indicated by a control digital signal superimposed on the vertical blanking period (VBL) of the video signal of the program, and the charge is recorded in the memory within the receiver. Generally, if you receive a certain program for more than 2 to 10 minutes, you are often required to pay for the entire program.

To pay the fee, for example, add a card reader to the data processing circuit 2o in Figure 2, insert the purchased card (such as a coupon ticket) into it, and check the amount paid. Data processing circuit 2 only for the time corresponding to
There is a method of sending a descrambling control signal from o to the descrambler 21. Alternatively, you can pay the fee in advance to the bank 18 and send the prepaid fee as data to DBS.
A code representing the paid fee is sent from the center 11 via the geostationary satellite 13 to each terminal (individually assigned an address), and the fee code is written in the memory of the terminal. There is also a method of changing (decreasing) the charge code of , and when it reaches rOJ, paying the money to the bank 18 again and repeating the above procedure.

Now, here, the contents of the data processing circuit 2° in Fig. 2 are configured as shown in 31 to 6o in Fig. 4, and when a pay program is received, it is superimposed on the BL period of the video signal. The charge according to the viewing time is written to the non-volatile memory according to the charge data, every month.

Pay the viewing fee to the bank, poll and send the paid fee from the DBS center 11 for each terminal (each address), reduce the contents of the memory 47, and unless the contents of the memory 47 become rOJ, the next month The system will be such that it will no longer be possible to watch paid programs.

In FIG. 4, 31 shapes the waveform of the binary data signal superimposed on the vBL period during output from the IDU 19 (7) to create a pulse waveform as shown in the left end part of FIG. 6B. This is a useless binarization circuit. 32 is a clock detection circuit, and the 2-byte [IJ, rOJ signal repetition clock run number CR (C1ock Run
) to regenerate a clock synchronized with it, detect the 7-raming code at the 8th bit of the 7-raming code signal FC in the received signal B, and establish frame synchronization.
The sampling clock generated by the sampling clock generation circuit 33 is synchronized with the received signal B. 33 is a sampling RAM 37 with an appropriate phase controlled in this manner.
, work ROM38. center prosaison unitino) (
It forms the main clock that drives the CPU) 39, etc.

From the output of the sampling clock generation circuit 33, FIG.
A clock synchronized with each bit of the received signal B is supplied to the sampling circuit 35, and each bit of the received signal B is sampled. It is difficult to operate the work RAM 37 to CPU 39 in FIG. 4 at this cycle of the received signal B. In addition, when an 8-bit microprocessor is used as the CPU 39, it is more convenient to handle the received data as an 8-bit parallel signal. Therefore, as the sampling circuit 36, a serial input/parallel output type shift register such as 5N74LS164 is used. Are suitable.

The output is changed every 8 bits in the latch circuit 36 at the cycle of the memory with the 8th bit of the framing code as a reference. This cycle is suitable for the operation of each circuit. Its output is connected to line 40.

37 is a work RAM of the CPU 39, 38 is a work ROM of the CPU 39, and the CPU 39 is an 8-bit microprocessor (for example, MB12O3E).

Now, in Fig. 5, the control codes C0°C1 to C in the received signal B
To explain about 7, co and 01 are “1j.

This is a clock run signal CR that repeats "○".

C2 is a framing code signal of rllloo 01J. C3 consists of 4 bits of information, 3 bits of Hamming check code, and 1 bit of parity.

The data after C4 also has the same structure for each byte. The contents of the information section of C3 and 04 are summarized in Table 1. Here, only three types necessary for explanation are described. In reality, several types or more are possible.

Similarly, Table 2 shows the contents of the 4-bit information section of 06.

Table 1 Table 2 In the case of satellite broadcasting, the 8 bits of C3 and C4 are "01000".
000J, C5 is rloooJ, r.

IC) Use either OJ or rl 100J.

FIG. 6C shows a case where 28 bytes of data in the received signal as shown in FIG. 5A is program data. A number indicating the type of program is represented by a 4-byte, 4-digit BCD code as a tag code. Therefore, 9999 types can be specified.

The next keyword is a key code that changes every month. This key code is essential for descrambling the received signal on the terminal side, and this key code will not be sent from the DBS center to terminals that do not pay the fee. You can prevent reception by doing so. For example, assume that the bill payment deadline is the 20th of every month, and the key code is changed from the 1st of every month.The receiver 16 in Figure 2 is always energized, so it will continue to operate unless the power cord is unplugged. .

The next charge code is 4 bytes and contains 4 digits of BCD information. The charge code changes over time, and a charge proportional to the time the program was viewed (the time it was displayed on the CRT) is recorded. This content will be described in more detail later.

The next PN key represents the initial value of the PN code for descrambling the scrambled signal in 4 bytes (16 bits as information).

The first safety measure is to prevent wiretapping using a PN key.

For the next month and day, the month is represented by two BCD digits and the day is represented by two BCD digits, so 5 BOD digits, that is, 4 information bits in 4 bytes are used. The time is also expressed in two-digit BCD, and the minute is also expressed in two-digit BCD. (Program data pack) (When C6 is "1"), the above is the content.

Next, when C6 indicates that scrambled data is being sent with 2J rOoloj,
28 bytes (of which, information data I'i14
All of the bytes) are data, and 14 bytes of information are written to a predetermined location in the work RAM. This data has different contents for each program. There are various possible contents and uses for the scrambled data, but they will be omitted here.

Next, when C6 is r3J rool 1 J, an address data packet is sent in 28 bytes as shown in C". This address data packet consists of two packets in one packet, as shown in FIG. 6C". Contains the address indicating the terminal. This C'' is shown enlarged in Fig. 6.If the first 14 bytes are shown enlarged, it becomes as shown in Fig. 6.D
The information bits in the first 7 bytes are 28 pins out of 7 bytes, and can distinguish 2, or approximately 268 million terminal addresses.

The latter 8 bytes are divided as shown in Figure 6E. E indicates only information bits, that is, 32 bits out of 8 bytes. The 2 bytes at the front end of E (1 byte if only information) is used to send up to 2 instructions from the DBS center to each terminal.
This is for sending up to 55 types, for example, "1" as shown in Figure 6.
If table J is specified, it shows the total amount of pay TV that the terminal has watched so far. If the amount is in 25 cent increments, 210
Up to the dollar can be specified using the 12 bits (1.6 bytes of information in 3 bytes of data) at the right end of FIG. Therefore, when clearing the charge, the amount will be (maximum 1024 dollars 76 cents)
code is sent to each terminal, and on the other hand, the amount paid by the terminal to the bank is sent to each terminal of the DES 7 tanter 11, and the contents of the amount memory 47 of the terminal are changed. Assuming that the amount of money for viewing is written in the amount memory 47 in increments of 25 cents, the amount sent from the DBS center 11 is subtracted from the content, and when the content of the amount memory 47 becomes zero, it is It is detected by the CPU 39 and the key code shown in FIG. 6 is read. If the amount in the amount memory 47 does not become zero,
That is, if the paid-in amount is insufficient, the key code is not inputted, and the scrambled information (images, audio) cannot be decoded and viewed from the next month onward. The amount is written to the memory 47 (i.e., subtracted) once a month,
If the DBS Center 11 sends rate data continuously for about one week at the end of each month and beginning of January, even if you accidentally turn off the power to the receiver, you will not have to turn off the power for at least one day during those two weeks. When connected, the amount to be paid is written to the amount memory 47, its content becomes zero, and the key code can be read. The key code, month, date (time), etc. of writing into the amount memory 47 are written to a non-volatile memo +753 similar to the amount memory 47 in FIG. In the memory 53, the date and time of data writing to the amount memory 47 is stored, and even if the payment is mistakenly paid in two or more installments, the first payment is made.

It is used to manage the data so that it is correctly written into the amount memory 47 the second time...

Next, let's talk about key codes. The key code is composed of 12 bits and indicates a generating polynomial forming the PN sequence of 212-1. For example, rolloooool 0001
If J and the key code are sent, the generator polynomial is xt
t+ x74− z2+ X ” f (x).

It may be a polynomial of 11 bits or less instead of 12 bits. Alternatively, the message in FIG. 6E may be reduced from 1 byte to 4 bits by setting the key code to 16 bits.

Next, the actual operation will be explained. When the terminal device is purchased, the contents of the buffer circuit 46 in FIG. 4 are all zero, so when the terminal (assumed to be X) is supplied with power, it first captures the key code. If the device is purchased in the middle of the 20th century, the DBS center 11 does not perform regular polling of all terminals, so it temporarily polls the number of terminals installed (for example, 10,000) on or around that day. go to As is clear from Figure 6, 1H (horizontal period)
2 terminals can be polled with 6H during the VBL period.
is allocated for polling, 10 terminals/field =
eoo/sec = 36,000/min, and polling of all newly joined terminals is completed within one minute. Therefore, a newly installed terminal can import the current month's key code within about one minute. If installed at the end of the month, the next month's key code will be sent regularly to all subscribers, but if only half of 1H out of 6H of the VBL period is used for polling the current month's keycode of new subscribers, As is clear from the previous explanation (
(36000/10)
Its unique address is given in 28 bits. These 28 bits are scattered in the 256-bit memory to prevent eavesdropping, or they are stored in the work ROM 38 so that the correct address can be obtained by performing arithmetic operations on the 28-bit address code according to the keywords in Figure 6C. Written in part or in a separate chip.

If calculations are to be performed using keywords, it is necessary to receive the packet shown in FIG. 5C. Considering data transmission efficiency, if the same packet is superimposed on all 6H and sent out once every second, the receiving side receives the key code within 1 second and writes it into the work RAM 37. This keyword has 16 bits of information. The second security (prevention of eavesdropping) is achieved by decoding the encrypted data by performing calculations using the keyword on data after the keyword and other data.

After receiving the keyword, it receives a packet in the form of "C" in Figure 6 and searches for the 28-bit address of terminal X. The 28-bit address data sent and the aforementioned work ROM are
When 28 bits of address in 38 match, Fig. 6E
The 8 bytes of are taken into the work RAM 37. Terminal X
Since the content of the amount memory 47 is zero, the MSB of the message shown in FIG. Such a program is stored in the work ROM 38. The following explanation also assumes that the CPU 39 follows the program in the work ROM 38.

In the middle of the month, its MSB is rIJ, so it is 1 of the key code (assuming other bits are ignorable code assignments).
Load 2 bits into work RAM 37 and pass line 4
o to the nonvolatile memory 63, where the words are memorized. Hereinafter, using this 1,000-code,
, C" is decoded.

If the received program is a paid program, the charge code indicates the charge per unit time. For paid programs, it is ideal to charge a fee directly proportional to the viewing time (Charge Y).One way to do this is to charge $6 for a 60-minute program, and 25 cents for every 2.6 minutes. The fee shall be charged separately. Therefore, as a rate code, the content of the code changes every 2.5 minutes, and each time the code changes, 1 bit (equivalent to 25 cents) is supplied to the counters 43 to 46 to generate a pulse corresponding to the viewing time. Counter 43
The output of .about.45 (which represents a multiple of 25 cents) is written via a buffer to an amount memory 47 consisting of non-volatile memory. The amount memory is a non-volatile memory including a 47-digit adding circuit, and is, for example, a 12-bit memory. When the power is turned off, the pantry supports the counter 43 to amount memory 47 for a short time, and the data of the counters 43 to 45 is written to the amount memory 47 via the buffer 46.

Another method is to send the viewing amount as a code every 2 to 5 minutes from the start of the program, and terminal X stores the difference between the first received fee code and the last received fee code in the amount memory 4.
There is also a method of writing to 7. In this case, each time the charge code changes, the unit charge is calculated to detect how many times 26 cents it is, and pulses corresponding to that number are supplied to the counters 43 to 45 via the up detection circuit 41 to the count amplifier. let

In either method, the counters 43 to 46 are set to 1 through the up detection circuit 41 every time a period of time equivalent to 25 cents has elapsed.
Count up bit by bit.

The structure of the amount memory 47 is as shown in FIG.
It has two sets of memories 47A and 47B, and always writes the contents of the buffer 46 to the memo IJ 47A, so that when one program is finished watching (i.e., when changing channels, when detecting an end code, when turning off the power) etc.) memo IJ 47 A
is added to the contents of memory 47B, and the contents of memory 47B are added to the contents of memory 47B.
There is also a method in which the data is stored in the memory 47B, and when read, the data is read from the memory 47B.

Next, the PN key will be explained. As previously mentioned, receiver 16 stores the 12 bits of the key code. There are 16 PN keys, which indicate the lowest bit value, and the four bits near the most significant bit (MSB) indicate how many bits the PN sequence is moved from the initial value. 1 obtained by substituting the 12-bit initial value indicated by this PN key as the initial value of the above-mentioned generator polynomial and shifting it by the number indicated by the 4 pintos.
Using a 2-bit sequence, the video signal is switched between inverted and non-inverted, and the audio signal is subjected to arithmetic processing (audio is quantized to 12 bits), and then descrambled to restore the video and audio to their original state. do.

Another possible method is to shift the PN sequence obtained by substituting the 12-bit initial value by 1 bit every 1H, thereby changing the video and audio decoding method every 1H.

The 2nd day of the month, 2nd time, etc. are stored in the work RAM 37 and used as appropriate.

Next, the fee addition will be closed after one month or on the 10th of every month, and the contents of the aforementioned memory 47B will be transferred to the memory 47C (
It is assumed that the amount memory 47 is composed of three memories 47A to 47C). This is configured to be automatically performed when the message of price display shown in FIG. 6E is received. As the address at this time, it is possible to use a number common to all terminals (special number), or to use a spare one in C5 as a bucket for the address "-Shi".

After the price display message, the key code and price code are ignored.

Upon receiving the price display message, the CPU 39 transfers the contents of the memory 47B of the price memory 47 to the memory 47C, and writes the contents to the brightness memory 49 via the lines 40 and 48.
The work ROM 38 and the CPU 39 convert the contents into numbers) and write the number pattern into the brightness memory 49, so the contents are read out in synchronization with the scanning of the electron beam of the CRT 52 and sent to the CRT through the buffer amplifier 61.
If it is supplied to the RT 53, the charge will be displayed in numbers on the CRT. This is an address circuit that allows the buffer amplifier 51 to have a function of superimposing normal program video and charge information, or to display only the charge.

For terminals that do not pay the displayed fee to the bank by, for example, the 20th of each month, the amount of address control data is set to zero after the 21st of each month, and the polling continues with the key code set to rOJ. As a result, when the key code is changed to a new key code from the 1st of the following month, the terminal will no longer be able to decode data, and scrambled video and audio will not be decoded and cannot be viewed.

Also, if the fee is insufficient, a key code will be sent, but the memo 1J47c will be sent due to the function of the CPU 39 of the receiver 16.
If the content is not zero, the key code cannot be stored in the nonvolatile memory 63 in an appropriate size, so the scrambled video and audio cannot be decoded. In addition, it is extremely easy to automatically display the difference in amount to be paid in case of a shortage of charges.

Next, an example of the charge settlement operation will be explained with reference to FIG. 4. It is assumed that the counters 43, 44, and 45 are CMOS counters (for example, 74LS192), and their input and output are separately connected to the panzer memory 46. When data corresponding to paid charges is sent from the DBS center 11, this data is stored in the work RAM 37. On the other hand, in response to an instruction from the CPU 39, the contents are transmitted to the counters 43-45 via the buffer amplifier 46. next,
According to instructions from the CPU 39, the charge data in the work RAM 3γ is divided into 25 cent increments, pulses corresponding to an integral multiple of 25 cents are supplied to the countdown terminal of the counter 43 via the down detection circuit 42, and the contents of the counters 43 to 45 are Count down by the number of pulses. counter 4
The configuration is such that once the outputs of counters 3 to 46 all become "o", the outputs of counters 43 to 45 do not change any further.

In this state, the outputs of the counters 43 to 46 are written to the amount memory 47 again, and if the outputs of the counters 43 to 45 are all rOJ, it will be possible to receive the key code from next month, and if the output of the counters 43 to 46 is 1. However, if there is only 1 coin, it will be judged that the charge is insufficient and this will be displayed on the CRT52.

With the above configuration, even in a one-sided television system such as satellite broadcasting, a billing method for pay TV broadcasting can be easily implemented, and protection against eavesdropping can be sufficiently secured.

Next, the structure of the amount memory 47 will be explained with reference to FIG. In FIG. 7, a memory 47A is a memory that stores the fee for the pay television program currently being watched, and a memo IJ
47B is a memory that stores the cumulative charges up to that point. As mentioned above, when viewing the program is stopped from the memory 47A, the charge data for that program is added to the adder 47F according to the instruction from the write/read control circuit 47D, and is added to the contents of the memory lj47B. The results are newly stored in the memory 47B.

When it comes time to bill monthly charges, a message indicating the next month's key code as shown in FIG. and clear the contents, and move the contents of memory 47B to memory 47C.Memory 47B
Immediately after being moved to Memo 1J47c, the contents become zero, and the new month's pay program fees begin to be stored. The write/read control circuit 47D and adder 47E are controlled by the CPU 39.
This is implemented by a specific address among the 16 bits of the address signal.

In addition, to prevent eavesdropping, it is possible to customize a part of the program of the contents of the work ROM 38 by putting it in the CPU 39, or by dividing the work ROM 38 into two and using only the address as a fuse ROM, and storing that fuse ROM for each terminal. The contents of the program may be changed, and if the amount of the program is small, it can all be written in the ROM inside the CPU 39.

Effects of the Invention As described above, according to the billing method of the present invention, the following effects can be obtained.

(1) A pay TV system can be implemented in a one-way transmission system.

(2) A fee is charged in proportion to the amount of time a pay TV program is actually watched.

(3) Eavesdropping is difficult.

(4) By changing the viewing time in the minimum unit without changing the minimum unit of charge, the unit price of one program can be determined in small increments.

(6) Good compatibility with teletext systems, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional pay television system, FIG. 2 is a block diagram of a pay television system in which the billing method of the present invention can be implemented, and FIG. 3 is a waveform diagram of a video signal in the same system. Figure 4 is a block diagram of an example receiver used in the same system, Figure 6 is a waveform diagram of a signal used in the receiver, and Figure 7 is a block diagram of an amount memory used in the receiver. It is. 11...DBS center, 12--large parabolic antenna, 13--geostationary satellite, 14--parabolic antenna,
15...Converter, 16-Receiver, 17-...
-Color television receiver, 18...silver, 19...
Intermediate frequency demodulation unit (IDU), 20 data processing circuit, 21- descrambler-122--4/V regeneration circuit, 23-RFi modulation circuit, 31- binarization circuit, 32.
Clock detection circuit, 33 sample clock generation circuit, 34 main clock generation circuit, 35-sampling circuit, 36-launch circuit, 37-work RAM,
3s - Work ROM, 39 - Center processing unit (CPU), 40 - Pass line, 41 - Amplifier detection circuit, 42, - Down detection circuit, 43.44
．． 45 - Counter, 46... Buffer memory, 47
...Amount memory, 48.--Nonvolatile memory, 49.
-...-Brightness memory, 60-address circuit, 61...
Buffer amplifier, 62...CRTo Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Cause of (C-Shuji) (J CJ (J group)

Claims (2)

[Claims] (1) A one-way television signal receiving device receives billing information corresponding to the content of the program in the form of a digital signal at regular intervals, and this and the time spent watching the television program are combined into the receiving device. The billing amount determination circuit determines the amount, writes charge data proportional to that amount to non-volatile memory,
A billing method characterized in that the billing data in the memory is read out as necessary and displayed on a display device. (2) When charge information for each terminal is sent from the TV program sending side to each terminal, this charge information is transmitted to the non-volatile memory, compared with the charge information in the non-volatile memory, and the two match. Claim 1 characterized in that the new key code sent from the sending side is stored only when the charge sent from the sending side is larger than the charge stored in the non-volatile memory. Billing method described in section.