JP2013172266A - Digital television broadcast viewing restriction method and system and card adapter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize viewing restriction for non-independent broadcast (general broadcast) at a relatively low cost.SOLUTION: An independent broadcast transmitter 14 sends out non-scrambled independent broadcast contents together with an EMM including viewing permission time information addressed to a card adapter of a television receiver 21 of a viewing restriction cancellation object. A card adapter 24 stores the viewing permission time information in a nonvolatile manner when detecting that the viewing permission time information is included in the EMM addressed to itself, and updates the residual time of viewing permission time indicated by the viewing permission time information every time of detecting ECM sent out from the television receiver 21 to an IC card 26 for digital broadcast viewing. The card adapter 24 allows transmission of a descrambling key based on the ECM from the IC card 26 to the television receiver 21 when the residual time is not zero according to the reception of the ECM, and sends out an invalid descrambling key to the television receiver 21 instead of the IC card 26 after the residual time becomes zero.

Description

  The present invention relates to a digital television broadcast viewing restriction method and system for restricting viewing of a digital television broadcast by a television receiver using a digital broadcast viewing IC card, and a card adapter used therefor. (In this specification, a television is abbreviated as a television.)

  Currently, in a specific facility, a television broadcast is distributed to the user for a fee. For example, in a facility such as a hospital or a nursing home, when a user watches a television broadcast with a television receiver (TV receiver) installed in the room, by paying a predetermined fee, only the time commensurate with the fee, A system has been introduced that allows users to watch TV broadcasts.

  As one method for restricting viewing of such television broadcasts, there is known a timer device that is attached to a television receiver and can view television broadcasts for a predetermined time according to the insertion of coins. This timer device shuts off the power of the television receiver when the accumulated viewing time reaches a predetermined time (timeout).

  Also, as disclosed in Patent Document 1, a digital broadcast viewing system has been proposed that makes it possible to provide pay broadcasting with viewing restrictions using data broadcasting to a digital television receiver. This system issues a PET card as a charging medium to a user at a card vending machine. In addition, the pay key content, the intermediate key generation function, the main key generation function, and all the card IDs are included in the BML content of the data broadcast and distributed to each room of the hotel from the headend device having an independent broadcast transmission function. A user who wishes to view paid content purchases a PET card at a card vending machine. In each room, a terminal device having a card reader for a PET card is installed. Each terminal device is connected to a digital television receiver via a LAN, and when information is read from an appropriate PET card, based on the intermediate key data received from the television receiver and the authentication ID data obtained from the PET card. This key data is generated and transmitted to the television receiver. The television receiver collates the real key data received from the terminal device with the real key data generated by itself, and when the two match, after the card ID is authenticated, the viewing restriction is released.

JP 2010-16557 A

Access control method for digital broadcasting Standards ARIB STD-B25 version 5.1, Japan Radio Industry Association

  By the way, depending on the facility, free broadcast content such as a guidance broadcast of the facility may be provided as an independent broadcast. In such a case, it is difficult to adopt the conventional technique in which the power of the television receiver is cut off when the viewing is restricted as described above, because the viewing of the television broadcast is uniformly restricted regardless of the broadcast channel. .

  In the prior art described in Patent Document 1, viewing restriction can be performed using data broadcasting, but a terminal device connected to the television receiver via a LAN is required for each television receiver. Each terminal device needs to have a PET card reader. Furthermore, the issuance of a PET card itself also has a corresponding cost. This increases the cost of the system. In addition, although viewing restriction of independent broadcasting can be performed, there is a problem that viewing restriction of non-independent broadcasting (general broadcasting) such as terrestrial digital television broadcasting and satellite digital television broadcasting cannot be performed.

  The present invention has been made in such a background, and an object of the present invention is to provide a digital television broadcast viewing restriction method and system capable of realizing viewing restriction for non-independent broadcasting (general broadcasting) at a relatively low cost, and to this. It is to provide a card adapter to be used.

  Another object of the present invention is to make it possible to perform viewing restrictions on non-voluntary broadcasts without performing viewing restrictions on independent broadcasts.

  The digital television broadcast viewing restriction method according to the present invention is a method for restricting the viewing of digital television broadcasts with a television receiver using a digital broadcast viewing IC card. In this digital TV broadcast viewing restriction method, a card adapter is connected between the TV receiver and the digital broadcast viewing IC card, and the self-broadcast transmission device receives the television reception for specifying the TV receiver whose viewing restriction is to be released. Receiving the device identification information and transmitting the unscrambled independent broadcast content together with the EMM including the viewing permission time information addressed to the card adapter of the television receiver specified by the television receiver identification information; , If it is detected that the viewing permission time information is included in the EMM addressed to itself, the step of storing the viewing permission time information in a non-volatile manner, and the card adapter is configured to view the digital broadcast from the television receiver. Each time an ECM sent to an IC card is detected, it is represented by the viewing permission time information. Updating the remaining time of the permitted viewing time, and in response to receiving the ECM related to the non-independent broadcast content, if the remaining time is not zero from the digital broadcast viewing IC card, The television receiver is allowed to transmit the descrambling key based on the ECM, and after the remaining time becomes zero, an invalid descrambling key is used instead of the digital broadcast viewing IC card. And the time limit viewing restriction of the non-independent broadcast content by the card adapter.

  With this configuration, viewing permission time information is sent to the target card adapter using the EMM from the independent broadcast transmission device. In response to this, the card adapter measures the viewing time of the non-voluntary broadcast by the television receiver, and allows viewing of the non-voluntary broadcast for the viewing permission time.

  In this digital television broadcast viewing restriction method, the card adapter stores the remaining time information indicating the remaining time in a non-volatile manner, and the card adapter stores the remaining time information at the present time at the predetermined time. And a step of receiving and displaying the remaining time information by the television receiver. The predetermined time is, for example, the time when the EMM addressed to the self-related broadcast content is received.

  With this configuration, the remaining time is displayed on the television receiver, and the user is informed of the current remaining time.

  In the independent broadcast transmission device, the card adapter can distinguish between independent broadcast and non-independent broadcast by omitting addition of ECM to the independent broadcast content.

  The viewing restriction system according to the present invention is a viewing restriction system that restricts viewing of broadcast content in a television receiver using a digital broadcast viewing IC card. This viewing restriction system includes a self-broadcast transmission device that transmits broadcast content including at least video and audio, a card adapter connected between the television receiver and the digital broadcast viewing IC card, and a viewing restriction release target. And a terminal device that receives input of television receiver identification information that identifies the television receiver. The self-broadcast transmission device receives the television receiver identification information input from the terminal device, and sends the unscrambled self-broadcast content together with the EMM including viewing permission time information addressed to the card adapter of the television receiver. To do. When the card adapter detects that the viewing permission time information is included in the EMM addressed to the card adapter, the card adapter stores the viewing permission time information in a non-volatile manner, and transmits the viewing permission time information from the television receiver to the digital broadcast viewing IC card. Each time the transmitted ECM is detected, the remaining time of the viewing permission time represented by the viewing permission time information is updated, and the remaining time becomes zero according to the reception of the ECM related to the non-independent broadcast content. Otherwise, the digital broadcast viewing IC card is allowed to transmit a descrambling key based on the ECM to the television receiver, and after the remaining time becomes zero, the digital broadcast viewing IC card is transferred to the digital broadcast viewing IC card. Instead, an invalid descrambling key is sent to the television receiver. In this way, it is possible to perform time-limited viewing restriction of non-independent broadcast content by the card adapter.

  The terminal device can accept input of the television receiver identification information together with payment of a predetermined price.

  In addition, the card adapter stores the remaining time information indicating the remaining time in a nonvolatile manner, and the remaining time information at the present time is received at a predetermined time, for example, when an EMM addressed to the non-voluntary broadcast content is received. Returning to the television receiver, the television receiver may receive and display the remaining time information.

  The card adapter according to the present invention is connected between the digital broadcast viewing IC card and the television receiver in a viewing restriction system for restricting viewing of broadcast content in a television receiver using a digital broadcast viewing IC card. It is a card adapter. The card adapter includes a first switch connected / disconnected so as to selectively conduct / cut off a communication path between the digital broadcast viewing IC card and the television receiver, and is complementary to the first switch. When the second switch connected / disconnected to turn on / off the communication path and the EMM addressed to itself are detected to contain the viewing permission time information, the viewing permission time information is nonvolatile. Each time the ECM sent from the television receiver to the digital broadcast viewing IC card is detected, the remaining viewing permission time indicated by the viewing permission time information is updated. If the remaining time is not zero in response to reception of ECM related to the non-independent broadcast content from the timer means, the digital broadcast viewing IC card is forwarded to the television receiver. Adapter control that allows an ECM-based descrambling key to be transmitted and sends an invalid descrambling key to the television receiver instead of the digital broadcast viewing IC card after the remaining time becomes zero Means.

  The adapter control means stores the remaining time in a non-volatile manner as remaining time information, and stores the remaining time information at the present time at the predetermined time, for example, when receiving an EMM addressed to the self-independent broadcast content. It is also possible to send it back to the receiver.

  According to the present invention, a terminal device connected to a television receiver via a LAN, which has been conventionally required, is not necessary. Further, a card reader for each television receiver is unnecessary, and such a prepaid card itself is also unnecessary. The user does not need to perform a special operation such as inserting a card to cancel the viewing restriction on the television receiver.

  Therefore, it is possible to implement viewing restrictions on television broadcasting at a relatively low cost, and to reduce the operational burden on the user.

  In addition, independent broadcasts and non-independent broadcasts can be distinguished based on the presence / absence of an ECM (Entitlement Control Message), thereby allowing viewing restrictions on non-independent broadcasts without restricting viewing on independent broadcasts. It becomes possible.

1 is a block diagram showing a schematic configuration of an entire viewing restriction system for digital television broadcasting in an embodiment of the present invention. It is a figure which shows the example of an external appearance structure of the card adapter shown in FIG. It is a block diagram showing the internal structure of the independent broadcast transmission apparatus shown in FIG. It is a figure which shows the structure of the ECM section prescribed | regulated to ARIB. It is a figure which shows the structure of the EMM section prescribed | regulated to ARIB. It is a figure which shows the example of an internal structure of the television receiver and card adapter in this Embodiment corresponding to the broadcast receiving system of FIG. It is a figure for demonstrating the main functions of the card adapter in embodiment of this invention. In the embodiment of the present invention, a description will be given of an operation and a mechanism when a viewing permission time (information) is stored in a card adapter when a self-broadcast is viewed on a television receiver of a user who has purchased viewing rights. FIG. It is a sequence diagram showing an example of transmission / reception of the signal between the television receiver in embodiment of this invention, the card adapter connected to this, and an IC card. It is a figure which shows the example of a display screen which superimposed and displayed the message showing remaining time on the video screen of the independent broadcast in embodiment of this invention. It is a sequence diagram when the television receiver in the embodiment of the present invention is switched from an independent broadcast channel to another non-independent broadcast channel in accordance with a user instruction. It is a flowchart showing the outline process of the card adapter in embodiment of this invention. It is a flowchart which shows the specific process example regarding the display of the remaining time in a television receiver. 13 is a flowchart showing a specific processing example of the card adapter viewing restriction processing S105 shown in FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of the entire viewing restriction system for digital television broadcasting in the present embodiment. This viewing restriction system is a viewing restriction system that restricts viewing of non-voluntary broadcasts (general broadcasts) in a digital television receiver using an IC card for viewing digital broadcasts. Hereinafter, the digital television receiver is simply referred to as a television receiver or a TV. An example of use in a specific facility, here in a hospital, will be described.

  A broadcast distribution system 10 installed in a hospital is connected to a broadcast reception system 20 installed in each room (patient room) as a distribution destination via a high-frequency transmission interface such as a coaxial cable.

  The broadcast distribution system 10 includes a self-broadcast transmission device 14 that transmits self-broadcast content such as a free guide broadcast that is broadcast on a specific channel, and a purchase device 18 that purchases viewing rights (payment of consideration) for non-voluntary broadcasts. The control device (PC) 16 that controls the independent broadcast transmission device 14 and the purchase device 18, the non-independent broadcast content source 11, the RF signal from the non-independent broadcast content source 11 and the RF output from the independent broadcast transmission device 14 The mixer 12 is configured to be mixed and sent to each broadcast receiving system 20. Here, the non-independent broadcast content source 11 includes a terrestrial digital broadcast reception antenna 11a, a satellite digital broadcast reception antenna 11b, and the like. It may receive non-voluntary broadcast content from the outside with a cable or the like regardless of the antenna.

  In this specification, “non-voluntary broadcast” is broadcast that can be received by a normal television receiver, such as terrestrial digital television broadcast or satellite digital television broadcast. In the present invention, such involuntary broadcast is broadcast in which broadcast content is encrypted (scrambled) with a scramble key, and refers to broadcast content accompanied by packet data called ECM, which will be described later. In contrast, voluntary broadcasts are broadcasts that are voluntarily provided at individual facilities, such as a guide broadcast that guides the services and usage of the facility, and the ECM packet data is attached to the broadcast content. That which does not. “Broadcast content” is typically information including video and audio sent to viewers using broadcast waves, but is sent via communication instead of broadcast waves. May be. Further, “limited reception” means limiting recipients of non-independent broadcast content. In this embodiment, the card adapter of the present invention is used for an IC card for viewing digital broadcasts necessary for viewing digital broadcast content in the existing viewing restriction system, and viewing restrictions on non-independent broadcasts on the condition of purchasing viewing rights. Is released. “Viewing right” means a right to view a non-voluntary broadcast. In the present invention, even if the viewing right is purchased, the user is not provided with a PET card or a prepaid card, but simply received that it is possible to view a non-voluntary broadcast for a predetermined time. Only a printed sheet is issued as a letter (preferably also serving as a receipt). Therefore, it is not necessary for the user to perform a special operation or instruction to the television receiver.

  The independent broadcast transmission device 14 receives the television receiver identification information for specifying the television receiver for which the viewing restriction is to be released, and includes an EMM (Entitlement Management Message) including viewing permission time information addressed to the card adapter of the television receiver. ) And unscrambled self-broadcast content. (The EMM will be described later.) For this purpose, the self-broadcasting transmission device 14 includes a digital terrestrial broadcasting SI (Service Information) information transmission function, a video / audio compression function, and orthogonal frequency division multiplexing (OFDM). A modulation function and an RF up-converter function are implemented. More specifically, the independent broadcast transmission device 14 does not perform encryption with a scramble key using an encryption method compliant with digital terrestrial television broadcasting, and includes a predetermined information as described above in a unique EMM. Broadcast broadcast content. The unique EMM is an EMM that is unique to the independent broadcast transmission device 14. The broadcast content can include data broadcast content (BML data). Terrestrial digital broadcast and satellite digital broadcast signals are received by the antennas 11a and 11b, mixed by the self-broadcast channel signal output from the self-broadcast transmission device 14 by the mixer 12, and sent together to the distribution destination. The detailed internal configuration of the independent broadcast transmission device 14 will be described later.

  The control device 16 is a device for controlling the independent broadcast transmission device 14 and the purchase device 18, and is configured by a personal computer (PC) in this example. More specifically, it is a terminal device that accepts input of predetermined information and payment of charges by a user and outputs a receipt. Here, the “predetermined information” is television receiver identification information (TV-ID) that identifies a television receiver that is a target for canceling viewing restrictions. For example, a television receiver number uniquely assigned to the television receiver. It is. The “predetermined information” may further include time information indicating a time when the user desires to release the viewing restriction. The time information may be the number of hours such as 30 hours or 50 hours, or may be information representing a period such as 10 days, 1 week, or 1 month. The time may be specified by inputting a numerical value or by the user selecting buttons or keys representing a plurality of times. However, when the viewing permission time is uniformly set, it is not essential for the user to input time information in the present invention. The receipt is, for example, a form (paper) on which the date of purchase, viewing permission time, receipt amount, guidance for viewing, etc. are printed.

  The purchase device 18 is connected to the control device 16 via a communication interface such as a LAN. The television receiver identification information (and viewing time information) for specifying the television receiver targeted for canceling the viewing restriction input by the user is received by the control device 16 and transmitted to the independent broadcast transmission device 14. It is sufficient that at least one such purchase device 18 is installed in the hospital. However, when there are hospital rooms on a plurality of floors, at least one purchase device 18 may be installed on each floor. Of course, the purchase device 18 may be installed in each hospital room.

  As a form of payment of the fee, any of cash input to the purchase device 18, electronic money, use of a credit card, etc. may be used, and there is no particular limitation.

  The broadcast receiving system 20 includes a television receiver 21 with a remote controller (remote controller) 22, a card adapter 24, and an IC card 26. At least one broadcast receiving system 20 is installed in each room where a user can view a television broadcast. When there are a plurality of users (or beds) in one room, a plurality of broadcast receiving systems 20 may be installed in one room. In any case, a unique television receiver number (TV-ID) is assigned as the television receiver identification information to all the television receivers of the broadcast receiving system 20 that are restricted in viewing in the hospital.

  Generally, the IC card 26 is an existing digital broadcast viewing IC card called a B-CAS card, and can be viewed on encrypted (scrambled) broadcast content that is attached to a digital broadcast television receiver. To. The B-CAS card is a contact type IC card in which its ID number and master key are stored.

  The card adapter 24 is an adapter device connected (attached) between such a digital broadcast viewing IC card and the television receiver (television main body) 21. More specifically, the card adapter 24 restricts viewing of terrestrial digital broadcasting and satellite digital broadcasting as non-independent broadcasting on the television receiver 21 to which the card adapter 24 is connected, and when the user purchases viewing rights, The viewing restriction of the television receiver is canceled (viewing is permitted) for the viewing permission time. Therefore, the card adapter 24 measures the viewing restriction function of the non-independent broadcast, the function to release the viewing restriction, and the accumulated viewing time of the non-independent broadcast by the user, and whether the accumulated viewing time has reached the viewing permission time. A timer function is provided to determine whether or not. In this embodiment, whether or not the cumulative viewing time has reached the viewing permission time (whether or not it has timed out) is set to the viewing permission time initially set when the viewing right is purchased, as the viewing time of the non-independent broadcast. Subtraction is performed accordingly, and it is determined whether the remaining time becomes 0 (zero).

  The configuration and operation of the main part of this system, in particular, operations such as setting the viewing permission time in the timer function, updating the remaining time, and displaying the remaining time will be described later.

  The RF signal transmitted from the broadcast distribution system 10 is received by the television receiver 21 at each distribution destination. The user can use the remote controller 22 to select a non-independent broadcast channel that is a normal television broadcast. Since the present invention uses the existing viewing restriction system of the television receiver to restrict the viewing of non-independent broadcasts, the remote control 22 of the television receiver 21 is used as it is as a remote control for channel selection. be able to.

  Broadcast contents of digital broadcasting are encrypted (scrambled) by an encryption method called MULTI2. MULTI2 is an encryption method adopted as a standard encryption for the Japanese digital broadcast conditional access system (B-CAS). A descrambling key (scramble key) for decrypting broadcast content can be fetched from the IC card 26. In the present embodiment, the scramble key as the descrambling key is included in the ECM packet in the broadcast content and reaches the card adapter 24 via the television receiver 21.

  When the user purchases the right to view the non-independent broadcast channel, the card adapter 24 scrambles the scramble key from the IC card 26 if the remaining time is not zero while the ECM related to the non-independent broadcast content is received. It is allowed to be returned to the television receiver 21 as a key. The generated descrambling key is sent back to the television receiver 21, whereby the non-independent broadcast content is correctly decoded (descrambled), and the content is reproduced and displayed. For a certain television receiver 21, before the viewing right is purchased or after the remaining time has expired, the card adapter 24 prevents the IC card 26 from returning a regular descrambling key to the television receiver 21. By doing so, the viewing is restricted. For this purpose, the card adapter 24 sends an invalid descrambling key instead of the IC card 26 to the television receiver. In this way, the card adapter 24 restricts timed viewing of non-independent broadcast content.

  In FIG. 2, the example of an external appearance structure of the card adapter 24 in this Embodiment is shown. The card adapter 24 in this example is similar to the television receiver 21 in that the adapter main body 24a has a slot 24g for storing the IC card 26 and a circuit board (not shown) on which electronic components constituting a necessary circuit are mounted. And a card-like connecting member 24d connected to the slot 21a. Since the user does not need to attach or detach the IC card 26, the IC card slot 24g for storing the IC card 26 may be closed inside the adapter main body 24a.

  Originally, the IC card 26 is directly mounted in the slot 21 a, but in this embodiment, the IC card 26 is mounted on the television receiver 21 via the card adapter 24. Power is supplied to the adapter body 24a via a power cable 24f with a plug that can be connected to a power outlet. The card-like connecting member 24d and the adapter main body 24a are connected to each other by a cable 24b. In this example, a connector 24c is attached to the cable 24b, and is connected to the card-like connecting member 24d via this connector. However, the connector 24c is not essential, and the cable 24b may be directly attached to the card-like connecting member 24d. The same electrical contact 24e is formed at the same location as the IC card 26 in the card-like connection member 24d. A configuration in which the cable 24b is eliminated by directly connecting the card-like connecting member 24d to the adapter main body 24a may be employed.

  FIG. 3 is a block diagram showing the internal configuration of the independent broadcast transmission device 14. This self-broadcast transmission device 14 mainly has functions of generating a unique EMM packet to which viewing permission time information and the like are added, and sending a self-broadcast video / audio stream including this unique EMM packet. More specifically, the independent broadcast transmission device 14 includes a terrestrial digital broadcast SI information generation unit 140, a video / audio encoder 142, an EMM common message storage unit 143, a correspondence table 144, an OFDM modulator 148, an RF upconverter 149, and A unique EMM packet generator 150 is provided. The voluntary broadcast transmission device 14 receives at least TV-ID information for specifying a TV receiver whose viewing restriction is to be canceled, and viewing permission time information addressed to the card adapter 24 of the TV receiver specified by the TV-ID information. The original EMM including the message is sent together with the unscrambled independent broadcast content. However, the independent broadcast transmission device 14 omits the addition of ECM to the independent broadcast content. Preferably, information on a date (purchase date) when the viewing right is purchased is also added to the EMM including the viewing permission time information. The sending period of the original EMM may be changed according to the new and old purchase date. For example, it is possible to set the transmission cycle of a new purchase date shorter.

  The terrestrial digital broadcast SI information generation unit 140 is a circuit that generates SI information (additional information) such as PAT, PMT, SDT, BIT, TOT, and NIT necessary for terrestrial digital broadcast. Such SI information can be set from the control device 16. SI information is sent out as a TS packet at a timing compliant with ARIB (Association of Radio Industries and Business: Non-Patent Document 1) from the terrestrial digital broadcast SI information generation unit 140. Generally, TS (Transport Stream) is 188-byte unit fixed-length packet data standardized for use in broadcasting and communication, and usually includes video, audio, and data.

  The independent broadcast video / audio (broadcast content) is obtained from an arbitrary video / audio source such as a DVD player, and is compressed by the video / audio encoder 142 and converted into a TS stream. The location of the content source may be inside or outside the independent broadcast transmission device 14.

  In general, a video / audio stream of a non-voluntary broadcast is encrypted (scrambled), and an ECM is required on the television receiver side in order to decrypt (descramble) the video / audio stream. However, in the present invention, viewing of the independent broadcast is free, and the video / audio stream of the free broadcast is not encrypted (scrambled). Therefore, the television receiver side does not need to decode (descramble) the self-broadcast video / audio stream, and the ECM packet becomes unnecessary.

  The EMM common message is a message for displaying the remaining time of the viewing permission time in the present embodiment. The EMM common message is broadcast to the card adapters 24 of all television receivers.

  The correspondence table 144 associates the television receiver identification information (TV-ID) with the card identification information (card ID), and is stored in the nonvolatile memory together with the EMM common message when the system is initially set. In order to create this correspondence table 144, a function for displaying IC card identification information (for example, BCAS card number) corresponding to each television receiver on the television screen by using data broadcasting at the time of initial setting is implemented. Also good. Based on this display, a database for associating the television receiver identification information with the ID card identification information (card ID) for each television receiver is generated on a text basis, and the correspondence table 144 is stored in the non-volatile memory in the independent broadcast transmitter 14. Can be stored as

  Here, a general conditional access system (CAS) will be briefly described. In CAS, when viewing encrypted broadcast content, three keys, a master key (Km), a work key (Kw), and a scramble key (Ks) are used. The master key is a key distributed to each user, and is distributed to the user using an information medium such as a digital broadcast viewing IC card. Information called EMM (Entitlement Management Message) is periodically output to the broadcast wave. The EMM includes contract information (contract registration code) for each user as a contractor, a work key, and the like. Individual information for each user in the EMM is encrypted and decrypted with the master key. Broadcast content is transmitted together with common information called ECM (Entitlement Control Message). The ECM includes information related to a program, a scramble key, and the like. The ECM is also encrypted with a predetermined encryption method and can be decrypted with the work key. On the IC card 26 side, the ECM is decrypted with the work key, the contract information included in the EMM and the information in the ECM are collated, and if viewing is possible, the scramble key in the ECM is used as a descrambling key to receive the television. The machine 21 decrypts (descrambles) the content.

  The TS stream generated by each unit is multiplexed by the multiplexer 146. The TS stream is modulated as a terrestrial digital broadcast signal by the OFDM modulator 148, converted into a UHF signal by the RF up-converter 149, and output as RF. An empty channel for digital terrestrial broadcasting is selected as this RF output channel.

  FIG. 4 shows the structure of the ECM section defined in ARIB. One ECM section is included in one TS packet, and includes an ECM section header, an ECM body, and a section CRC. The ECM main body includes a fixed part, a variable part, and a tamper detection part. The fixed part includes a protocol number, provider identification information, work key identification information, scramble key (ODD), scramble key (EVEN), determination type, date and time, and recording control information. The protocol number is a protocol number for processing common information. The business operator identification information is a code for identifying a business entity in the conditional access system operation, and is information for specifying individual information to be referred to together with the work key identification information. The work key identification information is information that designates a work key for decrypting the common information. The scramble key (ODD) and the scramble key (EVEN) are the current and next two scramble keys transmitted in pairs. The determination type indicates a viewing determination type such as free, deer, or PPV. The date / time indicates the current year / month / day / minute used for viewing determination. The recording control information is information indicating the recording conditions of this program (recording is possible, not possible, only the purchaser can record). The variable part of the ECM includes necessary function information according to the purpose of transmitting the common information.

  FIG. 5 shows the structure of the EMM section defined in ARIB. The EMM section includes an EMM section header, a plurality of EMM bodies, and a section CRC. The EMM main body includes a fixed portion, a variable portion, and a tamper detection portion. “Card ID” is card identification information for uniquely specifying an IC card. The “related information byte length” represents the byte length from the protocol number to the falsification detection unit. The “protocol number” is a code that identifies an IC card processing function, an encryption algorithm, and the like. “Business entity identification” is a code for identifying a business entity in the conditional access system operation. The “update number” is a number that increases when the individual information is updated. “Expiration date” represents the expiration date of the individual information. Various function information can be arranged in the variable portion.

  The unique EMM packet generation unit 150 generates a unique EMM packet and outputs it to the multiplexer 146 at a predetermined time. Since the television receiver identification information (TV-ID) and the viewing time information are sent from the purchase device 18, the card identification information (card ID) corresponding to the television receiver identification information is confirmed with reference to the correspondence table 144. can do. In the present embodiment, the IC card identification information is also identification information that uniquely identifies the card adapter. This IC card identification information is set in the “card ID” of the fixed part of the unique EMM. In addition, the viewing permission time and purchase date information are set in the variable part or expiration date of the original EMM. If the viewing permission time is a predetermined time, the unique EMM packet generation unit 150 may set the uniform time as the viewing permission time. The purchase date information may be generated by the purchase device 18, or the date on which the independent broadcast transmission device 14 receives the television receiver identification information (TV-ID) and the viewing time information from the purchase device 18 is unique as the purchase date. The EMM packet generation unit 150 may set.

  FIG. 6 is a diagram showing an internal configuration example of the television receiver 21 and the card adapter 24 in the present embodiment, corresponding to the broadcast receiving system 20 of FIG.

  The television receiver 21 includes a tuner unit 211, a descrambler 212, a demultiplexer 213, a video / audio decoder 214, an input / output (I / O) unit 215, a control unit 216, a CAS processing unit 217, a display processing unit 218, an infrared ( Ir) It is configured to include a receiving unit 219, a display control unit 220, a display unit 221, an audio processing unit 222, and a speaker 223.

  The tuner unit 211 is a part that extracts broadcast content of a channel selected from the RF signal received by the television receiver 21. The descrambler 212 is a part that decrypts (descrambles) broadcast content encrypted (scrambled) by the MULTI2 encryption method. The decryption key (scramble release key) is given from the IC card 26 or the card adapter 24 via a CAS processing unit 217 described later.

  The demultiplexer 213 is a part that separates the multiplexed streams and extracts video / audio and decoded data (if any) in the broadcast content. The video / audio decoder 214 is a decoder such as an MPEG2 decoder that decodes and restores the separated video and audio. The SI information extracted by the demultiplexer 213 is sent to the control unit 216. Next, of the SI information, EMM, ECM packet, and the like are sent to the CAS processing unit 217. An ECM packet is one packet of SI information. Only the main part of the ECM packet shown in FIG. 4 is sent from the control unit 216 to the CAS processing unit 217.

  The CAS processing unit 217 performs command and response processing between the card adapter 24 and the IC card 26 via the input / output (I / O) unit 215, and also provides a scramble key as a descramble key to be given to the descrambler 212. This is the part where the extraction process is performed.

  The control unit 216 is a part that takes in the section information and BML data extracted from the demultiplexer 213 and controls each part of the television receiver 21 and performs necessary processing, and includes a CPU, a memory, and the like with a built-in peripheral circuit Is done.

  The display processing unit 218 performs a process of combining and displaying the data broadcast display screen based on the BML data stream separated by the demultiplexer 213 and the video signal obtained from the video / audio decoder 214 under the control of the control unit 216. This is the part to be performed. More specifically, the display processing unit 218 performs menu display including remaining time display, BML data display, EPG display, channel, volume, and the like.

  The display control unit 220 is a part that controls the display unit 221 to display a video based on the video signal from the video / audio decoder 214 and an image based on the display signal from the display processing unit 218. The display unit 221 is an arbitrary display device such as liquid crystal, organic EL, or plasma.

  The infrared receiving unit 219 is a part that receives an infrared command from the remote controller 22 and sends it to the control unit 216.

  The audio processing unit 222 is a part that drives the speaker 223 based on the audio signal obtained from the video / audio decoder 214.

  Note that the configuration of such a television receiver 21 is known.

  The card adapter 24 includes an analog switch 241, an analog switch 242, and an adapter control unit (adapter control means) 243. The card adapter 24 does not need a connection function to the LAN like the terminal device described in Patent Document 1. Further, an apparatus such as a card reader for reading a prepaid card is not necessary.

  The analog switch 241 is a first switch that is connected / disconnected so as to selectively conduct / cut off the communication path between the I / O unit 215 of the television receiver 21 and the IC card 26. The analog switch 242 is a second switch that is connected / disconnected so as to conduct / cut off the communication path in a complementary manner to the analog switch 241. The adapter control unit 243 is connected to a communication path between the IC card 26 and the I / O unit 215 of the television receiver 21, more specifically, a communication path between the analog switch 241 and the IC card 26. Normally, control is performed so that the analog switch 241 is conductive and the analog switch 242 is in a cut-off state, and the analog switch 241 is cut off and the analog switch 242 is turned on when necessary. For example, in a state where viewing of digital broadcasting (non-independent broadcasting) is restricted, the analog switch 241 is in a disconnected state and the analog switch 242 is in a conductive state, and the television receiver 21 and the IC card 26 are disconnected. .

  The adapter control unit 243 incorporates a processor (& memory) 244 and, as described above, realizes the detection of the ECM received from the television receiver 21, the analysis of the original EMM, and the timer processing related to the viewing time. Specific processing will be described later. The memory includes a nonvolatile memory such as an EEPROM and a volatile memory such as a RAM. The processor 244 constantly monitors signals exchanged between the television receiver 21 and the IC card 26, intercepts EMM and ECM output to the IC card 26, and executes necessary processing. The processor 244 can be realized, for example, by an 8-bit microcomputer with relatively simple and low cost.

  Since the ECM packet used in normal digital broadcasting is encrypted by a predetermined encryption method in the B-CAS standard, the processor 244 of the adapter control unit 243 cannot understand. Here, if it cannot be understood, the encryption of the ECM packet is to be decrypted with the original encryption of the card adapter 24, but the determination value of the alteration detection CRC32 (“falsification detection” in the ECM main body in FIG. 4) indicates non-falsification. Since it does not match a predetermined value (for example, 0), it is determined that it is not an ECM packet to be processed by itself. However, the ECM packet itself can be detected. In the present invention, by detecting this ECM, it is determined that the user is currently viewing the non-independent broadcast content.

  The main functions of the card adapter 24 in this embodiment will be described with reference to FIG. This figure shows the function of each part in blocks. Realization of the function of each unit shown in FIG. 7 is not limited to hardware and software.

  If the remaining time is not zero, the adapter control unit 243 (FIG. 6) in the card adapter 24 de-scrambles from the IC card 26 to the television receiver 21 if the remaining time is not zero. The key is allowed to be transmitted, and functions to send an invalid descrambling key to the television receiver 21 instead of the IC card 26 after the remaining time becomes zero. As a premise, when an EMM packet is detected by the EMM detection unit 244b, the EMM includes an EMM individual message addressed to itself, and the EMM individual message includes viewing permission time information related to viewing restriction release. If so, information on the viewing permission time and purchase date is stored in the memory 244d. (The card adapter 24 stores its own identification information in advance.) Thereafter, while the ECM detection unit 244a continues to detect the ECM, it is determined that the non-independent broadcast is being viewed, and every unit time. The viewing permission time is sequentially subtracted by the elapsed time, and the remaining time information of the viewing permission time is stored and managed in the memory 244d. Here, the memory 244d is a nonvolatile memory and / or a volatile memory in the adapter controller 243 described above. The adapter control unit 243 also stores the remaining time information in a non-volatile manner as the remaining time information as a result of the subtraction, and displays the remaining time information at the current time at the time of reception of the EMM addressed to itself related to the non-independent broadcast content. It has a function of returning to the television receiver 21. This is a function for displaying the remaining time on the television receiver 21 to inform the user of the current remaining time.

  The analog switch 242 as the second switch is turned on, and the analog switch 241 as the first switch is turned off, so that zero ("0") as an invalid descrambling key (ODD, EVEN key) is obtained. “) Data can be sent to the descrambler 212 of the television receiver. As a result, a viewing restriction state for non-independent broadcasting is realized.

  After the purchase of the viewing right, the card adapter 24 receives the TV receiver from the IC card 26 via the analog switch 241 that is the first switch while the remaining viewing permission time exists (when it is not zero). The scramble key (Ks) as the descrambling key sent to the terminal 21 is made conductive. At this time, the analog switch 242 which is the second switch is in a cut-off state.

  On the IC card 26 side, as before, the decryption processing unit 262 decrypts the EMM with the master key (Km) and outputs the work key (Kw) and the contract information. Also, the decryption processing unit 261 decrypts the ECM with the work key (Kw) and outputs the scramble key (Ks) and the program attribute information. The viewing condition determination processing unit 263 collates the contract information included in the EMM with the program attribute information in the ECM, and if it is determined that viewing is possible as a result of the collation, the switch 264 is closed and obtained from the ECM. The scramble key (Ks) is output to the descrambler 212 as a scramble release key.

  Hereinafter, a series of operations in the present embodiment will be described.

  First, referring to FIG. 8, the operation and mechanism when the viewing permission time or the like (information) is stored in the card adapter 24 when viewing the independent broadcast on the television receiver 21 of the user who purchased the viewing right will be described. To do.

  As described above, the correspondence table 144 stores television receiver identification information (TV-ID) and card identification information (card ID) in association with each other. From the “television receiver number” that is the television receiver identification information sent from the purchase device 18 via the control device 16, the “card number” that is the card identification information corresponding to this is specified. The EMM packet generator 150 receives this card number. Along with this, viewing permission time and purchase date information are also sent from the control device 16 to the EMM packet generation unit 150. The unique EMM packet generation unit 150 receives the EMM common message for displaying the remaining time from the EMM common message storage unit 143 in addition to the card number, the viewing permission time, and the purchase date, and the EMM incorporating the information. Generate a packet. The EMM packet is multiplexed together with, for example, a self-contained broadcast content including a guide video and audio by the encoder 142 and the like, and is sent to the mixer 12 as an RF signal.

  In the mixer 12, it is mixed together with the RF signal of terrestrial digital broadcast or satellite digital broadcast and sent to each broadcast receiving system 20.

  Of the plurality of broadcast receiving systems 20 that have received the guidance broadcast sent from the broadcast distribution system 10, the broadcast specified by the card identification information included in the EMM due to the user purchasing the viewing right For the receiving system 20, the card adapter 24 stores the received viewing permission time and purchase date information in a nonvolatile manner. That is, when the card adapter 24 newly detects that the viewing-permitted time information is included in the EMM addressed to itself associated with the independent broadcast content, the card adapter 24 stores the viewing-permitted time information and the purchase date in a nonvolatile manner. When “newly” is detected, it means that the same EMM received after that is processed once is ignored.

  Thereafter, the television receiver 21 of the broadcast receiving system 20 uses the card adapter 24 to activate the IC card 26 for the viewing permission time for the non-voluntary broadcast (that is, the legitimate output from the IC card 26). Using the descrambling key), viewing of the non-independent broadcast is permitted. During viewing of this non-independent broadcast, the viewing permission time is updated (reduced) by the viewing time, and the remaining time is managed. The card adapter 24 restricts the subsequent viewing of the non-independent broadcast by blocking the communication between the IC card 26 and the television receiver 21 when the remaining time of the viewing permission time becomes zero.

  FIG. 9 is a sequence diagram showing an example of signal exchange between the television receiver 21 and the card adapter 24 and the IC card 26 connected thereto. In the present embodiment, the viewing permission time and purchase date (information) are stored in the card adapter 24 when the independent broadcast is viewed for the first time after purchasing the viewing right. Therefore, it is assumed that the television receiver 21 in this viewing restriction system is configured to automatically select a specific channel (in this example, a non-voluntary broadcast channel for guidance) when the power is turned on. However, this is not essential. Even without this configuration, it is sufficient for the user to manually select a non-voluntary broadcast channel.

  When the television receiver 21 detects that the IC card 26 is mounted after power-on (S11), it supplies power to the IC card 26 (S12). At the same time, a clock having a predetermined frequency (for example, 4 MHz) is supplied (S13), and the initial reset state of the IC card 26 is released after the time for the circuit of the IC card 26 to stabilize (stable time) has elapsed. (S14).

  After the reset is released, the IC card 26 returns basic communication information such as a board rate, a clock frequency, and a timeout to the television receiver as an ATR (Answer To Reset) (S31). The television receiver 21 receives the ATR response (S15), and starts exchanging serial data in a format based on the response. In the case of B-CAS, the buffer size setting is changed first.

  Thereafter, the television receiver 21 issues an initial setting command (S16). In response to this, the IC card 26 returns its own card ID and a system key and initial data used for the MULTI2 encryption (S32).

  The television receiver 21 tunes to the channel of the independent broadcast (S17), receives the EMM packet, and issues an EMM command (EMM packet) to the IC card 26 to the card adapter 24 (S18). Even if the IC card 26 receives this EMM packet, it cannot process it correctly (S33). On the other hand, the card adapter 24 having a card ID that matches the card ID specified by the EMM can normally decode the EMM packet and execute the following expected process (S21).

  The card adapter 24 extracts viewing permission time and purchase date information from the EMM packet (S22). Further, the viewing permission time is stored in a nonvolatile manner as the remaining time (S23). Further, the remaining time (information) is returned to the television receiver 21 (S24). In response to this, the television receiver 21 displays the remaining time superimposed on the video screen of the independent broadcast (S19).

  Note that if the non-voluntary broadcast is interrupted when the remaining time is non-zero due to power-off of the television receiver 21 or switching to the independent broadcast channel, the remaining time is stored in a non-volatile manner. Maintained without.

  FIG. 10 shows an example of a display screen in which a message 52 representing the remaining time is superimposed on the video screen 50 for independent broadcasting. The message 52 includes a fixed common message part and a variable individual message part. In this example, the standard sentence “remaining viewing time is minutes” is the common message part, and “XX” is the individual message part. An arbitrary numerical value is inserted into XX. The common message part is a fixed character string prepared in advance, but it is also possible to prepare a plurality of fixed sentences in advance and select one to use.

  FIG. 11 shows a sequence diagram when the television receiver 21 is subsequently switched from the independent broadcast channel to the non-independent broadcast channel in accordance with a user instruction.

  The television receiver 21 switches to a non-independent broadcast channel according to a user instruction (S41). Thereafter, the television receiver 21 receives the EMM packet of the broadcast content of the non-independent broadcast channel and issues an EMM command (EMM packet) to the IC card 26 (S42). In addition, the television receiver 21 periodically issues an ECM command (ECM packet) after tuning the non-independent broadcast channel (S43). This ECM command is a command for requesting that a scramble key extracted by decrypting the ECM be returned as a descrambling key.

  The IC card 26 having a card ID that matches the card ID specified by the EMM can receive the EMM packet and correctly decode it (S61).

  On the other hand, even if the card adapter 24 detects the encrypted EMM packet, it cannot decrypt it normally (S51). However, it does not matter whether or not the card adapter 24 can decrypt the EMM of the broadcast content of the non-voluntary broadcast in this embodiment.

  When receiving the ECM packet, the card adapter 24 updates the remaining time if the remaining viewing permission time is not zero (S52). That is, the remaining time is subtracted for every unit time. Next, it is determined whether or not the remaining time after the update has become zero (S53). In the subsequent switch control step S54, the switches 241 and 242 are controlled so that the descrambling key from the IC card 26 is conducted to the television receiver. In this example, it is assumed that the remaining time does not become zero at this time. In this case, the IC card 26 can correctly decode the ECM packet (S62), and as a result, the scramble key is extracted from the ECM packet and returned to the television receiver 21 as a scramble release key. At this time, since the remaining time exists, the descrambling key reaches the television receiver 21 without being obstructed by the card adapter 24. Therefore, the television receiver 21 descrambles and reproduces the scrambled non-voluntary broadcast content with the descrambling key (S44).

  When the television receiver 21 issues the next ECM command (S45), the card adapter 24 updates the remaining viewing permission time accordingly (S55). Here, it is assumed that the remaining time becomes zero (S56). As a result, the card adapter 24 switches the analog switches 241 and 242 (S57). That is, the switch is switched so that the analog switch 241 is cut off and the analog switch 242 is turned on. On the other hand, the IC card 26 correctly decrypts the ECM packet (S64) and responds with a scramble key (scramble release key) (S65).

  However, at this time, the remaining time of the viewing permission time becomes zero and the analog switches 241 and 242 are switched, so that the scramble key (scramble release key) output from the IC card 26 to the television receiver 21 is blocked by the card adapter 24. Is done. Instead, zero output is performed as an invalid scramble key (scramble release key) from the card adapter 24 to the television receiver 21 (S58). As a result, the television receiver 21 fails to descramble the non-independent broadcast content, and cannot be viewed. This state continues until the non-zero viewing permission time is reset.

  FIG. 12 is a flowchart showing a schematic process of the card adapter 24. This process is executed by the processor 244 of the card adapter 24.

  When the card adapter 24 receives the EMM packet addressed to itself from the television receiver 21, the card adapter 24 checks whether or not an EMM individual message is included (S101). If included, the viewing permission time and purchase date information are stored in the nonvolatile memory on the condition that the current remaining time is zero (S102). If the remaining time is not zero, this EMM individual message is currently ignored. Even if the remaining time is not zero, when it is detected that the EMM addressed to itself includes new viewing permission time information, the new viewing permission time information is stored separately, and the remaining time becomes zero. You may make it use after. Alternatively, a new viewing permission time may be added to the current remaining time for use.

  When the card adapter 24 receives the EMM common message for the independent broadcast content from the television receiver 21 (S103), the card adapter 24 checks the current remaining time and adds the current remaining time to the EMM common message via the analog switch 242. And reply (S104).

  Further, the card adapter 24 always executes the viewing restriction process (S105). Detailed specific processing steps of the viewing restriction process will be described later.

  An example of a specific automatic display message display process related to the display of the remaining time in the television receiver 21 will be described with reference to FIG. To display the remaining time, the automatic display message function in 3.14 EMM message control of ARIB 2-STD-B25 can be used. In this method, a display message prepared in advance is displayed in a superimposed manner on a screen while a program is being viewed. In this embodiment, this function is used when displaying the independent broadcast channel.

  The display message can be configured by combining a common message prepared in advance for all the television receivers 21 and an individual message unique to each television receiver 21. When a plurality of fixed sentences are prepared as a common message, an individual message and a pointer that specifies a fixed sentence to be combined with the individual message can be returned to the television receiver 21 from the IC card side.

  In the present embodiment, the common message is an EMM common message prepared in the independent broadcast transmission device 14 as described in FIG. The individual message is the remaining time (information) of the viewing permission time sequentially updated in each card adapter 24.

  The self-broadcasting transmission device 14 also adds the card ID and viewing permission time (information) of the television receiver 21 that is the target of releasing the viewing restriction, a pointer indicating a fixed sentence, and difference information (initially) to the EMM individual message of the self-broadcasting channel. Send out including the value zero).

  When receiving the EMM individual message (S131), the television receiver 21 tuned to the independent broadcast channel does nothing if it is the same as that received previously (S132, Yes). That is, the EMM individual message is stored once received, and the same message is not received thereafter. If it is not the same as previously received, the received fixed sentence pointer and difference information are stored in a nonvolatile manner (S133).

  When the television receiver 21 is tuned to the digital broadcast channel, it receives a CAT (Conditional Access Table). When the service descriptor exists in the CAT of the independent broadcast channel (S134, Yes), the television receiver 21 activates the automatic display message service and outputs an automatic display message display information acquisition command to the IC card 26 (S135). ). When the card adapter 24 detects this command, it returns a fixed phrase pointer and difference information in place of the IC card 26 as a response. This difference information includes the remaining time of the viewing permission time at that time. The television receiver 21 acquires the fixed phrase pointer and difference information from the card adapter 24 (S136).

  Thereafter, when the television receiver 21 receives the EMM common message designated by the fixed phrase pointer (or if there is an EMM common message that has already been received and saved) (S137), the television receiver 21 adds EMM to the received EMM common message information. The difference information in the individual message information is added and superimposed (synthesized) display is performed (S138).

  FIG. 14 is a flowchart showing a specific processing example of the viewing restriction processing S105 of the card adapter 24 shown in FIG.

  The card adapter 24 checks the current remaining time (S111). If there is remaining time, the switch 241, so as to allow the IC card 26 to return the scramble key (descramble key) based on the ECM packet to the television receiver 21 when the ECM packet is detected (S112, Yes). 242 is controlled (S113). As described above, the detection of the ECM packet means that the user is currently viewing a digital broadcast that is a non-voluntary broadcast with the television receiver 21. If there is no remaining time in step S111 (if it is zero), when an ECM packet is detected (S122), a zero key is returned to the television receiver 21 as an invalid scramble key (scramble release key) (S123).

  Subsequent to step S133, the process proceeds to a timer management process for monitoring consumption of viewing permission time. First, timeout setting is performed (S114). This time-out setting is for initial setting of a timer for monitoring whether or not the non-detection state of the ECM packet has continued for a predetermined time (for example, 3 seconds). This timer is different from the timer that manages the remaining time of the viewing permission time.

  Thereafter, every time a unit time (here, 1 second) elapses (S115, Yes), the viewing permission time is remaining for the unit time (S116). That is, the immediately preceding remaining time is reduced by unit time. As a result, when the remaining time becomes zero (S117, No), the remaining time stored in the nonvolatile memory is overwritten and updated (S121). Thereafter, the process returns to the original process.

  When the ECM packet is detected before the predetermined time has elapsed (S118, Yes), the IC card 26 is allowed to return a scramble key (scramble release key) based on the ECM packet to the television receiver 21. Thus, the switches 241 and 242 are controlled (S120).

  Even if no ECM packet is detected in step S118, the process returns to step S115 until the predetermined time elapses, and the above processing is repeated.

  When the predetermined time has elapsed without detecting an ECM packet (S119, Yes), it is determined that a timeout has occurred, and the process returns to the original process via step S121. In step S121, the latest remaining time at this time is updated by overwriting the remaining time stored in the nonvolatile memory.

  Note that the update of the nonvolatile memory for storing the remaining viewing permission time may be performed every time the unit time is subtracted in step S116. However, the subtraction result in step S116 is retained in the volatile memory, and the nonvolatile memory is updated when the time-out and the remaining time are exhausted. Thus, the processing load is reduced, the processing time is shortened, and the nonvolatile memory is updated. The effect of extending the memory life can be obtained.

  Thereafter, the card adapter 24 keeps executing the steps S122 and S123 repeatedly until a new viewing permission time is set, thereby maintaining the viewing restriction state of the non-independent broadcast.

  Although the preferred embodiments of the present invention have been described above, various modifications and changes can be made in addition to those mentioned above.

  For example, the timer update shows a configuration where the viewing time is subtracted from the viewing permission time, but the viewing time is accumulated, and the remaining viewing time is calculated by subtracting the cumulative viewing time from the initial viewing permission time. You may make it do.

DESCRIPTION OF SYMBOLS 10 ... Broadcast distribution system, 11 ... Non-independent broadcast content source, 11a ... Terrestrial digital broadcast receiving antenna, 11b ... Satellite digital broadcast receiving antenna, 12 ... Mixer, 14 ... Independent broadcast sending device, 16 ... Control device, 18 ... Purchase 20: Broadcast receiving system, 21: Television receiver, 21a: Slot, 22: Remote control (remote controller), 24: Card adapter, 24a: Adapter body, 24b: Cable, 24c: Connector, 24d: Card-like connecting member 24e ... electric contact, 24f ... power cable, 24g ... card slot, 26 ... IC card (digital broadcast viewing IC card), 50 ... video screen, 52 ... message, 140 ... terrestrial digital broadcast SI information generation unit, 142 ... Video / audio encoder, 143 ... Common message storage unit, 144 Correspondence table, 146 ... multiplexer, 148 ... OFDM modulator, 149 ... upconverter, 150 ... EMM packet generator, 211 ... tuner, 212 ... descrambler, 213 ... demultiplexer, 214 ... video / audio decoder, 215 ... I / O unit, 216 ... control unit, 217 ... CAS processing unit, 218 ... display processing unit, 219 ... infrared receiving unit, 220 ... display control unit, 221 ... display unit, 222 ... audio processing unit, 223 ... speaker, 241, 242 ... Analog switch, 243 ... Adapter control unit, 244 ... Processor, 244a ... ECM detection unit, 244b ... EMM detection unit, 244d ... Memory, 261 ... Decoding processing unit, 262 ... Decoding processing unit, 263 ... Viewing condition determination processing unit 264 ... Switch

Claims (9)

In a digital television broadcast viewing restriction method for restricting viewing of a digital television broadcast by a television receiver using a digital broadcast viewing IC card,
A card adapter is connected between the television receiver and the digital broadcast viewing IC card;
The self-broadcasting transmission device receives the television receiver identification information for identifying the television receiver whose viewing restriction is to be released, and is not scrambled together with the EMM including the viewing permission time information addressed to the card adapter of the television receiver. Sending independent broadcast content;
If the card adapter detects that the viewing permission time information is included in the EMM addressed to itself, the step of storing the viewing permission time information in a nonvolatile manner;
Each time the card adapter detects an ECM sent from the television receiver to the digital broadcast viewing IC card, updating the remaining viewing permission time represented by the viewing permission time information;
If the remaining time is not zero, the card adapter transmits a descrambling key based on the ECM from the digital broadcast viewing IC card to the television receiver in response to receiving the ECM related to the non-independent broadcast content. And sending an invalid descrambling key to the television receiver in place of the digital broadcast viewing IC card after the remaining time becomes zero,
A digital television broadcast viewing restriction method for restricting timed viewing of non-independent broadcast content by the card adapter. The card adapter stores the remaining time information indicating the remaining time in a nonvolatile manner;
The card adapter returning the current remaining time information to the television receiver at a predetermined time;
The television receiver receiving and displaying the remaining time information;
The digital television broadcast viewing restriction method according to claim 1, further comprising:   3. The digital television broadcast viewing restriction method according to claim 1, wherein the independent broadcast transmission device omits adding an ECM to the independent broadcast content. A viewing restriction system for restricting viewing of broadcast content in a television receiver using a digital broadcast viewing IC card,
A voluntary broadcast transmission device for transmitting broadcast content including at least video and audio;
A card adapter connected between the television receiver and the digital broadcast viewing IC card;
A terminal device that receives input of television receiver identification information that identifies a television receiver that is subject to viewing restriction release,
The self-broadcast transmission device receives the television receiver identification information input from the terminal device, and transmits the unscrambled self-broadcast content together with the EMM including the viewing permission time information addressed to the card adapter of the television receiver. And
When the card adapter detects that the viewing permission time information is included in the EMM addressed to itself, the card adapter stores the viewing permission time information in a nonvolatile manner,
Each time an ECM sent from the TV receiver to the digital broadcast viewing IC card is detected, the remaining time of the viewing permission time represented by the viewing permission time information is updated, and the non-independent broadcast content is updated. In response to reception of the ECM, if the remaining time is not zero, the digital broadcast viewing IC card is allowed to transmit a descrambling key based on the ECM to the television receiver, and the remaining time is zero. After that, an invalid descrambling key is sent to the television receiver instead of the digital broadcast viewing IC card,
A viewing restriction system for restricting timed viewing of non-independent broadcast content by the card adapter.   The viewing restriction system according to claim 4, wherein the terminal device accepts input of the television receiver identification information together with payment of a predetermined price. The card adapter stores the remaining time information indicating the remaining time in a nonvolatile manner, and returns the remaining time information at the present time to the television receiver at a predetermined time point.
The viewing restriction system according to claim 4, wherein the television receiver receives and displays the remaining time information.   The viewing restriction system according to claim 4 or 5, wherein the self-broadcast transmission device omits adding an ECM to the self-broadcast content. In a viewing restriction system for restricting viewing of broadcast content in a television receiver using a digital broadcast viewing IC card, a card adapter connected between the digital broadcast viewing IC card and the television receiver,
A first switch connected / disconnected so as to selectively turn on / off a communication path between the digital broadcast viewing IC card and the television receiver;
A second switch connected / disconnected to conduct / cut off the communication path in a complementary manner to the first switch;
Storage means for storing the viewing permission time information in a non-volatile manner when it is detected that the EMM addressed to itself includes the viewing permission time information;
Timer means for updating the remaining time of the viewing permission time represented by the viewing permission time information each time an ECM sent from the television receiver to the digital broadcast viewing IC card is detected;
In response to the reception of the ECM related to the non-independent broadcast content, if the remaining time is not zero, the digital broadcast viewing IC card is allowed to transmit a descrambling key based on the ECM to the television receiver. A card adapter comprising: an adapter control means for sending an invalid descrambling key to the television receiver instead of the digital broadcast viewing IC card after the remaining time becomes zero.   9. The adapter control unit according to claim 8, wherein the adapter control unit stores the remaining time in a nonvolatile manner as remaining time information, and returns the remaining time information at the present time to the television receiver at a predetermined time. Card adapter.

Images