JP2002527959A - Apparatus and method for preventing unauthorized detour of TV program block function - Google Patents

Abstract

(57) Abstract: A method and apparatus for preventing unauthorized detouring of blocks of a television program. The system of the present invention prevents unauthorized persons from bypassing the V-chip block of a particular show or channel through tuning with a cable box. The controller monitors the vertical synchronization (VSync) of the video signal coming into the television (102). If a video break is identified by the controller without the TV sending an IR command to the cable box, the controller redials the cable box to the channel that was on before it detected the video break. This prevents unauthorized persons from bypassing the V-chip block function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates generally to parental control of television programs, and more particularly to a system for preventing unauthorized circumvention of television program block functions.

BACKGROUND OF THE INVENTION A system commonly known as the V-Chip System has been proposed to the United States and approved by the United States Congress. The system includes a vertical blanking interval ("VBI") of a standard television signal to include a code indicating one or more rating factors of the next program to be broadcast.
Including the use of These rating factors are similar to those published by the Motion Picture Association of America (eg, G, PG, PG-13, R, NC
-17), and may include numerical ratings for individual categories of program characteristics such as violence, verbal, naked, and sexual content. The consumer's V-chip television system allows the consumer to program his or her television system to reject programs according to their favorite level of one or more of these rating criteria. It could allow or otherwise be programmed to allow only programs with a certain level of content according to these rating categories.

A problem with V-chip systems is that there is no feedback to the V-chip controller (TV) as to whether the cable box is really tuned to the intended channel, especially when there is a cable box connected to the TV. It is. Any unauthorized person can walk to the cable box control panel or use the remote control to change the cable box channel without the knowledge of the television. Therefore, there is a need for an improved V-chip parental block system that cannot be easily bypassed.

SUMMARY OF THE INVENTION The present invention is directed to an apparatus and method that satisfies this need. for that reason,
According to one embodiment, an apparatus and method are provided for preventing unauthorized bypassing of the V-chip program block function. According to the invention, the child guard (child g
The uard) function prevents unauthorized persons from bypassing V-chips that block certain shows or channels through tuning with a cable box. 1
In one embodiment, the child guard function is implemented in a V-Chip or V-Chip Plus +. The child guard function monitors the vertical synchronization (VSync) of the video signal coming into the television.

[0005] Because the time between VSync is different between channel changes, the controller
By monitoring the timing between successive VSyncs of the video signal and comparing it to a predetermined value, it can be detected whether a channel change has occurred. If the TV does not send infrared commands to the cable box,
If a video break is identified by the child guard controller, the controller redials the cable box to the channel it was on before it detected the video break. This prevents unauthorized persons from bypassing the V-chip block function.

[0006] Other embodiments of the present invention will be understood by those skilled in the art from the following detailed description, which shows and describes only embodiments of the present invention, with a description of the best mode considered for implementing the present invention. It will be understood that this will be readily apparent. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various other respects, all without departing from the spirit and scope of the invention. It can be carried out. Accordingly, the drawings and detailed description should be regarded as illustrative in nature and not restrictive.

[0007] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description, appended claims, and accompanying drawings.

DETAILED DESCRIPTION The present invention is directed to a system that prevents unauthorized bypass of a V-chip based parental control system. Such a parental control system is described in U.S. Patent No. 5,382,983, which is hereby incorporated by reference as if fully set forth herein. The controller may use the VSy during a channel change caused by a disturbance in the video signal.
nc is identified. If a difference is detected during VSync, the controller sends an infrared signal to the cable box to change it to the correct channel.

FIG. 1 shows a typical arrangement for the connection of a cable box and a television in one embodiment of the invention. The television signal from the cable feeder is input to the cable box 7. The cable box 7 has a channel change control. The output of the cable box, which is a signal corresponding to the channel selected by the user, is input to the television receiver 8. The television receiver 8 includes a V-chip plus + controller circuit or a V-chip control circuit. The V-chip plus + controller circuit and the V-chip control circuit may be included inside the television receiver 8 or may be part of a separate device electrically connected to the television receiver 8. The television receiver 8 can be any conventional television receiver, digital television, PC
/ Television or any other embodiment capable of receiving, processing, and displaying television signals. The remote control device 9a can be used to change the channel of the cable box 7 and / or the television receiver 8.

At any time, the V-chip controller included in the television receiver 8 keeps track of which channel is being tuned. Tuning the channel
It may be performed directly inside the television or, if a cable box is used, by a V-chip controller (television) that emits some infrared signals to the cable box. However, since the tuning mechanism between the V-chip controller and the cable box is typically only one-way, there is no feedback to the V-chip controller as to whether the cable box is really tuned to the intended channel. .

[0011] Nevertheless, the V-chip controller provides a continuous VSy of the video signal.
By monitoring the timing during nc, it can be determined whether a channel change has occurred or not. During a channel change, the time between VSync will be different for one or two periods. This difference is caused by disturbances in the video signal when tuning occurs and is used in determining whether a channel change has occurred. If a difference in VSync is detected, the controller sends an infrared signal to the cable box to tune it to the correct channel.

Referring now to FIG. 1B, a flow process for the child guard function is shown. Whenever there is a tuning event, the Vertical Synchronization
nc) There is a difference (“Vsync Disturbance”) during the timing. The controller, at block 101, knows the exact time when the tuning signal was being sent, so sets the "timing window" after the tuning signal was sent. The controller then proceeds to block 1
As shown at 02, the timing between successive VSynces of the video signal is monitored. As shown by block 103, if VSync disturbance occurred outside the "time window", one of the following two events occurred. (1) disturbance came from the television channel source itself, or (2) someone tuned the cable box, either directly by remote control or from the panel.

In any case of block 104, the controller tunes the cable box channel to a channel (other than the last correct channel). At block 106, the controller tunes the cable box back to the correct channel. During the last step of tuning back to the correct channel, the controller sets a "timing window" after the infrared signal is sent, as shown in block 105.

As shown in block 107, if “VSync disturbance” is “
If not detected during the "timing window", the controller concludes that the path of the infrared signal is covered and that the previous "VSync disturbance" was from someone trying to bypass the system. Lower. The controller is
Block the screen, as shown in block 108. If "VSyn
If "c disturbance" is detected during the "timing window", the controller has tuned the cable box to the original correct channel and has done nothing special, as shown in block 109 Recognize that.

An embodiment of a parental control system for use with the V-chip system described above is shown in FIG. A multi-channel radio frequency (RF) television signal from a cable feeder is connected to an input of a cable box 10 having channel change control. The output of cable box 10, which is a single channel high frequency television signal at the frequency of the channel selected by the user, is coupled to television drive circuit 12. The output of the television drive circuit 12 is
Is connected to the television display 16. Block circuit 14 could be a conventional analog signal transfer gate, a digital block module, or any other similar device known in the art.

For the purpose of explaining the operation of the parental control system, the television signal of each channel carried by the cable feeder is HBO, CN
N, or have additional data including a channel identification such as NBC. Preferably, the channel identifier is embedded in the VBI of the signal of each channel in XDS format.

An output of the television drive circuit 12 is also connected to an input of a VBI decoder 18 that extracts an XDS signal from a baseband television signal. VB including a data signal representing the channel identifier of the channel for which cable box 10 is being tuned
The output of I-decoder 18 is coupled to a microprocessor 20 whose output controls block circuit 14. The microprocessor 20 has a RAM 2
2

The programs to be selectively blocked are stored in RAM 22. U.S. Pat. No. 5,539,897, incorporated herein by reference as if fully set forth herein.
382,983 ("the '983 patent") and co-pending U.S. application Ser.
As described in US Pat. No. 678, for each program, the date, time, channel and program length are stored in RAM 22 in an array of stacks. The program block database stored in RAM can be generated in many different ways. One way is to use a date, time, channel,
And transmitting a group of program data consisting of content of length and length to the RAM 22 from the VBI or telephone line of the television signal.

The user invokes an on-screen menu for selection of a customized rating service to be transmitted over the VBI or telephone line, key-in the selected service, and enter program data corresponding to the selected service. The microprocessor 20 can be instructed to download the group. Another method is to key in individual program data through a remote controller.
A third method is to cursor programs from an on-screen electronic program guide ("EPG"), such as the one in which the EPG database is used to determine both programs to be blocked and programs to watch or record. Is to select.

In each case, the microprocessor 20 is connected to the output of the real-time clock in the microprocessor 20 and the cable box 10, which is recovered by the VBI decoder 18 or by monitoring the tuner and using a channel map. The channel identifier of the tuned channel is continuously monitored. These monitored attributes are compared with data in the program block database. Preferably, this is the RAM2, such as the next program television broadcast where the top of the stack is blocked, as described in the '983 patent.
2 by placing the databases in a stack. Match
), Microprocessor 20 activates block circuit 14, thereby preventing television display 16 from showing the program.

When the override system is used with a V-chip system, a code indicating one or more rating factors for later broadcast programs is also included in the VBI. In this embodiment, the user programs the television system to exclude programs according to one or more of these rating criteria. The user's choice is
It is stored in RAM 22 and compared with the code transmitted during VBI. When an excluded program is detected by the microprocessor 20, the enable override list stored in the RAM 22 is referred to through the VBI decoder 18. Blocking circuit 14, under control of the microprocessor, prevents the excluded program from appearing on television display 16 if the program is not included in the enable override list. Conversely, if the program currently being broadcast is not excluded under the rating criteria established by the user, RA
The block override list stored in M22 is
Checked by 0. The block circuit 14 allows the program to be passed to the television display 16 under the control of the microprocessor if the program is not included in the block override list.

The television programs that make up the block override list and the enable override list are described by channel, date, start time and length (or end time), or in US Pat. No. 5,335,079. In the described embodiment, as defined through the use of compressed code such as
Other configurations are needed to accommodate the addition of a cable box or video cassette recorder ("VCR").

The connection of the conventional ordinary cable box or VCR connects the cable box or VCR to the front end of the television receiver. The cable box, or VCR, has a tunable bandpass filter to tune the desired channel. The television signal from the tuned channel is modulated on a fixed carrier frequency through example channel 3;
Connected to TV receiver. The television receiver is tuned to the carrier frequency output of the cable box or VCR, regardless of the particular channel selected. Since the television receiver is always tuned to a fixed frequency, the microprocessor of FIG. 2 will not be able to ascertain when the block or selected television program is selected in the cable box or VCR.

Referring to FIG. 3, one embodiment of the present invention is shown, adapted for a system using both a cable box and a VCR, implemented by a low cost mechanism using a simple switch S1. VCR tuning problem is VCR23
Of the TV tuner 24, which is always tuned to the program enabled by the parent.

For cable box tuning, cable box 26 is used to tune scrambled programs. During setup
The user identifies a scrambled (expensive) channel in his or her cable TV lineup. This can be done automatically or manually. In this embodiment, the providers of the scrambled programs have their names (HBO ESPN, etc.) in the VBI of the television signal.
Will be sent. Thus, when a scrambled channel is selected by the user, the cable box 26 is tuned to the respective channel and the VBI is scanned by the VBI decoder 28 for a name. If no name is identified, the channel is blocked.

The recording of the VCR can also be controlled by providing the video input of the VCR with the same signal provided by the TV tuner 24 to the display 30. This signal has already been processed to ensure that it contains the licensed program. Therefore, the user can record only the permitted program.

In operation, when a user requests an unscrambled channel, the microprocessor 32 determines whether the requested channel is indicated as a scrambled channel (from the setup table).
Check to make sure, and also check to see if this channel is blocked for a particular time slot (from the PlusCode table). If the television channel is not blocked and not scrambled, switch S1 is set to position 2;
TV tuner 24 is tuned to the requested channel. If the requested channel is to be blocked, S1 is set to position 4, so TV tuner 24 has no input. The user can also record the displayed program (but no other programs can be recorded because the VCR video input comes from the TV tuner output).

If the user requests a scrambled channel, the microprocessor 32 checks to see if the requested channel is designated as a scrambled channel and if the channel is Also check to see if it is blocked for a particular time slot (from the plus code table). If the television channel is not blocked and scrambled, switch S1 is set to position 3 and cable box 26 is tuned to the requested channel. VBI decoder 28 monitors the output of the cable box and
Search for channel names in BI (broadcast broadcasts names every minute). If the name is found, it is compared to the channel name in the channel setup table. If a match is found, TV tuner 24 is tuned to channel 3 and the program is displayed. If no match is found, S1
Is switched to position 4 and the display 30 goes blank. Thus, if the user wants to change the cable box channel manually,
The check of the VBI name will fail, S1 will be switched to position 4 and the display will be blank. The user can also record the displayed program (but no other programs can be recorded because the VCR video input comes from the TV tuner output).

If the user makes a request to play the tape on the VCR, S 1 is switched to position 1 and the TV tuner 24 is tuned to channel 3.
Note that in position 1, the VCR has no RF / video input.
Therefore, the user cannot use the VCR tuner.

Referring to FIG. 4, the V-chip system was incorporated into an override system (
"V-Chip Plus + system") A block diagram of one embodiment of the present invention is shown. Preferably, the V-Chip Plus + system responds to compressed code to create an override list, such as described in U.S. Pat. No. 5,335,079, and also enhances the performance of automatic channel mapping. Including. Specifically, television tuner 34 is located at the front end of a television receiver for passing selected channels of a multi-channel RF television signal. Television tuner 34, which may be any conventional tuner in the art, including PC / TV or digital television, provides not only frequency tuning, but also amplification, down conversion to an intermediate frequency ("IF"). I do.

The TV tuner 34 connects to a television drive circuit 36 that provides the necessary signal processing for amplifying the IF signal and downconverting it to a baseband television video signal. The output of the television drive circuit 36 is connected to the block circuit 38. Blocking circuit 38 could be a conventional analog signal transmission gate, a digital blocking circuit, or any other similar device known in the art. The output of the block circuit 38 is passed through a video mixer 40 for selectively displaying the television program currently being broadcast on the selected channel.
Connected to the TV display 42.

The television tuner 34 is tuned by the microprocessor 44 to the selected channel. A user input device 46, preferably in the form of a remote infrared ("IR") controller, is connected to the microprocessor 44 so that the user can operate the television channels. . The user input device 46 allows the user to remotely program the Vchip Plus + system to exclude or edit programs according to one or more rating factors as well as edit or change the Vchip Plus + override list. Can also.

When the user reviews a particular rating set in the V Chip Plus + System or V Chip Plus + Override list, the microprocessor 44
Retrieve the appropriate information from M48 and connect it to the video processor 50 where the information is to be formatted for display. Preferably, the information stored in video processor 50 is a bitmap of what is displayed on television display 42. The video processor 50 is connected to the video mixer 40. It will be understood by those skilled in the art that the information from the video mixer 40 could be displayed on the television display 42 as a window during a television program or as a full screen instead of a television program. Video mixer 40 outputs the information as a superimposition on the currently viewed television program.

Using the user input device 46 along with the information displayed on the TV display, the user programs the V-Chip Plus + system to exclude programs according to one or more rating factors. Preferably, the user input device 46 allows manipulation of the V Chip Plus + rating system and the V Chip Plus + override list by moving the cursor on the television display 42 and entering a separate command. . The cursor control is performed by the microprocessor 44 through the cursor position register 52 and the video processor 50.
It is realized by connecting to.

User editing of the V-Chip Plus + override list sent to the television display 42 is preferably performed using compressed code such as that described in US Pat. No. 5,335,079. Is done. G-code decoder 5
4 is used to process the compressed code. If the microprocessor 44 confirms that a G code has been received from the user input device 46,
The G code will be sent to the G code decoder 54 for decoding. G
The code decoder 54 supplies the V chip plus +
Channel, date, time and length, used by microprocessor 44 to override the rating system.
("CDTL") Convert G code into information. CDTL information is disclosed in US Pat.
No. 82,983, they are stored in the RAM 48 in a stack arrangement.

The V Chip Plus + system is implemented by decoding the VBI of a television signal. VBI connected to the output of the television drive circuit 36
The decoder 56 extracts the XDS signal from the baseband television signal. The output of VBI decoder 56, including one or more rating factors for the currently broadcast television program, is connected to microprocessor 44. These rating factors extracted from the VBI of the television signal are compared by microprocessor 44 to a user programmed rating factor in RAM 48. If the microprocessor 44 determines that the currently broadcast television program should be blocked based on the programmed rating factor, the enable override list stored in RAM 48 is consulted. Microprocessor 44 will activate block circuit 38 to block the currently broadcast television program from television display 42 if the television program is not included in the enable override list.

Conversely, if the currently broadcast television program is to be televised based on the programmed rating factors stored in RAM 48, RA
The block override list stored in M48 is referenced. By the block circuit 38, under the control of the microprocessor 44, if the television program is not included in the block override list, the television program is passed to the television display 42. The V Chip Plus + Override List is referenced by the microprocessor 44 by comparing the CDTL information stored in the RAM 48 with the tuner channel set by the microprocessor 44 and the internal clock in the microprocessor (not shown). Is done. Alternatively, the channel information can be extracted from the XDS data by the VBI decoder 56 if available there.

In summary, certain types of television services are automatically detected, in embodiments of the present invention, by monitoring the channel assignments of television stations. This is accomplished by sweeping the television tuner 34 by its microprocessor 44 over its RF band. A detector 57 connected to the television tuner 34 detects whether a television station has been assigned to each of the channels as the television tuner 34 is swept over the RF band by monitoring the stability of the horizontal sync pulse. .
Microprocessor 44 can then determine the type of television service based on the channel assignment for the given geographic area. This mechanism is
The user need only use the user input device 46 to key in his or her zip code. Alternatively, automatic detection of a particular television service utilized by the user may be provided to the user using the user input device 46 to provide a VCR
And by directly keying in information about the model and brand of the cable box.

Once the particular type of television service available to the user has been identified, an appropriate channel map can be extracted from the television signal by the VBI decoder 56 based on the user's geographic location. . Microprocessor 4
4 again sweeps the television tuner 34 to find a channel with the channel map information transmitted in the VBI portion of the television signal. Microprocessor 44 then extracts the channel map marked with the identification code corresponding to the geographical location entered by the user, and stores the extracted channel map in channel map memory 58.

The described embodiment of the V-Chip Plus + system shown in FIG. 4 is directed to a fully integrated system utilizing a single microprocessor. However, those skilled in the art will readily appreciate that many applications may emerge if it is desired to retrofit the V-chip Plus + system into a television receiver having an existing V-chip system. Would. As a result of Congressional approval of V-chip systems, many television manufacturers have developed V-chip ICs ("ICs") for users to program according to a standardized rating system, and
It is contemplated that chip capabilities will be included as a standard feature. These systems provide a V-chip that can be easily integrated into existing V-chip systems.
It would be advantageous to incorporate the upgrade to ChipPlus + on a single IC. An exemplary embodiment of such a Vchip Plus + system is shown in FIG.

Referring to FIG. 5, the V-chip system includes the basic television processing and drive circuits described with respect to FIG. Specifically, the television tuner 35 is located at the front end of the television receiver for passing selected channels of the multi-channel RF television signals to the television drive circuit 37. The output of the television drive circuit 37 is connected to a block circuit 39. The output of block circuit 39 is connected to a television display 43 through a video mixer 41 for selectively displaying a television program currently being broadcast on the selected channel.

The V chip 57 connected to the output of the television drive circuit 37 extracts an XDS signal from the baseband television signal. The rating factor for the currently broadcast television program is extracted from the XDS data and compared to a user programmed rating factor stored in the internal memory of the V-chip 57. If the V-Chip 57 determines that the currently broadcast television program should be blocked based on the programmed rating factor, the V-Chip 57 will block the currently broadcast television program from the television display 43. , Block circuit 3
7 is activated by the V-chip 57. Conversely, if the currently broadcast television program is to be televised based on the programmed rating factor in memory, block circuit 39 is disabled by V-chip 57,
The television program is allowed to pass to the television display 43.

The V-chip system allows a user to edit a rating factor by using an editor. Specifically, when the user wishes to review a particular rating set in the V-chip system, the V-chip 57 retrieves appropriate information from memory under the control of the user input device and retrieves it. , Connect the video processor 51 where the information is to be formatted for display. The video processor 51 is connected to the video mixer 41. It will be understood by those skilled in the art that the information from the video mixer 41 could be displayed on the television display 43 as a window during a television program or as a full screen instead of a television program, The video mixer 41 outputs the information as a superimposition on a currently viewed television program. Using the user input device with the information displayed on the television display 43, the user:
Program the V-Chip system to exclude programs according to one or more rating factors.

The customization of the block function of the V chip 57 is executed by the external V chip + IC 47. While implementing V-Chip Plus circuits in an IC is an economical approach, it will be appreciated by those skilled in the art that the functionality of V-Chip Plus can be implemented using separate components. Will be. Preferably, the V-Chip Plus + IC 47 is designed to be easily retrofitted into existing television receivers already equipped with V-Chip capabilities. V Chip Plus + IC47
It is inserted in the path between the V chip 57 and the block circuit 39. This requires that the V chip 57 be separated from the block circuit by removing the wire 59. In operation, when the V-Chip 57 determines that the currently broadcast television program should be blocked based on the programmed rating factor, the block signal is connected to the V-Chip Plus + IC 47.
In response to the block signal, the microprocessor 4 in the V-chip plus + IC 47
5 refers to the enable override list stored in the RAM 49.
Microprocessor 45 will activate block circuit 39 to block the currently broadcast television program from television display 43 if the television program is not included in the enable override list. Conversely, if the V-Chip 57 determines that the currently broadcast television program should be televised based on the programmed rating factor, the unblock (unb
locking) signal is connected to the V Chip Plus + IC 47. In response to the block release signal, the block override list stored in the RAM 49 is referred to. By the block circuit 39, under the control of the microprocessor 45, if the television program is not included in the block override list, the television program is passed to the television display 43.

The V Chip Plus + IC 47 is also connected to the video processor 51 for editing the user's V Chip Plus + Override List. In this form, the user can program the V-Chip system to exclude programs according to one or more rating factors, as well as edit or modify the V-Chip Plus + override list. When the user wants to review or edit the V-Chip Plus + override list, the microprocessor 45 retrieves the appropriate information from the RAM 49 and connects it to the video processor 51 where the information is to be formatted for display. I do. The video processor 51
The information is output through the video mixer 41, preferably as a superimposition on the currently viewed television program. Editing to the V-chip plus + override list is performed using, for example, compressed code. G code decoder 55
Is used to process the compressed code in the same way as described above with respect to the embodiment shown in FIG.

User input device 46 preferably takes the form of a portable remote IR transmitter that communicates with an IR receiver connected to microprocessor 44. As shown in FIG. 6, the IR transmitter has a housing 6 on which many control keys are located.
Has zero. Channel Surf (CHANNEL SURF) key 62, V chip plus + (V-CHI
A (P PLUS +) key 64, a review (REVIEW) key 69, a babysitter (BABYSITTER) key 71, a menu (MENU) key 63, an input (ENTER) key 65, and a change (CHANGE) key 67 are all provided on the housing 60. Can be Below a review key 69 and a babysitter key 71, an up key 66, a down key 68, a left key
A (left) key 70 and a right (right) key 72 are arranged. Numeric keypad 73
Are located below the input key 65 and the change key 67. The block and unblock functions are set and selected in two different modes, TV mode and Guide mode.

In the TV mode, the user interface is preferably fully menu driven. On-screen op
) is displayed on the television display for programming the V Chip Plus + system and editing the V Chip Plus + override list. These on-screen options can be accessed from a normal television viewing mode by selecting any of the channel surf keys 62, V-chip plus + keys 64, or menu keys 63 on the user input device. In guide mode, the user interface is provided through an electronic program guide displayed on the screen. On-screen options in the program guide are displayed on the television display to program the V-Chip Plus + system and edit the V-Chip Plus + override list. By pressing the VCR Plus + key on the remote control, the Guide's Schedule screen
) Displays the VCR Plus + interface. The user must enter the plus code (
Plus Code) and you can select the following actions you want to take on the program: Record (default), Watch, or Block. These options are displayed as tiles in the area within the guide.

Referring now to FIG. 7, an example of Vsync timing and its relationship to cable box channel change is shown. The V-chip controller can distinguish between tuning by the controller and when someone is trying to bypass the V-chip block function. If the tuning was initiated by the controller, the controller will send the VSync immediately after the tuning signal was sent.
A timing window for the turbulence Within the timing window,
If a difference is detected during VSync timing, the controller determines that the channel change is authentic, as shown in FIG. An example for the period during VSync is 16.67 ms for some cable boxes.
If a timing difference is detected outside this window, the controller will take the following actions: (a) If the correct channel is 2, the controller tunes the cable box to channel 3 And then send another IR signal to tune back to the correct channel (channel 2). (B) If the correct channel is something other than 2 (eg, channel x), the controller sends I
Send an R signal, then send another IR signal to tune back to channel x (the correct channel).

However, there may be rare cases where the VSync timing itself “glitches” even when channel tuning is not occurring. In other words, when the timing of VSync changes from the previous frame (rarely)
possible. For example, this may occur in the case of a "split channel", such as broadcasting programs from different sources during different times of the day. When the source of the program changes, the VSync timing also changes. The methods and systems described above are designed to address this situation. The controller tunes the cable box first to a nearby channel and then tunes it to the correct channel.

Nevertheless, anyone can block the IR signal from the controller with an object and then manually tune the cable box to the channel desired by the person.
To prevent this, during the process of tuning back to channel x (the correct channel), the controller sets a timing window, similar to what happens in a normal tuning process. If no VSync timing difference is detected within this timing window, the controller determines that someone has tampered with the process and is blocking the video screen.

The tuning of the “adjacent” channel ensures that a difference occurs during VSync timing by the next step of “tune back to the correct channel”. Keep track of the current channel number `` smart (sma
rt) "cable box. If a new channel number equal to its current channel number is received, the "smart" cable box will never tune. As a result, there is no difference in VSync timing as if someone blocked the path of the IR signal. If the "nearby" channel tuning step was omitted, the controller would not detect the difference when the timing difference came from the channel itself. Thus, tuning of the “nearby” channel ensures that there is a difference during VSync timing during the “tune to the correct channel” step.

However, if the “window” setting is too wide, the system can be broken. For example, suppose that the correct channel (current channel) is channel 5 and that an unauthorized person tunes to channel 11 on the "blocked list". Unlicensed persons can change the cable box channel to channel 1
Start tuning by hand to 1. However, the V-chip controller uses channel 1
“VSync disturbance” is detected from the tuning to “1”. It immediately sends an IR signal to tune it to channel 2. IR
It does not matter if the signal is blocked at this point. The V-chip controller then sends another IR signal to tune the cable box back to channel 5 with the timing window set immediately after the signal.
Unauthorized people can now use something that blocks the controller's IR signal,
At the same time, the cable box can be tuned to channel 9 by hand. If the timing window is set properly, a "VSync disturbance" created by manual tuning performed by an unauthorized person will not be detected within that timing window and the screen will be blocked.

The process of tuning in the cable box begins when the last digit of the channel number is received (or in some cases an “input key”), so the time between the channel number digits (the cable Randomization (up to the timing limitations of the numbers inside the box brand) can make the system more secure. The purpose of this is to make the detour method more difficult.

The values for the timing window vary with the type and brand of cable box. However, the exact setting of the timing window for each type of cable box can be determined with considerably higher accuracy.
In one embodiment, the determination of the timing window is performed automatically by the controller. The controller determines the timing window by sending an IR signal to tune the cable box to the first channel. The controller then sends another IR signal, such as tuning the cable box, to some other channel to measure the time between "VSync disturbance" and the IR signal to tune. Next, the extra margin (e
xtra margin) can be added as a threshold to the measured timing window.

For example, the controller sends an IR signal to tune the cable box to channel 9 and then asks if the cable box has been tuned to channel 9. After the brand has been identified, the controller displays "V
To measure the time between the "Sync Disturbance" and the IR signal to tune, sending another IR signal such as tuning the cable box to some other channel very similar to the real broadcast signal it can. A suitable combination would be channel 3 and channel 4, all carrying the real signal. Then, a small timing margin can be added to the measured time and used as a timing window setting. The above process can be performed during the "cable box branding" process or during the first use of the cable box by the user. The established timing window can then be saved in a memory such as a non-volatile memory for future reference. The user using the password can manually adjust this saved timing window.

In another embodiment, the timing window can be determined dynamically by the controller over a range of operating periods. Proper buffering is provided to store timing during VSync over the period of operation. The timing window containing the appropriate threshold is determined from the buffered data. The advantage of this method is that if the VSync timing changes for any reason, the controller will automatically adjust for it. The established timing window can be saved in a memory such as a non-volatile memory for future reference. The user using the password can manually adjust this saved timing window.

It will be understood by those skilled in the art that various modifications can be made to the above described described and other embodiments of the invention without departing from the broad invention scope of the invention. . Therefore, the invention is not to be limited to the specific embodiments or configurations disclosed, but any alterations, adaptations or modifications within the scope and spirit of the invention as defined by the appended claims. It will be understood that they are also intended to include

[Brief description of the drawings]

FIG. 1A is a block diagram in the form of a typical television and cable box.

FIG. 1B is an exemplary flow diagram for a child guard function.

FIG. 2 is an electrical block diagram of a parental control device according to one embodiment of the present invention.

FIG. 3 is an electrical block diagram of a parental control device used in a cable system, according to one embodiment of the present invention.

FIG. 4 is an electrical block diagram of a parental control device combined with a Vchip system using VCR Plus + and automatic channel mapping, according to one embodiment of the present invention.

FIG. 5 is an electrical block diagram of a parental control device combined with a VCR Plus + integrated circuit retrofitted into an existing V-chip system.

FIG. 6 is a plan view of a remote controller for operating the system of FIG. 4, according to one embodiment of the present invention.

FIG. 7 is a simple timing diagram for some example consecutive VSyncs.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID , IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW (72 ) Inventor Tam Tonity United States of America 90250 Hawthorn Isis Avenue 13604 F-term (reference) 5C025 AA23 BA13 BA18 BA25 BA30 DA05 DA08 DA10 5C064 BA01 BB08 BC08 BC20

Claims (25)

[Claims] 1. A method for preventing unauthorized detour of a television program block system including a cable box and a television tuner, comprising: setting a first timing window; and transmitting from the cable box to the television tuner. Continuous V of the video signal
Monitoring timing during Sync; if timing between consecutive VSyncs is not detected within the first timing window, recognizing an unauthorized channel change and reconnecting the cable box to a second; A method comprising: tuning to a channel; and tuning the cable box to return to the channel on which the cable box was tuned before an unauthorized channel change occurred. Setting a second timing window; monitoring a timing of the video signal for a next VSync; if a timing for a next VSync is detected within the second timing window. 2. The method of claim 1, further comprising the step of activating the function if not. 3. The method of claim 2, wherein the activated function is blocking the video signal. 4. The method of claim 2, wherein said first timing window is the same as said second timing window. 5. The method of setting a first timing window, comprising:
The method of claim 1, comprising measuring a period between two consecutive tuning events. 6. The method of claim 5, further comprising adding a threshold to the measured time period. 7. The step of setting a first timing window includes measuring timing between a plurality of successive tuning events and averaging the measured timings. The method of claim 1, wherein 8. A system for preventing unauthorized detour of a television program block system, comprising: a cable box for receiving a plurality of video signals; and an electrical cable for receiving the video signals. A means for setting a first timing window; and a continuous VSy of video signals from the cable box to the television receiver.
means for monitoring timing during nc; and means for tuning the cable box to a second channel if timing between successive VSyncs is not detected within the first timing window; Means for tuning the cable box to return to the channel on which the cable box was tuned before a channel change occurred;
A system comprising: 9. A means for setting a second timing window; a means for monitoring timing of a next VSync of the video signal;
9. The system of claim 8, further comprising: means for activating a function if a timing for a next VSync is not detected within the second timing window. 10. The system of claim 9, wherein the activated function is blocking the video signal. 11. The system according to claim 9, wherein the first timing window is the same as the second timing window. 12. The system of claim 8, wherein said means for setting a first timing window includes means for measuring a period between two consecutive tuning events. 13. The system of claim 12, further comprising means for adding a threshold to the measured time period. 14. The means for setting a first timing window includes means for measuring timing between a plurality of successive tuning events, and means for averaging the measured timings. 9. The system according to claim 8, wherein 15. A method for preventing an unauthorized detour of a TV program block function, comprising: responding to a channel change command from a television receiver electrically connected to a cable box, in response to a channel change command. Tuning to a first channel; and a continuous VSy of video signals from the cable box to the television receiver.
monitoring the timing during nc; comparing the monitored VSync timing to a predetermined value to determine if an unauthorized channel change has occurred; if the VSync timing is the predetermined value If not, recognizing an unauthorized channel change and tuning the cable box to the second channel; and tuning the cable box back to the first channel. A method characterized by the following. 16. The method of claim 15, wherein the predetermined value is a timing window set by a controller. 17. The method of claim 16, wherein the timing window is set by measuring a time period between two consecutive tuning events. 18. The method of claim 16, wherein the timing window is set by measuring timing between a plurality of successive tuning events and averaging the measured timing. The described method. 19. A child guard system for preventing an unauthorized detour of a TV program block function, the child guard system comprising: a first terminal that responds to a channel change command from a television receiver electrically connected to a cable box; The cable box being tuned to the channel of: and a continuous VSy of video signals from the cable box to the television receiver.
nc; a controller for monitoring the timing during nc; means for comparing the monitored VSync timing to a predetermined value to determine whether an unauthorized channel change has occurred; If not, means for tuning the cable box to the second channel, and means for tuning the cable box back to the first channel. 20. The system according to claim 19, wherein said controller is a V-chip controller. 21. The system of claim 19, wherein said controller is a V-chip plus + controller. 22. A method for preventing bypassing a television parental control system including a cable box and a television receiver, the method comprising: transmitting a first channel from the cable box to the television receiver. Monitoring the timing between successive VSynces of the video signal; responsive to the monitored timing, recognizing an unauthorized channel change;
Tuning the cable box to a second channel; and tuning the cable box back to the first channel. 23. A system for preventing bypass of a television parental control system, comprising: a cable box for receiving a plurality of video signals; and A connected television tuner, a controller for monitoring timing between successive VSynces of video signals for a first channel from the cable box to the television tuner; and responsive to the monitored timing, A system comprising: means for tuning a cable box to a second channel; and means for tuning the cable box back to the first channel. 24. The system according to claim 23, wherein said controller is a V-chip controller. 25. The system of claim 23, wherein said controller is a V-Chip Plus + controller.