JP4533950B2 - Information processing apparatus and video signal output control method - Google Patents

Description

  The present invention relates to an information processing apparatus capable of outputting an encrypted digital video signal and a video signal output control method.

  Currently, digital broadcasting is becoming the mainstream instead of analog broadcasting. Further, a source on which a digital signal such as a DVD is recorded is used. Along with the conversion from analog to digital, it is conceivable to output the digital signal as it is to the television.

  In the case of digital output, high-quality video content can be used, so the copyright protection should be strengthened so that the provided video content will not be illegally reproduced or illegally copied. is required. The HDCP (High-bandwidth Digital Content Protection System) standard has been proposed as a digital content protection method.

  The HDCP standard is a standard for safely transmitting video content requiring copyright protection in a digital video signal transmission system. Authentication between a transmission device and a reception device, sharing of a key for authentication, and transmission It stipulates specifications such as encryption of video signals to be transmitted.

In authentication such as the HDCP standard, a device key for individually authenticating a communication partner apparatus by public key cryptography is used. When the authentication is successful between the transmission device and the reception device, the transmission device encrypts and transmits the video signal using the device key, and the reception device decrypts the received video signal using the device key. For example, Patent Document 1 discloses a digital image transmission apparatus using an authentication method based on the HDCP standard or the like.
JP 2002-314970 A

  By the way, when a notebook personal computer is used as the information output device, it is conceivable to use a docking station to output a signal to a television. Consider installing a personal computer in the docking station and removing the personal computer (information processing apparatus) from the docking station (external device) with the encrypted video signal output to the television. In this case, the video signal may remain output from the personal computer.

  An object of the present invention is to provide an information processing apparatus that appropriately controls a video signal output to an external device and a video signal output control method that is executed by the information processing apparatus.

  In order to achieve the above object, an information processing apparatus according to an embodiment of the present invention includes a main body that can be locked to an external device by a lock mechanism, a display controller that is provided in the main body and outputs an encrypted video signal. A clock generator for supplying a clock signal to the display controller, and detecting whether the lock mechanism is in a locked state or an unlocked state, and when the lock mechanism is changed from the locked state to the unlocked state, And means for stopping the supply of the clock signal to the display controller in order to stop the output of the encrypted video signal to the external device by the display controller.

  A video signal output control method according to an embodiment of the present invention is a video signal output of an information processing apparatus comprising: a main body that can be locked to an external device by a lock mechanism; and a display controller that outputs an encrypted video signal. A control method for detecting whether the lock mechanism is in a locked state or an unlocked state, and when the lock mechanism changes from the locked state to the unlocked state, the encrypted video signal is In order to stop outputting to the external device by the display controller, supply of a clock signal to the display controller is stopped.

  It is possible to appropriately control the video signal output to the external device.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the configuration of an information processing apparatus according to an embodiment of the present invention will be described with reference to FIG. 1 and FIG. This information processing apparatus is realized as a battery-driven portable notebook personal computer 10.

  FIG. 1 is a perspective view of a notebook personal computer with a display unit opened and a docking station as an expansion unit. FIG. 2 is a perspective view from the back side of the computer.

  The computer 10 includes a computer main body 11 and a display unit 12. The display unit 12 incorporates a display device composed of an LCD (Liquid Crystal Display) 17, and the display screen of the LCD 17 is positioned substantially at the center of the display unit 12.

  The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position and a closed position. The computer main body 11 has a thin box-shaped housing, and a keyboard 13, a power button 14 for turning on / off the computer 10, a touch pad 16, and the like are arranged on the upper surface thereof.

  When the computer 10 is installed in the docking station 200 as an external device, the docking connector 201 provided in the docking station 200 and the docking port 20 provided on the back side of the computer 10 shown in FIG. Can be done.

  FIG. 3 shows the configuration of the back side of the docking station 200. As shown in FIG. 3, the docking station 200 includes a PS / 2 connector 202, a USB (Universal Serial Bus) connector 203, a DVI (Digital Visual Interface) connector 204, a parallel connector 205, a LAN connector 206, and a locking mechanism as a fixing mechanism. 207. When the computer 10 is installed in the docking station 200, the computer 10 can be fixed to the docking station 200 by operating the lock mechanism 207.

  As shown in FIG. 4, when the computer 10 is installed in the docking station 200, the docking station 200 and the external display 300 corresponding to the HDCP (High-bandwidth Digital Content Protection) standard as an external display device are connected via a DVI cable. By connecting, the video generated by the computer 10 can be displayed on the external display 300.

  Next, with reference to FIG. 5, the system configuration of the computer 10, the docking station 200, and the external display 300 will be described.

  As shown in FIG. 2, the computer includes a CPU 111, a north bridge 112, a main memory 113, a GPU (Graphics Processing Unit) 114, a south bridge 119, a TV tuner 120 as a receiving unit for receiving broadcast program data, A BIOS-ROM 121, a hard disk drive (HDD) 122, an embedded controller / keyboard controller IC (EC / KBC) 124, a LAN controller 126, an I / O controller 127, and the like are provided.

  The CPU 111 is a processor provided to control the operation of the computer 10 and executes an operating system (OS) and various application programs loaded from the hard disk drive 122 to the main memory 113.

  The CPU 111 also executes a BIOS (Basic Input Output System) program stored in the BIOS-ROM 121. The BIOS-ROM 121 is a program for hardware control.

  The north bridge 112 is a bridge device that connects the local bus of the CPU 111 and the south bridge 119. The north bridge 112 also includes a memory controller that controls access to the main memory 113. The north bridge 112 also has a function of executing communication with the GPU 114 via an AGP (Accelerated Graphics Port) bus or the like.

  The GPU 114 is a display controller that controls the LCD 17 or the external display 300 used as a display monitor of the computer 10. This GPU 114 has a video memory (VRAM), and a video signal forming a display image to be displayed on the LCD 17 of the display unit 12 or the external display 300 from display data written in the video memory by the OS / application program. Is generated.

  The GPU 114 has a coder 115 for encrypting video data in order to comply with the HDCP (High-bandwidth Digital Content Protection) standard. The coder 115 has a first key ROM 116 in which a plurality of encryption keys are stored for encrypting video data.

  The south bridge 119 controls each device on an LPC (Low Pin Count) bus. The south bridge 119 incorporates an IDE (Integrated Drive Electronics) controller, a PCI (Peripheral Component Interconnect) controller, and a USB controller for controlling a hard disk drive (HDD) 122 and an optical disk drive (ODD) 123.

  The optical disk drive 123 is a drive unit for driving a storage medium such as a DVD or a CD. Further, the optical disk drive 123 writes data to a recordable optical medium such as a CD-R or DVD-R, and writes data to a rewritable optical medium such as a CD-RW, DVD-RW, or DVD-RAM. It is a drive unit that performs writing / erasing.

  A LAN controller 126 for transferring data with devices connected to the network is connected to the south bridge 119 via a PCI bus.

  The embedded controller / keyboard controller IC (EC / KBC) 124 is a one-chip microcomputer in which an embedded controller for power management, a keyboard (KB) 13, and a keyboard controller for controlling the touch pad 16 are integrated. is there. The embedded controller / keyboard controller IC (EC / KBC) 124 has a function of powering on / off the computer 10 in accordance with the operation of the power button 14 by the user by operating in cooperation with the power supply controller. is doing.

  The EC / KBC 124 can detect the state (lock / unlock) of the lock mechanism 207.

  The I / O controller 127 has a function for transferring data with a device that supports the IEEE1284 standard.

  The external display 300 includes a decoder 301 for demodulating the video signal encrypted by the coder 115, a second key ROM 302 for storing an encryption key for demodulating the video signal, and a display conforming to the DDC (Display data Channel) standard. EEPROM 303 for storing device information such as resolution and refresh rate.

  The docking station 200 has a function for transmitting a video signal from the coder 115 to the decoder 301 of the external display 300, a function for transmitting a control signal between the coder 115 and the decoder 301, and display information stored in the EEPROM 303. To the EC / KBC 124 in accordance with the DDC standard, the PS / 2 connector 202 for connecting the keyboard / mouse, the USB connector 203, the DVI connector 204, the LAN controller 126, and the LAN cable 126 A LAN connector 206 into which one end is inserted, and a parallel port 205 into which an I / O controller 127 is connected and one end of an IEEE1284 standard cable is inserted.

  The computer 10 includes a Microsoft operating system 140 having a system power saving function called ACPI (Advanced Configuration and Power Interface). This ACPI function is effective not only in battery operation time for a so-called notebook personal computer equipped with a battery, but also for a so-called desktop personal computer not equipped with a battery. Effective for power consumption and temperature control.

  FIG. 6 is a block diagram showing ACPI and an external output function of a personal computer as an information processing apparatus according to an embodiment of the present invention.

  The application 142 on the operating system 140 accesses the DirectShow 143 via the kernel 141, and generates a reproduction signal from the data of mpeg2 using the function of the DirectShow 143. The reproduction signal is supplied from the DirectShow 143 to the GPU 114. The GPU 114 encrypts the reproduction signal and outputs it to the video signal output port 20 </ b> A included in the docking port 20.

  The EC / KBC 124 can detect the state of the lock mechanism 207 when the computer 10 is installed in the docking station 200. The EC / KBC 124 has a lock register 1241 for writing the state of the lock mechanism 207. The EC / KBC 124 has a function of notifying the BIOS program 1211 of the state of the lock mechanism 207 via the south bridge 119 and the north bridge 112 when the lock mechanism 207 is operated. The BIOS program 1211 has a function of notifying the GPU driver 146 that drives the GPU 114 of the state of the lock mechanism 207 notified from the EC / KBC 124 via an HCI (Host Controller Interface) 145. The GPU driver 146 has a function of requesting the ACPI driver 147 to stop supplying the clock signal from the clock generator 150 to the GPU 114 via the kernel 141 when the lock mechanism 207 is released. .

  The ACPI driver 147 rewrites the ACPI register 1131 provided in the memory 113 so as to stop the supply of the clock signal to the GPU 114. The BIOS program 1211 has a function of enabling a clock supply stop signal supplied from the south bridge 119 to the clock generator 150 when the ACPI register 1131 is rewritten and the supply of the clock signal to the GPU 114 is stopped. . The clock generator 150 has a function of stopping the supply of the clock signal to the GPU 114 when the clock supply stop signal is enabled.

  Processing when the computer 10 is installed in the docking station 200 will be described with reference to FIG.

  When the user places the computer 10 in the docking station 200 to which the external display 300 is connected, the lock mechanism 207 is locked, and the computer 10 is fixed to the docking station 200, the EC / KBC 124 has the lock mechanism 207 locked. It is detected (step S1). The EC / KBC 124 notifies the BIOS program 1211 that the lock has occurred (step S2). Further, the EC / KBC 124 writes that the lock state is in the lock register 1241 (step S3).

  Next, a procedure of processing when the external display 300 is detected and protected content is output to the external display 300 will be described with reference to FIG. The protected content (video source source) is broadcast program data received by the TV tuner 120 or data reproduced from a storage medium by the optical disc drive 123.

  If the power of the external display 300 is on, the EC / KBC 124 recognizes the external display 300 (step S11) and acquires device information of the external display 300 stored in the EEPROM 303 (step S12). The EC / KBC 124 notifies the GPU driver 146 of the acquired device information via the HCI 145 (step S13). The device information includes information on whether or not the external display 300 is compatible with HDCP.

  The GPU driver 146 refers to the lock register 1241 and determines whether or not the lock mechanism 207 is locked (step S14). If it is not locked (No in step S14), the output of the video signal is stopped.

  In the locked state (Yes in step S14), the GPU driver 146 determines whether the external display 300 supports HDCP (step S15). If the HDCP is not supported (No in step S15), the process is terminated.

  If it is compatible with HDCP (Yes in step S15), the GPU driver 146 performs authentication processing by communicating the encryption keys stored in the first key ROM 116 and the second key ROM 302 between the GPU 114 and the external display 300. Is performed (step S16).

  After the authentication process, the GPU driver 146 permits the coder 115 to output the encrypted video signal to the decoder 301, and the video signal is transmitted (step S17).

  As described above, since the video signal is not output to the docking station 200 when the lock mechanism 207 is unlocked, the video signal is not output even if the computer 10 is detached from the docking station 200. There is no fear of being copied.

  Next, a processing procedure when the computer 10 is removed from the docking station 200 while the encrypted video signal is being output will be described with reference to FIG.

  When the lock mechanism 207 is unlocked, the EC / KBC 124 detects that the lock mechanism 207 is unlocked (step S21). The EC / KBC 124 notifies the BIOS program 1211 that the lock mechanism 207 has been unlocked (step S22). The EC / KBC 124 writes an unlock state in the lock register 1241 (step S23). The BIOS program 1211 notifies the GPU driver 146 through the HCI 145 that an unlock state has been established (step S24). The GPU driver 146 requests the ACPI driver 147 to stop the clock supply to the GPU 114 via the kernel 141 (step S25). The ACPI driver 147 rewrites the ACPI register 1131 and sets to stop the clock supply to the GPU 114 (step S26).

  The BIOS program 1211 reads the setting written in the ACPI register 1131 (step S27). The BIOS program 1211 instructs the south bridge 119 via the north bridge 112 to enable the clock supply stop signal supplied to the clock generator 150 (step S28).

  The clock generator 150 detects that the clock supply stop signal is enabled, and stops the supply of the clock signal to the GPU 114 (step S29). When the supply of the clock signal is stopped, the GPU 114 does not operate and the video signal is not output from the video signal output port 20A.

  As described above, when the lock mechanism 207 is unlocked while the video signal is being output, the video signal is not output to the docking station 200, so that even if the computer 10 is removed from the docking station 200, the video signal is output. Since no signal is output, there is no fear that the video signal is copied.

  Note that the supply of the drive voltage to the GPU 114 may be stopped so that the video signal is not output from the video signal output port 20A. Further, a switching element may be provided between the video signal output port 20A and the GPU 114, and the video signal may not be output from the video signal output port 20A by controlling the switching element.

  As shown in FIG. 10, the coder 115 and the first key ROM 116 may not be built in the GPU 114. In this case, an 8-bit parallel bus or UART can be used as the low-speed control signal instead of the I2C signal.

  In the case of the computer 10 using the external coder shown in FIG. 10, the risk is higher than that in the case of the configuration shown in FIG. 5, so that it can be applied to the case without the docking station 200. That is, a signal indicating that the casing of the computer 10 has been opened (opened) may be used instead of the undock event. Since the detection itself of the opening of the personal computer casing is a conventional technique, description and illustration thereof are omitted.

  Further, in the configuration shown in FIG. 5, two independent I2C buses are provided, but of course, they can be integrated into one bus as shown in FIG. In that case, it is necessary to confirm that the transfer rate of the bus is sufficiently high with respect to the control signal or the like.

  In the case of FIG. 5, since the docking station 200 is originally provided with a mechanism and a circuit for generating an undock event, the connection between the notebook personal computer 10 and the docking station 200 is disconnected using this mechanism. Detected. Similarly, a means for detecting that the connection between the docking station 200 and the external display 300 is disconnected is also prepared as standard. In the case of the configuration of FIG. 5, there is a DVI_detect signal as one of the DVI signals, and the GPU 114 detects this and notifies the BIOS-ROM 121 that the external display device has been removed. Accordingly, in this case as well, processing for an undock event can be performed.

  Further, the computer described above has a DVI connector 204 and can output a signal conforming to the DVI standard. However, an HDMI connector is provided in place of the DVI connector so that a signal conforming to the DVI standard can be output. Also good.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a diagram showing a notebook personal computer as an information processing apparatus according to an embodiment of the present invention and a docking station as an external device. The perspective view which shows the back surface side of a computer. The perspective view which shows the structure of the back side of a docking station. The figure which shows the state which installed the computer in the docking station and enabled the output image of a computer to an external display. The system block diagram of a computer, a docking station, and an external display. The block diagram for showing ACPI and the external output function of a personal computer as an information processor concerning one embodiment of the present invention. The flowchart which shows the procedure of a process at the time of installing a computer in a docking station. The flowchart which shows the procedure of a process when detecting an external display and outputting the protected content to an external display. 7 is a flowchart showing a processing procedure when a computer is removed from a docking station while an encrypted video signal is being output. The figure which shows the modification of the system configuration | structure shown in FIG. The figure which shows the modification of the system configuration | structure shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Notebook-type personal computer, 11 ... Computer main body, 12 ... Display unit, 13 ... Keyboard, 14 ... Power button, 16 ... Touch pad, 17 ... LCD, 20 ... Docking port, 20A ... Video signal output port, 111 ... CPU, 112 ... North bridge, 113 ... Main memory, 1131 ... ACPI register, 114 ... GPU, 115 ... coder, 116 ... Key ROM, 119 ... South bridge, 120 ... TV tuner, 121 ... BIOS-ROM, 1211 ... BIOS program 122 ... Hard disk drive, 123 ... Optical disk drive, 124 ... Embedded controller / keyboard controller IC, 1241 ... Lock register, 126 ... LAN controller, 127 ... I / O controller, 40 ... operating system, 141 ... kernel, 142 ... application, 145 ... HCI, 146 ... GPU driver, 147 ... ACPI driver, 150 ... clock generator, 200 ... docking station, 201 ... docking connector, 203 ... USB connector, 204 ... DVI Connector, 205 ... Parallel connector, 206 ... LAN connector, 207 ... Lock mechanism, 300 ... External display, 301 ... Decoder, 302 ... Second key ROM, 303 ... EEPROM

Claims (8)

A body that can be fixed to an external device by a fixing mechanism;
A display controller provided in the main body for generating an encrypted video signal;
A clock generator for supplying a clock signal to the display controller;
Means for detecting whether the fixing mechanism is in a locked state or an unlocked state, and writing information indicating the detected state in the first register;
Means for controlling the operation of the controller in order to save power of the main body, wherein information written in the first register is changed from information indicating the locked state to information indicating the unlocked state. In case of change, the clock generator is stopped from supplying the clock signal to the display controller in order to stop outputting the encrypted video signal generated by the display controller to the external device. Means for writing the information indicating to the second register;
Means for instructing the clock generator to stop the supply of the clock signal to the display controller when information indicating that the supply of the clock signal is stopped is written in the second register. A characteristic information processing apparatus.   When the fixing mechanism is changed from the fixed state to the non-fixed state, the control unit controls the state in which the video signal is output to the external device to the state in which the output of the video signal to the external device is stopped. The information processing apparatus according to claim 1. A body that can be locked to an external device by a locking mechanism;
A display controller provided in the main body and outputting an encrypted video signal;
A clock generator for supplying a clock signal to the display controller;
When the lock mechanism detects whether it is locked or unlocked, and the lock mechanism changes from the locked state to the unlocked state, the encrypted video signal is transmitted by the display controller to the external Means for stopping the supply of the clock signal to the display controller in order to stop output to the device;
An information processing apparatus comprising: A body that can be locked to an external device by a locking mechanism;
A display controller provided in the main body and outputting an encrypted video signal;
A clock generator for supplying a clock signal to the display controller;
The display controller detects whether the lock mechanism is locked or unlocked, and stops the operation of the display controller when the lock mechanism changes from the locked state to the unlocked state. Means for stopping the supply of the clock signal to:
An information processing apparatus comprising: A body that can be locked to an external device by a locking mechanism;
A display controller provided in the main body for generating a video signal;
An encryption unit for encrypting a video signal generated by the display controller;
A clock generator for supplying a clock signal to the display controller;
When the lock mechanism detects whether the lock mechanism is locked or unlocked, and the lock mechanism changes from the locked state to the unlocked state, the video signal encrypted by the encryption unit is Means for stopping the supply of the clock signal to the display controller in order to stop output to the device;
An information processing apparatus comprising: An external device that outputs a video signal to an external display device having a decryption unit that performs decryption based on an encryption key, and a body that can be locked by a lock mechanism;
A display controller that is provided in the main body and generates a video signal encrypted based on the encryption key;
A clock generator for supplying a clock signal to the display controller;
When the lock mechanism detects whether it is locked or unlocked, and the lock mechanism changes from the locked state to the unlocked state, the encrypted video signal is transmitted by the display controller to the external Means for stopping the supply of the clock signal to the display controller in order to stop output to the device;
An information processing apparatus comprising: A video signal output control method for an information processing apparatus, comprising: a main body that can be locked to an external device by a lock mechanism; and a display controller that outputs an encrypted video signal,
Detecting whether the locking mechanism is locked or unlocked;
In order to stop outputting the encrypted video signal to the external device by the display controller when the lock mechanism changes from the locked state to the unlocked state, a clock signal to the display controller A video signal output control method characterized by stopping supply. A video signal output control method for an information processing apparatus, comprising: a main body that can be locked to an external device by a lock mechanism; and a display controller that outputs an encrypted video signal,
Detecting whether the locking mechanism is locked or unlocked;
A video signal output control method, wherein when the locking mechanism changes from the locked state to the unlocked state, the supply of a clock signal to the display controller is stopped in order to stop the operation of the display controller. .

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