Abstract:
An electronic device having a clock portion for counting time and having the time on the clock portion set based on time information acquired from outside has a notification portion that communicates information of the time counted by the clock portion to an external device via a physical line. Alternatively, an electronic device has a first clock portion counting time and an acquisition portion that acquires, from an external device having a second clock portion for counting time and having the time on the second clock portion set based on time information acquired from outside, information of the time counted by the second clock portion via a physical line, and the time on the first clock portion is set based on the information acquired by the acquisition portion.

Description:
[0001]    This application is based on Japanese Patent Application No. 2008-158712 filed on Jun. 18, 2008, the contents of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to automatic time (clock) setting in an electronic device. 
         [0004]    2. Description of Related Art 
         [0005]    Nowadays, digital home electronic appliances are widely spread, which include some, such as digital televisions, which can acquire time information automatically by receiving a digital broadcast wave, and others, such as digital movie cameras, which cannot acquire time information automatically. 
         [0006]    With a device that cannot acquire time information automatically, the user needs to set the time manually at its purchase, and on the occasions of replacement of a battery, updating of software, etc. as well. Depending on the device, the time so set may lead or lag by several seconds a month; thus the time needs to be set correct again whenever the error has become unduly large. Also, it is expected that, if a system of daylight saving time (summer time) is introduced in the future, the time will then need to be set correct regularly. 
         [0007]    An object of the present invention is to provide an automatic time setting system that enables automatic time setting on an electronic device that on its own requires manual setting of the time. 
       SUMMARY OF THE INVENTION 
       [0008]    To achieve the above object, according to one aspect of the invention, an electronic device having a clock portion for counting time and having the time on the clock portion set based on time information acquired from outside, the electronic device comprises a notification portion that communicates information of the time counted by the clock portion to an external device via a physical line (that is, wiredly). 
         [0009]    To achieve the above object, according to another aspect of the invention, an electronic device comprises a first clock portion counting time and an acquisition portion that acquires, from an external device having a second clock portion for counting time and having the time on the second clock portion set based on time information acquired from outside, information of the time counted by the second clock portion via a physical line. Here, the time on the first clock portion is set based on the information acquired by the acquisition portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is an overall schematic diagram of an automatic time setting system according to one embodiment of the invention; 
           [0011]      FIG. 2  is a schematic configuration diagram of a digital television according to one embodiment of the invention; 
           [0012]      FIG. 3  is a schematic configuration diagram of a digital movie camera according to one embodiment of the invention; 
           [0013]      FIG. 4  is a diagram showing a CEC communication sequence at the time of starting playback on the digital movie camera; 
           [0014]      FIG. 5  is a diagram showing a CEC communication sequence at the time of displaying a time setting screen on the digital movie camera; 
           [0015]      FIG. 6  is a diagram showing a CEC communication sequence at the time of transition into a stand-by state on the digital movie camera; 
           [0016]      FIG. 7  is a diagram showing a CEC communication sequence at the time of automatic time setting on the digital television; 
           [0017]      FIG. 8A  is a diagram showing the format of a time information notification command; and 
           [0018]      FIG. 8B  is a diagram showing the format of a time information request command. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    Embodiments of the present invention will be described below with reference to the accompanying drawings. 
         [0020]      FIG. 1  is an overall schematic diagram of an automatic time setting system according to one embodiment of the invention. The automatic time setting system according to one embodiment of the invention comprises a digital television  100  and a digital movie camera  200 . The digital television  100  can automatically acquire time information contained in a digital broadcast wave received via an antenna  1 , and can automatically set the time. The digital movie camera  200  on its own cannot automatically acquire time information, and requires manual time setting. The digital television  100  and the digital movie camera  200  are therefore connected together by an HDMI (High-Definition Multimedia Interface) cable so that, via an HDMI-CEC (Consumer Electronics Control) line, which allows two-way communication, time information is communicated from the digital television  100  to the digital movie camera  200  to enable automatic time setting on the digital movie camera  200 . 
         [0021]      FIG. 2  is a schematic configuration diagram of a digital television according to one embodiment of the invention. The digital television  100  according to one embodiment of the invention comprises a tuner  2 , an HDMI input/output portion  3 , an AV input portion  4 , a DEMUX (demultiplexer)  5 , an AV decoder  6 , a remote control receiver  8 , a switch  9 , a video processing portion  10 , an OSD/scaler  11 , a video output portion  12 , an audio processing portion  13 , an audio output portion  14 , a loudspeaker  15 , a CPU  16 , a clock portion  17 , a CPU  18 , a memory  19 , a display portion  20 , and a hot-plug control portion  21 . 
         [0022]    The antenna  1  is installed outdoors, receives a digital broadcast wave, and outputs a high-frequency digital modulated signal to the tuner  2 . 
         [0023]    The tuner  2  extracts from the high-frequency digital modulated signal a signal of a particular frequency. The tuner  2  then decodes the selected digital modulated signal to output a transport stream to the DEMUX  5 . 
         [0024]    The DEMUX  5  separates the transport stream into a video stream and an audio stream confirming to MPEG2 (Moving Picture Expert Group 2), PSI/SI (Program Specific Information/Service Information), etc. 
         [0025]    The AV decoder  6  comprises a video decoder that decodes the video stream and an audio decoder that decodes the audio stream, and outputs the decoded video and audio information to the switch  9 . 
         [0026]    The HDMI input/output portion  3  has three unillustrated HDMI terminals, to which an HDMI cable can be connected. Video/audio information inputted from an external device via a video/audio signal line included in the HDMI cable is inputted to the switch  9 . CEC commands inputted from the external device via an HDMI-CEC line included in the HDMI cable is inputted to the CPU  16 . CEC commends outputted from the CPU  16  to the HDMI input/output portion  3  is inputted via the HDMI-CEC line to the external device. Moreover, 5 V supply electric power is fed from the external device via a DDC5V line included in the HDMI cable and via the HDMI input/output portion  3  to the hot-plug control portion  21 . The hot-plug control portion  21  outputs a control signal to the HDMI input/output portion  3  thereby to control the level (low/high) of a hot-plug line. 
         [0027]    The AV input portion  4  has an S terminal and a D terminal, neither of which is illustrated. Video/audio information inputted from an external device via an S- or D-terminal cable is outputted to the switch  9 . 
         [0028]    The switch  9  is a switch that switches among the video/audio inputs from the AV decoder  6 , the HDMI input/output portion  3 , and the AV input portion  4 . The video processing portion  10  performs digital video processing on the video information fed to it via the switch  9 . The OSD/scaler  11  is a circuit that generates video data based on character information and color information specified from the CPU  18 , and that performs processing for reducing received broadcast video. The OSD/scaler  11  achieves display of an EPG (electronic program guide) based on broadcast program information, display of data broadcast, display of menu screens, etc. The video output portion  12  coverts the video information inputted to it from the OSD/scaler  11  into a format of an input signal to the display portion  20 . The display portion  20  displays video based on the video signal inputted to it from the video output portion  12 . 
         [0029]    The audio processing portion  13  receives audio information via the switch  9 , and performs D/A conversion on it to output an analog audio signal to the audio output portion  14 . The audio output portion  14  amplifies and otherwise processes the audio signal inputted to it from the audio processing portion  13 , and outputs the result to the loudspeaker  15 . The loudspeaker  15  reproduces sounds based on the audio signal inputted to it from the audio output portion  14 . 
         [0030]    A remote control transmitter  7  is a transmitter for feeding commands to the digital television  100 . When a key provided on the remote control transmitter  7  is operated, a remote control signal corresponding to the key is transmitted from a light-emitting portion of the remote control transmitter  7 . The remote control receiver  8  receives the remote control signal, converts it into an electrical signal, and feeds the result to the CPU  16 . 
         [0031]    The CPU  16  mainly performs processing on remote control signals from the remote control transmitter  7  and on signals resulting from keys on an unillustrated operation portion being operated, and controls the tuner  2  etc. Even when the power is turned off by the remote control transmitter  7 , the CPU  16  keeps being supplied with electric power so as to keep operating to perform processing such as monitoring of remote control signals. On the other hand, the CPU  18  mainly controls the OSD/scaler  11 , the video processing portion  10 , the display portion  20 , etc. The CPUs  16  and  18  can communicate with each other so that, under the control of the CPU  16 , the CPU  18  and the individual blocks in a video/audio processing portion  22  can be stopped and started. The memory  19  stores control programs and various kinds of data. 
         [0032]    The clock portion  17  keeps time to feed current time information to the CPU  16 , and sets the time based on time information fed from the CPU  16 . 
         [0033]      FIG. 3  is a schematic configuration diagram of a digital movie camera  200  according to one embodiment of the invention. The digital movie camera  200  according to one embodiment of the invention comprises a camera portion  30 , a microphone  31 , a loudspeaker  32 , a video/audio processing portion  33 , a control portion  34 , an external memory interface  35 , an operation portion  36 , a display portion  37 , an HDMI input/output portion  38 , and a clock portion  39 . 
         [0034]    During movie shooting, information of the video shot by the camera portion  30  is subjected to compression processing by the video/audio processing portion  33 , and is recorded, via the external memory interface  35 , to an external memory  40 . During sound recording, information of the audio inputted via the microphone  31  is subjected to compression processing by the video/audio processing portion  33 , and is recorded to the external memory  40 . 
         [0035]    During movie playback, information of video read out from the external memory  40  is subjected to decompression processing by the video/audio processing portion  33 , so that a movie is displayed on the display portion  37 . During sound playback, information of audio read out from the external memory  40  is subjected to decompression processing by the video/audio processing portion  33 , so that sounds are reproduced from the loudspeaker  32 . 
         [0036]    In a case where movie playback and/or sound playback is performed on an external device connected to the digital movie camera  200  by an HDMI cable, information on video and/or audio read out from the external memory  40  is subjected to decompression processing by the video/audio processing portion  33 , and is then transferred from the HDMI input/output portion  38  to the external device in a format conforming to TMDS (Transition Minimized Differential Signaling). The control portion  34  performs processing for CEC communication with the external device via the HDMI input/output portion  38 . 
         [0037]    The clock portion  39  keeps time to feed current time information to the control portion  34 , and sets the time based on time information fed from the control portion  34 . The operation portion  36  has various keys for giving instructions to the digital movie camera  200 . 
         [0038]    Next, automatic time setting operation according to one embodiment of the invention will be described. Here, it is assumed that the digital television  100  and the digital movie camera  200  are connected together by an HDMI cable, and that, in the digital television  100 , time information contained in the PSI/SI separated from a transport stream by the DEMUX  5  is regularly fed to the clock portion  17  by the CPU  16  so that, based on that time information, the clock portion  17  sets the time. 
         [0039]    At Start of Playback on Digital Movie Camera:  FIG. 4  shows a CEC communication sequence at the time of starting playback on the digital movie camera. First, when the operation portion  36  of the digital movie camera  200  is so operated as to start playback, at step S 40 , the control portion  34  transmits a playback start command (Image View On), which notifies of the start of playback, to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. The CPU  16  of the digital television  100  thus receives the playback start command via the HDMI input/output portion  3 . 
         [0040]    Then, at step S 41 , the control portion  34  of the digital movie camera  200  transmits an input switch command (Active Source) to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. The CPU  16  of the digital television  100  thus receives the input switch command via the HDMI input/output portion  3 , and switches the switch  9  for the video/audio input from the HDMI input/output portion  3 . Thus, playback video/audio information from the digital movie camera  200  is inputted via the HDMI input/output portion  3  to the switch  9 , so that the display portion  20  displays video and the loudspeaker  15  reproduces sounds. 
         [0041]    Then, at step S 42 , the control portion  34  of the digital movie camera  200  transmits a vendor ID notification command (Device Vendor ID), which notifies of a vendor ID, to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. The CPU  16  of the digital television  100  thus receives the vendor ID notification command, and if it verifies that the received vendor ID notification command indicates a predetermined vendor, then at step S 43 , the CPU  16  transmits a vendor ID notification command to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the vendor ID notification command via the HDMI input/output portion  38 , and verifies whether or not the received vendor ID notification command indicates a predetermined vendor. 
         [0042]    Then, at step S 44 , the CPU  16  of the digital television  100  transmits a time information notification command, which contains information of the current time counted by the clock portion  17 , to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. 
         [0043]      FIG. 8A  shows the format of the time information notification command. At the head comes address information on the destination, followed by information indicating the command type (OP_Code). This information is, for example, 0x89 to indicate a Vendor Command. Next comes information (for example, 0x10) that indicates, among different Vendor Commands, a time information notification command. To follow are individual items of information indicating the year, month, day, hour, and minute of the current time. 
         [0044]    Since the current time information contained in the time information notification command does not include information on the second, it is when the clock portion  17  counts a change in the minute that the CPU  16  transmits the time information notification command to the digital movie camera  200 . The control portion  34  of the digital movie camera  200  then receives the time information notification command via the HDMI input/output portion  38 , and feeds the current time information contained in the time information notification command to the clock portion  39 , so that, based on the current time information fed to it, the clock portion  39  sets the time. At this time, the second of the time is set to 0. 
         [0045]    After the transmission of the time information notification command at a change in the minute as described above, the time information notification command may be transmitted at the next increment in the minute again, to set the time on the digital movie camera  200  again. On the other hand, in a case where information on the second is added to the current time information contained in the time information notification command, the time information notification command is transmitted immediately, instead of at a change in the minute as described above. This applies to other embodiments described below as well. 
         [0046]    At Display of Time Setting Screen on Digital Movie Camera:  FIG. 5  shows a CEC communication sequence at the time of displaying a time setting screen on the digital movie camera. First, when the operation portion  36  of the digital movie camera  200  is so operated as to display a time setting screen, the control portion  34  displays a time setting screen on the display portion  37  and, at step S 50 , transmits a vendor ID notification command (Device Vendor ID) to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. 
         [0047]    The CPU  16  of the digital television  100  thus receives the vendor ID notification command via the HDMI input/output portion  3 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, then at step S 51 , the CPU  16  transmits a vendor ID notification command to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the vendor ID notification command via the HDMI input/output portion  38 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, then at step S 52 , the control portion  34  transmits a time information request command (Vendor Command), which requests time information, to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. 
         [0048]      FIG. 8B  shows the format of the time information request command. At the head comes address information on the destination, followed by information indicating the command type (OP_Code). This information is, for example, 0x89 to indicate a Vendor Command. Next comes information (for example, 0x11) that indicates, among different Vendor Commands, a time information request command. 
         [0049]    Then, when the CPU  16  of the digital television  100  receives the time information request command via the HDMI input/output portion  3 , an advance is made to step S 53 . At step S 53 , when the clock portion  17  counts a change in the minute, the CPU  16  transmits a time information notification command (Vendor Command), which contains information of the current time counted by the clock portion  17 , to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the time information notification command via the HDMI input/output portion  38 , and feeds the current time information contained in the received time information notification command to the clock portion  39 , so that, based on the current time information fed to it, the clock portion  39  sets the time. At this time, the second of the time is set to 0. 
         [0050]    At Transition into Stand-by State on Digital Movie Camera:  FIG. 6  shows a CEC communication sequence at the time of transition into a stand-by state on the digital movie camera. Here, the stand-by state denotes a power-saving state in which electric power is kept supplied only to those circuits that need to be in operation all the time. First, when the remote control transmitter  7  for the digital television  100  is so operated as to shift the digital movie camera  200  into the stand-by state, then at step S 60 , the CPU  16  transmits a vendor ID notification command (Device Vendor ID) to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. 
         [0051]    The control portion  34  of the digital movie camera  200  thus receives the vendor ID notification command via the HDMI input/output portion  38 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, then at step S 61 , the control portion  34  transmits a vendor ID notification command to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. 
         [0052]    The CPU  16  of the digital television  100  thus receives the vendor ID notification command via the HDMI input/output portion  3 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, an advance is made to step S 62 . At step S 62 , when the clock portion  17  counts a change in the minute, the CPU  16  transmits a time information notification command (Vendor Command), which contains information of the current time counted by the clock portion  17 , to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the time information notification command via the HDMI input/output portion  38 , and feeds the current time information contained in the received time information notification command to the clock portion  39 , so that, based on the current time information fed to it, the clock portion  39  sets the time. At this time, the second of the time is set to 0. 
         [0053]    Then, at step S 63 , the CPU  16  of the digital television  100  transmits a stand-by notification command (Standby) to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the stand-by notification command via the HDMI input/output portion  38 , and shifts the digital movie camera  200  into the stand-by state. 
         [0054]    At Automatic Time Setting on Digital Television:  FIG. 7  shows a CEC communication sequence at the time of automatic time setting on the digital television. When the CPU  16  feeds the time information contained in the PSI/SI separated from the transport stream by the DEMUX  5  to the clock portion  17  for time setting, at step S 70 , the CPU  16  transmits a vendor ID notification command (Device Vendor ID) to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. 
         [0055]    The control portion  34  of the digital movie camera  200  thus receives the vendor ID notification command via the HDMI input/output portion  38 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, then at step S 71 , the control portion  34  transmits a vendor ID notification command to the digital television  100  via the HDMI input/output portion  38  and via the HDMI-CEC line. 
         [0056]    The CPU  16  of the digital television  100  thus receives the vendor ID notification command via the HDMI input/output portion  3 , and if it verifies that the received vendor ID notification command indicates a predetermined vendor, an advance is made to step S 72 . In step S 72 , when the clock portion  17  counts a change in the minute, the CPU  16  transmits a time information notification command (Vendor Command), which contains information of the current time counted by the clock portion  17 , to the digital movie camera  200  via the HDMI input/output portion  3  and via the HDMI-CEC line. The control portion  34  of the digital movie camera  200  thus receives the time information notification command via the HDMI input/output portion  38 , and feeds the current time information contained in the received time information notification command to the clock portion  39 , so that, based on the current time information fed to it, the clock portion  39  sets the time. At this time, the second of the time is set to 0. 
         [0057]    As described above, according to the present invention, even a digital movie camera  200  that on its own requires manual time setting can acquire time information from the digital television  100  connected to it by an HDMI cable and set the time automatically. This permits the digital movie camera  200  to have a capability equivalent to the automatic time setting capability of the digital television  100 . 
         [0058]    The embodiments described above are simply examples, and allow any modifications and variations unless departing from the spirit of the invention. For example, the digital television  100  may be connected by an HDMI cable to a power supply cradle on which the digital movie camera  200  is mounted so that the digital movie camera  200  acquires time information from the digital television  100  via the HDMI cable and the power supply cradle. 
         [0059]    For example, another possible embodiment is one in which a PC that acquires time information from a server over the Internet and that sets the time automatically may be connected to a device such as a digital movie camera via a USB (Universal Serial Bus) so that the device acquires time information from the PC and sets the time automatically.