Abstract:
Disclosed is a data transmission system including: a server device including a title data obtaining section which obtains title data from content providing section in which digital data containing AV data and title data thereof is stored; and a client device including: a title display controlling section which displays on outputting section the obtained title data; a title data storing section which stores title data; and a title data managing section which stores plural title data obtained from plural content providing sections in the title data storing section for each of the content providing section, wherein the server device and the client device communicate with each other through a transmission path, and the title data managing section, based on predetermined input operation information, allows the title display controlling section to display the titles stored in the title data storing section on the outputting section.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a data transmission system capable of transmitting AV data (video data and audio data) with high bit rates through a wireless transmission path. More specifically, the present invention relates to a data transmission system capable of efficiently obtaining and displaying title data from a plurality of content providing sections.  
         [0003]     2. Description of Related Art  
         [0004]     In recent years, DVD/HDD recorders or personal computers have been remarkably widespread. Accompanying this tendency, video properties capable of being privately viewed at home are also increasing. Further, it is desired to freely enjoy viewing at any required time or place the contents such as video information stored in DVD/HDD recorders or personal computers. Therefore, there is proposed a technology for enabling the contents to be outputted to client devices such as TV sets or personal computers using a home network. For a technology for transmitting vast quantities of data such as video data or audio data at high speed-in real time, for example, IEEE 1394 is adopted for an interface for connecting digital TV sets or digital videos.  
         [0005]     Further, for simplifying the connection between devices, a wireless LAN has been recently used to allow connection of DVD/HDD recorders, personal computers or LCD monitors. For a typical technology using the wireless LAN, IEEE 802.11 standardized in IEEE is adopted, and a technology of using 2.4 GHz band becomes mainstream. The 2.4 GHz band is referred to as an ISM (Industrial, Scientific and Medical) band and is a frequency band used in an industrial, medical or household microwave oven. In Japan, a frequency band from 2.400 to 2.497 GHz is allocated to a wireless LAN.  
         [0006]     A data transmission system utilizing the above-described wireless LAN is configured by connecting between an AV source device (content providing section) such as a DVD/HDD recorder and a server device, and by connecting between outputting section such as an LCD monitor and a client device, thereby performing transmission of data such as video data via wireless communication between the server device and the client device. In such a data transmission system, remote control operation of the DVD/HDD recorder is performed to the client devices, so that the DVD/HDD recorder can be controlled through the server device. For example, information (e.g., a title of the AV data recorded in media) of the content providing section can be displayed on outputting section and further, when performing a predetermined input operation in this display screen, desired AV data can be easily played.  
         [0007]     For technologies for allowing information transmitted from content providing section to be displayed on this outputting section, for example, the following documents are disclosed. That is, JP 2003-174598A discloses an information processor in which a plurality of data strings can be inputted from a plurality of input sources (content providing section) to allow images respectively corresponding to the plurality of data strings to be simultaneously displayed. Further, WO 00/01191A discloses a technology that in an AVC system including a plurality of AV devices connected with each other through a transmission path, a controller with user interface is allowed to display operating screen information of a device as a controlling object.  
         [0008]     The above-described wireless transmission system has an advantage that wirings between devices can be omitted. On the contrary, the system has a defect that as compared with a case of directly wired-connecting the content providing section and the outputting section, data transmission process is complicated and therefore, a reaction rate to a remote control operation in the client device side is reduced (delay occurs). Further, in a case of using a plurality of content providing sections, only information from one enabled content providing section can be displayed on outputting section. Specifically, when switching of the content providing section to be enabled as well as display of desired information is not required from the client device, information from other content providing section cannot be displayed. Therefore, a wasting time is required for users, and moreover, an input operation from the remote controller becomes complicated.  
       SUMMARY OF THE INVENTION  
       [0009]     It is one of objects of the present invention to provide a data transmission system in which title data from a plurality of content providing sections can be efficiently obtained and displayed through a wireless transmission path as well as users can reduce a load due to input operations.  
         [0010]     According to a first aspect of the invention, a data transmission system comprises: a server device comprising a title data obtaining section which obtains title data from content providing section in which digital data containing AV data and title data corresponding to the AV data is stored; and a client device comprising: a title display controlling section which displays on outputting section the title data obtained by the title data obtaining section; a title data storing section which stores title data; and title data managing section which stores a plurality of title data obtained from a plurality of content providing sections in the title data storing section for each of the content providing section, wherein the server device and the client device communicate with each other through a transmission path, and the title data managing section, based on predetermined input operation information, allows the title display controlling section to display the plurality of titles stored in the title data storing section on the outputting section.  
         [0011]     Preferably, the title data obtaining section monitors the title data stored in the content providing section and, when the title data is updated in the content providing section, obtains the title data. Herein, the wording “the title data is updated” represents for example that DVD media is exchanged in a DVD recorder or the like, or a program is recorded to a hard disk in a HDD recorder or the like. For example, the exchange of DVD media can monitor by monitoring operation of a DVD player, and the recording of a program on a HDD can monitor by monitoring titles which are recorded to the HDD in predetermined intervals.  
         [0012]     Preferably, the title data contains command data for playing AV data corresponding to the title data, and the client device further comprises a playback controlling section which, based on received predetermined input operation information, transmits the playback command data to the server device so as to require playback of corresponding AV data. By doing so, users can easily play the AV data corresponding to a desired title and therefore, can reduce a load due to the input operation from the remote controller.  
         [0013]     Preferably, the title data managing section, based on received predetermined input operation information, allows the title display controlling section to display the plurality of titles stored in the title data storing section on the same screen of the outputting section. By doing so, the titles stored in the plurality of content providing devices can be confirmed on the same screen. As a result, users can easily select the titles to be played.  
         [0014]     Preferably, the server device is connected to the plurality of content providing sections. By doing so, the system constitution can be simplified, because it is not necessary to provide one on one the content providing device and server device.  
         [0015]     According to a second aspect of the invention, a video signal processor comprises: title display controlling section which displays, on outputting section, title data obtained from a plurality of content providing sections in which digital data containing AV data and title data corresponding to the AV data is stored; title data storing section which stores the title data; and title data managing section which stores a plurality of title data obtained from the plurality of content providing section in the title data storing section for each of the content providing section, wherein the title data managing section, based on received predetermined input operation information, allows the title display controlling section to display the plurality of titles stored in the title data storing section on the outputting section.  
         [0016]     According to the present invention, in the data transmission system configured such that the server device and the client device can communicate with each other through a transmission path, the client device comprises title data storing section which can store the title data, and title data managing section which stores a plurality of title data obtained from a plurality of content providing sections in the title data storing section for each of the content providing section. The title data managing section, on the basis that predetermined input operation information is received, allows the plurality of titles stored in the title data storing section to be displayed on the outputting section by the title display controlling section. Therefore, even if switching of the content providing section to be enabled is not required from the client device, desired information can be instantaneously displayed. As a result, a display time of the title data can be shortened as well as an input operation from a remote controller can be simplified. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The present invention will become more fully understood from the detailed description given hereinbelow and the appended drawings which given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, and wherein;  
         [0018]      FIG. 1  is a schematic construction view of a data transmission system according to the present embodiment;  
         [0019]      FIG. 2  is a schematic construction view of a server device  20 ;  
         [0020]      FIG. 3  is a schematic construction view of a client device  30 ;  
         [0021]      FIG. 4  is one display example of a title menu displayed on an output device  40 ;  
         [0022]      FIG. 5  is a flowchart showing a title data obtaining process; and  
         [0023]      FIG. 6  is a flowchart showing a title data displaying process.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Preferred embodiments of the present invention will be described below by referring to drawings.  FIG. 1  is a schematic construction view of a data transmission system according to the present embodiment.  
         [0025]     A data transmission system  100  according to the present embodiment is composed of content providing devices  11  and  12  which provides contents (analog data or digital data) containing video data and audio data, a server device  20 , a client device  30  and an output device  40  such as an LCD monitor. In the present embodiment, the system  100  is configured such that two content providing devices  11  and  12  of a PVR  11  and DVD recorder  12  such as a hard disk recorder are connected to the server device  20 .  
         [0026]     In the data transmission system  100 , for example, connection between the server device  20  and each of the content providing devices  11  and  12  is performed through a predetermined cable. Further, AV data as an analog signal and title data as a digital signal are supplied to the server device  20  from the content providing devices  11  and  12 . Herein, the system  100  may be configured such that also the AV data is supplied as a digital signal.  
         [0027]     In the content providing devices  11  and  12 , for example, digital AV data compression-coded in accordance with the MPEG 2 system and title data corresponding to the AV data are stored. This title data contains, for example, text data and command data for playing corresponding AV data. Further, the content providing devices  11  and  12  have an AV data forming section (not shown). The devices  11  and  12  read out contents (video data and audio data) from recording media such as a hard disk or DVD and then convert the contents into a predetermined format to output the contents as analog AV data.  
         [0028]      FIG. 2  is a schematic construction view of the server device  20 . As shown in  FIG. 2 , the server device  20  has A/D converters  21   a  and  21   b , an MPEG encoder  22 , a title data obtaining section  23 , a wireless LAN communication section  24 , a high-frequency amplifier  25 , an antenna  26  and a server controller  27 . The server device  20  transmits AV data  1  and  2  as well as title data  1  and  2  supplied from the content providing devices  11  and  12  to the client device  30  in an MPEG2 transport stream format.  
         [0029]     The A/D converter  21   a  converts the analog AV data transmitted from the content providing device  11  into digital data. The A/D converter  21   b  converts the analog AV data transmitted from the content providing device  12  into digital data. The MPEG encoder  22  compression-codes, in accordance with an MPEG2 scheme, the digital AV data supplied from the A/D converters  21   a  and  21   b.    
         [0030]     The title data obtaining section  23  obtains, from the content providing devices  11  and  12 , the title data  1  and  2  respectively corresponding to the AV data  1  and  2 . Herein, the title data obtaining section  23  is configured so as to monitor the title data stored in the content providing devices  11  and  12  and, when the title data is updated in the content providing devices  11  and  12 , obtains the title data. For example, the section  23  monitors the title data recorded in a hard disk at a predetermined time interval and, when program is newly recorded in the content providing device (PVR)  11 , obtains the title data. Further, the section  23  monitors a switching action in a disk tray of the content providing device (DVD)  12  and, when it is determined that DVD media are exchanged, obtains the title data.  
         [0031]     The wireless LAN communication section  24  performs protocol processing and modulation-demodulation processing on the digital data outputted from the MPEG encoder  22  and the title data obtaining section  23 . The high frequency amplifier  25  amplifies a high frequency component of RF signals and transmits the amplified signals to the client device  30  through the antenna  26 . For example, through a communication channel with a frequency band of which the center frequency is 2.412 GHz, the amplifier  25  transmits the RF signals.  
         [0032]     The server controller  27  is composed of a CPU, RAM and ROM (not shown). The ROM stores various control programs, and the CPU operates according to the control program within the ROM while using the RAM as a work area. For example, when receiving an AV data playback request from the client device  30 , the server controller  27  reads out the corresponding AV data from the content providing devices  11  and  12 , and controls each circuit to allow the AV data to be transmitted to the client device  30 .  
         [0033]      FIG. 3  is a schematic construction view of the client device  30 . As shown in  FIG. 3 , the client device  30  has an antenna  31 , a high-frequency amplifier  32 , a wireless LAN communication section  33 , an MPEG decoder  34 , a D/A converter  35 , a title data managing section  36 , a title data storing section  37 , a client controller  38  and a remote control receiver  39 . The device  30  receives the digital data transmitted from the server device  20  and outputs the data to the output device  40 .  
         [0034]     The antenna  31  receives RF signals transmitted through the communication channel from the server device  20  and supplies the received RF signals to the high-frequency amplifier  32 . The high-frequency amplifier  32  amplifies a high frequency component of RF signals received by the antenna  31  and supplies the amplified RF signals to the wireless LAN communication section  33 . The wireless LAN communication section  33  performs protocol processing and modulation/demodulation processing on the digital data supplied from the high-frequency amplifier  32 .  
         [0035]     The MPEG decoder  34  expansion-decodes the digital AV data supplied from the wireless LAN communication section  33 . The D/A converter  35  analog-converts the digital AV data supplied from the MPEG decoder  34  or the title data supplied from the title data managing section  36  and then outputs the analog data to the output device  40 .  
         [0036]     The title data managing section  36  stores the title data supplied from the wireless LAN communication section  33  in the title data storing section  37  for each of the content providing devices. Specifically, the section  36  stores the title data  1  as title data from the content providing device  11  and stores the title data  2  as title data from the content providing device  12 . Further, the section  36 , on the basis that input operation information on a title list display is received from the remote controller  50 , allows the plurality of titles stored in the title data storing section  37  to be displayed on the output device  40  by the title display controlling section.  
         [0037]     The remote control receiver  39  receives signals (e.g., infrared rays) transmitted from the remote controller  50  operated by users.  
         [0038]     The client controller  38  is composed of a CPU, RAM and ROM (not shown). The ROM stores various control programs, and the CPU operates according to the control programs within the ROM while using the RAM as a work area. For example, the section  38  serves as the above-described title display controlling section. Further, the section  38 , on the basis that the remote control receiver  39  receives from the remote controller  50  the input operation information on playback, serves as playback controlling section which transmits playback command data contained in the title data to the server device  20  to thereby require playback of corresponding AV data.  
         [0039]      FIG. 4  is one display example of a title menu displayed on the output device  40 . As shown in  FIG. 4 , the titles T 1  and T 2  corresponding to the AV data stored in the content providing devices  11  and  12  are simultaneously displayed on the output device  40 . In a conventional technology, the title data can be obtained only from the enabled content providing device. Therefore, there can be displayed either the title T 1  corresponding to the AV data stored in the content providing device  11  or the title T 2  corresponding to the AV data stored in the content providing device  12 .  
         [0040]     Further, in the title menu shown in  FIG. 4 , when moving a cursor C to a desired title (“movie B” in  FIG. 4 ) to perform an input operation of the Play button using the remote controller  50 , users can play the AV data corresponding to the title.  
         [0041]      FIG. 5  is a flowchart showing process control in obtaining the title data from the content providing devices  11  and  12 .  
         [0042]     First, in the server device  20 , the title data obtaining section  23  obtains the title data  1  from the content providing device  11  (step S 101 ). Next, the title data obtaining section  23  obtains the title data  2  from the content providing device  12  (step S 102 ).  
         [0043]     Next, the section  23  transmits the title data  1  and  2  to the client device  30  (step S 103 ). Further, in the client device  30 , the title data managing section  36  stores the title data  1  and  2  in the title data storing section  37  (step S 104 ).  
         [0044]     Thus, the title data corresponding to the AV data stored in the content providing devices  11  and  12  is stored in the title data storing section  37 . For example, the above-described title data obtaining process is performed when the power sources of the server device  20  and the client device  30  are turned on. Thereafter, the obtaining process is further performed when the title data stored in the content providing devices  11  and  12  is updated.  
         [0045]     In the flowchart of  FIG. 5 , after obtaining the title data  1  and  2 , these data is simultaneously transmitted to the client device  30 . Further, the title data may be transmitted to the client device  30  every time the title data is obtained.  
         [0046]      FIG. 6  is a flowchart showing process control in displaying the title data on the output device  40 .  
         [0047]     First, in the client device  30 , it is determined whether display of the title list is required, specifically, whether an input operation for displaying the title list is performed from the remote controller  50  (step S 201 ). When it is determined that the display of the title list is required, the title data  1  and  2  corresponding to the AV data stored in the content providing devices  11  and  12  is simultaneously displayed on the output device  40  (step S 202 ). At this time, the title menu shown in  FIG. 4  is displayed on the output device  40 .  
         [0048]     Subsequently, it is determined whether the title is specified in this title list display menu, specifically, whether an input operation for selecting and playing the title is performed from the remote controller  50  (step S 203 ). Further, when it is determined that the title is specified, playback process of the AV data corresponding to the specified title is performed (step S 204 ). In other words, the client device  30  transmits to the server device  20  the playback command data contained in the title data of the selected title to thereby request playback of corresponding AV data. Then, the device  30  receives and plays the relevant AV data sent back from the server device  20 .  
         [0049]     Thus, in the present embodiment, the client device  30  comprises title data storing section  37  which can store title data, and title data managing section  36  which stores a plurality of title data  1  and  2  obtained from a plurality of content providing sections  11  and  12  in the title data storing section  37  for each of the content providing section  11  and  12 . Further, the title data managing section  36 , on the basis that predetermined input operation information is received from the remote controller  50 , allows the plurality of titles  1  and  2  stored in the title data storing section  37  to be displayed on the output device  40 . Therefore, even if switching of the content providing device to be enabled is not required from the client device  30 , desired information (e.g., a title list) can be instantaneously displayed. As a result, a display time of the title list can be shortened as well as an input operation from the remote controller  50  can be simplified.  
         [0050]     Further, users can easily play the AV data corresponding to a desired title and therefore, can reduce a load due to the input operation from the remote controller  50 . Further, the title data managing section  36 , on the basis that the input operation information from the remote control device  50  is received, allows the plurality of titles stored in the title data storing section  37  to be simultaneously displayed on the output device  40  by the title display controlling section. Therefore, the titles stored in the plurality of content providing devices  11  and  12  can be confirmed on the same screen. As a result, users can easily select the titles to be played.  
         [0051]     The invention performed by the present inventor is described in detail above with reference to the embodiment. The present invention is not limited to the above-described embodiment, and alterations can be made therein as appropriate without departing from spirit and scope of the inventions.  
         [0052]     For example, in the above embodiment, the wireless LAN with a 2.4 GHz band specified by IEEE 802.11g is described. In addition thereto, other transmission technologies can also be used. For example, a wireless LAN with a 5.2 GHz band specified by IEEE 802.11a, a wireless LAN with a 2.4 GHz band specified by IEEE 802.11b or an optical wireless LAN can be used. Further, the present embodiment can be applied not only to a case of using wireless transmission technology but also to a case of using wire-line transmission technology.  
         [0053]     Further, in the above embodiment, a system configuration in which two content providing devices  11  and  12  are connected to the server device  20  is described. Further, a system configuration in which three or more content providing devices are connected to a server device can also be used. Alternatively, a server device may be installed for each content providing device to allow title data to be transmitted to one client device from a plurality of server devices.  
         [0054]     The entire disclosure of Japanese Patent Application No. 2005-0087777 filed on Mar. 25, 2005, including description, claims, drawings and summary are incorporated herein by reference.