Patent Publication Number: US-2012044424-A1

Title: Wireless communication system

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present application is related to the Japanese Patent Application No. 2010-184294, filed Aug. 19, 2010, the entire disclosure of which is expressly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wireless communication system, in particularly, that wirelessly communicates a control data that follows the CEC (Consumer Electronics Control) standard through the HDMI (High-Definition Multimedia Interface). 
     2. Description of the Related Art 
     An AV system that wirelessly communicates a video signal, an audio signal and control data between a source apparatus and a link apparatus is disclosed (for example, Japanese Patent Laid-Open (Tokuhyo) 2006-503,455, Japanese Patent Laid-Open No. 2004-343,725, Japanese Patent Laid-Open No. 2004-336,729, and Japanese Patent Laid-Open No. 2001-077821). 
     As an interface to realize such a wireless communication, the HDMI (High-Definition Multimedia Interface) is known. Control data can be sent and received through the HDMI. Therefore, in the HDMI system, for example, one apparatus can be controlled to drive by control data sent from other apparatus. 
       FIG. 5  is a figure to explain a flow of a conventional communication that follows the HDMI standard between a source apparatus and a link apparatus. When the wireless communication is performed, between a source apparatus and a link apparatus, a radio transmitter and a radio receiver are intervened, and they convert various wired signals into a radio signal and thus they wirelessly communicate with each other. 
     For example, according to the standard, when control data are transmitted through the radio transmitter by the source apparatus, the link apparatus which received the control data replies response data (a reply signal) in return through the radio receiver. 
     While the communication is not performed in the conventional wireless communication, the establishment of the wireless communication may be cancelled in order to reduce electricity consumption. When the establishment of the wireless communication has been canceled, for example, if the source apparatus sends the control data, it is necessary to establish communication between the radio transmitter and the radio receiver, before performing communication of the control data. 
     However, it sometimes takes some period before the wireless communication has been established. Therefore the wireless communication may not be performed smoothly. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention provides a wireless communication system that can cancels the establishment of the communication while it does not perform wireless communication, and thus can reduce electricity consumption. Further, when the wireless communication is restarted, the wireless communication system can perform wireless communication smoothly. 
     According to an embodiment of the present invention, a wireless communication system that wirelessly communicate between apparatuses video signal, voice signal, and control data which follows HDMI standard comprises a function and state maintenance unit that holds a function and a state of receiving side apparatus communicating through wireless communication; a reply unit, while the wireless communication is not established, when transmission side apparatus sends control data to the receiving side apparatus before establishing the wireless communication, that sends pseudo reply signal corresponding to the control data to the transmission side apparatus based on the function and state data held in the receiving side apparatus; a wireless communication establishment unit that establishes wireless communication; a command transmission unit that sends the control data to the receiving side apparatus through the established wireless communication. 
     According to the embodiment, the function and state maintenance unit holds a function and a state of receiving side apparatus communicating through wireless communication. 
     In addition, the a reply unit, while the wireless communication is not established, when the transmission side apparatus sends control data to the receiving side apparatus before establishing the wireless communication, sends pseudo reply signal corresponding to the control data to the transmission side apparatus based on the function and state data held in the receiving side apparatus. And the command transmission unit sends the control data to the receiving side apparatus through the established wireless communication which the wireless communication establishment unit establishes. 
     Therefore the transmission side apparatus is able to receive the reply signal before the wireless communication has been established and carry out following process more effectively. Here, the transmission side means an apparatus that issues the control data, and the receiving side means an apparatus that receives the issued control data. Therefore the concept of the present invention includes a concept in that a link apparatus becomes the transmission side apparatus where the link apparatus issues the control data as well as in that a source apparatus becomes the transmission side apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram to explain an AV system  100 . 
         FIG. 2  is a block diagram to explain an AV system  100 . 
         FIG. 3  is a figure to explain registering process performed by the AV system  100  in an embodiment. 
         FIG. 4  is a figure to explain wireless communication process performed by the AV system  100  in the embodiment. 
         FIG. 5  is a figure to explain a flow of the conventional communication when the wireless communication that follows an HDMI standard between the source apparatus and the link apparatus is performed. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In one of embodiments of this invention, status of the receiving side apparatus is judged by the function and the state of the receiving side apparatus. However, since the function and the state are variable, it will be better to be available to cope with such dynamic change. Therefore the wireless communication system may comprises an update unit that notifies the function and the state of the receiving side apparatus at certain scheduled time thus makes to perform update of the function and the state held. According to the embodiment, precision of practice in the process can be raised. 
     In addition, in another embodiment of this invention, the command transmission unit receives the reply signal which is sent for the control data after the communication is established from the receiving side apparatus, compares the reply signal that the reply unit replied and the reply signal replied by the receiving side apparatus, and notifies an error when the comparison results are different from each other. 
     According to the present invention, even if the response data which were issued artificially are different from the response data replied after the wireless communication has been established, stability of processing can be realized by notifying the error. 
     In addition, the function means a function corresponding to the control data, and the state means whether the receiving side apparatus is in a state to be able to perform corresponding process to the control data. 
     In a more concrete embodiment of the present invention, the wireless communication system is comprised of an update unit that notifies the function and the state of the receiving side apparatus at certain scheduled time thus makes to perform update of the function and the state held, and is characterised in the command transmission unit that receives the reply signal which is sent by the control data after the communication is established from the receiving side apparatus, compares the reply signal replied by the reply unit and the reply signal replied by the receiving side apparatus, and notifies an error when the comparison result is different from each other. 
     Hereinafter, one of embodiments of the present invention will be explained in a following orders. 
     1. The first embodiment:
 
1.1. AV systems  100 :
 
1.2. Update and registering process:
 
1.3. Process of wireless communication:
 
2. Other embodiments:
 
1. The first embodiment:
 
1.1. AV systems  100 :
 
     Hereinafter, the first embodiment of the present invention as a wireless communication system will be explained. 
       FIG. 1  is a block diagram of AV system  100 . The AV system  100  comprises a recorder  90  (a source apparatus), a display unit  94  (a link apparatus), a wireless communication system (a radio transmitter  80  and a radio receiver  70 ). The wireless communication system performs wireless communication between the recorder  90  and the display unit  94 . 
     The recorder  90  can play picture data and sound data. The recorder  90  can outputs the data to the display unit  94 . The data that the recorder  90  plays are converted into radio signals by the radio transmitter  80 . The radio signals are received by the radio receiver  70 . The radio signals are converted into digital data by the radio receiver  70  again, and they are output as picture and sound by the display unit  94 . In addition, the wireless communication that the radio transmitter  80  and the radio receiver  70  performs follows the CEC standard. In the CEC standard, one device can control another device by transmitting control data from one device to another device. 
       FIG. 2  is a block diagram explaining an AV system  100 . Hereinafter, based on  FIG. 2 , a concrete structure of each device in the AV system  100  will be explained. 
     The recorder  90  is comprised of a recording portion  91 , a controller  92 , and an interface  93 . The recording portion  91  is comprised of a HDD (hard disk drive) and a BD (Blue-Ray Disk (registered trademark)). The recording portion  91  records picture data and sound data in the HDD or the BD. The controller  92  controls playing of various data recorded in the recording portion  91 . The controller  92  issues control data (or response data). The interface  93  controls communication between the recorder  90  and the radio transmitter  80 . 
     The command follows the CEC standard. And the control data prescribes orders to the receiving side apparatus by the transmission side apparatus. For example, the control data includes commands for recording orders and total management of power ON/OFF to the recorder  90  issued by the display unit  94 . The response data are the commands that follow the CEC standard. And the apparatus that received the control data replies signals that represent the response data to the apparatus of the transmission side. 
     The display unit  94  is comprised of a front end part  95 , a back end part  96 , a display  97 , a controller  98 , and an interface  99 . The front end part  95  includes a tuner part to receive television broadcast that the antenna received (not illustrated). The back end part  96  performs converting process of number of the pixels depending on a resolution of the display  97  to the picture data. The picture data are data of television broadcast input from the front end part  95  or input data from the interface  99 . The display  97  displays a picture based on the picture data input from the back end part  96 . The controller  98  generally controls driving of the display unit  94 . The controller  98  issues control data and response data depending on an input command. The interface  99  controls communication between the display unit  94  and the radio receiver  70 . 
     The radio transmitter  80  is connected to the recorder  90 . The radio transmitter  80  converts picture data, sound data and control data (response data) which are transmitted from the recorder  90  into a radio signal and outputs them. The radio transmitter  80  is comprised of a HDMI receiver  81  and a radio transmitting and receiving module  82 , a RF circuit  83 , an antenna  84 , and a controller  85 . 
     The HDMI receiver  81  locates between the recorder  90  and the radio transmitting and receiving module  82 . And the HDMI receiver  81  transfers various data between them. The radio transmitting and receiving module  82  performs reversible conversion between digital data and radio wave. The RF circuit  83  transmits radio wave converted by the radio transmitting and receiving module  82  to a certain high frequency as a radio signal through antenna  84 . The RF circuit  83  modulate radio wave converted by the radio transmitting and receiving module  82  to a certain high frequency, and transmits the modulated radio signal through the antenna  84 . When the RF circuit  83  receives radio signal through the antenna  84 , the RF circuit  83  demodulates the radio signal and outputs it to the radio transmitting and receiving module  82 . 
     The controller  85  is comprised of a CPU, a ROM, and a RAM. As for the ROM, program data for the CPU to carry out predetermined operation are recorded. The RAM acts as working area for the CPU. The CPU carries out program data recorded in the ROM, thus realizes functions of a function and state maintenance module (a function and state maintenance unit) M 1 , an update module M 2 , and a wireless communication control module M 3 . 
     A function and state maintenance module M 1  controls each part of the radio transmitter  80  and performs update and registering process. The update and registering process is a process to record a function and a state of receiving side device that receives the control data. When the function and state maintenance module M 1  is realized as one of functions of the radio transmitter  80 , the function and state maintenance module M 1  records the function and the state of the display unit  94  to which the radio receiver  70  is connected. Here, the function means a function corresponding to the control data. In addition, the state means whether a device that receives the control data is in a state to be able to perform corresponding process to the control data. And further it is a concept that includes a channel number that is being watched and heard, or the presence of the input of the data from other apparatuses. 
     The update module M 2  controls each part of the radio transmitter  80 . And the update module M 2  makes the function and state maintenance module M 1  update recorded function or state when the update module M 2  receives functions sent from the receiving side apparatus, a notice of change, and a request for setting. The update module M 2  realizes an update unit of the present invention. 
     The wireless communication control module M 3  controls the wireless communication that follows the CEC standard. In other words, the wireless communication control module M 3  makes each part of the radio transmitter  80  perform establishment of wireless communication between the radio receiver  70 , communication of picture data, sound data and control data using the established wireless communication. In the present embodiment, the wireless communication control module M 3  issues a pseudo response data that will be sent for the transmission of control data while wireless communication is not established between the radio receiver  70  and the radio transmitter  80 . And after the recorder  90  replies, the wireless communication control module M 3  establishes wireless communication with the radio receiver  70 . The wireless communication control module M 3  realizes a wireless communication establishment unit, a reply unit, and a command transmission unit of the present invention. 
     The radio receiver  70  is connected to the display unit  94 . And the radio receiver  70  converts radio signal transmitted from the radio transmitter  80  into picture data, sound data, and control data again, and outputs them to the display unit  94 . The radio receiver  70  is comprised of a HDMI receiver  71 , a radio transmitting and receiving module  72 , a RF circuit  73 , an antenna  74 , and controller  75 . The controller  71  is comprised of functions of a function and state maintenance module M 11 , an update module M 12 , a wireless communication control module M 13 . The structure and functions of the HDMI receiver  71 , the radio transmitting and receiving module  72 , the RF circuit  73 , the antenna  74 , and the controller  75  are almost same with those of the HDMI receiver  81 , the radio transmitting and receiving module  82 , the RF circuit  83 , the antenna  84 , and the controller  85 . Therefore explanation of them will be omitted. 
     1.2. Update and Registering Process: 
       FIG. 3  is a figure to explain registering process that is performed by the AV system  100  in this embodiment. Hereinafter, referring to  FIG. 3 , process to register the function and the state of the display unit  94  to the radio transmitter  80  will be explained. 
     When the registering processing is chosen by operating a wireless remote controller (not illustrated) in step S 1 , the display unit  94  requests the radio receiver  70  the function of registering. 
     In step S 2 , the wireless communication control module M 13  of the radio receiver  70  establishes wireless communication between the radio transmitter  80  and the radio receiver  70 . 
     In step S 3 , the update module M 12  of the radio receiver  70  transmits a list of control data which can be performed by the display unit  94  through the established wireless communication to the radio transmitter  80 . 
     In step S 4 , based on the received control data, a function and state maintenance module M 1  of the radio transmitter  80  records the list of control data which can be performed by the display unit  94  into an internal memory. Thereafter, the radio transmitter  80  judges the function of the display unit  94  based on the recorded control data. 
     In step S 5 , the wireless communication control module M 3  of the radio transmitter  80  cuts off the established wireless communication. 
     Next, a process that the state of the display unit  94  is notified to the radio transmitter  80  and the update is promoted will be explained. When the display unit  94  receives input from an external equipment except the recorder  90 , in step S 6 , the display unit  94  notifies current state (a change of state) to the radio receiver  70 . In step S 7 , the wireless communication control module M 13  of the radio receiver  70  establishes wireless communication between the radio transmitter  80  and the radio receiver  70 . 
     In step S 8 , the update module M 12  of the radio receiver  70  transmits a current state of the display unit  94  to the radio transmitter  80  through the wireless communication. 
     In step S 9 , based on the change of state of the display unit  94 , the function and state maintenance module M 1  of the radio transmitter  80  records the current change of state of the display unit  94  that the radio transmitter  80  received into the internal memory. 
     In step S 10 , the wireless communication control module M 3  of the radio transmitter  80  cuts off the established wireless communication. In addition, when the input from the external equipment (not illustrated) stopped in the display unit  94 , the radio transmitter  80  records a new change of state (the end of the external input) of the display unit  94  by carrying out processes of step S 6  to S 10 . Therefore, when the function and state of the transmitting side apparatus have changed, precision of practice in the process can be raised. So far, the update and registering process have been explained. 
     1.3. Wireless Communication Processing: 
       FIG. 4  is a figure to explain wireless communication process performed by the AV system  100  in the present embodiment. The process where the control data are transmitted to the display unit  94  from the recorder  90  is shown in the figure as one example. Hereinafter, referring to  FIG. 4 , the wireless communication process will be explained. 
     When the recorder  90  issues control data that is to be transmitted to the display unit  94  in step S 11 , the wireless communication control module M 3  of the radio transmitter  80  refers to control data which the display unit  94  can perform and current state of the display unit  94  in step S 12 . Those control data and current state are recorded in the internal memory. 
     In step S 13 , the wireless communication control module M 3  of the radio transmitter  80  replies response data to the recorder  90  depending on the reference result of step S 12 . When the issued control data exists in the list of the recorded control data and the recorded state of the display unit  94  is a state which the display unit  94  is capable of receiving the control data, the wireless communication control module M 3  replies affirmative response data to the recorder  90  for a reply to the control data. 
     In step S 14 , the wireless communication control module M 3  establishes wireless communication between the radio transmitter  80  and the radio receiver  70 . In step S 15 , the wireless communication control module M 3  transmits control data to the radio receiver  70  through the established wireless communication. 
     In step S 16 , the wireless communication control module M 13  of the radio receiver  70  converts the received control data into a digital signal, and transmits the digital signal to the display unit  94 . The display unit  94  receives the digital code from the radio receiver  70  and gets the control data. In step S 17 , the display unit  94  issues a response data corresponding to the control data, and transmits the response data to the radio receiver  70 . Then the radio receiver  70  receives the response data. 
     In step S 18 , the radio receiver  70  converts the response data into a radio signal and transmits it to the radio transmitter  80 . Then the radio transmitter  80  receives the radio signal and gets the response data. In step S 19 , the wireless communication control module M 3  of the radio transmitter  80  compares the response data which is issued in step S 13  with the received response data. 
     When the response data issued in step S 13  matches with the received response data from the display unit  94  (step S 20 :Yes), the process concerning the issued control data will be finished. On the other hand, when the issued response data are different from the received response data from the display unit  94  in step S 13  (step S 20 :NO), the wireless communication control module M 3  issues an error message and transmits the message to the radio receiver  70  (step S 21 ). When the display unit  94  receives the error message, the display unit  94  warns users by showing the error message on screen. Therefore, even if the pseudo response data which were issued are different from the response data replied after the wireless communication has been established, stability of processing can be realized by notifying the error. The first embodiment is as mentioned above. 
     As mentioned above, in the present embodiment of the AV system  100 , the function and the state of the receiving side apparatus that makes communication through radio are held beforehand. And while the wireless communication is not established, when the transmission side apparatus sends control data to the receiving side apparatus before establishing the wireless communication, the AV system  100  sends a pseudo reply signal corresponding to the control data to the transmission side apparatus based on the function and state data held in the receiving side apparatus at first, then sends the control data to the receiving side apparatus through the established wireless communication. Therefore the transmission side apparatus can receive the reply signal before the wireless communication has been established and perform following process more effectively. In addition, since radio transmission can be cut off while the wireless communication is not used, thus electricity consumption can be reduced. 
     2. Other Embodiments: 
     There are various embodiments of the present invention. In the above mentioned structure, the recorder is the source apparatus and the display unit is the link apparatus. However it is just one example of the present invention. Thus where the system that adapts the HDMI standard for the wireless communication between apparatus, the present invention may be applied to between the another kind of apparatus. 
     While the invention has been particularly shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. 
     Although the invention has been described in considerable detail in language specific to structural features and or method acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as preferred forms of implementing the claimed invention. Therefore, while exemplary illustrative embodiments of the invention have been described, numerous variations and alternative embodiments will occur to those skilled in the art. 
     It should further be noted that throughout the entire disclosure, the labels such as left, right, front, back, top, bottom, forward, reverse, clockwise, counter clockwise, up, down, or other similar terms such as upper, lower, aft, fore, vertical, horizontal, proximal, distal, etc. have been used for convenience purposes only and are not intended to imply any particular fixed direction or orientation. Instead, they are used to reflect relative locations and/or directions/orientations between various portions of an object. 
     In addition, reference to “first,” “second,” “third,” and etc. members throughout the disclosure (and in particular, claims) is not used to show a serial or numerical limitation but instead is used to distinguish or identify the various members of the group.