JP2006253882A - Wireless av apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the matter of a wireless AV apparatus such as a wireless TV receiving set having separated display section and broadcast receiving section that the delay time until completion of the operation after something is inputted by a user is long as compared with that of an integrated AV apparatus. <P>SOLUTION: Only when the state is not synchronized at the display section and on the broadcast receiving section, e. g. during actuation of a power supply, synchronization of state transition is carried out. After completion of state synchronization, a control signal is transmitted from the display section where switching of channel or switching of input of an external AV apparatus was performed. At a moment in time when wireless transmission was performed normally by receiving an ACK frame, state transition of the display section is performed so that synchronization of state transition between the display section and the broadcast receiving section side is removed thus shortening the function switching time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to improvement of responsiveness in a wireless AV device using wireless LAN such as 802.11a or 802.11b and wireless communication such as Bluetooth.

  FIG. 4 shows a conventional wireless AV device. FIG. 4 is an example of a wireless TV receiver in which the display unit 200 and the broadcast receiving unit 100 are separated. The broadcast receiving unit 100 is connected to an external AV device 105 such as a VTR in addition to a function of receiving a television broadcast and demodulating a video or audio signal. The display unit 200 can be installed without being limited by the location of the television broadcast receiving antenna terminal in the house.

  Control signals such as channel switching, input switching of the external AV device 105 and volume adjustment are input by the remote control 301, the control signals are received by the IrDA 303, and the control microcomputer 201 receives the broadcast reception unit 100 from the wireless module 202 via the antenna 109. The broadcast receiving unit 100 receives the control signal by the antenna 108 and notifies the display unit 200 using a method wirelessly connected to the display unit 200. As a wireless connection, a wireless LAN such as IEEE802.11a or IEEE802.11b (IEEE802.11 High-Rate Direct Sequence) and Bluetooth are used.

  Alternatively, by directly inputting to the setting button 302 on the display unit 200, the display unit 200 similarly notifies the broadcast receiving unit 100 using a method wirelessly connected to the broadcast receiving unit 100.

  In the broadcast receiving unit 100 that receives channel switching, input switching, and the like from the display unit 200 via the antenna 108 and the wireless module 101, the control microcomputer 107 controls the AV switch 104, the MPEG encoder 102, and the wireless module 101 to control the channel. The contents requested by the display unit 200 such as switching and input switching are executed, the execution result is notified to the display unit 200, and the confirmation of the state transition synchronization between the display unit 200 and the broadcast receiving unit 100 is completed. The display of the unit 200 is switched.

  In the broadcast receiving unit 100, video signals and audio signals received from the antenna 106 or the external AV device 105 are input to the MPEG encoder 102 via the AV switch 104 and the A / D conversion unit 103. Under the control of the control microcomputer 107, the MPEG encoder 102 encodes the input data in the MPEG (Moving Picture Experts Group) system (data compression), and the wireless module 101 converts the encoded data into a data frame and transmits it through the antenna 108. To the display unit 200.

  The display unit 200 receives the video signal and audio signal transmitted from the broadcast receiving unit 100 via the antenna 109 and the wireless module 202, accumulates a certain amount in the buffer 203, and then performs MPEG decoder according to the control of the control microcomputer 201. The video is decoded by 204, D / A converted by the D / A converter 205, displayed on the display 207, and uttered by the speaker 206.

In the conventional wireless AV device configured as described above, as shown in Patent Document 1 and Patent Document 2, the video content rate and the wireless transmission rate are determined according to the wireless state between the broadcast receiving unit 100 and the display unit 200. There is something to switch.
JP 2003-179663 A JP 2004-80321 A

  However, control signals such as channel switching input to the display unit 200 and input switching of an external AV device can determine the content requested by the display unit 200, but the function is in the broadcast receiving unit 100. Therefore, once the control signal is transmitted to the broadcast receiving unit 100 and the state transition of the broadcast receiving unit 100 is executed, the state of the broadcast receiving unit 100 is transmitted to the display unit 200, and the display unit 200 is transmitted. Since the state transition of the display unit 200 is performed after synchronization of the state transition between the broadcast receiving unit 100 and the broadcast receiving unit 100, functions that are installed in the broadcast receiving unit 100 such as channel switching and external AV device input switching When the control is performed, the delay time from the function switching input to the function switching is longer than that of the TV receiver in which the display unit 200 and the broadcast receiving unit 100 are integrated.

  In addition, when switching between video signals and audio signals that have been transmitted / received so far, such as by channel switching or external AV device input switching, since data of a certain frame is stored in the buffer 203 and then decoded, The decoding process cannot be started until the data of a certain frame is accumulated in the buffer 203, and the delay time from the video switching input to the video switching is determined by the display unit 200 and the broadcast receiving unit 100. It is larger than an integrated TV receiver.

  Only when the state of the display unit and the broadcast receiving unit is not synchronized, such as when the power is turned on, the state transition is synchronized. Once the state synchronization is completed, input such as channel switching or input switching of external AV equipment is performed. The display unit that has been transmitted transmits the control signal, and when wireless transmission is normally performed by receiving the ACK frame, the state of the display unit and the broadcast receiving unit side is changed by performing the state transition of the display unit Transition synchronization can be eliminated, and the time for switching functions can be shortened.

  Also, when channel switching or external AV device input switching occurs, the encoding rate is lowered only for a certain period of time when switching video signals and audio signals, so that data of a certain frame can be obtained in a short time. By accumulating on the display unit side, the decoding start time is shortened, thereby shortening the video switching time.

  When function switching such as channel switching or input switching of an external AV device is performed by button input mounted on the remote controller or the display unit, the time required for function switching or video switching can be shortened.

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

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a wireless AV device according to Embodiment 1 of the present invention. In FIG. 1, the same reference numerals are given to components that perform the same operations as those in FIG. In FIG. 1, under the control of the control microcomputer 1070, when the wireless module 1010 normally receives a data frame transmitted from the display unit 200, the wireless module 1010 transmits an ACK frame to the transmission destination of the data frame.

  FIG. 2 shows an operation flow in the present embodiment.

  First, it is assumed that the broadcast receiving unit 100 and the display unit 200 are in the same state A.

  First, when making a setting request from the remote control 301 to the broadcast receiving unit 100, the display unit 200 receives the setting request from the remote control 301 using the IrDA 303. The control microcomputer 201 converts the setting request control signal received by the IrDA 303 into a data frame, and transmits the data frame to the broadcast receiving unit 100 via the wireless module 202 and the antenna 109 (step S2001).

  When the wireless module 1010 of the broadcast receiving unit 100 normally receives the data frame transmitted from the display unit 200, the wireless module 1010 transmits an ACK (ACKknowledgement) frame to the display unit 200 (step S2002). The display unit 200 that has received the ACK frame transitions to the state B requested by the remote controller 301.

  When the broadcast receiving unit 100 transitions to the state B in which the setting request is received from the display unit 200, the broadcast receiving unit 100 transmits a setting request response to the display unit 200 in a data frame.

  As described above, when the wireless transmission is normally performed by receiving the ACK frame, the state transition of the display unit and the broadcast receiving unit side can be eliminated by performing the state transition of the display unit. Switching time can be shortened.

(Embodiment 2)
The configuration of the wireless AV device in the present embodiment is the same as that in the first embodiment.

  FIG. 3 is a flowchart showing the operation of the wireless AV device in the present embodiment.

  Hereinafter, the operation of the present embodiment will be described with reference to FIG.

  When video 1 is being displayed at video rate A (A> 0) (step S3001), when the remote controller 301 makes a video switching request to video 2 to the broadcast receiving unit 100, the display unit 200 is controlled by the remote controller 301. The video switching request is received by the IrDA 303, and the display unit 200 converts the video switching request control signal into a data frame and transmits it to the broadcast receiving unit 100 (step S3002). When the wireless module 1010 of the broadcast receiving unit 100 normally receives the data frame transmitted from the display unit 200, the wireless module 1010 transmits an ACK (ACKknowledgement) frame to the display unit 200 (step S3003).

  The broadcast receiving unit 100 that has received the video switching request encodes the video 2 signal at the video rate B (0 <B <A) lower than the video rate A in the MPEG encoder 102 under the control of the control microcomputer 1070. The wireless module 1010 converts the data frame and transmits it (step S3004).

  The display unit 200 that has received the video 2 signal converted into the data frame stores the amount of data that can be displayed in the buffer 203 under the control of the control microcomputer 201, displays the video 2, and the wireless module 202 displays the video 2. A signal for informing that the display of the image is started is converted into a data frame and transmitted to the broadcast receiving unit 100 (step S3005).

  The broadcast receiving unit 100 that has received the signal notifying that the display of the video 2 has started is transmitted by the wireless module 1010 to the display unit 200 according to the control of the control microcomputer 1070 (step S3006). Returns the video rate to the video rate A, performs the encoder, and continues to transmit the video 2 signal from the wireless module 1010 (step S3007).

  This is a problem not only for wireless TV receivers but also for all wireless AV devices that stream video and audio, and can be a solution, so it can be applied to all wireless AV devices.

The block diagram which shows one structure of the wireless AV apparatus of this invention Flow chart showing the procedure for improving responsiveness Flow chart showing the procedure for changing the video rate Block diagram showing the configuration of a conventional wireless AV device

Explanation of symbols

102 MPEG encoder 103 A / D converter 104 AV switch 105 External AV device 106, 108, 109 Antenna 201, 1070 Control microcomputer 202, 1010 Wireless module 203 Buffer 204 MPEG decoder 205 D / A converter 206 Speaker 207 Display device 300 Setting Input device 301 Remote control 302 Setting button 303 IrDA section

Claims (3)

A wireless AV device in which a data receiving unit and a display unit are separated to perform wireless communication with each other,
When receiving the operation request from the display unit, the receiving unit notifies the display unit that the operation request has been received normally,
When the display unit receives the notification, the display unit changes its own state to the requested state. A wireless AV device in which a data receiving unit and a display unit are separated to perform wireless communication with each other,
When receiving a data transmission request from the display unit, the receiving unit lowers an encoding rate of data to be transmitted for a certain period after receiving the data transmission request, from a normal rate. 3. The wireless AV device according to claim 2, wherein upon receiving a notification from the display unit that display of received data has started, the encoding rate of the data to be transmitted is returned to a normal rate.

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