Patent Application
20110072473
The present invention relates to an adapter device for use in a source device, and a wireless communication method provided for the adapter device for the source device. In particular, the present invention relates to an adapter device for use in a source device for wirelessly transmitting a video signal outputted from the source device such as a DVD player or a set-top box to a sink device such as a digital television, and a method of controlling the adapter device for use in the source device.
A DVI (Digital Visual Interface) is known as an interface standard for transmitting a video signal from a source device such as a DVD player to a sink device such as a plasma display device (referred to as a PDP device hereinafter). In addition, an HDMI (High Definition Multimedia Interface) for transmitting a video signal and an audio signal using one cable has been developed (See Non Patent Document 1) as an interface standard extended from the DVI for next-generation digital television, and AV devices adopting the HDMI begin to penetrate the market.
According to the HDMI, the source device includes a transmitter circuit, the sink device includes a receiver circuit and an EDID (Extended Display Identification Data) memory, and the source device is connected to the sink device via an HDMI cable, which is a digital data transmission bus compliant with the HDMI. In addition, according to the DVI, the source device is connected to the sink device via a DVI cable, which is a digital data transmission bus compliant with the DVI. In this case, the EDID memory previously stores therein EDID data, which is configuration information including identification information of the sink device and a plurality of video display formats and a plurality of audio output formats of the sink device. Each of the HDMI cable and the DVI cable includes a TMDS (Transition Minimized Differential Signaling) channel and a DDC (Display Data Channel) channel. The source device reads out the EDID data on the sink device via the DDC channel.
According to the HDMI, the source device selects one video display format and one audio output format from among a plurality of video display formats and a plurality of audio output formats of the sink device read-out from the EDID data, respectively. Further, the source device generates a baseband video signal having a selected video output signal, a digital audio signal having a selected audio output signal, and auxiliary data, and transmits the baseband video signal, the digital audio signal, and the auxiliary data to the sink device via the TMDS channel together with data on the video display format and data on the audio output format.
In addition, according to the DVI, the source device reads out the EDID on the sink device via the DDC channel, and thereafter, selects one video display format from among a plurality of video display formats on the sink device read-out from the EDID. Further, the source device generates a baseband video signal having the selected video output signal, and transmits the baseband video signal together with data on the video display format to the sink device via the TDMS channel.
Further, in a video data wireless transmission system according to a prior art as described in Patent Document 1, the source device generates a wireless signal including the video signal transmitted via the TMDS channel, and wirelessly transmits the wireless signal to the sink device using a certain frequency band.
Patent Document 1: Japanese patent laid-open publication No. JP-2007-511977-A.
Non Patent Document 1: “High-Definition Multimedia Interface Specification, Version 1.3a”, HDMI Licensing, LLC, California in USA, Nov. 10, 2006.
In the video data wireless transmission system according to the prior art, a band having a data transmission rate higher than a data transmission rate actually required is allocated for wireless transmission of the video signal, so as to wirelessly transmit the video signal with certainty. Therefore, there was such a problem that the video signal cannot be wirelessly transmitted efficiently.
It is an object of the present invention to provide an adapter device for use in a source device and method of controlling the adapter device for use in the source device each capable of solving the above-mentioned problem, and being capable of wirelessly transmitting a video signal received from the source device more efficiently as compared with the prior art.
According to the first aspect of the present invention, there is provided an adapter device for a source device for use in a wireless communication system. The wireless communication system includes the adapter device for the source device wirely connected to the source device, and an adapter device for a sink device wirely connected to the sink device. The adapter device for the source device wirelessly transmits a transmitting signal including a video signal from the source device in a predetermined band. The sink device stores therein data on a plurality of video display formats. The adapter device for the sink device wirelessly receives the transmitting signal, and outputs the video signal included in a wirelessly received transmitting signal to display means of the sink device so as to display the video signal. The adapter device for the source device includes controller means for wirelessly receiving a format notification signal including the data on the plurality of video display formats of the sink device from the adapter device for the sink device. The controller means selects one video display format having highest data transmission rate based on the data on the plurality of video display formats, and reserves a band for wirelessly transmitting a video signal having a selected video display format as the predetermined band.
In the above-mentioned adapter device for the source device, the controller means calculates data transmission rates for wirelessly transmitting video signals having the plurality of video display formats based on the data on the video display formats, respectively, and selects the video display format having the highest data transmission rate based on calculated data transmission rates.
In addition, the above-mentioned adapter device for the source device further includes storage means for previously storing therein a band management table for storing therein the video display formats and the data transmission rates for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the data transmission rates for wirelessly transmitting the video signals having the video display formats. The controller means selects the video display format having the highest data transmission rate with reference to the band management table.
Further, the above-mentioned adapter device for the source device further includes storage means for previously storing therein a band management table for storing therein the video display formats and priorities representing the data transmission rates for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the priorities. The controller means selects the video display format having highest priority as the video display format having the highest data transmission rate with reference to the band management table.
Still further, in the above-mentioned adapter device for the source device, the band management table further stores therein band reservation parameters for reserving bands for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the band reservation parameters. The controller means reserves the band for wirelessly transmitting the video signal having the selected video display format as the predetermined band using a band reservation parameter corresponding to the selected video display format with reference to the band management table.
In addition, in the above-mentioned adapter device for the source device, the band for wirelessly transmitting the video signal having the selected video display format includes repetition of a plurality of reservation periods. Each of the band reservation parameters includes at least a time width of each of the reservation periods, a time interval of each of the reservation periods, and a repetition number of the reservation periods.
Further, in the above-mentioned adapter device for the source device, the transmitting signal includes the video display format of the video signal included in the transmitting signal. When a video display format of the video signal included in the transmitting signal is different from the selected video display format, the controller means releases a reserved predetermined band, and reserves a band for wirelessly transmitting the video signal included in the transmitting signal as the predetermined band.
Still further, in the above-mentioned adapter device for the source device, the format notification signal includes EDID data including the data on the plurality of video display formats of the sink device.
In addition, in the above-mentioned adapter device for the source device, the transmitting signal further includes an audio signal from the source device, the sink device further stores therein data on a plurality of audio output formats, and the adapter device for the sink device outputs the audio signal included in the transmitting signal to the sink device. The format notification signal further includes the data on the plurality of audio output formats of the sink device. The controller means selects one audio output format having highest data transmission rate based on the data on the plurality of audio output formats, and reserves a band for wirelessly transmitting the video signal having the selected video display format and an audio signal having the selected audio output format as the predetermined band.
Further, in the above-mentioned adapter device for the source device, upon receiving a transmittable-or-not notification signal representing that the source device can transmit the transmitting signal from the source device, the controller means reserves the predetermined band.
Still further, in the above-mentioned adapter device for the source device, upon wirelessly receiving a receivable-or-not notification signal representing that the sink device can receive the transmitting signal from the adapter device for the sink device, the controller means reserves the predetermined band.
In addition, in the above-mentioned adapter device for the source device, upon receiving a transmittable-or-not notification signal representing that the source device cannot transmit the transmitting signal from the source device, the controller means releases the reserved predetermined band.
Further, in the above-mentioned adapter device for the source device, upon wirelessly receiving a receivable-or-not notification signal representing that the sink device cannot receive the transmitting signal from the adapter device for the sink device, the controller means releases the reserved predetermined band.
According to the second aspect of the present invention, there is provided a method of controlling an adapter device for a source device for use in a wireless communication system. The wireless communication system includes the adapter device for the source device wirely connected to the source device, and an adapter device for a sink device wirely connected to the sink device. The adapter device for the source device wirelessly transmits a transmitting signal including a video signal from the source device in a predetermined band. The adapter device for the sink device wirelessly receives the transmitting signal, and outputs the video signal included in a wirelessly received transmitting signal to display means of the sink device so as to display the video signal. The method includes a control step of wirelessly receiving a format notification signal including the data on the plurality of video display formats of the sink device from the adapter device for the sink device, selecting one video display format having highest data transmission rate based on the data on the plurality of video display formats, and reserving a band for wirelessly transmitting a video signal having a selected video display format as the predetermined band.
In the above-mentioned method of controlling the adapter device for the source device, the control step includes calculating data transmission rates for wirelessly transmitting video signals having the plurality of video display formats based on the data on the video display formats, respectively, and selecting the video display format having the highest data transmission rate based on calculated data transmission rates.
In addition, the above-mentioned method of controlling the adapter device for the source device further including a step of previously storing a band management table in storage means. The band management table stores the video display formats and the data transmission rates for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the data transmission rates for wirelessly transmitting the video signals having the video display formats. The control step includes selecting the video display format having the highest data transmission rate with reference to the band management table.
Further, the above-mentioned method of controlling the adapter device for the source device further includes a step of previously storing a band management table in storage means. The band management table stores the video display formats and priorities representing the data transmission rates for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the priorities. The control step includes selecting the video display format having highest priority as the video display format having the highest data transmission rate with reference to the band management table.
Still further, in the above-mentioned method of controlling the adapter device for the source device, the band management table further stores therein band reservation parameters for reserving bands for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the band reservation parameters. The control step includes reserving the band for wirelessly transmitting the video signal having the selected video display format as the predetermined band using a band reservation parameter corresponding to the selected video display format with reference to the band management table.
In addition, in the above-mentioned method of controlling the adapter device for the source device, the band for wirelessly transmitting the video signal having the selected video display format includes repetition of a plurality of reservation periods. Each of the band reservation parameters includes at least a time width of each of the reservation periods, a time interval of each of the reservation periods, and a repetition number of the reservation periods.
Further, in the above-mentioned method of controlling the adapter device for the source device, the transmitting signal includes the video display format of the video signal included in the transmitting signal. The control step includes releasing a reserved predetermined band, and reserving a band for wirelessly transmitting the video signal included in the transmitting signal as the predetermined band, when a video display format of the video signal included in the transmitting signal is different from the selected video display format.
In addition, in the above-mentioned method of controlling the adapter device for the source device, the format notification signal includes EDID data including the data on the plurality of video display formats of the sink device.
Further in the above-mentioned method of controlling the adapter device for the source device, the transmitting signal further includes an audio signal from the source device, the sink device further stores therein data on a plurality of audio output formats, and the adapter device for the sink device outputs the audio signal included in the transmitting signal to the sink device. The format notification signal further includes the data on the plurality of audio output formats of the sink device. The control step includes selecting one audio output format having highest data transmission rate based on the data on the plurality of audio output formats, and reserving a band for wirelessly transmitting the video signal having the selected video display format and an audio signal having the selected audio output format as the predetermined band.
According to the adapter device for use in the source device and the method of controlling the adapter device for use in the source device according to the present invention, the format notification signal including the data on the plurality of video display formats stored in the sink device is wirelessly received from the adapter device for the sink device, one video display format having the highest data transmission rate is selected based on the data on the plurality of video display formats, and the band for wirelessly transmitting the video signal having the selected video display format is reserved as the predetermined band. Therefore, it is possible to wirelessly transmit the video signal received from the source device more efficiently as compared with the prior art.
Preferred embodiments according to the present invention will be described below with reference to the attached drawings. Components similar to each other are denoted by the same reference numerals and will not be described herein in detail.
Referring to
Referring to
In this case, the 5V-voltage signal is defined in the HDMI and the DVI. The 5V-voltage signal is a transmittable-or-not notification signal representing whether or not the source device can transmit an audio and visual signal (a video signal in the case of the DVI) to the sink device. The source device generates a low-level 5V-voltage signal representing that the source device cannot transmit the audio and visual signal, and outputs the low-level 5V-voltage signal to the sink device, by setting a voltage level of the 5V-voltage signal included in the HDMI cable or DVI cable to 0V. The source device generates a high-level 5V-voltage signal representing that the source device can transmit the audio and visual signal, and outputs the high-level 5V-voltage signal to the sink device, by changing the voltage level of the 5V-voltage signal line from 0V to 5V.
In addition, the HPD signal is defined in the HDMI and the DVI. The HPD signal is a receivable-or-not notification signal representing whether or not the sink device can receive the audio and visual signal (video signal according to the DVI) from the source device. The sink device generates an HPD signal representing that the sink device cannot receive the audio and visual signal, and outputs the HPD signal to the source device by setting a voltage level of the HPD signal line included in the HDMI cable or DVI cable to a low level. The sink device generates an HPD signal representing that the sink device can receive the audio and visual signal, and outputs the HPD signal to the source device, by changing the voltage level of the HPD signal line from the low level to a high level.
Referring to
In the source device 10, the controller 11 controls operation executed by the decoder 12. The decoder 12 reproduces contents stored in the DVD 14 using the DVD drive 13, generates video data, audio data, a horizontal synchronization signal and a vertical synchronization signal of a video signal, and auxiliary data, and outputs the generated data and signal to the controller 11. The controller 11 generates an audio and visual signal including a digital video signal, a display format of the digital video signal, a digital audio signal, an output format of the digital audio signal, and the auxiliary data based on the video data, the audio data, the horizontal synchronization signal and vertical synchronization signal of the video signal, and the auxiliary data. In addition, the controller 11 outputs the audio and visual signal to the adapter device 20 via the audio and visual signal lines included in the HDMI cable 51.
Referring to
Under control of the controller 21, the packet processing circuit 23 converts the audio and visual signal inputted from the interface 21 into a digital signal having a predetermined packet format, and outputs the digital signal to the high-rate wireless transmitter circuit 24a. The high-rate wireless transmitter circuit 24a modulates a carrier wave having a high frequency fallen within a millimeter wave band of, for example, about 60 GHz according to the digital signal from the packet processing circuit 23, so as to generate an audio and visual wireless signal including uncompressed video signal and audio signal. Then, the high-rate wireless transmitter circuit 24a wirelessly transmits the audio and visual wireless signal toward the antenna 32 of the adapter device 30 via the antenna 25. Generally speaking, in the wireless communication system, as a carrier wave frequency is higher, a transmission rate can be set to be larger, and a transmission rate of the high-rate wireless transmitter circuit 24a is set to be larger than that of the low-rate wireless transceiver circuit 24b which will be described later.
Further, under control of the controller 21, the packet processing circuit 23 converts various command signals and message signals inputted from the controller 21 into a digital signal having a predetermined packet format, and outputs the digital signal to the low-rate wireless transceiver circuit 24b. The low-rate wireless transceiver circuit 24b modulates a carrier wave having a low frequency such as a millimeter wave or a microwave according to the digital signal from the packet processing circuit 23, so as to generate a wireless signal. Then, the low-rate wireless transceiver circuit 24b wirelessly transmits the wireless signal toward the antenna 32 of the adapter device 30 via the antenna 25.
On the other hand, a wireless signal transmitted from the adapter device 30 is received by the antenna 25, inputted to the low-rate wireless transceiver circuit 24b, and demodulated into a digital signal. The digital signal is outputted to the packet processing circuit 23. The packet processing circuit 23 extracts predetermined command signals and predetermined message signals from the inputted digital signal by a predetermined packet separation process under control of the controller 21, and then outputs extracted command signals and message signal to the controller 21.
As described later in detail, the adapter device 20 is characterized by including the controller 21. The controller 21 wirelessly receives a format notification signal including data on a plurality of video display formats and a plurality of audio output formats stored in the sink device 40 from the adapter device 30. Then, the controller 21 selects one video display format having highest data transmission rate based on the data on the received plurality of video display formats, and selects one audio output format having highest data transmission rate based on the data on the received plurality of audio output formats. The controller 21 reserves a band for wirelessly transmitting a video signal having the selected video display format and an audio signal having the selected audio output format as a band for wirelessly transmitting the audio and video signal from the source device 10.
Referring to
In addition, the low-rate wireless transceiver circuit 33b demodulates a wireless signal received via the antenna 32 into a baseband signal using a predetermined digital demodulation format, and then outputs the baseband signal to the packet processing circuit 34. In this case, a transmission rate of the low-rate wireless receiver circuit 33b is set to be equal to that of the low-rate wireless receiver circuit 24b. The packet processing circuit 34 extracts predetermined command signals and predetermined message signals from the inputted baseband signal by a predetermined packet separation process based under control of the controller 31, and then outputs the predetermined command signals and message signals to the interface 35.
Further, under control of the controller 31, the packet processing circuit 34 converts various command signals and message signals inputted from the controller 31 into a digital signal having a predetermined packet format, and outputs the digital signal to the low-rate wireless transceiver circuit 33b. The low-rate wireless transceiver circuit 33b modulates a carrier wave having a predetermined frequency according to the digital signal from the packet processing circuit 34, so as to generate a wireless signal, and wirelessly transmits the wireless signal toward the antenna 22 of the adapter device 20 through the antenna 32.
The interface 35 executes an interface process for interfacing with the sink device 40, and outputs a signal and data compliant with the HDMI to the sink device 40 via the HDMI cable 52. In addition, the interface 35 receives a signal inputted from the sink device 40 via the HDMI cable 52, executes a predetermined interface process including signal conversion and protocol conversion on the received signal, and outputs a resultant signal to the packet processing circuit 34.
Referring to
The controller 41 outputs an inputted audio and visual signal to the audio and visual processing circuit 43. The audio and visual processing circuit 43 separates an inputted audio and visual signal into a video signal and an audio signal, executes a predetermined signal process on the video signal and audio signal, and thereafter, outputs the video signal and audio signal to the display with the loudspeaker 36, so as to display an image and to output a voice. In addition, the EDID memory 45 previously stores therein EDID data on the sink device 40 such as a plurality of video display formats and a plurality of audio output formats. Each of the plurality of video display formats includes data on the sink device 40 such as product information, a manufacturer name, a video coding format (such as RGB, YCBCR4:4:4 or YCBCR4:2:2), a resolution, a field frequency and the number of scanning lines. Each of the plurality of audio output formats includes data on the sink device 40 such as audio output sampling rate, the number of bits per sample, and the number of channels.
Next, referring to
Referring to
On the other hand, upon detecting that the sink device 40 in the ON state is connected to the adapter device 30 via the HDMI cable 52, the adapter device 30 changes the voltage level of the 5V-voltage signal line included in the HDMI cable 52 from 0V to 5V. By changing the voltage level of the 5V-voltage signal line included in the HDMI cable 52 from 0V to 5V, the adapter device 30 generates a high-level 5V-voltage signal, and outputs the high-level 5V-voltage signal to the sink device 40. In response to this, the sink device 40 executes a predetermined initialization process. Then, the sink device 40 changes the voltage level of the HPD signal line included in the HDMI cable 52 from the low level to the high level, so as to generate a high-level HPD signal representing that the sink device 40 can receive a transmitting signal including an audio and visual signal, and so as to output the high-level HPD signal to the adapter device 30. In response to this, the adapter device 30 generates an EDID request command signal for requesting the EDID data, and outputs the EDID request command signal to the sink device 40 via the DDC signal line included in the HDMI cable 52. In response to this, the sink device 40 reads out the EDID data including data on a plurality of video display formats and a plurality of audio output formats of the sink device 40 from the EDID memory 45, and outputs an EDID data signal including the read-out EDID data to the adapter device 30 via the DDC signal line included in the HDMI cable 52.
In response to the EDID data signal from the sink device 40, the adapter device 30 generates an HPD notification message signal representing that the sink device 40 can receive a transmitting signal including an audio and visual signal, and wirelessly transmits the HPD notification message signal toward the antenna 25 of the adapter device 20 via the antenna 32 as a receivable-or-not notification signal. In response to this, the adapter device 20 generates an EDID request message signal for requesting the EDID data on the sink device 40, and wirelessly transmits the EDID request message signal toward the antenna 32 of the adapter device 30 via the antenna 25 as a format request signal. In response to this, the adapter device 30 generates an EDID response message signal including the EDID data received from the sink device 40, and wirelessly transmits the EDID response message signal toward the antenna 25 of the adapter device 20 via the antenna 32 as a format notification signal.
Referring back to
Next, at step S14 of
For example, the EDID data wirelessly received from the adapter device 30 includes the following formats.
In this case, a data transmission rate (1920×1080×60×24=2.985984 Gbps) required for transmitting a video signal having the 1080/60p/24 bit video display format is the highest. Therefore, the adapter device 20 selects the 1080/60p/24 bit, allocates and reserves a reservation period in which the data transmission rate is equal to or higher than 2.985984 Gbps.
Referring back to
Upon receiving the EDID data signal from the adapter device 20, the source device 10 reads out the plurality of video display formats and the plurality of audio output formats of the sink device 40 from the received EDID data, and selects one video display format and one audio output format from among the read-out video display formats and audio output formats, respectively. Further, the source device 10 generates an audio and visual signal having the selected video display format and the selected audio display format, and outputs the audio and visual signal to the adapter device 20 via the audio and visual signal line included in the HDMI cable 51. The adapter device 20 generates an audio and visual wireless signal based on the audio and visual signal from the source device 10, and executes a media access control process for wireless transmission to the adapter device 30 for the allocated reservation period. The adapter device 30 generates an audio and visual signal based on a received audio and visual wireless signal, and outputs the audio and visual signal to the sink device 40 via the audio and visual signal lines included in the HDMI cable 52. The sink device 40 outputs the audio and visual signal from the adapter device 30 to the display with the loudspeaker 30 so as to display an image and output a voice.
On the other hand, upon receiving the audio and visual signal from the source device 10, the adapter device 20 executes a band change process at step S3.
According to the band release process of
As described above in detail, according to the present embodiment, the adapter device 20 wirelessly receives the format notification signal including the plurality of video display formats and the plurality of audio output formats of the sink device 40 from the adapter device 30, selects the video display format having the highest data transmission rate based on the data on the received video display formats, selects the audio output format having the highest data transmission rate based on the data on the received audio output formats, and reserves the band for wirelessly transmitting the video signal having the selected video display format and the audio signal having the selected audio display format as the band for wirelessly transmitting the audio and visual signal from the source device 10. Therefore, as compared with the prior art, it is possible to wirelessly transmit the audio and visual signal from the source device 10 to the adapter device 30 efficiently.
The adapter device 20 may store the EDID data on the sink device 40 received from the adapter device 30. In this case, when the adapter device 20 receives the HPD notification message signal representing that the sink device 40 can receive the audio and visual signal from the adapter device 30, the adapter device 20 executes the band reservation process of
As compared with the adapter device 20 according to the first embodiment, the adapter device 20A according to the second embodiment further includes the table memory 26 for storing therein the video signal band management table and an audio signal band management table. The video signal band management table stores therein the video display formats of the sink device 40 and the data transmission rates for wirelessly transmitting video signals having the video display formats with establishing a correspondence between the video display formats and the data transmission rates for wirelessly transmitting the video signals having the video display formats. The audio signal band management table stores therein audio output formats of the sink device 40 and the data transmission rates for wirelessly transmitting audio signals having the audio output formats with establishing a correspondence between the audio output formats and the data transmission rates for wirelessly transmitting the audio signals having the audio output formats. The controller 21 is characterized by selecting one video display format having the highest data transmission rate with reference to the video signal band management table, and selecting one audio output format having the highest data transmission rate with reference to the audio signal band management table.
As shown in
Next, a band reservation process executed by the controller 21 of the adapter device 20A will be described. Upon wirelessly receiving the EDID response message signal (See
Therefore, according to the second embodiment, it is possible to reduce time required for the band reservation process for allocating the reservation period for wirelessly transmitting the audio and visual signal outputted from the source device 10 as compared with the first embodiment.
The table memory 26 may previously store a video signal band management table storing therein the video display formats of the sink device 40 and priorities representing the data transmission rates for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the priorities. In this case, the controller 21 of the adapter device 20 may select a video display format having the highest priority with reference to the video signal band management table as the video display format having the highest data transmission rate from among the plurality of video display formats.
In addition, the table memory 26 may previously store an audio signal band management table storing therein the audio output formats of the sink device 40 and priorities representing the data transmission rates for wirelessly transmitting the video signals having the audio output formats with establishing a correspondence between the audio output formats and the data transmission rates for wirelessly transmitting the audio signals having the audio output formats. In this case, the controller 21 of the adapter device 20 may select an audio output format having the highest priority with reference to the audio signal band management table as the audio output format having the highest data transmission rate from among the plurality of video display formats.
As compared with the second embodiment, a modified embodiment of the second embodiment is characterized in that the video signal band management table further stores therein the video display formats of the sink device 40 and band reservation parameters for reserving bands for wirelessly transmitting the video signals having the video display formats with establishing a correspondence between the video display formats and the band reservation parameters. The modified embodiment of the second embodiment is further characterized in that the controller 21 selects one video display format having the highest data transmission rate, and reserves the band for wirelessly transmitting the video signal having the selected video display format as the band for wirelessly transmitting the video signal included in the audio and visual signal from the source device 10, using the band reservation parameter corresponding to the selected video display format with reference to the video signal band management table.
In this case, the band for wirelessly transmitting the video signal included in the audio and visual signal from the source device 10 includes repetition of a plurality of reservation periods. Each of the band reservation parameters includes a time width of each of the reservation periods, a time interval of each of the reservation period, a repetition number of the reservation periods, and a transmission mode. The transmission mode includes a transmission mode 1 for transmitting a video and audio signal using the high-rate wireless transmitter circuit 24a and a transmission mode 2 for transmitting the audio and visual signal using the low-rate wireless transceiver circuit 24b.
Next, a band reservation process executed by the controller 21 of the adapter device 20A will be described. Upon wirelessly receiving the EDID response message signal (See
Therefore, according to the modified embodiment of the second embodiment, it is possible to reduce time required for the band reservation process for allocating the reservation period for wirelessly transmitting the video signal included in the audio and visual signal from the source device 10 as compared with the second embodiment. It is to be noted that the band reservation parameters are not limited to those of
In the respective embodiments and the modified embodiment, the video display formats of the sink device 40 are 1080/60 p/24 bit, 1080/60 i/24 bit, 720/60 p/24 bit and 480 p. However, the present invention is not limited to these, and the video display formats of the sink device 40 may be other video display formats.
In addition, in the respective embodiments and the modified embodiment, the adapter device 20 or 20A wirelessly transmits the EDID request message signal for requesting the EDID data on the sink device 40 to the adapter device 30. In addition, in response to this, the adapter device 30 wirelessly transmits the EDID response message signal including the EDID data on the sink device 40 to the adapter device 20 or 20A. However, the present invention is not limited to this. The adapter device 20 or 20A may wirelessly transmit a format request signal for requesting data on the plurality of video display formats and the plurality of audio output formats of the sink device 40, to the adapter device 30. In this case, in response to this, the sink device 40 wirelessly transmits a format notification signal including the data on the plurality of video display formats and the plurality of audio output formats of the sink device 40 to the adapter device 20 or 20A.
Further, in the respective embodiments and the modified embodiment, the audio and visual wireless signal including the audio and visual signal is transmitted using the high-rate wireless transmitter circuit 24a and the high-rate wireless receiver circuit 24b, and the wireless signal including the message signal and the command signal is transmitted using the low-rate wireless transceiver circuits 24b and 33b. However, the present invention is not limited to this. A wireless signal including the video signal may be transmitted using the high-rate wireless transmitter circuit 24a and the high-rate wireless receiver circuit 24b, and the wireless signal including the audio signal, message signal and the command signal may be transmitted and received using the low-rate wireless transceiver circuits 24b and 33b. In addition, a wireless signal including the audio and visual signal, the message signal, and the command signal may be transmitted and received using the high-rate wireless transmitter circuit 24a and the high-rate wireless receiver circuit 24b. Further, antennas may be provided for the high-rate wireless transmitter circuit 24a and the high-rate wireless receiver circuit 24b, respectively, and antennas may be provided for the low-rate wireless transceiver circuits 24b and 33b, respectively.
In the band release process of
Still further, in the respective embodiments and the modified embodiment, the source device 10 is the DVD player. However, the present invention is not limited to this. The source device 10 may be a source device such as a set-top box or a DVD recording and reproducing device for outputting an audio and visual signal. In addition, in the respective embodiments, the sink device 40 is the PDP device. However, the present invention is not limited to this. The sink device 40 may be a sink device such as a projector device with a loudspeaker for outputting a video signal to a display so as to display the video signal and for outputting an audio signal to a loudspeaker.
In addition, in the respective embodiments and the modified embodiment, the adapter device 20 or 20A allocates and reserves the reservation period having the data transmission rate required for transmitting the audio and visual signal (step S16 of
Further, in the respective embodiments and the modified embodiment, the source device 10 is the signal source device for transmitting and receiving signals compliant with the HDMI, and the sink device 40 is the signal sink device for transmitting and receiving the signals compliant with the HDMI. However, the present invention is not limited to this. The source device 10 may be a signal source device for transmitting and receiving signals compliant with the DVI, and the sink device 40 may be a signal sink device for transmitting and receiving the signals compliant with the DVI.
In this case, the adapter device 20 is connected to the source device 10 via a DVI cable, and wirelessly transmits a transmitting signal including a video signal from the source device 10 in a predetermined band. In addition, the adapter device 30 is connected to the sink device 40 via a DVI cable, wirelessly receives the transmitting signal, and outputs the video signal included in the wirelessly received transmitting signal to display means of the sink device 40 so as to display the video signal. In addition, the controller 21 of the adapter device 20 wirelessly receives a format notification signal including a plurality of video display formats of the sink device 40 from the adapter device 30, selects one video display format having the highest data transmission rate based on data on the video display formats, and reserves a band for wirelessly transmitting a video signal having the selected video display format as the predetermined band.
As described above in detail, according to the adapter device for use in the source device and the method of controlling the adapter device for use in the source device according to the present invention, the format notification signal including the data on the plurality of video display formats stored in the sink device is wirelessly received from the adapter device for the sink device, one video display format having the highest data transmission rate is selected based on the data on the plurality of video display formats, and the band for wirelessly transmitting the video signal having the selected video display format is reserved as the predetermined band. Therefore, it is possible to wirelessly transmit the video signal received from the source device more efficiently as compared with the prior art.
10 . . . Source Device,
11, 21, 31, and 41 . . . Controller,
12 . . . Decoder,
13 . . . DVD Drive,
14 . . . DVD,
15, 22, 35, and 42 . . . Interface,
20 and 20A . . . Adapter Device for Source Device,
30 . . . Adapter Device for Sink Device,
23 and 34 . . . Packet Processing Circuit,
24 and 33 . . . Wireless Transceiver Circuit,
24
a . . . High-Rate Wireless Transmitter Circuit,
24
b and 33b . . . Low-Rate Wireless Transceiver Circuit,
25 and 32 . . . Antenna,
26 . . . Table Memory,
33
a . . . High-Rate Wireless Transmitter Circuit,
43 . . . Audio and Visual Processing Circuit,
44 . . . Display With Loudspeaker,
45 . . . EDID Memory,
51 and 52 . . . HDMI Cable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-131656 | May 2008 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2009/002200 | 5/19/2009 | WO | 00 | 11/9/2010 |
