JP2002171495A - Signal transmission system, signal transmitter, and signal receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal transmission system that transmits a video signal, an audio signal and a control signal used for control at a receiver side subjected to time division multiplex processing. SOLUTION: The signal transmission system is provided with a signal transmitter 11 having a time base compression section 101 that applies time base compression to the audio signal and having a multiplexer section 102 that applies time division multiplex of a control signal and the audio signal subjected to the time base compression to a video signal for its blanking period and transmits the resulting signal to a signal receiver 12 through a transmission line 106 and with the signal receiver 12 having a demultiplexer section 103 that demultiplexes the signal resulting from applying the time division multiplex processing to the video signal, the control signal and the audio signal subjected to the time base compression into the video signal, the control signal and the audio signal subjected to the time base compression, and having a time base expansion section 104 that expands the audio signal subjected to the time base compression.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission system, a signal transmission device, and a signal reception device capable of transmitting or transmitting an audio signal and a control signal together with a video signal.

[0002]

2. Description of the Related Art Conventional DVI (Digital Visual Interface)
ce) A standard signal transmission system will be described with reference to the drawings. FIG. 25 is a block diagram showing a configuration of a conventional signal transmission system. In FIG. 25, a conventional signal transmission system includes a TMDS encoder / serializer 2601-2603 provided on the transmission side and a TMDS decoder / recovery 2604-2 provided on the reception side.
606.

In a conventional signal transmission system, R
Video signal such as ED, GREEN, BLUE is TMD
Input to the S encoder / serializer 2601-2603 and the TMDS encoder / serializer 2601
2603 to TMDS encode the video signal, serialize it, and send it out to the transmission path. And on the receiving side,
Received signal is converted to TMDS decoder / recovery 2604
At 2606, TMDS decoding is performed and the video signal is restored by recovery.

[0004] The DE (data enable) signal is an RE signal.
A signal indicating a period during which a video signal such as D, GREEN, or BLUE exists, and is a HIGH active signal.
For example, a period during which the DE signal is LOW is a horizontal blanking period or a vertical blanking period of a video signal. The CTL (control) signal is CTL0,
There are four CTL1, CTL2, and CTL3, which are prepared as control signals. However, in the current DVI standard, these CTL signals are unused. Specifically, the levels of these signals are always 0.

[0005] The TMDS encoders / serializers 2601 to 2603 on the transmission side convert an 8-bit input video signal into 10-bit, serialize it, and send it out to a transmission path. The purpose of the 8-bit / 10-bit conversion is to reduce data change points and make the data suitable for high-speed transmission. The TMDS encoders / serializers 2601 to 2603 convert 2 bits of the control signal into 10 bits and transmit the converted signal to the transmission path. Also, the data enable signal is encoded and serialized together and sent to the transmission path. The TMDS decoders / recoveries 2604 to 2606 on the receiving side decode the 10-bit serial data received from the transmission line into 8 bits of a color signal, 2 bits of a data enable signal, and 2 bits of a control signal and develop the same.

[0006]

The DVI standard is a standard for transmitting only video signals (RGB signals), and a conventional signal transmission system transmits an audio signal and a control signal used for controlling a monitor. There was a problem that can not be.

Further, even when transmitting a video signal other than the DVI standard, the video signal, the audio signal, and the control signal are transmitted through different transmission paths, respectively. The transmission line is required separately from the transmission line for transmitting the video signal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a signal transmission system, a signal transmission device, and a signal capable of transmitting an audio signal and a control signal together with a video signal through the same transmission path. An object is to provide a receiving device.

[0009]

To achieve the above object, a signal transmission system according to the present invention receives a signal transmitted from a signal transmission device via a transmission path and transmits the signal. A signal transmission system having a signal reception device, wherein the signal transmission device compresses an audio signal on a time axis, and controls a video signal and a signal reception device or a control signal used for controlling a device connected to the signal reception device. And time-division multiplexed time-compressed audio signal, and transmits the signal to the signal receiving device via the transmission path.The signal receiving device converts a signal transmitted from the signal transmitting device into a video signal. And a control signal and a time-axis-compressed audio signal, and extend the time-axis-compressed audio signal.

[0010] The signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission device includes:
The control signal and the time-axis-compressed audio signal are multiplexed in a blanking period of the video signal.

Further, the signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission device includes:
The control signal is multiplexed in a predetermined period of the blanking period, and the time-axis-compressed audio signal is multiplexed in the blanking period other than the predetermined period.

Further, the signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission device includes:
A vertical synchronizing signal, and a horizontal synchronizing signal are transmitted to the signal receiving device, wherein the signal receiving device receives the vertical synchronizing signal, the horizontal synchronizing signal, the vertical synchronizing signal, and the horizontal synchronizing signal. To separate the video signal, the control signal, and the time-axis-compressed audio signal.

Further, the signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission device includes:
A predetermined non-signal period is provided before the control signal and the time-axis-compressed audio signal, respectively.
The signal receiving device detects the non-signal period to specify the control signal, and a period in which the time-axis-compressed audio signal is multiplexed, and specifies the control signal and the time-axis-compressed audio. Signal and a signal.

Further, the signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission system uses a DVI transmission standard for transmitting RGB video signals serially.
The control signal and the time-axis-compressed audio signal are multiplexed on a predetermined channel among the respective channels of the channel, and the signal receiving device includes the control signal multiplexed on the predetermined channel and the time The audio signal is separated from the axis-compressed audio signal.

Further, the signal transmission system according to the present invention comprises:
In the signal transmission system, the signal transmission device includes:
The time-axis-compressed audio signal is decomposed into a plurality, the decomposed audio signal is divided into a plurality of channels and multiplexed, and the signal receiving device separates the decomposed audio signal, and It is characterized by synthesizing an audio signal.

A signal transmitting apparatus according to the present invention is a signal transmitting apparatus connected to a signal receiving apparatus via a transmission line, and includes a time axis compressing means for compressing an audio signal on a time axis, a video signal and a signal receiving section. Signal multiplexing means for time-division multiplexing a control signal used for control on the side and a time-axis-compressed audio signal by the time-axis compression means, and transmitting the signal to the signal receiving device via the transmission path. It is characterized by the following.

In the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing unit multiplexes the control signal and the time-axis-compressed audio signal in a blanking period of the video signal. It is characterized by the following.

Further, in the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing means multiplexes the control signal in a predetermined period of the blanking period, and outputs the time-axis-compressed audio signal. Multiplexing is performed in the blanking period other than the predetermined period.

Further, in the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing means transmits a vertical synchronizing signal and a horizontal synchronizing signal used for detecting the blanking period to the signal receiving apparatus. It is characterized by doing.

Further, in the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing unit provides a predetermined non-signal period before the control signal and the time-axis-compressed audio signal, respectively. It is characterized by the following.

Further, in the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing means uses a DVI transmission standard for transmitting an RGB video signal serially. The control signal and the time-axis-compressed audio signal are multiplexed on the channel (1).

Further, in the signal transmitting apparatus according to the present invention, in the signal transmitting apparatus, the signal multiplexing unit decomposes the time-axis-compressed audio signal into a plurality of signals and divides the decomposed audio signals into a plurality of channels. It is characterized by multiplexing.

Also, a signal receiving apparatus according to the present invention is a signal receiving apparatus connected to a signal transmitting apparatus via a transmission path, wherein a video signal transmitted from the signal transmitting apparatus via the transmission path is provided. A signal obtained by time-division multiplexing of a control signal used for controlling a signal receiving device or a device connected to the signal receiving device and a time-axis-compressed audio signal is subjected to time-axis compression with a video signal and a control signal. A signal separating unit for separating the audio signal into an audio signal; and a time axis expanding unit for expanding the time axis compressed audio signal.

Further, in the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the signal separating means includes: a control signal multiplexed during a blanking period of the video signal; and a time-axis-compressed audio signal. Is separated.

Further, in the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the signal separating means may include the control signal multiplexed in a predetermined period of the blanking period and the block signal other than the predetermined period. It is characterized by separating the time-axis-compressed audio signal multiplexed during the ranking period.

In the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the signal separating means receives a vertical synchronizing signal and a horizontal synchronizing signal from the signal transmitting apparatus, and outputs the vertical synchronizing signal and the horizontal synchronizing signal. The video signal, the control signal, and the time-axis-compressed audio signal are separated using a signal.

Further, in the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the signal separating means includes a predetermined non-signal signal provided before the control signal and the time-axis-compressed audio signal. By detecting a period, the control signal and the time-axis-compressed audio signal are specified in a multiplexed period, and the control signal and the time-axis-compressed audio signal are separated. Is what you do.

Further, in the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the signal separating means uses a DVI transmission standard for receiving a serially transmitted RGB video signal. And separating the control signal multiplexed on a predetermined channel from the time-axis-compressed audio signal.

Further, in the signal receiving apparatus according to the present invention, in the signal receiving apparatus, the time-axis-compressed audio signal is decomposed into a plurality of pieces, and the decomposed sound signals are divided into a plurality of channels and multiplexed. , The signal separating means,
It is characterized in that the decomposed audio signal is separated and the decomposed audio signal is synthesized.

[0030]

(Embodiment 1) Hereinafter, a signal transmission system, a signal transmission apparatus, and a signal transmission system according to Embodiment 1 of the present invention will be described.
And the signal receiving device will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of the signal transmission system according to the first embodiment.

In FIG. 1, a signal transmission system according to the first embodiment includes a signal transmitting device 11 and a signal receiving device 1.
2 is provided. The signal transmitting apparatus 11 includes a time axis compression unit 101 that compresses an audio signal on a time axis, time division multiplexing of a video signal, a control signal, and a time axis compressed audio signal, and a signal transmitting apparatus 11 and a signal receiving apparatus. And a multiplexing unit 102 for transmitting the data to a data line 106 which is a serial transmission path connecting
And Here, the control signal is the signal receiving device 1
2, or a signal for controlling equipment such as a monitor connected to the signal receiving device 12 (for example, control of brightness (brightness) of the monitor, control of volume (volume), etc.). Further, the signal receiving device 12 separates the video / audio control multiplexed signal in which the video signal, the audio signal, and the control signal flowing from the data line 106 are multiplexed into each signal, The audio signal is reproduced on the basis of a time axis extending unit 104 for extending the time axis of the received audio signal and restoring the original audio signal, and a video clock transmitted from the signal transmission device 11 via the clock line 107. And an audio clock reproducing unit 105.

FIG. 6 is a block diagram showing the configuration of the multiplexing unit 102. In FIG. 6, a multiplexing unit 102 selects a first one of a control signal and a time-base compressed audio signal.
Selector 1001, a first multiplexing control unit 1002 for controlling the first selector 1001, a first horizontal line counter 1003 for counting the number of horizontal lines on the screen,
A second selector 1004 for selecting one of a video signal and an output of the first selector 1001 and a second multiplexing control unit 1005 for controlling the second selector 1004 are provided.

FIG. 8 is a block diagram showing the structure of the separation unit 103. In FIG. 8, a separating unit 103 includes a third selector 2001 for distributing a video / audio control multiplexed signal into a video signal and other signals, and a third selector 2001.
, A fourth selector 2003 for distributing a signal in which an audio signal and a control signal are multiplexed into an audio signal and a control signal, and a fourth selector 2
003, and a second horizontal line counter 2005 for counting the number of horizontal lines on the screen.

Next, the operation of the signal transmission system, the signal transmission device, and the signal reception device according to the first embodiment will be described. First, the operation of the signal transmission device 11 will be described.

FIG. 2 is a schematic diagram showing the relationship between a video signal and an audio signal before time axis compression. As schematically shown in FIG. 2, the video signal generally has a larger data amount per unit time than the audio signal. Therefore, one sample of the audio signal substantially corresponds to several samples of the video signal in time. The signal transmission system according to the first embodiment temporally compresses the audio signal, and multiplexes the control signal and the compressed audio signal in an area where no video signal exists.

As a time region where no video signal exists,
For example, there are a horizontal blanking period and a vertical blanking period of a video signal as shown in FIG. FIG.
, A black portion other than the effective screen corresponds to the blanking period (a period obtained by adding the horizontal blanking period and the vertical blanking period). In FIG. 3, MP
An SD screen of MP @ ML (main profile main level) of EG2 is taken as an example. 858 full screen horizontally
Pixels are 525 lines vertically. The effective screen among them has 720 horizontal pixels and 480 vertical lines, and the difference between the entire screen and this effective screen is a blanking period. The audio signal and the control signal are multiplexed during this blanking period.

FIG. 4 is a block diagram showing the configuration of the time axis compression unit 101. Time axis compression section 101 shown in FIG.
Is provided with a memory 1011 and a compression control unit 1012, and converts the rate of an input audio signal. Specifically, an input clock of an audio signal to the memory 1011 is an audio clock (frequency: fa), and an output clock from the memory 1011 is an image clock (frequency: fv). Here, “fa” is the sampling clock frequency of audio, and “fv” is the sampling clock frequency of video. The compression control signal output from the compression control unit 1012 is used for output control of the memory 1011. This compression control signal is transmitted to the compression control unit 101
2 is the logical product (AND) of the horizontal synchronization signal and the vertical synchronization signal
Is taken when the multiplex control signal from the multiplexing unit 102 is “1” (that is, the first selector 1001
Is output to the audio signal side (B) is selected). The memory 1011 stores the compression control signal in the LO
During the period of W, a time-base compressed audio signal is output. Thus, a time-axis-compressed audio signal is obtained. However, the horizontal synchronization signal (HSYNC) and the vertical synchronization signal (V
SYNC) has negative logic (Active Low).

FIG. 5 is a diagram for explaining how the time axis is compressed. In FIG. 5, an audio signal before time axis compression is input to a memory 1011 at a sampling frequency fa.
The audio signal after the time axis compression is output from the memory 1011 at the sampling frequency fv. The time-compressed audio signal is output when the compression control signal from the compression control unit 1012 is LOW. In FIG. 5, for convenience of description, the number of sample points of the audio signal output during the LOW period of the compression control signal is shown as a small number, but the number of sample points actually output is much larger.

Next, the operation of the multiplexing unit 102 for multiplexing a video signal, a control signal, and a time-axis-compressed audio signal and outputting a video / audio control multiplexed signal will be specifically described with reference to FIG.

As described above, the control signal and the time-base compressed audio signal are multiplexed in a period in which no video signal exists. As shown in FIG. 3, since the first to forty-fiveth lines of the screen are the vertical blanking period, in the first embodiment, the monitor control signal is superimposed on the first line and the second to 45th lines are superimposed. The audio signal is superimposed on the eyes.
The audio signal is also superimposed on the horizontal blanking period on the 46th line and thereafter.

The first horizontal line counter 1003 starts counting from the falling edge of the vertical synchronization signal (VSYNC) and counts up each time the falling edge of the horizontal synchronization signal (HSYNC) to count the number of horizontal lines. The initial value of the first horizontal line counter 1003 is 1. The first multiplex control unit 1002 includes a first horizontal line counter 10
If the output of 03 is 1, "0" is output as a multiplex control signal. If the output of the first horizontal line counter 1003 is 2 or more, "1" is output as a multiplex control signal. The first selector 1001 selects the control signal side (A) when the multiplex control signal received from the first multiplex control section 1002 is “0”, and selects the audio signal side when the multiplex control signal is “1”. Select (B). In this way, the control signal side (A) is selected for the first line of the screen, and the audio signal side (B) is selected for the second and subsequent lines. The first
Is input only when the first selector 1001 selects the control signal side (A). The multiplex control signal from the first multiplex control unit 1002 is also output to the time axis compression unit 101.

The second multiplexing control unit 1005 controls the first multiplex control unit during the vertical blanking period (the period when VSYNC is LOW) or the horizontal blanking period (the period when HSYNC is LOW).
Select the selected output side (D) of the selector 1001 of the video signal side (C) during a period that is not a vertical blanking period and is not a horizontal blanking period, that is, an effective screen period.
The second selector 1004 is controlled so as to select.
In this way, it is possible to obtain a video / audio control multiplex signal in which the video signal, the control signal, and the time-axis-compressed audio signal are multiplexed.

FIG. 7 is a diagram for explaining how the video signal, the audio signal, and the control signal are multiplexed in the first embodiment. 7 are, in order from the top, a video signal input to the signal transmission device 11, a control signal input to the signal transmission device 11, an audio signal after time axis compression output from the time axis compression unit 101, and a horizontal signal. Synchronization signal (HSYNC),
A vertical synchronizing signal (VSYNC), a horizontal line counter output which is an output of the first horizontal line counter 1003, and a video / audio control multiplex signal output from the multiplexing unit 102.
This video / audio control multiplex signal is transmitted from the signal transmitting device 11 to the signal receiving device 12 via the data line 106. Here, white circles are sample points of the video signal, triangles are sample points of the control signal, and black circles are sample points of the audio signal. In FIG. 7, a control signal is superimposed on the first line of the vertical blanking period (that is, when the horizontal line counter output is 1), and the second and subsequent lines of the vertical blanking period (that is, when the horizontal line counter output is 2 to 2). 45, the audio signal is superimposed during the vertical blanking period, and the audio signal is superimposed during the horizontal blanking period. Note that a video signal is present in an effective screen period after the end of the vertical blanking period.

Next, the operation of the signal receiving device 12 will be described. First, the operation of the separation unit 103 that separates a video / audio control multiplexed signal in which a video signal, a control signal, and a time-axis-compressed audio signal are multiplexed into respective signals and outputs the separated signals will be described with reference to FIG.
This will be specifically described with reference to FIG.

As described above, the control signal and the time-base-compressed audio signal are multiplexed in a period in which no video signal exists. Therefore, first, the video / audio control multiplex signal transmitted from the signal transmission device 11 by the third selector 2001 is separated into a video signal and a signal other than the video signal,
Thereafter, the fourth selector 2003 separates the control signal from the time-base compressed audio signal.

The control signal is superimposed on the first line of the screen, which is the vertical blanking period, and the audio signal is superimposed on the subsequent vertical blanking period and horizontal blanking period. The separation control unit 2002 selects the output side (E) of the video signal during periods other than the vertical blanking period and the horizontal blanking period (that is, the blanking period), and during the blanking period, the fourth selector 2003 (F). ) So that the third selector 20 is selected.
01 is controlled.

The second horizontal line counter 2005 counts the number of horizontal lines in the same manner as the first horizontal line counter 1003. If the output of the second horizontal line counter 2005 is 1, the second separation control unit 2004 outputs “0” as a separation control signal, and the second horizontal line counter 2
If the output of 005 is 2 or more, "1" is output as the separation control signal. The fourth selector 2003 selects the control signal output side (G) if the separation control signal received from the second separation control unit 2004 is “0”, and if the separation control signal is “1”, outputs the sound. Select the signal output side (H). In this manner, the output side (G) of the control signal is selected on the first line of the screen, and the output side (H) of the audio signal is selected on the second and subsequent lines. Note that the separation control signal from the second separation control unit 2004 is
4 is also output.

FIG. 9 is a diagram for explaining how the video signal, the audio signal, and the control signal are separated in the first embodiment. The signals in FIG. 9 are, in order from the top, a video / audio control multiplex signal input to the signal
03, the horizontal synchronizing signal (HSY)
NC), a vertical synchronization signal (VSYNC), a horizontal line counter output which is an output of the second horizontal line counter 2005, a control signal separated by the separation unit 103, and a separation unit 1.
3 is a time-axis-compressed audio signal separated by the signal 03. As in FIG. 7, white circles are sample points of video signals, triangles are sample points of control signals, and black circles are sample points of audio signals. In FIG. 9, the first line in the vertical blanking period (that is, the horizontal line counter output is 1).
), The control signal is separated, the audio signal is separated in the second and subsequent lines of the vertical blanking period (that is, when the horizontal line counter output is 2 to 45), and when the vertical blanking period ends, the effective screen is The figure shows that a video signal is separated during a period and an audio signal is separated during a horizontal blanking period.

Next, the time axis extending unit 104 will be described. FIG. 10 is a block diagram illustrating a configuration of the time axis extension unit 104. The time axis extending unit 104 shown in FIG.
It includes a memory 2011 and a decompression control unit 2012, and performs rate conversion on a time-axis-compressed audio signal. More specifically, the input clock of the time-axis-compressed audio signal input to the memory 2011 is used as a video sampling clock (frequency: fv), and the output clock from the memory 2011 is used as an audio sampling clock (frequency: fa). And The expansion control signal output from the expansion control unit 2012 is used for input control of the memory 2011. The decompression control signal is obtained by calculating the logical product (AND) of the horizontal synchronization signal and the vertical synchronization signal by the decompression control unit 2012, and when the demultiplexing control signal from the demultiplexing unit 103 is “1” (ie, the fourth control signal). (When the selector 2003 selects the output side (H) of the audio signal). When the decompression control signal is LOW
During this period, a time axis compressed audio signal is input. In this way, an audio signal whose time axis is expanded as before is obtained. However, both the horizontal synchronization signal and the vertical synchronization signal have negative logic.

FIG. 11 is a diagram for explaining how the time axis is extended. In FIG. 11, a time-axis-compressed audio signal is input to a memory 2011 at a sampling frequency fv, and an audio signal after time-axis expansion has a sampling frequency fv.
a is output from the memory 2011. The audio signal after the time axis compression is input to the memory 2011 when the decompression control signal is LOW.

Finally, the operation of the audio clock reproducing unit 105 will be described. In the signal receiving device 12, a PLL (Phase Locked Loop) is used in the audio clock reproducing unit 105 based on the video clock transmitted from the signal transmitting device 11.
p), the video clock is frequency-divided to reproduce the audio clock, and the audio clock is supplied to the time base extension unit 104.
As described above, according to the signal transmission system, the signal transmission device, and the signal reception device according to the first embodiment, time axis compression section 101 compresses the audio signal on the time axis, and multiplex section 102
Multiplexes the control signal in the first line of the vertical blanking period, and multiplexes the time-axis-compressed audio signal in the second and subsequent lines of the vertical blanking period and in the horizontal blanking period, so that the video signal and the control signal are multiplexed. And audio signals can be time-division multiplexed and transmitted on the same data line, so that the number of transmission line lines for transmitting video signals, audio signals, and the like can be reduced or narrowed. Further, the separation unit 103 can specify a blanking period using the horizontal synchronization signal and the vertical synchronization signal, and can separate the video signal, the control signal, and the audio signal.

Embodiment 2 Hereinafter, a signal transmission system, a signal transmission device, and a signal reception device according to Embodiment 2 of the present invention will be described with reference to the drawings. Similarly to the signal transmission system according to the first embodiment, the signal transmission system according to the second embodiment multiplexes a control signal and a compressed audio signal during a blanking period of a video signal and transmits the multiplexed signal. A feature of the signal transmission system according to the second embodiment is that a non-signal period (L2 cycle of a video clock) is provided before a control signal is superimposed in a vertical blanking period, and the number of control signal sample points is set to a constant value (M2 In addition, a non-signal period (L1 cycle of the video clock) is provided before the audio signal is superimposed in the vertical blanking period or the horizontal blanking period, and the number of sample points of the audio signal is set to a fixed value (M1 Sample), the horizontal synchronization signal and the vertical synchronization signal used for separating the audio / video control multiplex signal are not transmitted from the signal transmitting device to the signal receiving device. Also, the period can be identified that are multiplexed in the control signal and the audio signal by detecting a no-signal period in the signal receiving device, as it can separate the control signal and the video signal and the audio signal. However, L1, M
1, L2 and M2 are natural numbers.

FIG. 12 is a block diagram showing a configuration of a signal transmission system according to the second embodiment. 12, the signal transmission system according to the second embodiment includes a signal transmission device 21 and a signal reception device 22. The signal transmission device 21 includes a time axis compression unit 201 that compresses the audio signal on the time axis, and a multiplexing unit that performs time division multiplexing of the video signal, the control signal, and the time axis compressed audio signal, and sends out the data line 106. 202. The signal receiving device 22 includes a separation unit 203 that separates a video / audio control multiplexed signal in which the video signal, the audio signal, and the control signal flowing through the data line 106 are multiplexed into each signal, and the audio separated by the separation unit 203. It includes a time axis expansion unit 204 for performing time axis expansion on a signal and restoring an original audio signal, and an audio clock reproduction unit 105. Note that the audio clock reproducing unit 105 is the same as that in the first embodiment, and a description thereof will be omitted.

FIG. 15 is a block diagram showing the structure of the multiplexing unit 202. 15, a multiplexing unit 202 includes a fifth selector 3001 that selects one of a control signal and a time-base compressed audio signal, a third multiplexing control unit 3002 that controls the fifth selector 3001, A third horizontal line counter 300 that counts the number of horizontal lines in the same manner as the first horizontal line counter 1003 according to the first embodiment.
3, a sixth selector 3004 for selecting one of the video signal and the output of the fifth selector 3001,
And a fourth multiplex control unit 3005 for controlling the selector of

FIG. 17 is a block diagram showing the structure of the separation unit 203. In FIG. 17, a separating unit 203 includes a seventh selector 4001 for distributing a video / audio control multiplexed signal into a video signal and other signals, and a seventh selector 40.
A third separation control unit 4002 that controls the 01 and eighth selectors 4004, a first no-signal detection unit 4003 that detects a no-signal period (L1 cycle of the video clock), and an audio signal and a control signal are multiplexed. An eighth selector 4004 for distributing the divided signal into an audio signal and a control signal, a fourth separation controller 4005 for controlling the seventh selector 4001 and the eighth selector 4004, and a non-signal period (L2 of the video clock). And a second non-signal detector 4006 for detecting the period.

Next, the operation of the signal transmission system, the signal transmission device, and the signal reception device according to the second embodiment will be described. First, the operation of the signal transmission device 21 will be described.

FIG. 13 is a block diagram showing the configuration of the time axis compression section 201. Time axis compression unit 2 shown in FIG.
01 is a memory 3011 and a compression control signal delay unit 301
2 and a compression control unit 1012 for rate-converting the input audio signal. The compression control unit 1012 is the same as that according to the first embodiment. The memory 3011 includes a compression control signal delay unit 3012 instead of the compression control signal from the compression control unit 1012.
It is the same as the memory 1011 according to the first embodiment except that the output control is performed by the delay compression control signal from. The compression control signal delay unit 3012
12 to the period (L1 × 1 / fv) of the L1 cycle of the video clock (frequency: fv) from the fall of the compression control signal from
sec) and then falls, and a period of M1 cycle of the video clock (M1 × 1 / fv s) from the fall
ec) The delay compression control signal that rises after the elapse is output to the memory 3011. This delay compression control signal is used for output control of the memory 3011 in a non-signal period (L of video clock) before the audio signal after time axis compression.
One period) is provided, and by detecting this non-signal period by the signal receiving device 22, it is possible to recognize the timing of switching between the video signal and the audio signal.

FIG. 14 is a diagram for explaining how the time axis is compressed. In FIG. 14, the audio signal before the time axis compression is input to the memory 3011 at the sampling frequency fa, and the audio signal after the time axis compression is the sampling frequency fv
Is output from the memory 3011. The time-compressed audio signal is output because the compression control signal delay unit 301
2 is a LOW period (period of M1 cycle) of the delay compression control signal. Therefore, as shown in FIG.
The period of L1 cycle from the fall of the compression control signal (L1 ×
After a no-signal state of (1 / fv sec), an audio signal is output from the memory 3011 during a period of M1.

Next, the operation of the multiplexing unit 202 that multiplexes the video signal, the control signal, and the audio signal that has been subjected to time axis compression, and outputs a video / audio control multiplex signal will be specifically described with reference to FIG.

The control signal and the time-axis-compressed audio signal are divided into a period in which no video signal exists, that is, a vertical blanking period from the first line to the 45th line of the screen, and a horizontal blanking period in the 46th line and thereafter. The point that the signal is multiplexed with the period is the same as that of the first embodiment. However, in the second embodiment, there is a predetermined non-signal period before the multiplexed control signal and the time-axis-compressed audio signal. This is different from the first embodiment.

The third horizontal line counter 3003 is the same as the first horizontal line counter 1003 according to the first embodiment, and counts the number of horizontal lines on the screen. The third multiplexing control unit 3002 sets “0” as a multiplexing control signal when the period of the L2 cycle (L2 × 1 / fv sec) of the video clock has elapsed since the output of the third horizontal line counter 3003 became 1 The signal is output during the period of the M2 cycle of the clock, and at other times, that is, when the output of the third horizontal line counter 3003 is 2 or more, "1" is output as the multiplex control signal. Fifth selector 30
01 selects the control signal side (I) if the multiplex control signal received from the third multiplex control unit 3002 is “0”,
If the multiplex control signal is "1", the audio signal side (J) is selected. In this way, on the first line of the screen, the control signal side (I) is selected during the M2 cycle period after the elapse of the L2 cycle of the video clock, and the audio signal side (J) is otherwise selected.
Will be selected. However, the fifth selector 30
Even when the audio signal side (J) is selected at 01, as shown in FIG. 14, before the audio signal compressed on the time axis, L1 periods (L1 × 1 / L1) of the video clock are provided.
fv sec). Note that the control signal input to the fifth selector 3001 is input only when the fifth selector 3001 selects the control signal side (A). Therefore, a non-signal state for the period of the L2 cycle of the video clock exists before the control signal. The multiplex control signal from the third multiplex control unit 3002 is also output to the time axis compression unit 201.

The fourth multiplex control section 3005 is similar to the second multiplex control section 1005 according to the first embodiment, and selects the selected output side (N) of the fifth selector 3001 during the blanking period. Then, during a period other than the blanking period, the sixth selector 3004 is controlled so as to select the video signal side (K). In this way, it is possible to obtain a video / audio control multiplex signal in which the video signal, the control signal, and the time-axis-compressed audio signal are multiplexed.

FIG. 16 is a diagram for explaining how a video signal, an audio signal, and a control signal are multiplexed in the second embodiment. FIG. 16 is the same as FIG. 7 in Embodiment 1, except that there is a predetermined non-signal period before the audio signal and the control signal.

Next, the operation of the signal receiving device 22 will be described. First, the operation of the separation unit 203 which separates and outputs a video / audio control multiplexed signal in which a video signal, a control signal, and a time-axis-compressed audio signal are multiplexed into each signal is described with reference to FIG.
7 will be specifically described.

As described above, in the blanking period of the video signal, the audio signal compressed on the time axis after the non-signal period of the L1 cycle of the video clock is superimposed, and the non-signal of the L2 cycle of the video clock is superimposed. After the period, the control signal is superimposed.

When the first no-signal detecting unit 4003 detects a no-signal period of the L1 cycle period from the video / audio control multiplex signal transmitted from the signal transmitting device 21, the first no-signal detecting unit 4003 notifies the third separation control unit 4002 of the detection. Output to Then, the third separation control unit 4002 determines that the audio signal is superimposed during a period other than the vertical blanking period, and the eighth selector 40
The seventh selector 4001 selects the 04 side (Q).
And controls the eighth selector 4004 so as to select the output side (S) of the audio signal, to output an audio signal of only M1 samples, and then to set the output side (P) of the video signal to Select the seventh selector 4001
Control.

When the second no-signal detecting unit 4006 detects a no-signal period of the L2 cycle period from the video / audio control multiplexed signal, it outputs the fact to the fourth separation control unit 4005. Then, the fourth separation control unit 4005 determines that the control signal is superimposed during the vertical blanking period, and
Control the seventh selector 4001 so as to select the selector 4004 side (Q), and control the eighth selector 4004 so as to select the output side (R) of the control signal, thereby controlling only the M2 samples. After that, the seventh selector 4001 is controlled so as to select the output side (P) of the video signal. Further, the fourth separation control unit 4
005 is equal to M after the lapse of one horizontal line (calculated from the output from the second no-signal detecting unit 4006) and the L1 period from the start of the no-signal period of the L2 cycle.
It is determined that the audio signal of one cycle period is superimposed on the vertical blanking period, and the seventh selector 4001 is controlled so as to select the eighth selector 4004 side (Q), and the audio signal output side ( The eighth selector 4004 is controlled so as to select S) to output a control signal of only M1 samples, and then the seventh selector 4001 is controlled so as to select the output side (P) of the video signal. I do. Note that the separation control signals from the third and fourth separation control units 4002 and 4005 are also output to the time axis expansion unit 204.

FIG. 18 is a diagram for explaining a state of separation of a video signal, an audio signal, and a control signal in the second embodiment. FIG. 18 is the same as FIG. 9 in the first embodiment, except that there is a predetermined non-signal state before the audio signal and the control signal.

Next, the time axis extending section 204 will be described. FIG. 19 is a block diagram illustrating a configuration of the time axis extension unit 204. The time axis extension unit 204 shown in FIG.
As with the time axis decompression unit 104 according to the first embodiment, a memory 4011 and a decompression control unit 4012 are provided. Specifically, the input clock of the time-axis-compressed audio signal input to the memory 4011 is set to the video clock (frequency:
fv), and the decompression control signal output from the decompression control unit 4012 is used for input control of the memory 4011 using the output clock from the memory 4011 as an audio clock (frequency: fa). This decompression control signal is generated as follows using two separation control signals from the separation unit 203.

Third and fourth separation control units 4002 and 40
05, the eighth selector 400
During the period in which the output side (S) of the audio signal No. 4 is controlled to be selected, since the audio signal is output from the separation unit 203, the decompression control unit 4012 outputs the LO signal during that period.
A decompression control signal of W is generated. However, this expansion control signal is negative logic.

FIG. 20 is a diagram for explaining how the time axis is extended. In FIG. 20, a time-axis-compressed audio signal is input to a memory 4011 at a sampling frequency fv only during a period in which an expansion control signal is LOW, and an audio signal after time-axis expansion is input to a memory 4011 at a sampling frequency fa.
Output from In this way, it is possible to obtain a sound signal whose time axis is expanded.

As described above, according to the signal transmission system, the signal transmission device, and the signal reception device according to the second embodiment, when multiplexing section 202 multiplexes the control signal and the time-axis-compressed audio signal, By providing a predetermined non-signal period before these signals, in the separation of the signal by the separation unit 203, the non-signal period is detected to specify the period in which the control signal and the audio signal are multiplexed. These signals can be separated, and the signals can be separated without using a horizontal synchronization signal or a vertical synchronization signal. Therefore, the same effect as in the first embodiment can be obtained without transmitting the horizontal synchronization signal or the vertical synchronization signal from the signal transmitting device 21 to the signal receiving device 22.

The multiplexing unit 202 according to the second embodiment
Is that the audio signal is multiplexed only for the period of M1 periods after the non-signal period of L1 period in the vertical blanking period. In order to multiplex more audio signals in the vertical blanking period, the multiplexing unit 202 The audio signal may be multiplexed in the vertical blanking period from the second horizontal line to the 45th horizontal line. However, in this case, it is necessary that the separation unit 203 in the signal receiving device 22 can also separate the audio signal correspondingly.

(Embodiment 3) Hereinafter, a signal transmission system, a signal transmission apparatus, and a signal reception apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings. The signal transmission system according to the third embodiment differs from the signal transmission system according to the first embodiment in that the DVI (Digital Visual Inter
face) Applied to the standard.

FIG. 21 is a block diagram showing a configuration of a signal transmission system according to the third embodiment. 21, the signal transmission system according to the third embodiment includes a signal transmission device 31 and a signal reception device 32.

The signal transmission device 31 is the same as the time axis compression section 101 according to the first embodiment.
01 and the time-axis-compressed audio signal according to the DVI standard CT
A decomposing unit 302 for decomposing into L0, CTL1, and CTL2 lines, a first selector 303 that selectively outputs a control signal and a time-axis-compressed audio signal, and a first selector that counts horizontal lines on a screen. Horizontal line counter 304
And TMDS encoder / serializers 305-30
7 is provided. The signal receiving device 32 includes a TMDS decoder / recovery 308 to 310, a second selector 311 for separating a control signal and an audio signal, a second horizontal line counter 312 for counting horizontal lines on a screen, and C
A synthesizing unit 313 for synthesizing audio signals coming from the lines TL0, CTL1 and CTL2, and a time axis expanding unit 3 for expanding the time axis compressed audio signal output from the synthesizing unit 313
14 and a PLL 315. The time axis compression section 301, the time axis expansion section 314, the first horizontal line counter 304, and the second horizontal line counter 312 are the time axis compression section 101 and the time axis expansion section 1 according to the first embodiment.
04, the first horizontal line counter 1003, and the second horizontal line counter 2005, and the PLL 315 is the same as the audio clock reproducing unit 105 according to the first embodiment, and 3
The audio clock is reproduced based on the video clock transmitted via the audio clock 16. Further, TMDS encoders / serializers 305 to 307 and TMDS decoders / recoveries 308 to 310 are the same as those in the conventional example. Here, the disassembling unit 30 according to the third embodiment is used.
2, first selector 303, first horizontal line counter 304, and TMDS encoder / serializer 3
Reference numerals 05 to 307 correspond to the multiplexing unit 102 according to the first embodiment, and the TMDS decoder / recovery 308 to 310 and the second selector 31 according to the third embodiment.
1, the second horizontal line counter 312, the synthesizing unit 313,
And the PLL 315 correspond to the separating unit 103 according to the first embodiment.

In FIG. 21, a horizontal synchronization signal (HSYN) of a BLUE signal and a video signal is
C) and a vertical synchronizing signal (VSYNC) are time-division multiplexed and transmitted serially. Further, a signal in which a GREEN signal, audio signals (CTL0, CTL1), and a control signal (CTL0) are time-division multiplexed is transmitted to channel 1. A signal obtained by time-division multiplexing of a RED signal and an audio signal (CTL2) is transmitted to channel 2 in a serial manner. In the third embodiment, not only the audio signal but also the control signal is multiplexed on the line of CTL0.

Next, the operation of the signal transmission system, the signal transmission device, and the signal reception device according to the third embodiment will be described. First, the operation of the signal transmission device 31 will be described.

The audio signal input to the signal transmission device 31 is time-axis compressed by the time axis compression section 301 and output to the decomposition section 302. The decomposition unit 302 converts the time-axis-compressed audio signal into CT signals in accordance with the order of sampling points.
L0, CTL1, CTL2, CTL0, CTL1, CT
The line is decomposed into these three lines so that the order of L2 is repeated. The decomposition of the audio signal into three lines may be performed for each sampling point, or may be performed for each of a plurality of sampling points. Also,
Depending on the transmission rate of the audio signal, one CTL
Only the 0 line or two lines CTL1 and CTL2 may be used.

The first selector 303 selects a control signal for the first horizontal line according to the count from the first horizontal line counter 304, and outputs a sound from the decomposing unit 302 for the second and subsequent horizontal lines. The signal is selected and output to the CTL0 line. By doing this, C
The control signal and the audio signal can be multiplexed on TL0.

Since the control signal is superimposed on the first line of CTL0, the first line of CTL1 and CTL2 may be unused (Reserved) in order to match the timing with the sound superimposed on CTL0.

TMDS encoder / serializer 30
5 to 307 perform TMDS encoding of the input signal, serialize the signal, and transmit the serialized signal to the transmission path.

FIG. 22 is a diagram for explaining the appearance of signals on the transmission path according to the third embodiment. The signal input to the TMDS encoder is shown in the upper part of FIG. CL while the DE (data enable) signal is LOW
A T signal is inserted, a control signal and a time-axis-compressed audio signal are superimposed on this CTL0, and CTL1, CT
The time axis compressed audio signal is superimposed on L2 and T
MDS encoded.

FIG. 22 shows signals on the transmission line in the middle. CTL2, CT encoded on channel 2
L3 is superimposed and encoded in channel 1
L0 and CTL1 are superimposed. In the DVI standard, C
Since the TL signal is superimposed during the blanking period of the video signal, in the signal on the transmission line, the audio signal is superimposed during the horizontal blanking period, and the audio signal and the control signal are superimposed during the vertical blanking period. Will be.

In the lower part of FIG.
The DS decoded and recovered signals are shown. The recovered signal is exactly the same as the input signal in the signal transmission device 31.

Next, the operation of the signal receiving device 32 will be described. FIG. 23 is a diagram for explaining a method of separating the video signal, the audio signal, and the control signal in the signal receiving device 32.

As shown in FIG. 23, first, a channel 0 decoder 350 decodes a signal of channel 0,
A UE signal, a DE signal, a horizontal synchronization signal (HSYNC), and a vertical synchronization signal (VSYNC) are generated. And this D
The E signal is supplied to the channel 1 decoder 351 and the channel 2 decoder 352. Channel 1 decoder 3
51 and the channel 2 decoder 352 determine that the LOW period of the received DE signal is a period in which the audio signal and the control signal are multiplexed, and separate the video signal from the audio signal and the control signal. Thus, CTL0
, The control signal, the CTL1 audio signal, and the CTL2 audio signal can be separated.

FIG. 24 shows a channel 2 decoder 352,
FIG. 7 is a diagram for describing a method of decoding a video signal, an audio signal, and a control signal in a channel 1 decoder 351.

As shown in FIG. 24, the serial / parallel converter 360 performs serial / parallel conversion on the video / audio multiplex signal transmitted on channel 2. And D
Since the signal of channel 2 is determined to be a video signal while the E signal is HIGH, the decoder 362 performs 10-bit / 8-bit TMDS decoding on the video signal after conversion from the serial / parallel converter 360. Do, R
Outputs the ED signal. On the other hand, during the period when the DE signal is LOW, the signal of channel 2 is determined to be an audio signal.
It performs bit / 2-bit TMDS decoding and outputs an audio signal to the CTL2 line.

Similarly, the serial / parallel converter 361 performs serial / parallel conversion on the video / audio control multiplex signal transmitted on channel 1. Since the signal of channel 1 is determined to be a video signal while the DE signal is HIGH, the decoder 364 applies a 10-bit / 8-bit TMD to the converted video signal.
S decoding is performed, and a GREEN signal is output. on the other hand,
Since the signal of channel 1 is determined to be a signal other than the video signal while the DE signal is LOW, the decoder 36
5 is 10 bits / 2 bits TMD for the converted signal
S decoding is performed, a multiplexed signal of the control signal and the audio signal is output to the line CTL0, and an audio signal is output to the line CTL1.

Next, a method for separating the control signal and the audio signal multiplexed on the CTL0 will be described. When the output of the second horizontal line counter 312 is the first line, the second selector 311 determines that the signal on the CTL0 line is a control signal, and separates and outputs the control signal from CTL0. On the other hand, when the output of the second horizontal line counter 312 is the second or subsequent line, CTL
It is determined that the signal on line 0 is an audio signal, and CTL0
, And separates the audio signal into a synthesizing unit 313.
Output to

The synthesizing unit 313 decodes the audio signal flowing through the transmission path and outputs the decoded audio signal to the CT.
It is assumed that L0, CTL1, and CTL2 are in order,
Performs synthesis of audio signals. The order of the audio signals is
CTL0, CTL1, and CTL2 do not have to be in the order,
It is necessary for the signal transmitting device 31 and the signal receiving device 32 to determine the order. The audio signal synthesized by the synthesizing unit 313 is rate-converted by the time axis decompression unit 314 and restored to the original audio signal.

As described above, according to the signal transmission system, the signal transmission device, and the signal reception device according to the third embodiment, the configuration of the signal transmission system according to the first embodiment is
The present invention is applied to a DVI transmission standard for transmitting a GB video signal serially, and the decomposing unit 302 converts the time-division compressed audio signal into a CVI signal.
TL0, TL1, and TL3, the first selector 303 superimposes the control signal and the audio signal, and the TMDS encoders / serializers 305 to 307 disassemble the audio signal into RGB channels. Multiplexes the control signal and the audio signal, and the TMDS decoders / recoveries 308 to 310 separate the audio signal and the control signal decomposed into each of the RGB channels, and
By synthesizing the decomposed audio signal, the video signal, the control signal, and the audio signal can be separated on the receiving side. In a signal transmission system of the DVI standard, which has conventionally been able to transmit only the video signal, Transmission of a control signal and an audio signal using a signal transmission line can be realized.

In the third embodiment, the control signal is described as being multiplexed on the line of CTL0. However, other control signals such as CTL1, 2, 4, and 5 of the DVI standard are used in a similar manner.
The control signal may be superimposed on the line of the L signal, or the control signal may be superimposed on a plurality of lines of the CTL signal.

In the first to third embodiments, the control signal is superimposed on CTL0 on the first line of the screen.
The control signal may be superimposed on any line in the vertical blanking period, or the control signal may be superimposed on a plurality of lines of the screen.

[0096]

As is apparent from the above description, according to the signal transmission system of the present invention, a signal transmitting apparatus for transmitting a signal and a signal transmitted from the signal transmitting apparatus via a transmission path are received. A signal transmission system having a signal reception device, wherein the signal transmission device compresses an audio signal on a time axis, and controls a video signal and a signal reception device or a control signal used for controlling a device connected to the signal reception device. And time-division multiplexing of the time-axis-compressed audio signal and transmitting the signal to the signal receiving device via the transmission path, wherein the signal receiving device transmits a signal transmitted from the signal transmitting device,
The video signal, the control signal, and the time-axis-compressed audio signal are separated, and the time-axis-compressed audio signal is expanded, so that the video signal, the control signal, and the audio signal are time-division multiplexed. Data can be transmitted through the same transmission path, and the effect of reducing or narrowing the number of transmission path lines can be obtained.

[0097] According to the signal transmission system of the present invention, in the signal transmission system, the signal transmission device converts the control signal and the time-axis-compressed audio signal into a blanking period of the video signal. By multiplexing, the effect of being able to perform time division multiplexing so that the video signal, the control signal and the audio signal do not overlap in the same period is obtained.

[0098] According to the signal transmission system of the present invention, in the signal transmission system, the signal transmission device multiplexes the control signal in a predetermined period of the blanking period, and outputs the time-axis-compressed audio signal. By multiplexing the signal in the blanking period other than the predetermined period, an effect is obtained that the control signal and the audio signal can be time-division multiplexed so that the control signal and the audio signal do not overlap in the same period in a period where there is no video signal. .

According to the signal transmission system of the present invention, in the signal transmission system, the signal transmission device transmits a vertical synchronization signal and a horizontal synchronization signal to the signal reception device. The apparatus receives the vertical synchronization signal and the horizontal synchronization signal, and separates the video signal, the control signal, and the time-axis-compressed audio signal using the vertical synchronization signal and the horizontal synchronization signal. By doing so, on the receiving side, a blanking period is detected using the vertical synchronization signal and the horizontal synchronization signal, and the control signal and the audio signal multiplexed in the blanking period are separated. The effect that can be obtained is obtained.

Further, according to the signal transmission system of the present invention, in the signal transmission system, the signal transmission device sets a predetermined non-signal period before the control signal and the time-axis-compressed audio signal. The signal receiving device detects the non-signal period, identifies the control signal, and the period in which the time-axis-compressed audio signal is multiplexed, and includes the control signal and the control signal. By separating the time-axis-compressed audio signal, the signal transmission apparatus does not transmit the vertical synchronization signal and the horizontal synchronization signal to the signal reception apparatus, and the control signal and the audio signal are not transmitted on the receiving side. The effect that separation can be performed is obtained.

Further, according to the signal transmission system of the present invention, in the signal transmission system, the signal transmission system includes a DVI for transmitting RGB video signals serially.
A transmission standard is used, and the signal transmission device uses R
The control signal and the time-axis-compressed audio signal are multiplexed on a predetermined channel of each of the GB channels, and the signal receiving device is configured to multiplex the control signal and the control signal multiplexed on the predetermined channel. By separating the time axis compressed audio signal, the transmission of the control signal and the audio signal using the transmission line of the video signal is realized in the system of the DVI standard, which could only transmit the video signal conventionally. The effect that can be obtained is obtained.

According to the signal transmission system of the present invention, in the signal transmission system, the signal transmission device decomposes the time-axis-compressed audio signal into a plurality of signals.
The decomposed audio signal is divided into a plurality of channels and multiplexed, and the signal receiving device separates the decomposed audio signal and synthesizes the decomposed audio signal, so that the audio signal Even if the transmission rate is high, without thinning out the sampling points of the audio signal,
The effect that an audio signal can be transmitted is obtained.

According to the signal transmitting apparatus of the present invention, there is provided a signal transmitting apparatus connected to a signal receiving apparatus via a transmission line, wherein the time axis compressing means for compressing the audio signal on the time axis, Signal multiplexing means for time-division multiplexing a control signal used for control on the signal receiving side with the audio signal compressed on the time axis by the time axis compressing means, and transmitting the multiplexed signal to the signal receiving apparatus via the transmission path. By that
The video signal, the control signal, and the audio signal can be time-division multiplexed and transmitted via the same transmission path, and the effect of reducing the number of transmission path lines or narrowing the transmission path can be obtained.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
The control signal and the time-axis-compressed audio signal are multiplexed in a blanking period of the video signal, so that the video signal, the control signal, and the audio signal are time-division multiplexed so that they do not overlap in the same period. The effect that can be obtained is obtained.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
The control signal is multiplexed in a predetermined period of the blanking period, and the time-axis-compressed audio signal is multiplexed in the blanking period other than the predetermined period, so that the control signal And an audio signal can be time-division multiplexed so that they do not overlap in the same period.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
By transmitting a vertical synchronization signal and a horizontal synchronization signal used for detecting the blanking period to the signal receiving device, a blanking period is detected on the receiving side using the vertical synchronization signal and the horizontal synchronization signal. Control signals that are multiplexed during that blanking period,
And an effect that audio signals can be separated.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
By providing a predetermined no-signal period before the control signal and the time-axis-compressed audio signal, a vertical synchronization signal and a horizontal synchronization signal are transmitted from the signal transmission device to the signal reception device. In addition, an effect that the control signal and the audio signal can be separated on the receiving side can be obtained.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
Conventionally, a DVI transmission standard for transmitting RGB video signals serially is used. By multiplexing the control signal and the time-axis-compressed audio signal on a predetermined channel among RGB channels, In a system of the DVI standard that can transmit only a video signal, an effect that transmission of a control signal and an audio signal using a transmission line of the video signal can be realized is obtained.

Further, according to the signal transmitting apparatus of the present invention, in the signal transmitting apparatus, the signal multiplexing means includes:
The time-axis-compressed audio signal is decomposed into a plurality of signals, and the decomposed audio signal is divided into a plurality of channels and multiplexed, so that even when the transmission rate of the audio signal is high, the sampling point of the audio signal can be determined. The effect that the audio signal can be transmitted without thinning is obtained.

According to the signal receiving apparatus of the present invention, there is provided a signal receiving apparatus connected to a signal transmitting apparatus via a transmission path, wherein the signal receiving apparatus has been transmitted from the signal transmitting apparatus via the transmission path. A time-division multiplexed signal of a video signal, a control signal used for controlling a signal receiving device or a device connected to the signal receiving device, and a time-axis-compressed audio signal is converted into a video signal, a control signal, and a time-axis multiplexed signal. Signal separation means for separating the audio signal and the time axis expansion means for expanding the time axis compressed audio signal, has been transmitted from the transmission side via the same transmission path, The effect is obtained that the time-division multiplexed video signal, control signal, and audio signal can be separated into respective signals.

Further, according to the signal receiving apparatus of the present invention, in the signal receiving apparatus, the signal separating means includes:
By separating the control signal and the time-axis-compressed audio signal multiplexed during the blanking period of the video signal, a time is ensured so that the video signal, the control signal, and the audio signal do not overlap in the same period. The effect of being able to separate the divided and multiplexed signals into respective signals is obtained.

Further, according to the signal receiving apparatus of the present invention, in the signal receiving apparatus, the signal separating means includes:
By separating the control signal multiplexed in a predetermined period of the blanking period and the time-axis-compressed audio signal multiplexed in the blanking period other than the predetermined period, there is no video signal. During the period, an effect is obtained in which a time-division multiplexed signal can be separated into individual signals so that the control signal and the audio signal do not overlap in the same period.

Further, according to the signal receiving apparatus of the present invention, in the signal receiving apparatus, the signal separating means includes:
A vertical synchronization signal and a horizontal synchronization signal are received from the signal transmission device, and the video signal, the control signal, and the time-axis-compressed audio signal are separated using the vertical synchronization signal and the horizontal synchronization signal. Thus, an effect is obtained in which the control signal and the audio signal multiplexed in the blanking period can be separated.

Further, according to the signal receiving device of the present invention, in the signal receiving device, the signal separating means includes:
The control signal and the time-axis-compressed audio signal are multiplexed by detecting a predetermined non-signal period provided before the control signal and the time-axis-compressed audio signal, respectively. By specifying a period and separating the control signal and the time-axis-compressed audio signal, the signal transmission device does not transmit a vertical synchronization signal and a horizontal synchronization signal to the signal reception device. In this case, the effect that the control signal and the audio signal can be separated can be obtained.

Further, according to the signal receiving device of the present invention, in the signal receiving device, the signal separating means includes:
DV for receiving RGB video signal transmitted serially
Conventionally, only a video signal could be transmitted by separating the control signal and the time-axis-compressed audio signal multiplexed on a predetermined channel among RGB channels using the I transmission standard. In the system of the DVI standard, an effect that transmission of a control signal and an audio signal using a transmission line of a video signal can be realized is obtained.

Further, according to the signal receiving apparatus of the present invention, in the signal receiving apparatus, the time-axis-compressed audio signal is decomposed into a plurality of pieces, and the decomposed sound signals are divided into a plurality of channels and multiplexed. The signal separating means separates the decomposed audio signal and synthesizes the decomposed audio signal, so that even if the transmission rate of the audio signal is high, the sampling point of the audio signal can be determined. An audio signal can be transmitted without thinning out, and on the receiving side, the decomposed audio signal can be synthesized and restored to the original audio signal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a signal transmission system according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between a video signal and an audio signal before time axis compression.

FIG. 3 is a diagram for explaining a horizontal blanking period, a vertical blanking period, and an effective screen.

FIG. 4 is a block diagram illustrating a configuration of a time axis compression unit according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining a state of time axis compression according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a multiplexing unit according to the first embodiment of the present invention.

FIG. 7 is a diagram for explaining how a video signal, an audio signal, and a control signal are multiplexed in the first embodiment of the present invention.

FIG. 8 is a block diagram illustrating a configuration of a separation unit according to the first embodiment of the present invention.

FIG. 9 is a diagram for explaining a state of separation of a video signal, an audio signal, and a control signal according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a time base extension unit according to the first embodiment of the present invention.

FIG. 11 is a diagram for explaining how the time axis is extended in the first embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a signal transmission system according to a second embodiment of the present invention.

FIG. 13 is a block diagram illustrating a configuration of a time axis compression unit according to a second embodiment of the present invention.

FIG. 14 is a diagram for explaining a state of time axis compression according to the second embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a multiplexing unit according to a second embodiment of the present invention.

FIG. 16 is a diagram for explaining how a video signal, an audio signal, and a control signal are multiplexed in Embodiment 2 of the present invention.

FIG. 17 is a block diagram illustrating a configuration of a separation unit according to the second embodiment of the present invention.

FIG. 18 is a diagram for explaining a state of separation of a video signal, an audio signal, and a control signal according to the second embodiment of the present invention.

FIG. 19 is a block diagram showing a configuration of a time base extension unit according to the second embodiment of the present invention.

FIG. 20 is a diagram for explaining how the time axis is extended in the second embodiment of the present invention.

FIG. 21 is a block diagram illustrating a configuration of a signal transmission system according to a third embodiment of the present invention.

FIG. 22 is a diagram illustrating a state of a signal on a transmission line according to Embodiment 3 of the present invention.

FIG. 23 is a diagram for describing a method of separating a video signal, an audio signal, and a control signal according to Embodiment 3 of the present invention.

FIG. 24 is a diagram for describing a method for decoding a video signal, an audio signal, and a control signal according to Embodiment 3 of the present invention.

FIG. 25 is a block diagram illustrating a configuration of a conventional signal transmission system.

[Explanation of symbols]

11, 21, 31 Signal transmitting device 12, 22, 32 Signal receiving device 101, 201 Time axis compressing section 102, 202 Multiplexing section 103, 203 Separating section 104, 204 Time axis extending section 105 Audio clock reproducing section 106 Data line 107 Clock Line 301 time axis compression section 302 decomposition section 303 first selector 304 first horizontal line counter 305-307 TMDS encoder / serializer 308-310 TMDS decoder / recovery 311 second selector 312 second horizontal line counter 313 synthesis Section 314 Time axis decompression section 315 PLL 350 Channel 0 decoder 351 Channel 1 decoder 352 Channel 2 decoder 360, 361 Serial / parallel converter 362, 363, 364, 365 Decoder 100 First selector 1002 First multiplex control unit 1003 First horizontal line counter 1004 Second selector 1005 Second multiplex control unit 1011, 2011, 3011, 4011 Memory 1012 Compression control unit 2001 Third selector 2002 First Control unit 2003 fourth selector 2004 second separation control unit 2005 second horizontal line counter 2012, 4012 decompression control unit 2601-2603 TMDS encoder / serializer 2604-2606 TMDS decoder / recovery 3001 fifth selector 3002 Third multiplexing control unit 3003 Third horizontal line counter 3004 Sixth selector 3005 Fourth multiplexing control unit 3012 Compression control signal delay unit 4001 Seventh selector 4002 Third separation control unit 4003 No-signal detector 4004 selector 4005 fourth isolation control unit 4006 second no-signal detector of the eighth

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Claims (21)

[Claims] 1. A signal transmission system comprising: a signal transmission device that transmits a signal; and a signal reception device that receives a signal transmitted from the signal transmission device via a transmission path, wherein the signal transmission device includes: The audio signal is time-axis-compressed, and the video signal is time-division-multiplexed with the signal receiving device or a control signal used for controlling a device connected to the signal receiving device and the time-axis-compressed audio signal. The signal receiving apparatus separates the signal transmitted from the signal transmitting apparatus into a video signal, a control signal, and a time-axis-compressed audio signal. A signal transmission system for expanding a compressed audio signal. 2. The signal transmission system according to claim 1, wherein the signal transmission device multiplexes the control signal and the time-axis-compressed audio signal in a blanking period of the video signal. Signal transmission system. 3. The signal transmission system according to claim 2, wherein the signal transmission device multiplexes the control signal in a predetermined period of the blanking period, and multiplexes the time-axis-compressed audio signal in the predetermined period. Multiplexing during the blanking period other than the above. 4. The signal transmission system according to claim 2, wherein the signal transmission device transmits a vertical synchronization signal and a horizontal synchronization signal to the signal reception device, and the signal reception device transmits the vertical synchronization signal and the vertical synchronization signal. Receiving the signal and the horizontal synchronization signal, and separating the video signal, the control signal, and the time-axis-compressed audio signal using the vertical synchronization signal and the horizontal synchronization signal. A signal transmission system characterized by the above. 5. The signal transmission system according to claim 2, wherein the signal transmission device provides a predetermined non-signal period before the control signal and the time-axis-compressed audio signal, respectively. The signal receiving device detects the non-signal period to identify the control signal, and a period in which the time-axis-compressed audio signal is multiplexed, and specifies the control signal and the time-axis-compressed audio. A signal transmission system for separating a signal from a signal. 6. The signal transmission system according to claim 1, wherein the signal transmission system uses a DVI transmission standard for transmitting RGB video signals serially. Wherein the control signal and the time-axis-compressed audio signal are multiplexed on a predetermined channel, and the signal receiving apparatus is configured to multiplex the control signal and the time-axis-compressed signal on the predetermined channel. A signal transmission system for separating an audio signal from an audio signal. 7. The signal transmission system according to claim 6, wherein the signal transmission device decomposes the time-axis-compressed audio signal into a plurality of signals, and multiplexes the decomposed audio signals into a plurality of channels. The signal transmission system, wherein the signal receiving device separates the decomposed audio signal and synthesizes the decomposed audio signal. 8. A signal transmission device connected to a signal reception device via a transmission line, comprising: a time axis compression means for compressing an audio signal on a time axis; and a control signal used for control on a video signal and a signal reception side. And a signal multiplexing means for time-division multiplexing the audio signal time-compressed by the time-axis compression means and transmitting the time-division-multiplexed audio signal to the signal receiving apparatus via the transmission path. . 9. The signal transmitting apparatus according to claim 8, wherein the signal multiplexing unit multiplexes the control signal and the time-axis-compressed audio signal in a blanking period of the video signal. Signal transmitting device. 10. The signal transmitting device according to claim 9, wherein the signal multiplexing unit multiplexes the control signal in a predetermined period of the blanking period, and multiplexes the time-axis-compressed audio signal in the predetermined period. A signal transmitting apparatus for multiplexing in the blanking period other than the above. 11. The signal transmitting device according to claim 9, wherein the signal multiplexing unit transmits a vertical synchronizing signal and a horizontal synchronizing signal used for detecting the blanking period to the signal receiving device. Signal transmitting device. 12. The signal transmitting apparatus according to claim 9, wherein the signal multiplexing unit provides a predetermined non-signal period before the control signal and the time-axis-compressed audio signal. Signal transmitting device. 13. The signal transmitting apparatus according to claim 8, wherein said signal multiplexing means uses a DVI transmission standard for transmitting RGB video signals serially, and a predetermined channel among RGB channels is provided. A signal transmission device multiplexing the control signal and the time-axis-compressed audio signal. 14. The signal transmitting apparatus according to claim 13, wherein the signal multiplexing unit decomposes the time-axis-compressed audio signal into a plurality of signals, and divides and multiplexes the decomposed audio signals into a plurality of channels. Characteristic signal transmission device. 15. A signal receiving device connected to a signal transmitting device via a transmission line, wherein the video signal and the signal receiving device transmitted from the signal transmitting device via the transmission line or the signal receiving device. Signal separation for separating a signal obtained by time-division multiplexing a control signal used for controlling a device connected to the device and a time-axis-compressed audio signal into a video signal, a control signal, and a time-axis-compressed audio signal Means, and a time axis expanding means for expanding the time axis compressed audio signal. 16. The signal receiving apparatus according to claim 15, wherein the signal separating unit separates the control signal multiplexed during a blanking period of the video signal from the time-axis-compressed audio signal. A signal receiving device characterized by the above-mentioned. 17. The signal receiving apparatus according to claim 16, wherein the signal separating unit multiplexes the control signal multiplexed in a predetermined period of the blanking period with the control signal multiplexed in the blanking period other than the predetermined period. A signal receiving device that separates the processed time-axis-compressed audio signal. 18. The signal receiving device according to claim 16, wherein the signal separating unit receives a vertical synchronizing signal and a horizontal synchronizing signal from the signal transmitting device, and uses the vertical synchronizing signal and the horizontal synchronizing signal. A signal receiving apparatus for separating the video signal, the control signal, and the time-axis-compressed audio signal. 19. The signal receiving apparatus according to claim 16, wherein the signal separating unit detects a predetermined no-signal period provided before the control signal and the time-axis-compressed audio signal, respectively. A signal receiving apparatus that specifies a period in which the control signal and the time-axis-compressed audio signal are multiplexed, and separates the control signal from the time-axis-compressed audio signal. . 20. The signal receiving apparatus according to claim 15, wherein the signal separating means uses a DVI transmission standard for receiving a serially transmitted RGB video signal.
A signal receiving apparatus for separating the control signal multiplexed on a predetermined channel among the RGB channels from the time-axis-compressed audio signal. 21. The signal receiving apparatus according to claim 20, wherein the time-axis-compressed audio signal is decomposed into a plurality of signals, and the decomposed audio signals are divided into a plurality of channels and multiplexed. Means for separating the decomposed audio signal;
A signal receiving device for synthesizing decomposed audio signals.