JP3491496B2 - Digital audio system - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to digital audio systems.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing an example of a conventional digital audio system. In FIG. 6, 1
Is a Dolby (registered trademark) digital (5.1ch) compatible DVD (digital versatile disc) player,
11 is a receiver.

Since the DVD player 1 supports Dolby Digital (5.1 ch), it has a 6-channel analog output and a 1-channel digital output based on IEC958. From the 6-channel analog output, a Dolby digital signal read from the DVD disc 3 is output. (5.1ch)
Through the signal processing circuit 4 to the Dolby digital decoder 5
Decode with 6 channel D / A converter 6
Signals that have been A-converted and passed through the configuration filter 7 (L, R, C (center), SL (rear L), SR
(Rear R) and SW (Subwoofer) are output through 6 analog pin codes APC, and the Dolby digital signal (5.1ch) from the Dolby digital decoder 5 as compressed is output from the digital output. O
It is output via the PTC. The microcomputer 2 controls the operations of the signal processing circuit 4, the Dolby digital decoder 5, and the configuration filter 7.

On the other hand, in the receiver 11, the Dolby digital compressed signal (5.1c) input from the digital input is input.
h) is decoded by the Dolby Digital Decoder 14 via the DIR (Digital Interface Receiver) 13, and is D / A by the 6-channel D / A converter 15.
It is converted and passes through the configuration filter 16.
The selector 17 selects the 6-channel analog input from the configuration filter 7 of the DVD player 1 and the 6-channel analog signal obtained by D / A converting the digital input from the Dolby digital decoder 5, and the amplifier 1
8 to be output to the speakers 22a to 22f of the speaker system 22. The microcomputer 12
The operation of the Dolby digital decoder 14, the configuration filter 16 and the selector 17 is controlled.

Here, the Dolby Digital is a digital application of the Dolby Surround system, and is used for digital disks such as DVDs and the like, which have five basic channels (L, R, C (center), SL (rear L), SR.
(Rear R)) data is recorded. Some discs have data for the SW (subwoofer) channel having a low-frequency component called LFE in addition to the above-mentioned basic 5 channels, but this component is not the data amount for one channel. Therefore, the number of channels is set to 0.1, and the channel including these 0.1 channels is called Dolby Digital (5.1ch). The addition of LFE cannot be performed digitally, and the addition is performed by an analog circuit called a configuration filter. Then, as a result of the addition, the configuration filter is L, R, C, S.
6 channels of L, SR and SW are output. When there is no SW, it outputs 5 channels.

The method of identifying the category of the signal processed by the configuration filter is as follows.
FIG. 7 shows a sub-frame format of digital data, and FIG. 8 shows a channel status data format (mode 0) for consumer digital audio equipment. 8 to 15 bits in the C-bit channel status data format are category codes, for example, 10000000 for a CD and 1 for a DVD.
001100X, which can be identified by this code.

The method of distinguishing Dolby Digital signals is as follows. 9 to 11 respectively show a digital output IEC958 format, an IEC958 frame bit allocation table, and a data burst format. In order to determine whether or not a Dolby digital audio signal, the channel status bit (C bit) is 1 Whether or not the information signal of 16-bit data is XXX1 is confirmed. The C-bit area is 1 for a compressed signal and 0 for linear PCM audio of CD or DVD. The 16-bit data area is a linear P for CDs and DVDs.
In the case of a CM voice (at 16 bits), only voice data is provided, and in the case of a compressed voice signal, a compressed voice signal, a sync signal and an information signal are sent.

In the data burst format of FIG. 11, the data burst is Pa: sync signal 1 F87.
2 (H) and Pb: synchronization signal 2 4E1F (H) and Pb
c: preamble including information signal XXX (H), and Burst-Payload: compressed signal (for example, Dolby). Pc is an information signal indicating the type of compressed signal. For example, XXX1 (H) is a Dolby digital signal, XXX4 (H) is MPEG-1 layer 1 data,
XXX8 (H) represents the low sample rate of MPEG-2 or 3. Therefore, first, the bit 1 of C bit is “1”, the synchronization signals of Pa and Pb are detected in the 16-bit data, and if the value of Pc is XXX1, it can be said that the signal is a Dolby digital signal.

Next, the configuration filters 7 and 17 will be described. The configuration filter is a filter that distributes low-frequency sounds to each speaker according to the individual system configuration such as the presence or absence of a SW (subwoofer) speaker connected to the receiver 11 and the size of the LR speaker aperture. is there. That is, S
Distributing low-frequency components to each speaker with or without a W speaker, when the LR speaker has a large aperture and can reproduce low frequencies, or when the aperture is small and insufficient for low frequency reproduction. Is a filter that can be changed appropriately.

12 to 15 show six types of configuration filters "A", "B", "C-1" and "C".
-2 "," D-1 ", and" D-2 "are configuration examples. The configuration filter" A "in Fig. 12 has L, C, R, LS, and RS input medium and high frequency components, respectively. High-pass filters (HPF) 31, 32, 33, 34 and 3 for passing L, C, R, LS and RS outputs
5 and L, C, R, LS and RS inputs are 0 dB and LF
It is composed of an adder 36 that adds the E input at +10 dB, and a low-pass filter (LPF) 37 that passes only the low-frequency component of the added signal to produce a SUB output.

The configuration filter "B" of FIG. 13 includes HPFs 32, 34 and 35, an adder 36 for adding C, LS and RS inputs at 0 dB and an LFE input at +10 dB, and a low frequency component of the addition signal. L to pass
The PF 37, an attenuator 40 that attenuates the output of the LPF 37 by 4.5 dB, an adder 38 that adds the L input and the output of the attenuator 40 into an L output, and an R input that adds the output of the R input and the attenuator 40. And an adder 39 for

The configuration filters "C-1" and "C-2" of FIG. 14 are the HPF 32 and the adder 3
LPF4 that passes 8 and 39 and the low frequency component of C input
1, an attenuator 42 that attenuates the output of the LPF 41 by 4.5 dB and outputs it to the adders 38 and 39, and an LFE input, and a YES terminal corresponding to “with SW” and a NO terminal corresponding to “without SW” And adders 38 and 3
A switch 43 having a NO terminal for outputting to 9, 45 and 46; an amplifier 44 for amplifying the LFE input via the YES terminal of the switch 43 by +10 dB to obtain a SUB output;
An adder 45 for adding the LS input and the LFE input via the NO terminal of the switch 43 to produce an LS output, and an adder 46 for adding the RS input and the LFE input via the NO terminal of the switch 43 to produce an RS output. It consists of and. Here, when the switch 43 is switched to the NO side, "C-
When the switch 43 is switched to the YES side, the configuration is 1 "(without SW), and the configuration is" C-2 "(with SW).

The configuration filters "D-1" and "D-2" of FIG. 15 are HPFs 32, 34 and 3 respectively.
5, the adders 38 and 39, the adder 47 for adding the C, LS and RS inputs, and the output of the adder 47 is 4.5 dB.
An attenuator 48 for attenuating, an LPF 49 for passing a low frequency component of the output of the attenuator 47, and a switch 5 which is supplied with the output of the LPF 49 and has a terminal for outputting to the adders 38 and 39 and a b terminal for outputting to the SUB output side.
0 and the output from the b terminal of the switch 50 is 10.5 dB.
It is composed of an attenuator 51 that attenuates, an adder 52 that receives the output of the attenuator 51 to obtain a SUB output, and an attenuator 53 that attenuates the LFE input by 5.0 dB and supplies the attenuated signal to the adder 52. Where switch 50
When the switch 50 is switched to the a side, the configuration becomes "D-1" (without SW), and when the switch 50 is switched to the b side, "D-1" is set.
-2 "(with SW).

FIG. 16 shows a comparison of the output voltage (Vrms) of each configuration filter. Here, the output voltage of each part for an input voltage of 2 Vrms is shown. Then, returning to FIG. 6, the configuration filters 7 and 17 are of the types “B”, “C-1” (group A) or “D-” among the above six types when there is no SW. If either 1 "(DVD) is selected and there is a SW, type" A "," C-2 "
Either (Group A) or "D-2" (DVD) is selected. The group A is a grouping of so-called digital audio systems, where A means high performance, B means popular products, and C means car or portable. A DVD is a DVD configuration filter.

[0015]

By the way, in the digital audio system having the above-described structure, when the DVD player and the receiver are connected, a problem may occur depending on the type of the receiver and the form of the speaker system. As an example, in FIG. 6, a case where the receiver 11 is a group B, that is, a popular receiver, and a speaker other than the SW speaker 22f is connected to the speaker system 22 (that is, when there is no SW) and the setting is performed will be described.

First, both the analog and digital outputs of the DVD player 1 are connected to the receiver 11. At this time, "B" is selected as the configuration filter on the receiver 11 side, but unless the speaker is set on the DVD player 1 side, a configuration filter 17 different from the receiver 11 may be selected. . It can be seen from FIG. 16 that the output power greatly differs depending on the type of configuration filter. Therefore, even with the same source, DVD player 1 and receiver 11
If the same configuration filter is not selected in, there occurs a problem that the levels of the reproduced sound of the speaker are different between digital and analog. Further, when a SW (subwoofer) is newly added, it is troublesome to reconfigure the configuration filters of the receiver and the DVD player.

An object of the present invention is to solve the above-mentioned conventional problems and provide a digital audio system in which setting of a configuration filter is simple.

[0018]

In a digital audio system according to the present invention, a disc player for outputting an analog reproduction signal of a digital disc through a plurality of types of configuration filters is connected to the disc player, and the digital signal of the disc player is connected. What is claimed is: 1. A digital audio system comprising a receiver for outputting an analog signal obtained by D / A converting a reproduction signal to a speaker system through a plurality of types of configuration filters, wherein the receiver is of the plurality of types according to a connection state of the speaker system. Select one type from the configuration filters, the configuration filter of the disc player matches the type of configuration filter selected at the receiver. It is characterized in that is chosen such. (Claim 1)

Further, in the digital audio system according to the present invention, in the system according to claim 1, the disc player and the receiver each include a remote control light receiving and transmitting unit, and selection of each configuration filter is performed by a command signal from the remote control commander. It is done. (Claim 2)

[0020]

1 is a block diagram showing an embodiment of a digital audio system according to the present invention. In FIG. 1, 1 is a Dolby Digital (5.1ch) compatible DVD (Digital Versatile Disc) player, and 11 is a receiver. Here, the DVD player 1
The receiver 11 and the receiver 11 serve as configuration filters 7 and 16, respectively, of type “A” and “A”.
B "," C-1 "," C-2 "," D-1 "and" D-
It is equipped with all 6 types of configuration filters of 2 ". Also, the DVD player 1 and the receiver 11 have six analog pin codes APC for analog signals and one optical cable OPTC for digital signals.
And one data communication serial control code SCC.

The DVD player 1 is Dolby Digital compatible (5.1 ch) and has 6-channel analog output and 1-channel digital output based on IEC958. From the 6-channel analog output, the Dolby Digital read from the DVD disc 3 is used. Signal (5.1ch)
Through the signal processing circuit 4 to the Dolby digital decoder 5
Decode with 6 channel D / A converter 6
The signals (L, R, C, SL, SR, SW) that have been A-converted and passed through the configuration filter 7 are output, and the digital output from the Dolby digital decoder 5 (5 .1 ch) is being output. The microcomputer 2 controls the operations of the signal processing circuit 4, the Dolby digital decoder 6, and the configuration filter 7.

On the other hand, in the receiver 11, the Dolby digital compressed signal (5.1c) input from the digital input is input.
h) is decoded by the Dolby Digital Decoder 14 via the DIR 13, and the 6-channel D / A converter 1
D / A converted in 5, configuration filter 1
Go through 6. The 6-channel analog input from the configuration filter 7 of the DVD player 1 and the 6-channel analog signal obtained by D / A converting the digital input from the Dolby digital decoder 5 are selected by the selector 17, passed through the amplifier 18, and then the speaker system. It is output to each of 22 speakers 22a to 22f.

The microcomputer 12 includes a Dolby digital decoder 14 and a configuration filter 1.
6, the operation of the selector 17 and the display device 20 is controlled. Further, the microcomputers 2 and 12 are interconnected by a serial control code SCC, and can recognize their own system configuration and operating state and exchange data representing them. The recognition of the system configuration and the operating state is performed by the microphone computer 12,
It includes the size and connection status of each speaker 21a to 21f, the selection status of the configuration filter 16, and the like.

In the above configuration, the setting operation of the configuration filter based on the speaker setting in the receiver will be described with reference to the flowchart shown in FIG.
First, in S1, the microcomputer 12 determines whether or not the SW speaker 22f is connected.
If not, the process proceeds to S3. In S2, the main L
Also, the microcomputer 12 determines whether or not the speaker size of the R speakers 22a and 22b is larger than a predetermined size (for example, a size capable of sufficiently reproducing the low frequency), and if it is larger, the configuration filter 16 is used as a type. "C-2" is selected (S4), and if smaller, type "A" is selected (S5).

In S3, the microcomputer 12 determines whether or not the speaker sizes of the SL and SR speakers 22d and 22e are larger than a predetermined size (for example, a size capable of sufficiently reproducing the low frequency), and if larger, Type "C" as the configuration filter 16
-1 "is selected (S6), and if it is smaller, type" B "is selected (S7). A normal receiver makes the above settings on the setup screen of the display device 20 based on the control of the microcomputer 12.

Next, the setting operation of the configuration filter of the receiver when there is a digital input will be described with reference to the flowchart shown in FIG. Here, the configuration filter 16 of the receiver 11 is S in FIG.
4 is assumed to be set to type "C-1".

First, in S11, the microphone computer 12 judges whether or not there is a digital input through the optical cable to the receiver 11, and if there is no digital input, the type "C-1" determined as the configuration filter 16 in FIG. If there is a digital input, the category of the input source is DVD (10).
0111001), the microphone computer 12 determines whether it is a DVD or not, and if it is a DVD, proceeds to S13, and if it is not a DVD (S1)
Proceed to 6). In S13, the microcomputer 12 determines whether or not the DVD signal is the Dolby Digital signal (5.1 ch). If so, the configuration filter 16 of the receiver 11 is changed from type "C-2" to type "D-2". To "" (S14). If they are different, the process proceeds to (S16).

After S14, (SW on the DVD player 1 side
(There is a possibility that it is not known whether or not) has been changed from the receiver 11 side to the type "D-2" as the configuration filter 16, and the data indicating that is changed from the microcomputer 12 via the serial control code SCC. To the microphone computer 2 of the DVD player 1 to inform the DVD player 1 side (S1
5). Therefore, on the DVD player 1 side, the microcomputer 2 based on the above data sets the type "C-" as the configuration filter 7 according to the setting from the receiver 11 as the first set filter type as the configuration filter 7.
Control is performed to select 2 "or" D-2 ".

In this way, the type of the configuration filter 16 selected according to the speaker connection status on the receiver 11 side and the input source connected to the receiver 11, that is, the type of the configuration filter of the DVD player 1 are set. Can be matched automatically.

Therefore, when a receiver and a DVD player of models equipped with a Dolby digital decoder and a configuration filter are connected, the settings of both configuration filters are automatically adjusted,
By selecting analog input or digital input of the receiver, it is possible to eliminate the level difference of the sound reproduced by the speaker.

[0031]

FIG. 4 is a block diagram showing another embodiment of the digital audio system according to the present invention. Figure 4
Then, the serial control code SCC is deleted from the configuration of FIG. 1 and a component for performing remote control transmission / reception is added. The DVD player 1 and the receiver 11 have remote control light receiving and transmitting units 9 and 21 respectively.
Is provided, and the configuration of the configuration filter is set by exchanging remote control signals with the learning remote control commander 23.

FIG. 5 is a flow chart showing the setting operation of the configuration filter of the DVD player in the block diagram of FIG. Here, it is assumed that the configuration filter 16 of the receiver 11 is set to the type "C-1" in S4 of FIG.

First, in S21, the microcomputer 12 determines whether or not a play command from the learning remote controller commander 23 is generated, based on a signal from the remote controller light receiving / transmitting section 21, and if no, the operation is repeated until it is generated.
If it occurs, the microcomputer 12 determines whether the disc is a DVD or not in S22. S except DVD
In S23, the data is reproduced as it is, and in the case of DVD, in S24, the microcomputer 24 determines whether the data is a Dolby digital signal. If it is not a Dolby digital signal here, it is reproduced as it is in S23, and if it is a Dolby digital signal, the learning remote controller commander 23 asks the receiver 11 for the type setting status of the configuration filter 16 in S25.

Then, in S26, when the data indicating the setting status of the configuration filter 16 is transmitted from the receiver 11 to the learning remote controller commander 23 via the remote control light-receiving / transmitting unit 21, the setting of the configuration filter 16 is indicated in S27. The data is sent to the microcomputer 2 of the DVD player 1 via the remote control light-receiving / transmitting unit 9, and on the DVD player 1 side, the microcomputer 2 uses the above-mentioned data as the configuration filter 7 and sets the filter type initially set. According to the setting from the receiver 11, type "C-
Control is performed to select 2 "or" D-2 ".

In this way, the DVD is transmitted via the remote control system, for example, based on the transmission of the play command.
The configuration filters 7 and 16 of the player and the receiver 11 can be unified into the same type, and it is possible to eliminate the level difference of the speaker reproduced sound by selecting analog input or digital input of the receiver.

[0036]

According to the present invention, when models having configuration filters are connected to each other, the types of the configuration filters can be automatically matched with each other.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital audio system according to the present invention.

FIG. 2 is a flowchart showing setting work of a configuration filter based on speaker setting in the receiver in the block diagram of FIG.

FIG. 3 is a flowchart showing a setting operation of a configuration filter of a receiver when there is a digital input in the block diagram of FIG.

FIG. 4 is a block diagram showing another embodiment of the digital audio system according to the present invention.

5 is a flowchart showing a setting operation of a configuration filter of the DVD player in the block diagram of FIG.

FIG. 6 is a block diagram showing an example of a conventional digital audio system.

FIG. 7 shows a subframe format of digital data.

FIG. 8 shows a channel status data format (mode 0) for consumer digital audio equipment.

FIG. 9 shows an IEC958 format for digital output.

FIG. 10 shows a bit allocation table of an IEC958 frame.

FIG. 11 shows a data burst format.

FIG. 12 shows a configuration example of a configuration filter type “A”.

FIG. 13 shows a configuration example of a configuration filter type “B”.

FIG. 14: Configuration filter type “C”
An example of the configuration of "-1" and "C-2" is shown.

FIG. 15: Configuration filter type “D”
An example of the configuration of "-1" and "D-2" is shown.

FIG. 16 shows a comparison of the output voltage (Vrms) of each configuration filter.

[Explanation of symbols]

1 DVD player 2 microcomputer 3 DVD disc 4 Signal processing circuit 5 Dolby Digital Decoder 6 6-channel D / A converter 7 Configuration filter 8 key input section 9 Remote control light receiving / transmitting section 11 receiver 12 Microcomputer 13 DIR 14 Dolby Digital Decoder 15 6-channel D / A converter 16 Configuration filter 17 Selector 18 Amplifier 19 Key input section 20 display 21 Remote control receiver 22 speaker system 23 Learning Remote Commander

Claims (2)

(57) [Claims] 1. A disc player for outputting an analog reproduction signal of a digital disc through a plurality of types of configuration filters and the disc player are connected, and the digital reproduction signal of the disc player is D
A digital audio system comprising a receiver that outputs analog-to-A converted analog signals to a speaker system through a plurality of types of configuration filters, the receiver of the plurality of types of configuration filters according to the connection status of the speaker system. A digital audio system, characterized in that one of the types is selected and the configuration filter of the disc player is selected to match the type of configuration filter selected at the receiver. 2. The digital audio system according to claim 1, wherein the disc player and the receiver each include a remote control light receiving and transmitting unit, and selection of each configuration filter is performed by a command signal from the remote control commander.