JPH01319173A - Signal processing unit - Google Patents

Abstract

PURPOSE:To prevent dubbing without degrading the quality of a music signal by inserting and transmitting a signal, which shows the propriety of the dubbing, in the no signal interval of an audio signal. CONSTITUTION:In a signal processing circuit 111, an audio-digital signal to be reproduced from a tape is converted to an analog signal and outputted to a terminal (a) of a switch circuit 120 as an audio signal 111a. In a control signal generating circuit 122, the pulse of a frequency in a silent signal part, except an audio band, is generated and a control signal 122a is outputted to a terminal (b) of the switch circuit 120. A switch control circuit 121 obtains a control signal 110a, which is outputted from the signal processing circuit 111, as an input and controls the switch circuit 120. Then, in this control signal, a signal to instruct the no signal interval or the signal of the dubbing propriety of a source, etc., is included. Thus, the control signal is detected and recording in the part with music can be stopped, and a tone without sound quality degradation can be outputted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to compact disc players (hereinafter referred to as CD
The present invention relates to a signal processing device that processes and outputs analog signals such as audio signals reproduced and output by a digital audio tape recorder (hereinafter referred to as DAT), a BS tuner, or the like.

[Prior Art] In recent years, digitalization of audio has progressed rapidly, and CD, DAT, and BS tuners have become widely used.

With the advent of CDs, it has become possible to obtain high-quality reproduced audio signals, and it has become possible to enjoy sounds that are faithful to the original sounds even at home.

Furthermore, with the advent of DAT, it has become possible to dub high-quality sources without degrading them. In particular, since this DAT does not cause any deterioration in sound quality due to dubbing, it is possible to make unlimited copies of the same quality as the source, resulting in problems such as copyright infringement.

FIG. 4 is a block diagram showing a connection example when dubbing from DAT to DAT. In the same figure, (100), (
101) is DAT, (l port Oa) is cable, (102
) is an amplifier, and (103) is a speaker.

A dubbing operation using the connection example shown in FIG. 4 will be explained.

The audio signal reproduced by the DAT (100) is input to the amplifier (102) through the cable (100a), and after being amplified in this amplifier (102),
It is output through the speaker (103). On the other hand, D.A.
T (101) converts the audio signal input through the cable (100a) into a digital signal using an analog-digital converter and records, that is, dubs.

Fig. 5 is a block diagram showing an example of the conventional copy gobo old system, in which (110) is DAT (100).
(111) is a signal processing circuit, (112) is a filter, and this filter (
112) is the audio band (fl
) is extracted from a specific frequency (fl) component. (113
) is a frequency detector that detects the presence or absence of a frequency (fl) component, (114) is a signal processing circuit, and (115) is D A
This is an output terminal for recording signals supplied to the head of T (102). Also, (llla) is the cable (1) shown in Figure 4 above.
00a).

Next, the operation of the copy prevention system shown in FIG. 5 will be explained.

The signal reproduced by the DAT (100) undergoes predetermined processing in a signal processing circuit (LIT) and is output as an analog audio signal (lla). Then, in the filter (112), the audio signal (lla
), extract the frequency component (fl) included in the DAT
(100) is output as an audio signal (t:xb).

D A T (101), D A T (100)
The audio output (lllb) of the signal processing circuit (114
) and perform the specified processing. On the other hand, frequency detection 1 (113) detects the presence or absence of the frequency component (fl), and if there is no frequency component (fl), it determines that the audio signal (100b) is a signal that prohibits dubbing. The city signal (113a) is output to the signal processing circuit (114).

As a result, the signal processing circuit (114) controls the system to stop recording or record silence, and audio signals that are prohibited from being dubbed are not recorded, making it possible to protect copyright.

[Problems to be Solved by the Invention] Conventional signal processing devices are configured in one or more ways, so in order to prevent dubbing, there is a problem that a specific frequency of the audio signal is lost, resulting in deterioration of sound quality. Ta.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a signal processing device that can prevent dubbing without deteriorating sound quality.

[Means for Solving the Problems] A signal processing device according to the present invention is configured to superimpose a control signal having a frequency component outside the audio band on an audio signal and output the same in the silent portion between songs. It is characterized by

[Function] According to the present invention, recording can be stopped by detecting a control signal, and a certain part of the music can output sound without deterioration in sound quality, and the control signal part can also be used to detect sounds outside the audio band. Since it is a sound source, it will be played as the same silence as the source.

[Embodiment 151] An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing the configuration of a dubbing prevention system in a signal processing device according to an embodiment of the present invention, in which (120) is a switch circuit;
1) is a switch control circuit, (122) is a control signal generation circuit, (12:l) is a control signal detection circuit, (124) is a display circuit, and the other configurations are the same as the conventional example shown in FIG. Therefore, the same reference numerals are given and the explanation is omitted.

Next, the operation of the above configuration will be explained.

First, the processing operation of D A T (100) will be explained.

The signal processing circuit (111) converts the audio digital signal reproduced from the tape into an analog signal and outputs it as an audio signal (lla) to the terminal a of the switch circuit (120). Also, a control signal generation circuit (122)
Now, as shown in FIG. 2, pulses at frequencies (f3) and (f4) of the silent signal part outside the music signal part, that is, outside the audio band, are generated, and the control signal (122a) is sent to the switch circuit (120). ) is output to the terminal.

The switch control circuit (121) is connected to the signal processing circuit (11).
The switch circuit (120) is controlled by inputting the control signal (110a) output from the circuit 1). This control signal (1
10a) includes a signal instructing a silent signal portion, a signal indicating whether or not the source can be dubbed, and the like.

Figure 3 shows the output (120a) of the switch circuit (120), and as shown in the figure, the music signal section performs signal processing (
1, 11), and the control signal (122a) from the control signal generation circuit (122) in the no-signal section.

The pulses of frequencies (f3) and (f4) transferred in a time-division manner in the control u4 signal (122a) are synchronization signals, respectively.
Used as a dubbing prohibition signal.

On the other hand, the D A T (101) inputs the input audio signal (120a) to the signal processing circuit (114) and also to the control signal detection circuit (123).

The signal processing circuit (114) is the same as the signal processing circuit (111) above.
A circuit similar to the above generates a signal for converting an audio signal into a digital signal and recording it on a magnetic tape in a predetermined format, and outputs it from a terminal (ttS) and supplies it to the head.

In addition, the control signal detection circuit (123) also detects the control signal (
122a) and supplies a control signal to the signal processing circuit (114) and display circuit (124) based on Table 1 below.

When the dubbing prohibition signal is output, the signal processing circuit (11
In step 4), processing such as setting the audio data of the recording signal to O or stopping the recording operation is performed.

On the other hand, the display circuit (124) displays that the recording is prohibited.

As shown in Table 1, by allowing dubbing only when the frequency (f3) can be detected and the frequency (f4) cannot be detected, it is not possible to record only the music signal part while avoiding the control signal area. Rights are protected.

Also, although not shown, there is an E
By inserting an ND signal, it is possible to protect each song.

In the above embodiment, the audio signal and the control signal were selected and outputted by the switch circuit (120), but the same effects as in the above embodiment can be obtained even if the two signals are added and outputted by the addition circuit. play.

In addition, although a signal having a predetermined frequency was used as the control signal, a synchronization signal,
The control signal may be transmitted in a digitally detectable manner.

Furthermore, the control signal may be inserted anywhere in the song as long as it is a no-signal section.

Furthermore, although the above embodiment describes a DAT, it can also be applied to other devices.

[Effects of the Invention] As described above, according to the present invention, the signal indicating whether or not dubbing is possible is inserted into the no-signal section of the audio signal and transmitted, so that the quality of the music signal is not degraded. Dubbing can be prevented, and as a result, problems such as copyright infringement can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a dubbing prevention system in a signal processing device according to an embodiment of the present invention, and FIG.
The figure shows the frequency components of the control signal, Fig. 3 is an output waveform diagram, Fig. 4 is a block diagram showing a connection example when dubbing using DAT, and t55 shows the configuration of a conventional copy protection system. The block diagram, FIG. 6, is a diagram showing frequency components of a signal output from a conventional copy protection system. (111), (114) ---signal processing circuit, (1
20)... Switch circuit, (121)... Switch control circuit, (122)... Control signal generation circuit, (12)...
3)...Control signal detection circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a signal processing device configured to output an analog signal for outputting analog information, a control signal generating means for generating at least a first control signal and a second control signal; a signal synthesizing means for adding first and second control signals, and adding a second control signal to the no-signal period of the analog information based on the first control signal and whether or not the analog information can be copied. A signal processing device configured to output.