JPH0555360U - Voice control circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] In digital audio, in a digital audio device capable of recording and reproducing additional signals (subcode information etc.) and reproducing emphasis information which is one of the subcode information, When the recorded information is lost due to some reason, it is common to interpolate from the data obtained correctly by holding the previous value.However, when this interpolation is performed, the interpolated music signal is Prevents annoying sound due to many wave components. [Structure] When interpolated, the de-emphasis circuit of the reproduction circuit is automatically operated to attenuate high frequency frequencies, thereby reducing annoying sound.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a voice control circuit for digital audio.

[0002]

[Prior Art]

 In digital audio equipment, if the recorded information is lost for some reason, it is common to interpolate from the data obtained correctly by holding the previous value. However, when the signal waveform is reproduced by this interpolation, the music signal generally has more harmonic components than the original music signal, and thus tends to be an offensive sound.

[0003]

[Problems to be solved by the device]

 In the case of reproducing an interpolated music signal, which is apt to produce a jarring sound as in the prior art, the high frequency reduction filter is operated to attenuate the high frequency and limit the frequency characteristic of the music signal. This will reduce the offensive noise.

[0004]

[Means for Solving the Problems]

 Interpolation is detected, and the emphasis circuit of the playback circuit is automatically operated to attenuate high frequency frequencies, thereby reducing harsh sounds. As a result, the existing de-emphasis circuit can be used as a dedicated high-frequency reduction filter, and it is possible to easily attenuate annoying sound.

[0005]

【Example】

 The present invention will be described with reference to an embodiment. FIG. 1 is a block diagram showing an embodiment of the present invention, and DAT will be described as an embodiment. The signal read by the RAM memory 3 for decoding the reproduction signal and the signal processing circuit 4 is decoded through the RF amplifier 2 which amplifies the signal read by the drum 1 which reads the signal on the tape, and the D / A The music signal is transmitted to the converter 6, and when interpolation is required, the signal processing circuit 4 detects this and performs interpolation.

When the interpolated data is output from the signal processing circuit 4, this is detected, the CPU 5 operates the de-emphasis circuit 8 to turn on the switch 9, and the low-pass filter 7 and the de-emphasis circuit 8 are output. To output via the output buffer 10.

FIG. 2 shows a general de-emphasis characteristic. The signal read from the drum 1 is amplified by the RF amplifier 2 and decoded into a music signal by the signal processing circuit 4 and the RAM memory 3. At this time, if the error rate of the signal read from the drum 1 is not sufficiently high for some reason, the signal processing circuit 4 transmits the interpolation data to the data to be transmitted to the D / A converter 6. Then, when transmitting this complement data, the CPU 5 causes the switch 9 for turning on and off the de-emphasis circuit 8 to operate to automatically attenuate the high frequency. At this time, the music signal attenuates and limits the high frequency range by about 10 dB according to the characteristic shown in FIG.

Further, in the present embodiment, the de-emphasis characteristic is operated in the analog circuit. However, by transmitting the de-emphasis code to the digital out sub-code data, the same effect can be obtained on the receiving side. That is, even if the error rate of the transmitted data is deteriorated, the reproduced signal can be easily heard. Although the D / A circuit of the DAT has been described in the present embodiment, similar operational effects can be obtained even in a similar digital audio device.

[0009]

[Effect of the device]

 As described above, when the recorded information is lost due to some reason, when interpolation is performed, the de-emphasis circuit of the playback circuit is automatically operated to attenuate the high frequency range. By doing so, it is possible to easily attenuate annoying sounds without providing a dedicated high-frequency reduction filter.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part showing an embodiment of the present invention.

FIG. 2 is a diagram showing a de-emphasis characteristic.

[Explanation of symbols]

 1 Drum 2 RF amplifier 3 RAM memory 4 Signal processing circuit 5 CPU 6 D / A converter 7 Low-pass filter 8 De-emphasis circuit 9 Switch 10 Output buffer

Claims (1)

[Scope of utility model registration request] 1. Emphasis information of sub-code information of a digital audio device such as a CD, DAT, etc. is recorded, and a certain amount of attenuation is controlled by a predetermined frequency by the emphasis information, and the recorded information is lost for some reason. In such a case, in a device that interpolates from the data obtained correctly by holding the previous value, etc., if the information recorded during playback is missing, it is detected and the de-emphasis circuit of the playback circuit is automatically operated. , A voice control circuit characterized by attenuating high frequency frequencies and reducing annoying sounds.