JPH0249036Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an audio information processing device, and more particularly to an audio information processing device that processes digitized audio information.

Background technology In audio information processing devices such as digital audio disk players, PCM
(Pulse Code Modulation) method is used to reproduce audio information that has been digitized and recorded. When a sound system is formed using conventional audio information processing devices, amplifiers, speakers, etc., when the distance between the audio information processing device and the amplifier is long, the reproduced audio signal obtained by the audio information processing device can be It becomes necessary to use a long signal cable to transmit the signal to the amplifier. In such a case, there are many places where the signal cable for transmitting the reproduced audio signal is close to other signal cables, and external noise such as crosstalk noise is mixed into the reproduced audio signal, resulting in a deterioration in the quality of the reproduced sound. was occurring. In addition, the quality of the reproduced sound deteriorates due to fluctuations in the signal level of the reproduced audio signal due to unstable contact resistance at the connection point between the signal cable for transmitting the reproduced audio signal and the audio information processing device and amplifier. was also occurring.

Summary of the invention Therefore, an object of the invention is to provide an audio information processing device that can prevent deterioration in the quality of reproduced sound.

The audio information processing device according to the present invention includes conversion means that is detachable from a main body that processes digital signals containing audio information and that converts one of a digital signal and an analog signal containing audio information into the other. It has a structure with blocks.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, recorded information on a digital audio disk 2 which is rotationally driven by a spindle motor 1 is read by an optical pickup 3. In FIG. The pick-up 3 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, etc.
It is configured to read EFM (Eight to Fourteen Modulation) signals and output various servo control signals. The output of this pickup 3 is supplied to each of a focus error generation circuit 4, a tracking error generation circuit 5, a demodulation circuit 6, and a phase comparison circuit 7. The focus error generation circuit 4 generates a focus error signal according to the amount and direction of deviation of the convergence point of the laser beam emitted from the laser diode and then converged by the objective lens with respect to the recording surface of the disk 2. It is structured as follows. The output of this focus error generation circuit 4 is supplied to a drive amplifier 8 that drives a focus actuator, and the distance between the objective lens and the recording surface of the disk 2 is, for example, ±1 μm.
The position of the objective lens in the direction perpendicular to the recording surface of the disk 2 is controlled so that the laser beam is accurately focused on the recording surface of the disk 2. Further, the tracking error generation circuit 5 is configured to generate a tracking error signal according to the amount of deviation in the direction perpendicular to the convergence point of the laser beam with respect to the pit example formed on the recording surface of the disk 2, and the direction thereof. It's summery. The output of the tracking error generation circuit 5 is supplied to the drive amplifier 9 that drives the tracking actuator, and the position of the laser beam convergence point in the direction perpendicular to the pit row is controlled, and the pit row of the laser beam convergence point is controlled. For example, the amount of deviation from the surface is 0.1 μm or less.

Further, the phase comparator circuit 7 is configured to generate a reproduced clock signal using the EFM signal output from the pickup 3, and then generate a signal according to the phase difference with the reference clock signal from the clock generation circuit 10. ing. The output of the phase comparison circuit 7 is supplied to the drive amplifier 11 that drives the spindle motor 2, and the spindle motor 2 is driven so that the phase difference between the reproduced clock signal and the reference clock signal becomes zero, and the track line of the disk 2 is The speed remains constant.

Further, the demodulation circuit 6 is configured to demodulate the EFM signal output from the pickup 3 to obtain PCM data. The PCM data obtained by this demodulation circuit 6 is supplied to an error correction circuit 16.
The error correction circuit 16 is configured to detect and correct code errors using parity bits added in advance to the PCM data. The PCM data whose errors have been corrected by the error correction circuit 16 is delivered to the contacts of the output connector 13 of the main body 12. The output connector 13 is compatible with the input connector 15 of the D/A (digital-to-analog) conversion block 14, and when the output connector 13 and input connector 15 are combined, the PCM led out to the contacts of the output connector 13 Data is supplied to the D/A conversion circuit 17 via the contacts of the input connector 15 to form an analog signal.
The analog signal output from the D/A conversion circuit 17 is supplied to a low-pass filter 18 including an amplifier to remove unnecessary components outside the audio signal band, and the reproduced audio signal is sent to the output connector 19 of the D/A conversion block 14. is derived from the contact. In addition, D/
The A conversion block 14 is housed in a rectangular parallelepiped housing arranged such that two mutually perpendicular surfaces form a part of the surface opposite to the operation panel surface 12a and a part of the side surface 12b of the main body 12, respectively. There is. This D/A conversion block 14 is connected to the main body 12 by an output connector 13 and an input connector 15.
It can be attached and detached at will.

FIG. 3 shows an audio system including the audio information processing apparatus according to the present invention as described above. In FIG. 3, the D/A conversion block 14 detached from the main body 12 of the audio information processing device is attached to an amplifier 20 by coupling the output connector 19 to the input connector of the amplifier 20. The input connector 15 of the D/A conversion block 14 and the output connector 13 of the main body 12 are connected via a signal cable 21. The output of the amplifier 20 is supplied to a speaker 23 via a signal cable 22.

In the above-described acoustic system, even when the distance between the audio information processing device and the amplifier 20 is long, the reproduction audio signals can be exchanged between the output connector 19 and the amplifier 20 without going through the signal cable. Since this is done only through the input connector, it is possible to prevent external noise such as crosstalk noise from entering the reproduced audio signal, and to reduce the number of connection points in the path through which the reproduced audio signal is transmitted, reducing interference to the reproduced audio signal. The influence of stable contact resistance is reduced, and deterioration of sound quality is prevented. Furthermore, even if noise is induced in the signal cable 21, as long as the level of this noise does not exceed the threshold level, it will not affect the PCM data transmitted by the signal cable 21, so the playback audio will not be affected. There is no effect on the signal.

FIG. 4 is a block diagram showing another embodiment of the present invention, in which the error correction circuit 16 is removed from the main body 12 and the error correction circuit 16 is inserted between the input connector 15 and the D/A conversion circuit 17 in the D/A conversion block 14. additionally connected. The other parts except for this error correction circuit 16 are constructed in the same manner as in FIG.

It is clear that even with such a configuration, an acoustic system as shown in FIG. 3 can be formed and the same effect as the device shown in FIG. 1 can be obtained. Furthermore, in this example, even if the level of noise induced in the signal cable 21 in the system of FIG. 3 exceeds the threshold level, the error correction included in the D/A conversion block 14 circuit 16
The effect on the reproduced audio signal can be eliminated by this action.

The digital audio disc player has been described above, but digital audio equipment such as a PCM tape recorder, a PCM processor, etc. has a conversion means for converting one of a digital signal and an analog signal containing audio information into the other. The present invention can be applied to any device.

Effects As detailed above, the audio information processing device according to the present invention has a structure in which a block including a conversion means for converting one of a digital signal containing audio information and an analog signal into the other is detachably attached to the main body. This makes it possible to send and receive audio signals between devices in a digital audio system without using signal cables, which reduces sound quality due to external noise contamination, non-linear distortion due to unstable contact resistance, etc. This means that deterioration can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a perspective view showing the external appearance of the device shown in FIG. 1, and FIG. 3 is a perspective view showing an acoustic system including the device shown in FIG. 4 are block diagrams showing other embodiments of the present invention. Explanation of symbols of main parts, 12...Main body, 14...
...D/A conversion block.

Claims (1)

[Scope of utility model registration request] An audio information processing device comprising a conversion means for converting either one of a digital signal and an analog signal containing audio information into the other, and processing the audio information using the digital signal, the audio information processing device processing the audio information using the digital signal, What is claimed is: 1. An audio information processing device comprising a block that is detachably attached to a main body that performs processing and that includes the conversion means.