JPH05266409A - Digital signal reproducing device - Google Patents

Abstract

PURPOSE:To provide a digital signal reproducing device which can reproduce a signal having high S/N. CONSTITUTION:In a magnetic head assembly 1 a first head line 2 consisting of array of plural magnetic resistance heads 22 for reproducing corresponding to track numbers of a magnetic tape and a second head line 3 consisting of the array of magnetic resistance heads 31 for reproducing of the same numbers are arranged in the direction of running of the magnetic tape, leaving the prescribed space L. And reproduced outputs of each head to scan the same track are connected to a signal processing circuit which adds the reproduced outputs and values processed with time adjusting corresponding to the prescribed space respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reproducing a digital signal from a recording medium on which the digital signal is recorded, such as a digital compact cassette (DCC) player.

[0002]

2. Description of the Related Art In a DCC player, a digital compact cassette (7) similar to a conventional analog tape cassette is used as shown in FIG. 5, and a magnetic tape (7) exposed from the front surface of a rectangular cassette shell (71) Signal reproduction is carried out by sliding the magnetic head assembly (9) on 8).

As shown in FIG. 4, the magnetic head assembly (9) has a plurality of recording winding heads (IRHs) (21) and reproducing magnetic fields according to the number of tracks on the sliding contact surface with the magnetic tape (8). A digital head array (2 consisting of an array of resistive heads (MRH) (22)
0), right channel head (41) and left channel head
Analog head array for analog signal reproduction consisting of (42)
(4) and (Japanese Patent Laid-Open No. 2-232802 [G11B5 / 00
8)).

[0004]

By the way, in the digital head array (20) of the conventional magnetic head assembly (9), the signal of one channel corresponds to one magnetoresistive head (2).
Although reproduced by 2), since the level of the head output is minute, it is amplified to a level at which signal processing is possible by an amplifier. However, if the amplification rate increases, the S / N
It causes a problem that the ratio is lowered.

It is an object of the present invention to provide a digital signal reproducing device capable of reproducing a signal having a high S / N ratio.

[0006]

In a digital signal reproducing apparatus according to the present invention, a head array consisting of an array of a plurality of signal reproducing heads according to the number of tracks of a recording medium is provided along a relative moving direction of the recording medium. A signal processing circuit which is arranged in a plurality of stages at intervals and adds the reproduction outputs of the respective signal reproduction heads for scanning the same track of the recording medium to each other by subjecting the reproduction outputs to time adjustment processing according to the predetermined intervals. Connected to.

A plurality of signal reproducing heads for scanning the same track of the recording medium are provided with a predetermined offset in a direction orthogonal to the relative movement direction of the recording medium.

[0008]

Each track of the recording medium is first scanned by the corresponding head of the frontmost head row to reproduce the recording signal. After that, each track is sequentially scanned by the corresponding head of the head row in the subsequent stage, and the same recording signal is reproduced.

The reproduction outputs of a plurality of heads that scan the same track are subjected to time adjustment processing by the signal processing circuit to have their time axes aligned, then added together, and output to the circuit at the subsequent stage. The level of the signal output to the circuit in the subsequent stage is
The number of heads is doubled as compared with the reproduction output by one head.

At this time, if a plurality of signal reproducing heads for scanning the same track are provided with offsets, even if there are fine scratches on the tracks of the recording medium, the size of the scratches may be smaller than the offset amount. For example, since only one head is affected by the scratch, the reproduction output obtained from the signal processing circuit has a high S / N ratio.

[0011]

According to the digital signal reproducing apparatus of the present invention, a reproduced signal having a high S / N ratio can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a DCC player having a 9-channel digital head and a 2-channel analog head will be described in detail with reference to the drawings.

As shown in FIG. 1, a magnetic head assembly (1)
Are 9 recording winding heads (21) for 9 channels and 9 reproducing magnetic resistance heads (2) for sliding contact with the magnetic tape.
2) is arranged to form the first head row (2), and nine reproducing magnetoresistive heads for nine channels (31) are provided at a position separated from the first head row (2) by a predetermined distance L. ) Are arranged to form the second head row (3).

Recording winding head (21) of the first head row (2)
Track width is 185μm, reproducing magnetoresistive head (22) (31)
Has a track width of 70 μm.

Of the 9 channels, an auxiliary signal such as a control signal is recorded on 1 channel, and a digital audio signal is recorded on the remaining 8 channels.

Below the first head row (2), an analog head row (4) consisting of a right channel head (41) and a left channel head (42) is arranged, and a digital compact in which digital signals are recorded. Not only the cassette but also a tape cassette in which analog signals are recorded can be reproduced.

FIG. 3 shows a signal processing circuit to which the reproducing magnetoresistive heads (22) and (31) of the first and second head rows (2) and (3) are connected. The reproducing magnetoresistive heads (22) of the first head row (2) are respectively added via the delay line (5).
(6) is connected to one input end, and the reproducing magnetic resistance heads (31) of the second head row (3) are directly connected to the other input end of the adder (6).

The delay time of each delay line (5) is the first
The tape speed is the distance L between the head row (2) and the second head row (3).
It is set to a value divided by (4.76 cm / sec), whereby the time axes of the heads (22) and (31) outputs of both head rows are aligned.

In the above magnetic head assembly and signal processing circuit, the reproduction signal level output from the adder (6) is two magnetoresistive heads (22) reproducing the same track.
It is the sum of (31).

On the other hand, regarding the noise level included in the output of the adder (6), the root mean square value of the noise waves is the root mean square of the noise waves of the two reproducing magnetoresistive heads (22) and (31). As the sum of the values, the S / N ratio of the reproduction signal output from each adder (6) becomes larger than that of the DCC player having the conventional magnetic head assembly.

FIG. 2 shows another example of the structure of the magnetic head assembly (1). The nine sets of reproducing magnetoresistive heads (22) and (31) for scanning each track have a predetermined width in the track width direction. Offset A is provided. The offset A is
It can be arbitrarily set within the track width, and is set to 35 μm, for example.

When the offset is provided as described above, even if there is a minute scratch on the track of the magnetic tape, if the size of the scratch is smaller than the offset amount, only one head is affected by the scratch. Therefore, the reproduction output obtained from the signal processing circuit has a higher S / N ratio.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Further, the configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

For example, in the above-mentioned embodiment, the digital head array of the magnetic head assembly has two stages, but it is also possible to dispose in a plurality of stages of three or more.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a magnetic head assembly of a digital signal reproducing apparatus according to the present invention.

FIG. 2 is a perspective view showing another configuration example of a magnetic head assembly.

FIG. 3 is a diagram showing a signal processing circuit.

FIG. 4 is a perspective view showing a conventional magnetic head assembly.

FIG. 5 is a perspective view of a digital compact cassette.

[Explanation of symbols]

 (1) Magnetic head assembly (2) First head row (22) Reproducing magnetic resistance head (3) Second head row (31) Reproducing magnetic resistance head

Claims (2)

[Claims] 1. An apparatus for simultaneously reproducing digital signals from a recording medium having digital signals recorded on a plurality of tracks, wherein a head row composed of an array of a plurality of signal reproducing heads according to the number of tracks is recorded. The reproduction output of each signal reproducing head, which is arranged in a plurality of stages at predetermined intervals along the relative movement direction of the medium and should scan the same track of the recording medium, has a time adjustment process according to the predetermined interval. A digital signal reproducing device, characterized in that the digital signal reproducing device is connected to a signal processing circuit for applying and adding each other. 2. The digital signal according to claim 1, wherein a plurality of signal reproducing heads for scanning the same track of the recording medium are provided with a predetermined offset in a direction orthogonal to the relative movement direction of the recording medium. Playback device.