JPH09245308A - Date recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the magnitude of the constant current signal to be outputted from a recording amplifier always become the fixed value to be set by a reference voltage signal. SOLUTION: Recording data DREC are recorded on a magnetic tape T with a constant current by allowing a constant current signal SCC corresponding to the recording data DREC to be outputted by a recording amplifier 102. A voltage signal SVM corresponding to the constant current signal SCC is obtained in a current-voltage conversion circuit 111. The voltage signal SVM and a reference voltage signal VREF are compared in a comparator 112 and the compared error signal ERR is supplied to a current Miller circuit 110 as a feedback control signal and then the DC value of the voltage signal SV2 to be outputted from a DC shifting circuit 106 is controlled according to the magnitude of the constant current signal SCC. Thus, the magnitude of the constant current signal SCC to be outputted from the recording amplifier 102 always becomes the fixed value to be set by the reference voltage signal VREF.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording apparatus suitable for application when recording a digital signal on a magnetic tape, for example. Specifically, the constant current signal output from the recording amplifier corresponding to the recording data is converted into a voltage signal, the voltage signal is compared with a reference voltage signal, and the voltage is output from the recording amplifier based on the comparison error signal. The present invention relates to a data recording device in which the magnitude of a constant current signal output from a recording amplifier is always a constant value set by a reference voltage signal by negative feedback controlling the magnitude of a constant current signal. .

[0002]

2. Description of the Related Art FIG. 2 shows a conventional data recording device 200 for recording a digital signal on a magnetic tape using a rotary magnetic head.

The data recording device 200 records the recording data DR.
An input terminal 201 for inputting EC, a recording amplifier 202 for outputting a constant current signal SCC corresponding to the recording data DREC supplied to this input terminal 201, and for recording the above-mentioned recording data DREC on the magnetic tape T. The rotary magnetic head 203 and the rotary transformer 204 for supplying the constant current signal SCC output from the recording amplifier 202 to the coil of the magnetic head 203.

Here, the recording data DREC is serial data obtained by subjecting a digital signal to be recorded to processing such as error correction coding and recording coding. Further, the constant current signal SCC output from the recording amplifier 202 changes its flowing direction according to the data value (“1” or “0”) of the recording data DREC.

Further, the data recording device 200 detects the edge (rising edge, falling edge) of the recording data DREC, and the portion corresponding to this edge has the voltage value Va and the other portions have the voltage value Vb. Edge correction circuit 2 for generating voltage signal SV1 for current control
05, a DC shift circuit 206 for shifting the DC value of the voltage signal SV1 output from the edge correction circuit 205, and the recording amplifier 202 based on the voltage signal SV2 output from the DC shift circuit 206. Current mirror circuit 207 for controlling the magnitude of the constant current signal SCC.

The data recording device 200 also has an input terminal 208 for inputting digital data DREF for controlling the magnitude of the constant current signal SCC output from the recording amplifier 202, and a digital signal supplied to this input terminal 208. D / A (digita) for digital / analog conversion of the data DREF to obtain the reference voltage signal VREF
l-to-analog) converter 209 and this D / A converter 20
9 and a current mirror circuit 210 for controlling the shift amount of the DC value in the DC shift circuit 206 based on the reference voltage signal VREF output from

Next, the operation of the data recording device 200 shown in FIG. 2 will be described.

Recording data D supplied to the input terminal 201
The REC is supplied to the recording amplifier 202, and the recording amplifier 202 outputs a constant current signal SCC corresponding to the recording data DREC. Then, this constant current signal SCC is supplied to the primary side coil of the rotary transformer 204,
A current signal corresponding to the constant current signal SCC is supplied from the secondary coil to the coil of the rotary magnetic head 203. As a result, the magnetic head 203 records the recording data DREC on the magnetic tape T at a constant current.

The recording data DREC supplied to the input terminal 201 is also supplied to the edge correction circuit 205. The edge correction circuit 205 detects the rising and falling edges of the recording data DREC, and outputs the voltage signal SV1 for current control that has the voltage value Va in the portion corresponding to the edge and has the voltage value Vb in the other portions. Is generated. Then, the voltage signal SV1 is supplied to the DC shift circuit 206 to shift-control the DC value. Here, when the recording data DREC is as shown in FIG. 3A, the voltage signal SV1 is generated as shown in FIG. 3B.

The digital data DREF supplied to the input terminal 208 is also supplied to the D / A converter 209. In the D / A converter 209, the digital data D
REF is digital-to-analog converted to obtain the reference voltage signal VREF. Then, this reference voltage signal VRE
F is supplied to the current mirror circuit 210. As a result, in the DC shift circuit 206, the DC value of the voltage signal SV1 is shifted by a shift amount corresponding to the reference voltage signal VREF to form the voltage signal SV2.

The voltage signal SV2 output from the DC shift circuit 206 is supplied to the current mirror circuit 207. As a result, the magnitude of the constant current signal SCC output from the recording amplifier 202 is controlled according to the voltage signal SV2.

As described above, since the DC value of the voltage signal SV2 becomes a value corresponding to the reference voltage signal VREF,
Digital data DREF supplied to the input terminal 208
Is changed to change the reference voltage signal VREF, the constant current signal SCC output from the recording amplifier 202 is changed.
, And therefore the recording current of the magnetic head 203 can be changed.

The voltage signal SV2 for controlling the magnitude of the constant current signal SCC output from the recording amplifier 202 is
Voltage signal SV1 output from the edge correction circuit 205
The direct current value (see FIG. 3B) is shifted. Therefore, the constant current signal SCC output from the recording amplifier 202 is the recording data DR as shown in FIG. 3C.
The part corresponding to the edge of EC is emphasized.
As a result, as is well known in the art, the electromagnetic conversion distortion of the tape head system can be canceled and the error rate of the digital signal can be greatly improved.

[0014]

By the way, in the data recording apparatus 200 shown in FIG. 2, the current mirror circuit is caused by factors such as variations in parts such as the edge correction circuit 205, the DC shift circuit 206, the current mirror circuit 210, and temperature characteristics. The DC value of the voltage signal SV2 supplied to 207 changes,
Therefore, the constant current signal SC output from the recording amplifier 202
The size of C also changes. Therefore, there is a problem that adjustment and temperature compensation are required.

Therefore, the present invention provides a data recording device in which the magnitude of the constant current signal output from the recording amplifier is always a constant value set by the reference voltage signal.

[0016]

A data recording apparatus according to the present invention includes a recording amplifier for outputting a constant current signal corresponding to recording data, and a current for converting a constant current signal output from the recording amplifier into a voltage signal. / Voltage conversion means, comparison means for comparing the reference voltage signal with the voltage signal output from the current / voltage conversion means to obtain a comparison error signal, and output from the recording amplifier based on the comparison error signal output from the comparison means Current control means for controlling the magnitude of the constant current signal to a constant value set by the reference voltage signal.

A constant current signal corresponding to recording data is output from the recording amplifier. This constant current signal is supplied to the coil of the magnetic head, for example, and the recording data is recorded on the magnetic tape by the magnetic head. Further, the constant current signal output from the recording amplifier is converted into a voltage signal, and this voltage signal is compared with the reference voltage signal. Then, the magnitude of the constant current signal output from the recording amplifier is subjected to negative feedback control based on the comparison error signal. As a result, the magnitude of the constant current signal output from the recording amplifier is always a constant value set by the reference voltage signal.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a data recording device 100 as an embodiment.

The data recording device 100 uses the recording data DR.
An input terminal 101 for inputting EC, a recording amplifier 102 for outputting a constant current signal SCC corresponding to the recording data DREC supplied to this input terminal 101, and for recording the above-mentioned recording data DREC on the magnetic tape T. The rotary magnetic head 103 and the rotary transformer 104 for supplying the constant current signal SCC output from the recording amplifier 102 to the coil of the magnetic head 103.

Here, the recording data DREC is serial data obtained by subjecting a digital signal to be recorded to processing such as error correction coding and recording coding. Further, the constant current signal SCC output from the recording amplifier 102 changes its flowing direction according to the data value (“1” or “0”) of the recording data DREC.

Further, the data recording apparatus 100 detects the edge (rising edge, falling edge) of the recording data DREC, and the portion corresponding to this edge has the voltage value Va and the other portions have the voltage value Vb. Edge correction circuit 1 for generating voltage signal SV1 for current control
05, a DC shift circuit 106 for shifting the DC value of the voltage signal SV1 output from the edge correction circuit 105, and the recording amplifier 102 based on the voltage signal SV2 output from the DC shift circuit 106. Current mirror circuit 107 for controlling the magnitude of the constant current signal SCC.

The data recording device 100 also has an input terminal 108 for inputting digital data DREF for controlling the magnitude of the constant current signal SCC output from the recording amplifier 102, and a digital signal supplied to this input terminal 108. D / A (digita) for digital / analog conversion of the data DREF to obtain the reference voltage signal VREF
l-to-analog) converter 109 and this D / A converter 10
9 and a current mirror circuit 110 for controlling the shift amount of the DC value in the DC shift circuit 106 based on the reference voltage signal VREF output from

In the data recording device 100, the current / voltage conversion circuit 111 for converting the current signal SCM output from the current mirror circuit 107 into the voltage signal SVM, and the voltage signal output from the current / voltage conversion circuit 111. S
The comparator 112 has a comparator 112 for comparing the VM and the reference voltage signal VREF output from the D / A converter 109 and supplying the comparison error signal ERR to the current mirror circuit 110 as a negative feedback signal. Where the current signal SC
M is a constant current signal SCC output from the recording amplifier 102
It corresponds to. Therefore, the current / voltage conversion circuit 111 is equivalent to converting the constant current signal SCC into the voltage signal SVM.

Next, the operation of the data recording device 100 shown in FIG. 1 will be described.

Recording data D supplied to the input terminal 101
The REC is supplied to the recording amplifier 102, and the recording amplifier 102 outputs a constant current signal SCC corresponding to the recording data DREC. Then, this constant current signal SCC is supplied to the primary side coil of the rotary transformer 104,
A current signal corresponding to the constant current signal SCC is supplied from the secondary coil to the coil of the rotary magnetic head 103. As a result, like the data recording device 200 shown in FIG.
The recording data D is recorded on the magnetic tape T by the magnetic head 103.
REC is recorded at constant current.

The recording data DREC supplied to the input terminal 101 is also supplied to the edge correction circuit 105. The edge correction circuit 105 detects the rising and falling edges of the recording data DREC, and outputs the current control voltage signal SV1 having the voltage value Va in the portion corresponding to the edge and the voltage value Vb in the other portions. Is generated. Then, the voltage signal SV1 is supplied to the DC shift circuit 106 to shift-control the DC value. Here, when the recording data DREC is as shown in FIG. 3A, the voltage signal SV1 is generated as shown in FIG. 3B.

The digital data DREF supplied to the input terminal 108 is also supplied to the D / A converter 109. In this D / A converter 109, the digital data D
REF is digital-to-analog converted to obtain the reference voltage signal VREF. Then, this reference voltage signal VRE
F is supplied to the current mirror circuit 110. As a result, in the DC shift circuit 106, the DC value of the voltage signal SV1 is shifted by a shift amount corresponding to the reference voltage signal VREF to form the voltage signal SV2, as in the data recording device 200 shown in FIG.

The voltage signal SV2 output from the DC shift circuit 106 is supplied to the current mirror circuit 107, and the constant current signal SC output from the recording amplifier 102.
The magnitude of C is controlled according to the voltage signal SV2. As described above, since the DC value of the voltage signal SV2 becomes a value corresponding to the reference voltage signal VREF, the input terminal 108
By changing the digital data DREF supplied to the reference voltage signal VREF to change the reference voltage signal VREF, the magnitude of the constant current signal SCC output from the recording amplifier 102, that is, the magnetic field, is changed, as in the data recording device 200 shown in FIG. The recording current of the head 103 can be changed.

Further, the current signal SCM output from the current mirror circuit 107 is supplied to the current / voltage conversion circuit 111. In the current / voltage conversion circuit 111, the current signal S
When the CM is converted into current / voltage, the recording amplifier 102
Voltage signal S corresponding to the constant current signal SCC output from
VM is obtained. This voltage signal SVM and D / A converter 1
The reference voltage signal VREF output from the output terminal 09 is supplied to the comparator 112 for comparison. Then, the comparison error signal ERR output from the comparator 112 is supplied to the current mirror circuit 110 as a negative feedback control signal.

In this case, when the voltage signal SVM becomes smaller than the reference voltage signal VREF, the shift amount of the DC value is controlled so that the DC value of the voltage signal SV2 output from the DC shift circuit 106 becomes large, and the recording amplifier 102 is controlled. The output constant current signal SCC is increased. Conversely, when the voltage signal SVM becomes larger than the reference voltage signal VREF, the voltage signal SV output from the DC shift circuit 106.
The shift amount of the DC value is controlled so that the DC value of 2 becomes small, and the constant current signal SC output from the recording amplifier 102.
C is reduced. As a result, the magnitude of the constant current signal SCC output from the recording amplifier 102 is always a constant value set by the reference voltage signal VREF.

The voltage signal SV2 for controlling the magnitude of the constant current signal SCC output from the recording amplifier 102 is
Voltage signal SV1 output from the edge correction circuit 105
The direct current value (see FIG. 3B) is shifted. Therefore, similar to the data recording device 200 shown in FIG. 2, the constant current signal SC output from the recording amplifier 102.
In C, the portion corresponding to the edge of the recording data DREC is emphasized.

In the present embodiment, the recording amplifier 10
The comparator 112 outputs the voltage signal SVM corresponding to the constant current signal SCC output from the reference numeral 2 and the reference voltage signal VREF.
And the comparison error signal ERR is supplied to the current mirror circuit 110 as a negative feedback control signal, and the magnitude of the constant current signal SCC output from the recording amplifier 102 is
It is always a constant value set by the reference voltage signal VREF.

That is, variations in the components such as the edge correction circuit 105, the DC shift circuit 106, and the current mirror circuit 110, temperature characteristics, etc. are absorbed by the negative feedback loop, and the magnitude of the constant current signal SCC output from the recording amplifier 102. Is always a constant value set by the reference voltage signal VREF. Therefore, there is an advantage that adjustment and temperature compensation are unnecessary.

In the above embodiment, the digital data DREF supplied to the input terminal 108 is digital-to-analog converted to obtain the reference voltage signal VREF. However, the reference voltage signal VREF is directly supplied. It may be done.

[0035]

According to the present invention, a constant current signal output from a recording amplifier corresponding to recording data is converted into a voltage signal, the voltage signal is compared with a reference voltage signal, and the comparison error signal is obtained. Based on this, the magnitude of the constant current signal output from the recording amplifier is subjected to negative feedback control, and the magnitude of the constant current signal output from the recording amplifier can always be a constant value set by the reference voltage signal. Therefore, variations in components, temperature characteristics, etc. are absorbed by the negative feedback loop, so that adjustment and temperature compensation can be eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a data recording device as an embodiment.

FIG. 2 is a block diagram showing a configuration of a conventional data recording device.

FIG. 3 is a diagram showing a signal waveform of a main part of the data recording device.

[Explanation of symbols]

100 ... Data recording device, 101, 108 ... Input terminal, 102 ... Recording amplifier, 103 ... Rotating magnetic head, 105 ... Edge correction circuit, 106 ...
DC shift circuit, 107, 110 ... Current mirror circuit, 109 ... D / A converter, 111 ... Current /
Voltage conversion circuit, 112 ... Comparator

Claims (4)

[Claims] 1. A recording amplifier for outputting a constant current signal corresponding to recording data, a current / voltage converting means for converting a constant current signal output from the recording amplifier into a voltage signal, a reference voltage signal and the current / current. The magnitude of the constant current signal output from the recording amplifier based on the comparison error signal output from the comparison means and the comparison error signal obtained by comparing the voltage signals output from the voltage conversion means is determined. A data recording device, comprising: a current control unit for controlling a constant value set by the reference voltage signal. 2. The current control means comprises a direct current shift section for shifting the direct current value of the current control voltage signal, and a constant current signal output from the recording amplifier based on the voltage signal output from the direct current shift section. And a current control unit for controlling the magnitude of the DC voltage, and the DC shift unit shifts the DC value using the reference voltage signal and the comparison error signal. Data recorder. 3. The data recording device according to claim 1, wherein the reference voltage signal is obtained by converting digital data into an analog signal. 4. The current control voltage signal is a signal that has a first voltage value in a portion corresponding to an edge of the recording data and has a second voltage value in other portions. 3. The data recording device according to claim 2, wherein the constant current signal output from the recording amplifier is emphasized in correspondence with the edge of.