JP2001101610A - Reproducing device and reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproducing device capable of obtaining the stable reproduction property by improving such a state that the proper equalizer control is impossible due to the malfunction in the interchangeable reproduction, the running of a tape, or the like. SOLUTION: A reproduction signal outputted from a variable equalizer means 2 making the amplitude property and phase property of the amplified reproduction signal variable which is amplified by a head amplifier means 1, is quantized by an A/D conversion means 3, and the error of the reproduction signal subjected to digital conversion by the A/D conversion means 3 is corrected by a digital signal processing means 4, and the error unconverted to the original digital signal by this error correction is detected by an error detecting means 7. Then, the error value is integrated by an error calculating means 10 based on an output signal of the error detecting means 7, and also the amplitude of the reproduction signal amplified by the head amplifier means 1 is detected by an amplitude detecting means 5, and the error calculating area is changed by a variable means 6 of error calculating area in accordance with the detected amplitude of the reproduction signal, then the variable equalizer means 2 is controlled in accordance with the error value in the error calculating area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus such as a digital video camera for reproducing data digitally recorded on a recording medium such as a magnetic tape or a magnetic disk, and a reproducing method.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a main part of a conventional digital recording / reproducing apparatus. In FIG. 6, the configuration of the recording system is omitted.

In FIG. 6, reference numeral 31 denotes a head amplifier for amplifying the output of the magnetic head, and 32 denotes a head amplifier 3
This is a variable equalizer that can control the frequency amplitude characteristic and the phase characteristic by a voltage from a microcomputer so that the output (reproduced signal) of No. 1 has the optimum characteristic for the A / D converter.

Reference numeral 33 denotes A / D conversion means for quantizing the output of the variable equalizer means 32. Numeral 34 denotes digital signal processing means for performing signal processing on the digital data quantized by the A / D conversion means 33. Numeral 35 is an error detecting means for detecting an error which could not be restored to the original digital data from the digital signal processing means 34.

[0005] Reference numeral 36 denotes a microcomputer, in which an error calculating means 38 integrates error values in accordance with an output from the error detecting means 35. Further, the variable equalizer control means 37 in the microcomputer 36 controls the variable equalizer means 32 according to the output of the error calculation means 38.

[0006]

However, in the conventional digital recording / reproducing apparatus as described above, the digital signal processing means only uses the output of the error detection means for detecting an error which cannot be restored to the original data. Since the variable equalizer means is controlled, the state of the reproduction RF (reproduction signal), which is the output of the head amplifier, is not taken into account, and the variable equalizer control means malfunctions due to problems such as compatibility reproduction or tape running. That is, there has been a problem that proper equalizer control cannot be performed.

[0007] In addition, when an error rate indicates how many errors have occurred in a reproduced data block as an error rate, the weight of one error is constantly changed. As a result, there is a problem that it is impossible to perform appropriate equalizer control as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it has been proposed that an equalizer control cannot be performed properly due to compatibility reproduction, a tape running problem, and the like. It is an object of the present invention to provide a reproducing apparatus and a reproducing method capable of obtaining the above.

[0009]

A reproducing apparatus and a reproducing method according to the present invention are configured as follows.

(1) In a reproduction apparatus, a pickup for reproducing a digital signal, an amplifier for amplifying a reproduction signal output from the pickup, and an amplitude characteristic and a phase characteristic of the amplified reproduction signal can be varied. Variable equalizer means, analog-to-digital conversion means for quantizing the reproduction signal output from the variable equalizer means,
Error correction means for correcting an error in the reproduction signal digitally converted by the analog-to-digital conversion means, and error detection means for detecting an error that could not be converted to the original digital signal by the error correction by the error correction means. An error calculating means for integrating an error value based on an output signal of the error detecting means, an error calculating area variable means capable of changing an error calculating area by the error calculating means, and a reproduction signal amplified by the amplifier means. Amplitude detecting means for detecting the amplitude, and changing the error calculation area according to the amplitude of the reproduced signal detected by the amplitude detecting means, and controlling the variable equalizer means according to an error value in the error calculation area. Control means.

(2) In a reproducing apparatus, a pickup for reproducing a digital signal, an amplifier for amplifying a reproduced signal output from the pickup, and an amplitude characteristic and a phase characteristic of the amplified reproduced signal can be varied. Variable equalizer means, analog-to-digital conversion means for quantizing the reproduction signal output from the variable equalizer means,
Error correction means for correcting an error in the reproduction signal digitally converted by the analog-to-digital conversion means, and error detection means for detecting an error that could not be converted to the original digital signal by the error correction by the error correction means. Dividing means for dividing an output signal of the detecting means into several areas at predetermined time intervals, a plurality of error calculating means for integrating error values for each area divided by the dividing means, Selecting means for selecting means,
Amplitude detecting means for detecting the amplitude of the reproduced signal amplified by the amplifier means, and the selecting means selecting the error calculating means in accordance with the amplitude of the reproduced signal detected by the amplitude detecting means, and Control means for controlling the variable equalizer means according to the error value integrated by the error calculation means.

(3) In the reproducing apparatus of (1) or (2), the pickup is a magnetic head for reproducing a signal recorded on a recording medium.

(4) In the reproducing apparatus of (2), the area to be time-divided by the dividing means is a video area of an audio area, a video area, and a subcode area in a digital video camera.

(5) In the reproduction method, a reproduction signal output from a pickup for reproducing a digital signal is amplified by an amplifier means, and a variable equalizer means capable of changing the amplitude characteristic and phase characteristic of the amplified reproduction signal. The reproduction signal output from the digital signal is quantized by the analog-to-digital conversion means, the error of the reproduction signal digitally converted by the analog-to-digital conversion means is corrected by the error correction means, and the original digital signal is corrected by the error correction by the error correction means. An error that could not be converted is detected by an error detecting means, an error value is integrated by an error calculating means based on an output signal of the error detecting means, and a reproduced signal amplified by the amplifier means by an amplitude detecting means. Of the reproduced signal, and an error is generated in accordance with the detected reproduced signal amplitude. By calculating the area changing means changes the error calculation area, and to control the variable equalizer means in accordance with the error value in the error calculation area.

(6) In the reproduction method, a reproduction signal output from a pickup for reproducing a digital signal is amplified by an amplifier means, and a variable equalizer means capable of changing the amplitude characteristic and phase characteristic of the amplified reproduction signal. The reproduction signal output from the digital signal is quantized by the analog-to-digital conversion means, the error of the reproduction signal digitally converted by the analog-to-digital conversion means is corrected by the error correction means, and the original digital signal is corrected by the error correction by the error correction means. An error that could not be converted is detected by the error detection means, and the output signal of the detection means is time-divided into several areas by the division means at predetermined time intervals. The error value is integrated by a plurality of error calculating means, and the amplitude value is obtained by the amplitude detecting means. Detecting the amplitude of the reproduced signal amplified by the means, selecting the error calculating means by the selecting means according to the detected amplitude of the reproduced signal, and selecting the error calculating means according to the error value integrated by the selected error calculating means. Thus, the variable equalizer means is controlled.

(7) In the reproducing method of (5) or (6), the pickup is a magnetic head for reproducing a signal recorded on a recording medium.

(8) In the reproducing method of the above (6), the video area among the audio area, the video area and the subcode area in the digital video camera is time-divided by the dividing means.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram showing a main configuration of a recording / reproducing apparatus according to a first embodiment. In FIG. 1, the configuration of the recording system is omitted.

In FIG. 1, reference numeral 1 denotes a head amplifier for amplifying an output signal reproduced and output from a recording medium by a pickup such as a magnetic head, and 2 denotes an A / D converter for outputting the output (reproduction signal) of the head amplifier 1. This is a variable equalizer means that can control the frequency amplitude characteristic and the phase characteristic with a voltage from a control means such as a microcomputer so that the characteristic becomes optimal for (analog-to-digital conversion means).

Reference numeral 3 denotes A / D conversion means for quantizing the output of the variable equalizer means 2. Reference numeral 4 denotes digital signal processing means including error correction means for performing signal processing on the digital data quantized by the A / D conversion means 3. Reference numeral 5 denotes an amplitude detecting means for detecting the amplitude of the output of the head amplifier means 1. Reference numeral 6 denotes an error calculation area changing unit that changes the error calculation area according to the output of the amplitude detection unit 5.

Numeral 7 denotes an error detecting means for detecting an error which could not be restored to the original digital data from the digital signal processing means 4 in accordance with the output of the error calculating area changing means 6 (error number). Reference numeral 8 denotes a microcomputer serving as a control unit. The error calculation unit 10 integrates the error values in the error calculation area for each track according to the output from the error detection unit 7.

Reference numeral 9 denotes a variable equalizer control means, which outputs the error calculation area variable means 6 and the error calculation means 10
The variable equalizer means 2 is controlled according to the output of the head amplifier, and the variable equalizer means 2 changes the frequency amplitude characteristic and the phase characteristic of the head amplifier output.

FIG. 2 is a diagram showing each signal waveform according to the first embodiment. The relationship between the amplitude (detection voltage) of the reproduced RF, which is the head amplifier output detected by the amplitude detecting means 5, and the error calculation area. Is specifically shown. As shown in FIG. 2, no error is calculated in an unstable portion (area) of the head amplifier output where the detection voltage is equal to or lower than a predetermined threshold voltage (threshold voltage), and the detection voltage is equal to or higher than the threshold voltage. Error calculation is performed in an area where the amplifier output is stable.

FIG. 3 is a flowchart showing the equalizer control operation according to the first embodiment. The equalizer control according to the calculation result in the above-described error calculation area will be briefly described. This operation is executed in accordance with an instruction from a CPU (not shown) based on a program stored in a ROM (not shown).

First, in step S1, the amplitude of the output of the head amplifier 1 is detected. Next, step S2
, The error value is integrated at a portion where the head amplifier output is stable as shown in FIG. Then, in step S3, the variable equalizer 2 is controlled based on the integrated error value.

As a result, stable reproduction characteristics can be obtained.

As described above, in this embodiment, the state of the reproduced RF (reproduced signal), which is the output of the head amplifier, is always detected, and the digital signal processing means 4 outputs the original digital data from the digital signal processing means 4 in a portion where the head amplifier output is stable. By controlling the variable equalizer means 2 by detecting an error that could not be restored to the original, the variable equalizer control means 9 malfunctions due to problems such as compatibility reproduction and tape running, that is, it is impossible to perform appropriate equalizer control. Stable reproduction characteristics can be provided.

(Second Embodiment) FIG. 4 is a block diagram showing a main configuration of a recording / reproducing apparatus according to a second embodiment.
In FIG. 4, the configuration of the recording system is omitted.

In FIG. 4, reference numeral 11 denotes a head amplifier for amplifying the output of a pickup such as a magnetic head, and 12 denotes an output (reproduction signal) of the head amplifier 11 so as to have characteristics optimal for the A / D converter. This is a variable equalizer that can control the frequency amplitude characteristic and the phase characteristic by a voltage from a control unit such as a microcomputer.

Reference numeral 13 denotes A / D conversion means for quantizing the output of the variable equalizer means 12. 14 performs signal processing on the digital data quantized by the A / D converter 13;
Digital signal processing means including error correction means. The digital signal processing means (error detecting means) 14 detects an error that could not be restored to the original digital data and outputs it to an error calculating means described later. Reference numeral 15 denotes an amplitude detecting means for detecting the amplitude of the output of the head amplifier means 11.
Numeral 24 is a selection means (selection switch) for dividing an error which could not be restored from the digital signal processing means 14 to the original data at the output of the time division means described later.

Reference numerals 16 to 19 denote error calculating means for calculating (integrating) errors for each of the time-divided areas by operating the selecting means 24 based on the output of the time-dividing means. Reference numeral 25 denotes a selection unit (selection switch) for selecting an error calculation unit according to an output of the microcomputer 20 described later. Reference numeral 23 denotes time division means for dividing each track into a predetermined time by a control signal from a microcomputer. The area to be time-divided is, for example, a video area of an audio area / video area / subcode area in a digital video camera.

FIG. 5 is a diagram showing signal waveforms according to the second embodiment. The reproduction RF which is the output of the head amplifier, the time division signals 1 to 5 which are the outputs of the time division means 23, and the microcomputer 2
7 specifically shows the relationship with the output signal of the error calculation area selection means at 0.

In FIG. 1, reference numeral 20 denotes a microcomputer as control means, and an error calculation area selecting means 22 therein.
Outputs a signal for selecting an area for calculating an error value (the number of errors) in accordance with the output from the amplitude detection means 5 to the selection means 24 as shown in FIG. 5, and the variable equalizer control means 9 Controlling the variable equalizer means 12 according to the output and the output of the error calculation area selecting means,
The variable equalizer 12 changes the same wave number amplitude characteristic and phase characteristic of the head amplifier output.

Thus, stable reproduction characteristics can be obtained.

As described above, in the present embodiment, the output of the error detection means for detecting an error that could not be restored to the original data from the digital signal processing means is partially time-divided, and the reproduction RF ( The state of the reproduced signal is detected, and a portion where the head amplifier output is stable is selected by the error calculation area selecting means 22 to calculate an error. Since it is constant, it is possible to control the variable equalizer means 12 without changing the weight of one error, and the equalizer control means 21 malfunctions due to a failure in compatible reproduction or tape running, that is, it is possible to perform appropriate equalizer control. It is possible to improve what cannot be done and to provide stable reproduction characteristics.

[0036]

As described above, according to the present invention,
Even if there is a problem with the tape running in compatible playback etc. and stable playback output is not obtained, if it is partially stable, stable equalizer control without malfunction can be made possible and the equalizer characteristics can be optimized and good There is an effect that reproduction characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of a recording / reproducing apparatus according to a first embodiment.

FIG. 2 is a diagram showing signal waveforms according to the first embodiment.

FIG. 3 is a flowchart showing an equalizer control operation according to the first embodiment;

FIG. 4 is a block diagram showing a main configuration of a recording / reproducing apparatus according to a second embodiment.

FIG. 5 is a diagram showing signal waveforms according to a second embodiment.

FIG. 6 is a block diagram showing a main part configuration of a conventional recording / reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head amplifier means 2 Variable equalizer means 3 A / D conversion means 4 Digital signal processing means (error correction means) 5 Amplitude detection means 6 Error calculation area variable means 7 Error detection means 8 Microcomputer 9 Variable equalizer control means 10 Error calculation means 23 Time division means 24 Selection means 25 Selection means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 5/92 H04N 5/92 H

Claims (8)

[Claims] 1. A pickup for reproducing a digital signal, an amplifier for amplifying a reproduction signal output from the pickup, and a variable equalizer for changing an amplitude characteristic and a phase characteristic of the amplified reproduction signal. Analog-to-digital conversion means for quantizing the reproduction signal output from the variable equalizer means, error correction means for correcting an error in the reproduction signal digitally converted by the analog-to-digital conversion means, and error caused by the error correction means. Error detection means for detecting an error that could not be converted into the original digital signal by correction, error calculation means for integrating an error value based on an output signal of the error detection means, and error calculation by the error calculation means Error calculation area variable means capable of changing the area, and reproduction amplified by the amplifier means Amplitude detecting means for detecting the amplitude of the signal; and changing the error calculation area in accordance with the amplitude of the reproduced signal detected by the amplitude detection means, and changing the variable equalizer means in accordance with an error value in the error calculation area. A playback device comprising: a control unit for controlling the playback device. 2. A pickup for reproducing a digital signal, an amplifier for amplifying a reproduction signal output from the pickup, and a variable equalizer for changing an amplitude characteristic and a phase characteristic of the amplified reproduction signal. Analog-to-digital conversion means for quantizing the reproduction signal output from the variable equalizer means, error correction means for correcting an error of the reproduction signal digitally converted by the analog-to-digital conversion means, and error correction by the error correction means. Error detecting means for detecting an error which could not be converted into the original digital signal at a time, a dividing means for time-dividing an output signal of the detecting means into several areas at predetermined time intervals, A plurality of error calculating means for integrating error values for each of the divided areas; and a selection means for selecting the error calculating means. Selection means, amplitude detection means for detecting the amplitude of the reproduction signal amplified by the amplifier means, and the selection means select the error calculation means according to the amplitude of the reproduction signal detected by the amplitude detection means, A control unit for controlling the variable equalizer unit in accordance with the error value integrated by the selected error calculation unit. 3. The reproducing apparatus according to claim 1, wherein the pickup is a magnetic head for reproducing a signal recorded on a recording medium. 4. The reproducing apparatus according to claim 2, wherein the area to be time-divided by the dividing means is a video area among an audio area, a video area, and a subcode area in the digital video camera. 5. A reproduction signal output from a pickup for reproducing a digital signal, amplified by an amplifier means, and reproduced from a variable equalizer means capable of changing amplitude characteristics and phase characteristics of the amplified reproduction signal. The signal can be quantized by an analog-to-digital converter, the error of the reproduced signal digitally converted by the analog-to-digital converter can be corrected by an error corrector, and the original digital signal can be converted by the error correction by the error corrector. The missing error is detected by the error detection means,
An error value is integrated by an error calculating means based on an output signal of the error detecting means, and an amplitude of the reproduced signal amplified by the amplifier means is detected by an amplitude detecting means. Change the error calculation area by the error calculation area variable means,
A reproducing method characterized by controlling the variable equalizer means according to an error value in the error calculation area. 6. A reproduction signal output from a pickup for reproducing a digital signal, amplified by an amplifier means, and reproduced from a variable equalizer means capable of changing amplitude and phase characteristics of the amplified reproduction signal. The signal can be quantized by an analog-to-digital converter, the error of the reproduced signal digitally converted by the analog-to-digital converter can be corrected by an error corrector, and the original digital signal can be converted by the error correction by the error corrector. The missing error is detected by the error detection means,
The output signal of the detecting means is time-divided by the dividing means into several areas at predetermined time intervals, and error values are integrated by a plurality of error calculating means for each of the time-divided areas by the dividing means. Detecting the amplitude of the reproduced signal amplified by the amplifier means, selecting the error calculating means by selecting means according to the detected amplitude of the reproduced signal, and calculating the error integrated by the selected error calculating means. A reproducing method comprising controlling the variable equalizer means according to a value. 7. The reproducing method according to claim 5, wherein the pickup is a magnetic head for reproducing a signal recorded on a recording medium. 8. The reproducing method according to claim 6, wherein the dividing means time-divides a video area of the audio area, the video area, and the subcode area in the digital video camera.