JP2851772B2 - Recording / playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording and reproducing image and sound data, and more particularly to a recording / reproducing apparatus capable of optimally performing recording and reproduction in accordance with a change in a data recording environment and a reproduction environment. -It relates to a playback device.

[0002]

2. Description of the Related Art Generally, when recording and reproducing image data and sound data, these data are stored in the form of digital signals on a recording medium such as a magnetic tape or a magnetic disk. The recorded data is reproduced to restore the original image and sound. As described above, when images and sound data are recorded on a predetermined recording medium and reproduced, the amount of data recorded on a medium having a limited size is increased, and at the time of reproduction, image quality and sound quality are reduced. Efforts are being made to obtain better image and sound quality without deterioration.

[0003] However, the conventional digital recording / reproducing apparatus is basically configured to record and reproduce data with the recording rate, error correction capability, and compression rate fixed. Therefore, there is a problem in that the state of image quality and sound quality is affected by the characteristics of the recording medium, the performance of the setting device, and the like, making it difficult to optimally record and reproduce. Also, it is easy to manufacture the heads of the important elements of the device used for recording and reproducing data, the performance of the tape used is made equal, the set devices are all the same, and they are manufactured on the same production line. Even if the performance of thousands or tens of thousands of heads cannot be equalized, it is difficult to have the same sound quality and image quality even when recording and reproducing the same image and sound data. Therefore, there is a problem that not only a difference in image quality and sound quality is caused depending on which set device and tape is used, but also a deterioration in image quality and sound quality may be caused in some cases.

The above problems will be described below with reference to FIGS. 1 to 5 which show substantial experimental data. FIG. 1 is a view showing the relationship between the distance between the head and the tape of the recording medium in the setting device and the reproduction output. As shown in FIG. 1, it can be seen that the shorter the distance between the head and the tape, the greater the reproduction output. As described above, even if the setting devices are the same, it can be seen that there is a difference in reproduction output due to a minute change in the distance between the head and the tape.

FIG. 2 shows the relationship between the type of tape and the reproduction output. In the example shown in FIG. 2, Hc = 1680
(Oe), a tape having a component of Br = 4050 (Oe).
It can be seen that NEW ME has the best properties. As described above, even if recording / reproducing is performed using the same apparatus, a difference in reproduced output occurs depending on the composition of the tape on which data is recorded.

FIG. 3 is a diagram showing the relationship between the thickness of the magnetic material of the tape and the reproduction loss. FIG. 3 shows the difference in reproduction loss when the thickness of the magnetic material of the tape is 0.20 μm and 0.25 μm, respectively. It shows that the reproduction loss is small at 20 μm. That is, it can be seen from the above example that the smaller the tape thickness, the smaller the reproduction loss.

FIG. 4 is a diagram showing the relationship between the recording current and the reproduction characteristics. As shown in FIGS. 4A, 4B, and 4C, it can be seen that even in the case of the same recording signal, the reproduction characteristics are different even if the recording current is adjusted slightly differently in the set. FIG. 5 is a diagram showing the relationship between the recording bit rate and the reproduction characteristics. FIG. 5A,
As shown in FIGS. 5B and 5C, the lower the recording bit rate is, the better the reproduction characteristics are. The characteristics also depend on the type of tape used, the performance of the recording head, and the performance of the recording current.

As described above, the operation of a conventional digital signal recording / reproducing apparatus which does not consider the characteristics of the tape, head, and setting device will be briefly described with reference to FIGS. FIG. 6 is a schematic block diagram showing the configuration of a conventional digital recording device. In FIG.
Is an A / D that converts an analog input signal into a digital signal
The converter 15 is an error correction encoder for error correction.
Reference numeral 20 denotes a modulator for modulating data so as to match the channel characteristics, and 25 denotes an amplifier for amplifying a data signal to an appropriate size for recording on a recording medium.

Since the image or sound data input to the digital signal recording apparatus shown in FIG. 6 is in the form of an analog signal, it is converted into a digital signal by the A / D converter 10 in order to digitally process the data. . The converted data is input to an error correction encoder 15 which detects and corrects errors for error correction. Usually an error
Correction encoder is RS coder (Reed Solomon Coder)
Is used.

The error-corrected data is transmitted to the modulation unit 2
At 0, modulation is performed to match the characteristics of the channel. That is, if the digital data is communication data, the data is transmitted to the communication frequency band.
The data is frequency-modulated, and in the case of data to be recorded on a medium such as a magnetic tape, the data is modulated into a frequency band suitable for recording. In this manner, the digital data modulated appropriately to the characteristics of the channel is amplified to an appropriate size by the amplifier 25 and recorded on the recording medium.

FIG. 7 is a schematic block diagram of a conventional general digital recording / reproducing apparatus. 7, reference numeral 25 denotes an amplifying unit having the same function as the amplifying unit in FIG. 6, reference numeral 30 denotes a demodulation unit for performing a reverse process of the modulation performed at the time of recording, and reference numeral 35 denotes an error for decoding input data. A correction decoder 40 is a D / A converter for converting a digital signal into an analog signal.

The digital signal reproducing apparatus shown in FIG. 7 uses a head to record image or acoustic digital data on a recording medium.
The signal is reproduced and input to the amplifier 25, where it is amplified to a signal of a fixed magnitude. The amplified signal is subjected to a demodulation process corresponding to the inverse process of the modulation performed at the time of recording by the demodulation unit 30 and demodulated. In the demodulated data, an error is detected by an error correction decoder 35, and error correction is performed. Such an error correction decoder 35 is an RS decoder or Viterb.
An i decoder is used. The error-corrected image or sound digital data is converted into an analog signal by a D / A converter 40, and transmitted to a display device or a speaker (not shown) so as to be output in the form of an image or sound. You.

[0013]

As described above, FIG.
The general digital recording / reproducing apparatus shown in FIG. 7 records and reproduces data with the data recording rate and the track length of the recording medium fixed, as described above, thereby obtaining the characteristics of the recording medium. Alternatively, the image quality and the sound may be deteriorated due to a difference in performance of the system set.

Further, since most electric and electronic products are mass-produced, the same kind of heads and tapes used for recording media are used.
Even if a tape or system set is used, the performance is not the same, and the user uses tapes of different materials, which may make it difficult to record data at the optimum density on the recording medium. Also, during reproduction, recorded data is not reproduced optimally, and the sound quality and the image quality deteriorate.

Accordingly, it is an object of the present invention to provide image and audio data.
An object of the present invention is to provide a recording / reproducing apparatus capable of recording / reproducing data in an optimum state regardless of the performance of a recording medium material and a system set in recording and reproducing data. Another object of the present invention is to record and reproduce image and sound data in an optimal state on a predetermined recording medium, compress the recorded data to an optimal compression ratio, and convert the reproduced data to an optimal expansion ratio. It is an object of the present invention to provide a recording / reproducing device for decompression.

[0016]

In order to achieve the above object, a recording / reproducing apparatus according to the present invention records digital data on a predetermined recording medium by using a recording head, and records the recorded data. In a recording / reproducing apparatus for reproducing by using a reproducing head, a memory for storing an input digital data signal, and data read from the memory are modulated by a predetermined clock signal and channel characteristics and modulated. A modulator for supplying the recorded data to a recording head, an envelope detector for recording a data signal on a recording medium by the recording head, and detecting an envelope value from the data reproduced by the reproducing head. A clock generating unit for generating a clock signal whose clock speed changes according to the detection result of the envelope detecting means, A recording device for determining a data rate read from the memory and a modulation clock applied to the modulation section, a detector for detecting a recording signal from a reproduction signal reproduced through the reproduction head, and the detector For detecting the recovered clock signal from the output signal from the
An L circuit; a demodulation unit for demodulating data detected by the detector in accordance with channel characteristics in accordance with a reproduced clock signal output from the PLL circuit; and temporarily storing data supplied from the demodulation unit. And a reproducing apparatus including a memory for outputting stored data in response to a clock signal supplied from the PLL circuit.

[0017]

In this configuration, even if the performance of the head, tape or set slightly differs, the optimum sound quality and image quality can be enjoyed by performing the optimum recording suitable for the head, tape or set. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment according to the present invention will be described below in detail with reference to the drawings. FIG. 8 is a schematic block diagram of the optimum recording / reproducing apparatus in the embodiment. FIG. 8A schematically shows a head applied in the embodiment, and is configured to separately include recording heads W1 and W2 used for normal recording and reproduction heads R1 and R2 used for reproduction. .

FIG. 8B is a block diagram showing a configuration of the optimum recording / reproducing apparatus in the embodiment. At the time of recording / reproducing, the recording / reproducing head of the form shown in FIG. 8A is used. FIG.
In B, the modulator 20, the first amplifier 25, the second amplifier 27, and the demodulator 30 have the same functions as those used in the conventional digital signal recording / reproducing apparatus shown in FIGS. doing. 50 is a memory for temporarily storing an input digital recording signal, 55 is a switching unit for recording or reproduction conversion, 60 is an envelope detector for detecting the envelope of a signal detected from an optimal recording detection head, and 65 is an envelope detector. A clock generator for generating a clock signal whose clock cycle changes according to the magnitude of the input signal, 70 is an equalizer, 75 is a detector, and 80 is a phase lock loop (hereinafter, referred to as "PLL") circuit. .

The operation of the optimum recording / reproducing apparatus according to this embodiment having the above-described configuration will be described below. First, an example in which data recording is optimally performed will be described. Image and / or sound digital data to be recorded is input through an input terminal and stored in the memory 50. The stored data is output from the memory 50 in accordance with a predetermined reference clock signal generated from the clock generation unit 65, and after the output data is modulated by the modulation unit 20 to match the channel characteristics, The signal is amplified by the first amplifier 25 to a predetermined size suitable for recording, transmitted to the recording head, and recorded on the recording medium.

At the time of data recording, the data recorded together with the data recording is reproduced using the reproducing heads R1 and R2, and the switching unit 55 is operated in response to a switching control signal from a microcomputer (not shown). Is connected to the “H” terminal, and the amplified signal is transmitted to the envelope detector 60 through the switching unit 55. Envelope detector 60
Detects the envelope value of the amplified digital signal. The value detected at this time corresponds to the absolute value of the difference between the upper limit and the lower limit of the data input to the envelope detector 60.

The envelope detector 60 supplies the envelope value to the clock generator 65, and changes the clock speed of the clock generator 65 according to this value. That is, if the detected envelope value is equal to or smaller than the reference value, the speed of the clock generated by the clock generator 65 is changed so as to increase the envelope value. Conversely, if the envelope value is equal to or greater than the reference value, the clock generation unit 6 reduces the envelope value.
The speed of the clock generated in step 5 is changed. The configuration and operation of the clock generator 65 operating as described above will be described with reference to FIG.

9A includes an integrator 200, a comparator 205, and a voltage controlled oscillator (VC).
O) 210, which receives an output from the envelope detector 60, compares a signal integrated by the integrator 200 with a signal not integrated by the comparator 205, and controls the operation of the voltage controlled oscillator 210 based on the result. That is, if the envelope value is large, a fast clock is generated, and if the envelope value is small, a slow clock is generated, thereby optimizing the recording clock that determines the recording data rate.

FIG. 9B shows a modification of the clock generator shown in FIG. 9A. A plurality of clock generators 225A, 225B,.
5N. In FIG. 9B, after a signal integrated by the integrator 200 and a signal not integrated are received by the comparator 205 after receiving the output from the envelope detector 60, the result of the comparison is converted by the serial / parallel converter 215 into parallel data. Is converted to The converted data is compared with the respective reference values of the plurality of comparators 220A, 220B,..., 220N, and the output “H” from the comparator corresponding to the same value is output.
, 225N, the corresponding clock generator is enabled, and an optimum clock is searched for.

According to this principle, if the envelope value is larger than the reference value, it means that the recording data rate can be increased, so that the fastest clock generator is operated,
In the opposite case, an optimal clock can be found by operating a slower clock generator. As described above, the recording signal is reproduced together with the recording, the envelope value is checked, and the current clock speed is converted into the optimum clock signal, whereby the amount of data output from the memory 50 and the modulation of the modulator 20 are adjusted. By adjusting the clock, data can be optimally recorded on the recording medium.

Next, a case where the data recorded on the recording medium is optimally reproduced will be described with reference to FIG. 8B.
The data reproduced through the reproducing heads R1 and R2 is amplified to a signal of a predetermined magnitude or more by the second amplifying unit 27, and the switch of the switching unit 55 is turned on according to a control signal in a microcomputer (not shown). It is switched to the L "terminal. As a result, the signal amplified by the second amplifier 27 is input to the equalizer 70, and after the deterioration of the frequency characteristic is compensated, the data detected by the detector 75 is output to the PLL unit 8.
0, and the reproduced clock included in the detected data signal is detected.

The detected clock signal is supplied to the demodulation unit 30 and the memory 50, and data reproduced according to the clock signal is demodulated by the demodulation unit 30 and recorded in the memory 50. The data recorded in the memory 50 is stored in the PLL unit 80.
Output in an optimal state according to the clock signal supplied from the As described above, according to the present embodiment, recording can be performed at an optimum bit recording rate, and a signal reproducing operation is performed in accordance with a reproduction clock recorded in a signal at the time of reproducing a recording signal. Can be done.

FIGS. 10A and 10B are schematic block diagrams of another embodiment of the optimum recording / reproducing apparatus according to the present invention.
FIG. 10A schematically shows a head applied in another embodiment. For recording / reproduction, the same head RW1,
FIG. 1 shows a case where RW2 is used and separate heads OD1 and OD2 are provided for optimal recording / reproduction according to the present invention.
FIG. 0B is a schematic block diagram of a recording / reproducing apparatus using the head shown in FIG. 10A.

The recording / reproducing apparatus shown in FIG.
It has almost the same configuration as. Therefore, the same parts as those in the apparatus of FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 shows one of the other embodiments.
Since the recording / reproducing apparatus 0 uses the same head for recording and reproduction, the signal processing is slightly different. This will be described in more detail below.

First, an example in which data recording is optimally performed will be described. Since the apparatus of FIG. 10B performs recording and reproduction with the same heads RW1 and RW2, separate recording detection heads OD1 and OD2 are required to perform the optimal recording / reproduction operation. The input digital signal to be recorded is stored in the memory 50, and the stored data is output at a predetermined reference clock speed output from the clock generator 65 and modulated by the modulator 20. Then, after being amplified to a certain size by the first amplifier 25, it is recorded on a recording medium.

Through the above-described recording process, data is recorded on the recording medium and optimal recording / reproducing heads OD1, OD1 are recorded.
In step 2, the recorded data is immediately reproduced and output, and after the output data is amplified to a predetermined size through the second amplifying section 27, the switching section 55 performs switching from a microcomputer (not shown). The signal amplified according to the control signal is supplied to the envelope detector 60, and the envelope value is detected. The clock speed output from the clock generator 65 is determined based on the magnitude of the detected value, and the corresponding clock signal is supplied to the memory 50.
The optimal recording operation can be performed by adjusting the amount of the recording signal output from the memory 50.

The reproducing operation is the same as the reproducing operation in the apparatus shown in FIG. 8B except for the change of the signal flow due to the switching operation in the switching unit 55, so that the description is omitted. FIG. 11 shows another embodiment of the optimum recording / reproducing apparatus according to the present invention.
The present invention relates to an optimal recording / reproducing apparatus through processing such as correction and modulation.

Of the constituent elements of the other embodiment shown in FIG. 11, the same reference numerals are used for the same constituent elements used in the above-described embodiment, and the detailed description of the corresponding constituent elements is omitted. In FIG. 11, reference numeral 85 denotes a data compression unit for compressing data to a predetermined compression rate using a known compression method;
0 is a mixing section for mixing the compressed signal and an ID signal generated by an ID generation section 100 described later, 95 is an ECC encoder, 100 is an ID generation section, 105 is a compression ratio of a signal to be recorded, and 105 is an error. A recording adjustment unit for adjusting corrections and the like, 11
0 is a second switching unit that performs switching in accordance with the switching control signal, 115 is an ECC decoder, 12
Reference numeral 0 denotes an ID detection unit for detecting an ID signal from the reproduced signal, and reference numeral 125 denotes a data decompression unit for decompressing the compressed data.

The operation of another embodiment of the above configuration will be described as follows. In this example, the recording head and the reproducing head are the same head, and the optimum recording detection head is additionally provided. When data converted into digital data by analog / digital conversion in an analog / digital converter (not shown) is input to the data compression section 85, the recording adjustment section 105 is formed using a known compression method. The input digital data is compressed according to a predetermined reference data compression ratio.

The compressed data passes through an ECC encoder 95 having a reference correction capability, is modulated by a reference clock in a modulator 20, and the first amplifying unit 2 is adapted to the recording.
Amplified by 5. Then, the data is transmitted to the recording heads RW1 and RW2 and recorded on a recording medium. At the same time as this recording, the recorded signal is immediately reproduced using the optimum recording detection heads OD1 and OD2. The microcomputer recognizes that the reproduced signal is being recorded at the time of recording, and transmits the corresponding switching control signal to the second switching unit 110 and the first switching unit 5.
5 is transmitted.

The switching control signal from the microcomputer has a "high" state at the time of recording and a "low" state at the time of reproduction. The switching control signal is applied to the second switching section 100 at the time of recording, and the switch terminal is Connected to “L” side. As a result, the reproduced signal is input to the second amplifier 27, and the reproduced digital signal has a magnitude equal to or larger than a predetermined magnitude. The switching control signal is applied to the first switching unit 55, and switches the switching terminal to the “L” side.

When the first switching section 55 is switched to the “L” side according to the switching control signal, the reproduced and amplified signal is input to the envelope detector 60.
The envelope detector 60 detects the envelope value of the input signal and outputs it to the recording adjustment unit 105. Recording adjustment unit 1
Reference numeral 05 plays a role in determining a recording rate and a compression ratio for optimal recording according to an input signal.
5 will be described in detail with reference to FIG.

As shown in FIG. 12, the recording adjustment unit 105 has a clock generation unit 65 for generating a clock, an ECC
An error counter 140 for counting an error flag output from the decoder 115 (FIG. 11), a compression ratio adjustment unit 145 for adjusting a compression ratio, and an error correction capability adjustment unit 150 for adjusting an error correction capability. These operations are as follows.

The clock generator 65 adjusts the clock operation according to the magnitude of the envelope detected by the envelope detector 60, as described above. That is, if the detected envelope value is larger than the reference value, the fast clock generator is operated, and if the detected envelope value is smaller than the reference value, the slow clock generator is operated to generate an optimum clock. Output to the ID generation unit 100.

The error counter 140 receives an error flag from the ECC decoder 115, counts the number of the corresponding flag, and outputs a count value. The error correction capability adjustment unit 150 adjusts the error correction capability according to the input count value and the clock signal from the clock generation unit 65. Here, the adjustment of the error correction capability performed by the error correction capability adjustment unit 150 will be described with reference to FIG. 13 showing the inside of the error correction capability adjustment unit 150.

As shown in FIG. 13, the error correction capability adjusting section 150 includes a comparator 155 and an up / down counter -16.
The comparator 155 compares the output value counted and output by the error counter 140 with the value of a predetermined reference error set in the system, and based on the comparison result, the up-down counter 160 And the reference parity number is loaded to the up / down counter 160 to act as a reference value.

That is, if the output of the error counter 140, which is the result of the comparison in the comparator 155, is larger than the number of reference errors allowed by the system, the output of the comparator becomes "H" and the up / down counter 160 Increases the number, and vice versa, adjusts the parity-number by decreasing the number. Increasing the number of the up / down counters 160 means that many errors occur. Therefore, it is intended to increase the number of parities to increase the correction capability. Since the number of parities is excessive, the number of parities is reduced to lower the error correction capability.

As described above, the error correction capability adjusting unit 150
Are output to the ECC encoder 115, the ID generator 100, and the compression ratio adjuster 145, as shown in FIG. Also, the compression ratio adjusting unit 1
At 45 (FIG. 12), the clock signal supplied from the clock generator 65 is received to determine the recording bit rate, the parity number from the error correction capability adjuster 150 is received, and a compression ratio suitable for it is selected. You.

As shown in FIG. 14, the compression ratio adjusting unit 145
Is composed of a comparator 155, an inverter 157 and an up / down counter 160, and an error correction capability adjusting unit 1
The value output from 50 is compared with a predetermined reference parity number set in the system by a comparator 155, and the result is inverted by an inverter 157. The up / down counter 160 is operated according to the inverted comparison result, and the reference compression data rate is loaded on the up / down counter 160 to act on the reference value.

At this time, the process of determining the error correction capability and the data compression ratio will be described in detail with reference to FIG. FIG. 15 is a diagram showing a configuration and an example of an ID code.
As shown in FIG. 15A, the ID code is composed of an 8-bit recording bit rate, an 8-bit error correction capability, an 8-bit data compression ratio, and a large number of bits indicating various information related to the ID and the system. Made more. At this time, the information contained in the remaining bits includes information for audio / video division, information on frames and tracks, information for data and parity division, and digital copy. And information on permission or non-permission.

The principle of ID generation in the embodiment is as follows. First, when the recording bit rate is determined by the basic clock, the data is reproduced by the optimum recording detection head at the same time as recording, and is output from the ECC decoder 115 through the above-described reproduction process. In response to the error flag, the number of parities is increased or decreased according to the number of errors, thereby adjusting the data compression ratio so that the data rate after compression is adjusted to the final recording bit rate determined previously. adjust.

This will be described with reference to FIGS. 15B and 15C. The case of FIG. 15B is a case where the high-frequency characteristics of the system are better than the case of FIG. 15C described later. If the error correction capability is equal for each system, FIG.
Since the data compression rate in FIG. 15C can be increased by reducing the data compression in FIG. 15C, there is an advantage that the performance of image quality and sound quality can be greatly improved.

That is, when a system having the performance as shown in FIG. 15C is provided and recording and reproduction are performed with a fixed specification as shown in FIG. 15B, image and sound quality far worse than the performance of the system is recorded and reproduced. On the other hand, if the specifications as shown in FIG. 15C are applied to the system as shown in FIG. 15B, since the error correction capability and the data compression ratio are fixed, high-frequency degradation occurs and the performance of image quality and sound quality is reduced. It would have to be very badly recorded and played back.

As described above, the optimum clock signal, the compression ratio, and the recording rate are determined by the recording adjustment unit 105, and these signals form one synchronous block as shown in FIG. This synchronization block includes synchronization signals (SYNC) N1, I
D signal (ID) N2, data signal N3, and parity
It is composed of a signal N4. Usually, for these signals, once the recording bit rate is determined, the number N4 of parities that determines the error correction capability is determined, and finally the compression ratio N3 is determined. The compression ratio of the data signal is determined by the data compression unit 8.
5, the input signal is compressed according to a predetermined method according to a compression ratio and output. Further, a clock signal, a compression ratio, and information on error correction are supplied to the ID generation unit 100, and these signals are supplied to the data compression unit 85.
The signal is mixed by the mixing unit 90 together with the signal compressed by the multiplexing unit and output.

In FIG. 11, of the signals output from the recording adjustment unit 105, the parity related to error correction
The value is output to the ECC encoder 95, and at the same time, the modulation unit 2
0, the output from the ECC encoder 95 is the recording adjustment unit 1
After being modulated to match the channel characteristics in accordance with the clock signal supplied from 05, the modulated signal is amplified by the first amplifier 25 to a predetermined size and recorded.

At the time of signal reproduction, the second switch 110 is switched to “L” in accordance with a switching control signal from the microcomputer, and is amplified to a predetermined magnitude by the second amplifier 27. Equalizer 70, detector 7
5, an error is demodulated by the ID detector 120 from the demodulated signal through the PLL unit 80 and the demodulation unit 30.
The correction capability and the data compression ratio are detected, and control the ECC decoder 115 and data decompressor 125, respectively.

At the time of reproduction, the reproduced signal does not go to the envelope detection section 60 side, but is input only to the equalizer 70. In the next step, reproduction is performed through the above-described steps.
The occurrence of the error flag in the decoder 115 is not input to the recording adjustment unit 105. Referring to FIG. 17, which shows an example of a signal reproduced through the above-described process, when the optimum recording according to the present invention is performed, the reproduction level is constant after reproduction equalization, there is almost no peak shift, and there is no error. Since no reproduction is possible, it can be seen that clear image quality and high sound quality can be guaranteed.

[0053]

As described above, as described above, the optimum recording /
Even if the performance of the head, tape or set is slightly different due to the reproducing operation, not only can the optimum picture quality and sound quality be enjoyed by performing the optimum recording suitable for the head, tape or set, but also The reliability of the user can be further increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a distance between a head and a tape of a setting device and a reproduction output loss.

FIG. 2 is a diagram showing the relationship between the type of tape and the reproduction output.

FIG. 3 is a diagram showing the relationship between the thickness of the magnetic material of the tape and the reproduction loss.

FIG. 4 is a diagram showing a relationship between a recording current and a reproduction characteristic.

FIG. 5 is a diagram showing a relationship between a recording bit rate and reproduction characteristics.

FIG. 6 is a schematic block diagram of a conventional digital signal recording device.

FIG. 7 is a schematic block diagram of a conventional digital signal reproducing device.

FIG. 8 is a schematic block diagram illustrating a configuration of an optimum recording / reproducing apparatus according to the present embodiment.

FIG. 9 is a detailed circuit diagram of a clock generator used in the optimum recording / reproducing apparatus according to the embodiment.

FIG. 10 is a schematic block diagram showing a configuration of an optimum recording / reproducing apparatus according to another embodiment.

FIG. 11 is a schematic block diagram showing a configuration of an optimum recording / reproducing apparatus according to another embodiment.

FIG. 12 is a detailed block diagram of a recording adjustment unit in FIG. 11;

FIG. 13 is a detailed block diagram of an error correction capability adjusting unit in FIG. 12;

FIG. 14 is a detailed block diagram of a compression ratio adjusting unit in FIG. 12;

FIG. 15 is a diagram showing an ID code configuration and an example thereof.

FIG. 16 is a diagram showing a configuration of a synchronization block.

FIG. 17 is a diagram showing an example of an output waveform of the device according to the embodiment.

Claims (14)

(57) [Claims] A recording / reproducing apparatus for recording digital data on a predetermined recording medium using a recording head and reproducing the recorded data using a reproducing head. A memory for accumulating data signals; a modulator for modulating data read from the memory with a predetermined clock signal and channel characteristics to supply the data to a recording head; Envelope detecting means for recording and detecting an envelope value from data reproduced by the reproducing head, and clock generating means for generating a clock signal whose clock speed has changed in accordance with the detection result of the envelope detecting means. Determining a data rate read from the memory according to the clock signal and a modulation clock applied to the modulation unit. A recording device, a detector for detecting a recording signal from a reproduction signal reproduced through the reproduction head, and a phase lock loop (PLL) circuit for detecting a reproduction clock signal from an output signal from the detector. A demodulator for demodulating data detected by the detector in accordance with channel characteristics in response to a reproduced clock signal output from the PLL circuit; and temporarily storing data supplied from the demodulator;
A recording / reproducing device comprising: a memory for outputting data accumulated according to a clock signal supplied from an LL circuit. 2. The recording / reproducing apparatus according to claim 1, further comprising a separate recording signal detecting head for detecting the recorded data together with the recording of the data signal. 3. The apparatus according to claim 1, further comprising switching means for switching a reproduction output through said reproduction head to said recording device or reproduction device in accordance with a data recording operation or a data reproducing operation. Records of
Playback device. 4. The envelope detecting means outputs an envelope value corresponding to an absolute value of a difference between an upper limit value and a lower limit value of data which is read from the reproducing head when data is recorded and transmitted. 2. The recording / reproducing apparatus according to claim 1, wherein: 5. The clock generation means, wherein an integrator integrating an output detected from the envelope detection means, and a detected output from the envelope detection means and an output integrated through the integrator are compared. 2. The recording / reproducing apparatus according to claim 1, further comprising: a comparator for generating a clock signal that varies according to a comparison result output of the comparator. 6. The clock generating means for integrating an output detected from the envelope detecting means, and comparing an output detected from the envelope detecting means with an output integrated through the integrator. A serial-to-parallel converter for converting the output of the comparator into parallel data; and a plurality of comparators for comparing each data constituting the parallel data with a predetermined reference value. 2. The recording / reproducing apparatus according to claim 1, further comprising: a comparator configured to generate a clock signal based on a comparison result of the comparator. 7. A recording / reproducing apparatus for recording digital data on a predetermined recording medium using a recording head and reproducing the recorded data using a reproducing head. a data compression unit for compressing the compression ratio, and an error correction encoder for performing error <br/> error correction of the data that has been said compressed by a predetermined error correction capability, data given to the error-corrected clock signal and channel characteristics A modulation unit that modulates and supplies the recording head with a recording signal, an envelope detection unit that detects an envelope value from data reproduced by the reproduction head together with recording of a data signal on a recording medium by the recording head, and an envelope detection unit. The modulation unit and the data compression unit according to the detection result of the error correction and the error flag input from the error correction decoder. A recording adjustment unit for determining a reference clock, an error correction capability, and a data compression ratio supplied to the error correction encoder; and an ID for receiving information generated by the recording adjustment unit and recording the information in input data. A recording unit including: an ID generation unit that generates a signal; a mixing unit that mixes the ID signal from the ID generation unit and data from the data compression unit and outputs the mixed signal to the error correction encoder; A detector for detecting a recording signal from the reproduced reproduction signal, a phase lock loop (PLL) circuit for detecting a reproduction clock signal from an output signal from the detector, and a reproduction clock from the PLL circuit A demodulation unit for demodulating data detected from the detector by a signal output according to channel characteristics; An ID detector for detecting a D signal; an error correction decoder for performing error correction decoding according to the ID signal detected by the ID detector; and an ID signal detected by the ID detector for decoding the decoded signal. And a data decompression unit for decompressing and outputting the data at a predetermined decompression ratio corresponding to the above. 8. The recording / reproducing apparatus according to claim 7, further comprising a separate recording signal detecting head for detecting the recorded data together with the recording of the data signal. 9. The envelope detecting means outputs an envelope value corresponding to an absolute value of a difference between an upper limit value and a lower limit value of data which is read from the reproducing head when data is recorded and transmitted. The recording / reproducing apparatus according to claim 7, wherein: 10. A recording adjustment unit comprising: a clock generation unit for generating a clock signal whose clock speed changes according to a comparison result from the envelope detection unit; and an error flag from the error correction decoder. An error counter for counting the clock signal; a clock signal from the clock generation means;
An error correction adjuster for adjusting an error correction capability in response to an error count value from a counter; a clock signal from the clock generator and an error correction capability set by the error correction adjuster 8. The recording / reproducing apparatus according to claim 7, further comprising: a compression ratio adjusting unit for adjusting a compression ratio by using a compression ratio adjusting unit. 11. The clock generation means for integrating an output detected from the envelope detection means, and comparing an output detected from the envelope detection means with an output integrated through the integrator. The recording / reproducing apparatus according to claim 10, further comprising: a comparator; and a voltage-controlled oscillator that generates a clock signal that is varied according to a comparison result output from the comparator. 12. The clock generating means for integrating an output detected from the envelope detecting means, and for comparing an output detected from the envelope detecting means with an output integrated through the integrator. A serial-to-parallel converter for converting the output from the comparator into parallel data; and a plurality of comparators for comparing each of the data forming the parallel data with a predetermined reference value. 11. The recording / reproducing apparatus according to claim 10, further comprising: a comparator; and a plurality of clock generators that generate a clock signal according to the comparison result. 13. An error correction adjusting unit, comprising: a comparator for comparing a counter value of the error counter with a predetermined reference value; and a predetermined reference parity value in accordance with the comparison result. 11. The recording / reproducing apparatus according to claim 10, further comprising an up / down counter for counting up or down. 14. A compression ratio adjustment unit, comprising: a comparator for comparing an input from the error correction adjustment unit with a reference parity value; and a predetermined reference compression data ratio being inversely proportional to the comparison result. 11. The recording / reproducing apparatus according to claim 10, further comprising an up / down counter for counting up / down.