JPS59207438A - Recording and reproducing device of digital signal - Google Patents

Abstract

PURPOSE:To attain the recording with high density by making a data recording length on a fixed level after converting every (n) bits of the digital signal into a pulse having changed width with addition of a fixed wavelength and then adding the signal component obtained by subtracting a certain data from the largest information quantity. CONSTITUTION:An analog signal is converted into a digital signal by an A/D converter 2 and supplied to a bit train/bit length converting circuit 3 to be converted into a pulse having the width changed in response to the contents of information every prescribed (n) bits. Then a wavelength lambda0 is added and the data information having the width varying by the information based on the wavelength lambda0 is obtained. This signal is supplied to an optical modulator 6 and recorded in the form of bits. The optical signal of a disk 9 detects the duty of a reproduction signal via an RF signal processing circuit 15 and a reproduction duty correcting circuit 16. Then the duty of the reproduction signal is corrected, and this corrected signal is supplied to a bit length/bit train converting circuit 17. The circuit 17 converts the pulse signal having the width varying in response to the recording information into the digital signal of the original bit train. This digital signal is converted into an analog signal and extracted as a reproduction signal. Thus the recording is possible with high density.

Description

[Detailed Description of the Invention] The invention for each field of industrial application is a digital recording device suitable for recording digital signals on, for example, a video disk, etc. Regarding.

BACKGROUND ART AND PROBLEMS When recording digital signals on, for example, a video disc, it is desired to record them at high density.

However, there is a limit to the recording density of such video discs, and in order to record and reproduce more information than conventional discs, it is necessary to reduce the pitch of the trunk where information is recorded, for example. , the number of rotations of the disc may be changed depending on whether the inner circumference is skimmed or the outer circumference is skimmed, or the information to be recorded may be made into a multi-level signal.
(Methods such as changing the recording depth are possible.

However, when recording digital information on such a video disk, if it is not necessary to increase the frequency, the speed of the disk should not be increased or the bit length should not be changed. By using a special method for the recording medium, such as dividing the signal track into two tracks, the recording wavelength must be lengthened in practice, and as a result, the meat There was an inconvenience that the time was shortened.

Contamination is caused by recording each bit of the digital signal as it is on the recording medium, and depending on the signal processing method, the number of bits may be reduced to a fraction of the total recorded information. It may be possible to reduce the number of images, but if the recorded information is, for example, a video signal in which one picture is recorded per revolution of the disc, the image quality will inevitably be worse on the outer and inner peripheries of the disc, so this should be taken into account. When considering preservation of a certain image quality, there is a limit to its reduction, and therefore,
Satisfactory high-density recording was difficult.

Purpose of the Invention In view of the above, the present invention records information at +i'l+' density on a recording medium having a finite recording density without substantially deteriorating recorded information, and from this, a desired 4
The present invention provides a digital signal recording and reproducing device that can obtain No. 11 raw information.

Summary of the Invention A digital signal is converted into a pulse signal whose pulse width is changed by dividing a predetermined number of bits into a fixed length, and a pulse component of a predetermined length is added to the pulse signal. In this case, the recording wavelength for each bit is constant.

a reference pulse adding means for adding a reference Hals to the pulse signal of the two at regular intervals (=J) and recording it on a recording medium;
a correction means for detecting and correcting the regenerated signal based on the reference pulse 2, and the sleeve J1 knee f';
This is a digital signal recording and reproducing device comprising a pitch 1-length 1 hiso I column converting means for converting the output signal of the stage to the original digital signal, and the device has a more reliable iLi than the conventional one. , It's possible to record and reproduce data at '31 density.

Embodiments] - Examples of the present invention will be described in detail based on FIGS. 1 to 1] j).

First, the basic principle of this invention will be explained with reference to FIGS. 1 to 3. In this invention, serial or parallel digital signals that are continuous in time are converted into pulses (a type of array pulse) whose pulse width is changed in units of 1/21 of a fixed length for each rll pin. 1 cog length).

For example, if n Hiso I- is combined with 4 and 71, normally the first
As shown in 1, 1 corresponds to the hexadecimal value 0 to 15.
Six types of information can be considered, but in this invention, each information is considered as a change in time IIi+1+,,l2CJa, and in this case, 1/16 of the pulse width of 4 hin1-min (
The pulse width is changed to a pulse whose length is 1/2'). In Figure 2, the box with diagonal lines represents the following.In hexadecimal notation, 1 is the second number and is shown in IB.
3', I-/Hi12) expressed in length, 2
As shown in No. 21471C, 3 is expressed as 2L/H; similarly, 3 is 31. /16 (2nd Chen ID)
・ ・ ・15 is [1, /16 (2nd IE)
People are represented.

And, Heizumi u, considering the reading limit wavelength of darkness,''-
As described above, a wavelength λ0 (λm, usually a pulse corresponding to a portion of the minimum read wave) corresponding to a pulse with a changed blur width is added as indicated by the diagonal line. Therefore, ζ, the one wavelength λ0 and the changed pulse of 11 mo1 shown by diagonal lines become a substantial deque information (.u).

Assuming that this data information is X, in this invention, as shown in FIG. Your X is 1fi base l;, your X = (
Monote, j-co (l Ill) obtained from OFII-X)
is hexadecimal number nio is le most humane + t4 P (15 ni%・I
LCx ) '(: ipr Zv.

By adding the information of each X, the value obtained by adding X becomes exactly constant, and the recording wavelength for each data can be made substantially constant. And this third IA
The diagonal line in the border indicates the width that changes depending on the information.

In addition, in this invention, emotional (condolence (pulse)) by recording and reproducing is possible.
In order to detect a change in the duty of , an X quasi-pulse PR of constant wavelength λ0 is added as a reference pulse to each pin 1, as shown in FIG. 3B. In addition, in FIG. 3B, for ease of understanding, the X and X portions are shown in a reversed state Cho at the time of phase. This reference pulse is recorded again and again:
In this case, if there is no particular change in the duty of the J-information, that is, if the retention property is good, then it is necessary to intermittently, if not for each hint, e.g. after the vertical or horizontal signal of the video signal, after the You may also insert it.

The signal waveform thickened by /Iζj in this way is the actual waveform of recorded information, and here the width of the diagonal line that changes depending on the information (・K) is reduced. By doing so, the recording (hit) length can be made rectangular.The width of this diagonal line is the S/
'The limit value of the N ratio is determined.

Incidentally, in the case of 4 pins, the recording density of digital signals can be increased by at least about 1.6 times.
This effect appears as the value of n increases,
The recording density is reversed.

Figures 1 and 5 show the specific circuit configuration of this embodiment.
;-It is a thread.

In FIG. 4, when an analog signal, for example a video signal, as recorded information is fed from an input terminal (1) to an analog digital conversion circuit (2), the
Converted to a digital signal from the J'slJ Guigo issue (
Bi, 1 column - Hisoto conversion 1r + I ll'8 +3)
supplied to

This pitch-I sequence-hit location conversion circuit (3) converts the input digital signal hit sequence into a predetermined I
) Hint 4jJ, convert it into a pulse whose width changes depending on the information content (specifically, for example, by putting a pattern compatibility table in memory and storing it, or by scanning one change and doing 10). ) After that, λ0 is added for each wave to the pulse whose width has been changed to form data information whose width changes based on λ0 as shown in FIG. 2. And, as shown in Figure 3, in history 4i13 X for X
After adding the component and making the recording wave of each data jJj - 1 constant, the base pulse of the next stage (=t m times l Raku (4)
1.

The reference pulse controller (j addition circuit (4) is manually operated (No. 6,
1 knee 11. For example, by adding the basic iP pulse Pi (of λ0 as shown in FIG. 3B), the minimum wavelength that can be recorded as a standard for another duty 1'Ij, resulting in recording as shown in the whole of FIG. A waveform digital signal is supplied to an optical modulator (6) via an amplifier (5).

The optical modulator (6) converts the laser light from the laser light source (7) into a digital signal that is fed via the amplifier (5).
L -/change ii) M (on/off) and motor (8
) is irradiated onto the video disk (9) which is being rotated 119J. As a result, the disk (9) is exposed to light.
Only the 9th area is exposed to light, and the supplied digital information is recorded in the form of pin-nodes.

In this way, move the recorded disc (9) to the motor (
11) The disk is rotated and the laser beam from the laser light source (12) is focused and irradiated onto the disk (9) via the half mirror (13). The bit recorded on the disk (9) has a depth of approximately A, which is a wave of incident light. Every time the light phase shifts by 180', they interfere with each other and become dark.On the other hand, in the area where there is no pinot (180'), almost all the light is reflected.These lights are detected by the photodetector (14
), the optical signal is converted into an electric signal/bow +<
The signal (Jli) is supplied to the F-passing processing circuit (15), and after being waveform-shaped by \, it is supplied to the endogenous duty correction circuit (16).

ill, /: IF output +li +ll open circuit 16) is based on the reference pulse inserted at regular intervals during recording as described above.
The duty of the reproduced signal is detected from IJ (to give.

The bit length/hit string conversion circuit (I7) (41) converts the input signal supplied thereto from a pulse signal whose pulse width changes in accordance with the recording information to an internal signal of the length. This converted digital signal is converted from an internal signal into an analog signal by the digital-to-analog converter 1 (1B), and is then passed through the amplifier (19).
Playback is output to the C output terminal (20).

) Core Example Note that in the above-mentioned embodiments, the present invention has been explained by taking the case of digital video transmission as an example, but the present invention is not limited thereto, and can be similarly applied to, for example, digital audio signals. Needless to say.

Effects of the Invention As described above, according to the present invention, every n bits of a continuous digital signal is converted into a sawtooth pulse with a varying pulse width,
Considering the reading limit wavelength, add a signal component (X = OFll - Since it is possible to record data on a recording medium by increasing the rotational speed or recording by dividing into 2I-racks as before (without using any special method, but using conventional technology), You can use the recording materials as they are to record your condolences,
High-density recording becomes i+J capability.

1 mi, the basis f is used as a duty discrimination standard when recording.
Since the 11' pulse is set to 1) 11 people, it is possible to detect the duty of the reproduced signal based on the (quasi-barsm) pulse during operation.
) rlj degree I+11 fM y)! I can do d. Moreover, above the recording wavelength, that amount! Since a skewer with a magnetic field is actually used, it is possible to easily remove unnecessary components such as noise through digital processing.

[Brief explanation of the drawing]

Fig. 1 and Fig. 31 are illustrations for explaining the basic processing of this invention. Figs. , Fig. 4 bat its notes jφ
Figure 5 shows the circuit configuration of each of the 111 production systems (1). (2) is an analog-to-digital conversion circuit, (3) is a hit string to binotoni conversion circuit, (4) is a base f1]5 pulse addition circuit, (6) is an optical converter MiiJ, (71, (12) is a laser Light source, (9) is Hide'A eye disk, (14) is photodetector, (15) is RF signal processing circuit, (16) is re/
, JF Dudy? ili 11-circuit, (17) is a bit length-to-bin 1-column conversion circuit, and (18) is a digital-to-analog conversion circuit. Camellia No.

Claims (1)

[Claims] The digital signal is converted to a hacksaw pulse (No. 4) with a pulse width that changes in units of iIl "constant" Q for a fixed length for each predetermined number of bits, and a pulse component of a predetermined length is added. '' - converting means into a bit string with a constant recording wavelength for each bit string, and a pulse signal from the converting means.
1 series is added at regular intervals and recorded on the recording medium.
group 4 (-pulse adding means, II), the above group 1 at birth
a correction means for detecting the duty of the reproduced signal based on the 4i° pulse, and a pinot 1l for converting the output signal of the correction means into the above-mentioned digital signal.
B- A digital signal jS record relocation device comprising a Hiso I/column conversion means.