JPS58182168A - Driving controller for recording disk rotation - Google Patents

Abstract

PURPOSE:To facilitate control over the turn of a disk by detecting the width of a pulse width reproduced signal, generating a signal corresponding to the detected pulse in the, and comparing the signal with a reference signal. CONSTITUTION:An FFM reproduced signal is converted by a waveform shaping circuit 1 into a rectangular wave, which is supplied to the clear input of a counter 15 and also inverted by an inverter 7 to be supplied to the clear input of another counter 16. Both counters 15 and 16 count the clock inputs when the clear inputs are at a high level, and their counted contents are compared with each other by a comparator 17 synchronously with a comparison timing pulse, and the greater counted contents is latched in a latch circuit 18. Then, its latched output and the reference digital signal is compared digitally by a comparator 19 and their difference is converted by a D/A converter 20 into an analog value, which is used as a disk driving signal.

Description

[Detailed Description of the Invention] In particular, F FM (Eight to Four
The present invention relates to a synchronous drive control device for a recording disc recorded using a modulation method.

Various modulation methods have been proposed and put to practical use in order to record digital signals on a recording medium at a high density. As a modulation method that minimizes the maximum inversion interval (the maximum interval at which a 1-inclusive waveform inverts) to make it as good as possible (the minimum interval at which the waveform inverts) and to easily reproduce the bit clock pulse for demodulation during playback. 3PM (Three position)
ionModulation). Although the 7J method has the above-mentioned advantages, it has the drawback of including a large number of direct current components, so the EFM method has been proposed to improve this problem. This simply converts the digital information signal into groups of 8 bits and converts each group into a 14-bit signal according to a predetermined conversion table.
A 14-bit conversion is performed.

14 bits 1 ~ The combination state of the bit string after conversion is u I
There must be 2 or more 0'' between 11 and 1'' and 0
It is stipulated that 12 or more (maximum 11) "" cannot be consecutive.

Regarding recording disks for digital audio, the EFM signal is determined to have a level inversion interval between three times the reference clock period (pitch pulse period) T (3T) and 111 fB. In addition, repeating patterns of low level and high level each having a frame frequency of 7.35 KHz and an interval of 11T are always inserted. A method as shown in FIG. 1 is used to control the rotation of the recording disk when reproducing such EFM numbers.

In other words, the waveform shaping circuit 1 converts the FM playback pulse from the pick-up amplifier into a rectangular wave, and the PLL circuit 2 extracts and reproduces the FM clock pulse, which is combined with the reference clock signal. to the phase comparator 3. [Compare the phases.

Drive this comparison output? The amplified signal is amplified by the amplifier 4 and the disk daughter 5 is controlled to compensate for the time axis of the reproduced signal while reducing jitter.

In such a control system, if the P L, L circuit 2 causes a high frequency lock, it will be impossible to control the desired rotation speed, and the pH-
This is undesirable because it has drawbacks such as the impossibility of controlling the rotation speed outside the 1-1 range of the circuit, and runaway rotation once the P L and L circuits are unlocked.

Accordingly, an object of the present invention is to provide a recording disk rotation drive control device that enables a recording disk rotation drive and II control device that enables rotation control of a disk in a cylinder without using a PL1 circuit. .

The recording disk rotation drive control device according to the present invention has a pulse having a constant pulse width (11T>) at a constant period (1/7350 se).
For example, EF as recorded with the information signal with c)
This is a control device for rotational drive of a recording disk for an M signal, and its characteristics are that it detects the pulse width of the relevant pulse in the +l+/I signal, generates a signal corresponding to this pulse width, and The purpose of the present invention is to compare the signal and the signal 'I' 4g n and drive the recording disk to rotate in accordance with the signal difference.

The present invention will be explained below using the drawings.

FIG. 2 is a circuit diagram of an embodiment of the present invention, in which the EFM reproduction signal, which is a binary level modulation signal, becomes a rectangular wave a by waveform shaping 1 and is input to an integrating circuit 6, and then passes through an inverter 7. It becomes an input to another integrating circuit 8. The first integrating circuit 6 includes complementary transistors Q+, Q
2, resistors R1-R5, and a capacitor C1; Q4 and resistance R6~
It consists of R10 and further C2. The outputs C and d of the integrating capacitors C1 and C2 are connected to a common amplifier It through unidirectional diodes D+ and D2, respectively.
It is applied to C3 and the peak is held. There is a reset transistor Q! l
is connected, and a reset pulse hs is applied to the base of A via a resistor Ru.

The peak hold output e by the 1-in-1 C3 is 1 to
The signal is input to a sample hold circuit 9 consisting of a transistor Q and a transistor Q, and is limbed in the presence of a sample pulse 0, and its level is held. ′
''Hold output by C4 is buffered by amplifier 1, amplifier 12, resistor R+2 . The signal is applied to a level comparator 10 consisting of R+3, and is compared in level with a reference level F1.

The disk drive motor 5 is controlled by this comparison output.

Figure 3 (a) to mountain) 1.1 Signals a of each part of the circuit in Figure 2
The waveforms of ~h are shown correspondingly, and the waveforms of I
This fl-M signal is shown as in (a). Nasuwara, E
Set the pulse width equal to the maximum transition interval 111 of FM Goshi to 0.
The two pulses of low and high level are 1/7:)50
The data is recorded with a period of Sec, and is reproduced while containing jitter components. Note that this jitter component is not particularly shown in FIG. - Since transistor Q1 is turned on, its peak output waveform is as shown in the same figure (C
). That is, a signal waveform having a substantially constant slope is obtained during the low level period of waveform a, and the terminal level of each signal corresponds to the low level signal period.

-The inverted output from the h1 inverter 7 is the second integrator circuit 8.
When input to , the same figure (Ichi no Gotoku re(
A signal waveform having a substantially constant slope is obtained during the high level period of the F waveform a. The terminal level of each signal 4.1>a corresponds to the level signal period. Each integrating circuit6.
The peak value of the output level of 8 is stored in the -] node C3 as shown in Figure (e). If the sample pulse signal with a period of approximately 1/7350 sec is used, the time width signal of the reproduced wave corresponding to 111 degrees is obtained as shown in Figure (1) when the sample pulse rate is 1/1. [・shi, maximum transition interval of the next 101 signal periods (11[)
There are ways to detect this.

This detection output r is compared with a reference level 1u1 by a comparator 10, and this level F1 is the normal maximum ii! It can be seen that if the distance corresponding to the shift distance 111 is selected, accurate disk rotation control becomes possible. Note that the peak hold capacitor C3 needs to be larger than the capacitance of the sample hold capacitor C4. This is because it is necessary to prevent the charged acid of capacitor C4 from affecting capacitor C3.

In this example, one signal of the endogenous waveform is used to rotate the disk, but it is clear that C is also possible using only one signal. In this case, especially when the disk stops, the EFM signal is not input, so the integrator does not operate and the state is the same as high speed rotation. To prevent this situation, the FFM signal is input for a certain period of time. When there is no input, a pseudo signal may be generated as shown in FIG.

In other words, MMV (monos 1-
- A blue maru 1 pie radar) 13 is provided, and the output of this MMV controls an AMV (astable mar di vibrator) 14 with a strobe, and when the reproduced signal disappears, the AMVI 4 free-runs to oscillate and the integrating circuit 8 is operated to emit a predetermined integral output. Other configuration numbers 1 are equivalent to those in FIG. 2.

Figure 5 No. 1 is a circuit diagram of another embodiment of the present invention, 1''
This is an example of digital signal processing.

The FFM angle (1 signal is converted into a rectangular wave by the waveform shaping circuit 1, and when it becomes the clear input of the counter 15, it is inverted by the sympathetic J inverter 7 and becomes the clear input of the other counter 16. Both counters 15 and 16 are cleared. The clock input is counted when both of the two human forces are at a high level, and the contents of these counts are compared in the comparator 17 in synchronization with the comparison timing pulse, The 81 number contents of h are wrapped into flop circuit 1B.

These Rd output/J and MtF's 7'digital signals'P are digitally compared in the comparator 19, and the difference between them is r) // A 11 Inverter 20&G
There is a signal C that is converted into a disc drive signal.

Now, if the pulse shown in FIG. 3 (9> and the third output as the latch pulse) is used as the comparison timing pulse, the latch circuit 18 has a pulse length of 11 teeth width every 1/735 Osec. The 81 number content corresponding to
"Set the digital signal corresponding to the width of the first and second
As in the example shown in the figure, accurate disk rotation control is possible.

It should be noted that the circuits of the embodiments described in V are not limited to these, and various modifications can be made within the scope of the technical idea of the present invention.

As described above, according to the present invention, since the P[[1 circuit is not used, all of the above-mentioned drawbacks of the conventional PE1 circuit are overcome.
It is possible to perform a stable 7'' disk rotation servo with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional recording disk rotation drive control device, and FIG. 2 is a circuit diagram of an embodiment of the present invention. FIG. 3 is a waveform diagram showing the operation of each part of the circuit of FIG. 2, and FIGS. 4 and 5 are ten-step diagrams of other embodiments of the present invention. 1 Explanation of symbols for essential parts 6.8...Integrator circuit 9...Sample bold circuit 10...Comparator applicant PI Ania Co., Ltd. agent Patent attorney TL Muramotohiko

Claims (4)

[Claims] (1) A synchronous drive control device for a recording disk in which pulses with a constant pulse width are recorded with an information signal at a constant cycle, which detects the pulse width of the pulse in the reproduced signal and adjusts the pulse width to this pulse width. An apparatus characterized in that it has a signal generating means for generating a corresponding signal, and a control means for comparing the signal with a reference signal and controlling the rotation υ of the recording disk according to the difference between the two signals. . (2) The apparatus according to claim 1, wherein the pulse width is equal to the maximum transition interval of levels Jj of a binary bell modulated signal. (3) The signal generating means includes means for generating at least a signal having a substantially constant slope in response to the presence of the pulse;
3. The apparatus according to claim 1, wherein said control means includes means for comparing a terminal level of said constant slope signal with a definitive reference level. (4) The signal generating means detects the maximum transition l1l of the waveform.
Claim 1, characterized in that it has a counting means for counting M number of clock pulses of fi, and the stage IIIf has a means for comparing the contents of the counting means with a reference spear. The device according to paragraph 2 or paragraph 2.