JPH0782701B2 - Motor control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention records information on a disc-shaped recording medium (hereinafter referred to as a disc) used in a video disc and the like, and records information on the disc. The present invention relates to a motor control device mainly used for a recording / reproducing device for reading out.

2. Description of the Related Art FIG. 4 is a block diagram of a conventional example of a motor control device used in a system for recording information on a disc.

In FIG. 4, reference numeral 7 denotes a rotation speed detection circuit, which is composed of a speed generator and an operational amplifier (not shown), and outputs a signal having a frequency proportional to the rotation speed of the motor 10. Reference numeral 29 is a reference signal generating circuit, which is composed of a crystal oscillator or the like (not shown), and outputs a frequency serving as a reference of the rotation speed of the motor 10. Reference numeral 8 denotes a rotation phase detection circuit, which is composed of a light emitting diode and a light receiving element, detects a synchronization mark provided on a disk 9 attached to the motor 10, and outputs a pulsed signal. Reference numeral 30 is a synchronization signal input from the outside. The output of the rotation speed detection circuit 7 and the output of the reference signal generation circuit 29 are compared by the rotation speed error detection circuit 27, and the rotation speed error is detected. The output of the rotation phase detection circuit 8 and the external synchronization signal a from the external synchronization signal input terminal (hereinafter referred to as terminal) 30 are compared by the rotation phase error detection circuit 28 to detect the rotation phase error. The output of the rotation phase error detection circuit 28 and the output of the rotation speed error detection circuit 27 are added and input to the signal amplification circuit 14.
The output of the signal amplifier circuit is output to the motor drive circuit 15 to drive the motor 10.

As described above, in the conventional example, two types of standards are used in one motor control device. Therefore, in order to drive the motor 10 in synchronization with the external synchronizing signal a, a certain condition between the rotation speed of the motor 10 determined by the crystal oscillator of the reference signal generating circuit 29 and the frequency of the external synchronizing signal a is established. Had to set.

Problems to be Solved by the Invention In such a conventional configuration, the type of the external synchronization signal a,
There is a problem that the function of the recording / reproducing system is limited to a narrow range because the type of signal source that outputs the external synchronization signal a is limited.

The present invention has been made in view of the above problems, and an object of the present invention is to configure a motor control device that can synchronize the rotation of a motor with a synchronization signal having a relatively wide frequency range.

Means for Solving the Problems In order to solve the above problems, the present invention relates to a system for controlling a rotation speed of a motor, wherein a reference of the rotation speed of the motor is a synchronization signal input from the outside or a synchronization generated internally. The signal is created by multiplying the signal by an integer or by multiplying it by an integer.

With the above-described structure, the present invention makes the rotation of the motor responsive to the synchronizing signal of a wider frequency range than the conventional one in order to make the reference of the system for controlling the rotation speed of the motor and that of the system for controlling the rotation phase of the motor the same. This facilitates synchronization, and a system for recording / reproducing signals having a wider frequency range than in the past can be easily configured.

Embodiment FIG. 1 is a block diagram showing an embodiment of a motor control device of the present invention. In FIG. 1, 1 is a phase comparison circuit, 2
Is an integrator circuit, 3 is a voltage controlled oscillator (VCO), and 4 is a frequency divider circuit. As described above, a frequency multiplication circuit using a PLL 17
Are configured. Note that the same numbers are given to the same components in FIGS. 1 and 4. Reference numeral 7 denotes a rotation speed detection circuit, which is composed of a frequency generator (hereinafter abbreviated as FG) and an operational amplifier (not shown) and outputs a signal having a frequency proportional to the rotation speed of the motor 10. 8 is a rotation phase detection circuit,
It is composed of a light emitting diode and a light receiving element (not shown), and detects a sync mark provided on the motor 10 or the disk 9 attached to the motor 10, and outputs a pulsed signal f. Reference numeral 16 is an input terminal for an external composite sync signal b of the NTSC system which is input from the outside. This external composite sync signal b
Is separated into a horizontal synchronizing signal c and a vertical synchronizing signal d by a synchronizing signal separating circuit 11. The separated horizontal synchronizing signal c is input to the frequency multiplication circuit 17. In the frequency multiplication circuit 17, the frequency of the horizontal synchronizing signal c is multiplied by N, and the counter circuit 5
Is output to.

The frequency of the horizontal sync signal c is _HD . Further, the number of revolutions of the motor 10 per second is R. The frequency of the output signal of the rotation speed detection circuit 7 is: R · Z, where Z is a proportional constant (the number of FG pulses per rotation). From the above, the counter circuit 5 has a frequency = R.
The Z signal and the = _NHD signal are output.

The counter circuit 5 and the frequency difference detection circuit 6 constitute a speed error detection circuit 56. Next, the speed error detection circuit 56
The operation will be described with reference to FIG.

FIG. 2 (A) shows the output of the rotation speed detection circuit 7, T ₁ = 1 / R
・ Z. (C) is the output of the frequency multiplication circuit 17, and T ₃ =
1 / N _HD . (B) is a waveform created by counting the number of m cycles of the waveform of the output C from the rising edge e of the signal of FIG. 2 (A), and T ₂ = m / _HD · N. The frequency difference detection circuit 6 detects the frequency difference signal between the output A and the output B shown in FIG. 2 (D). In this frequency difference signal, when the number of circuits is lower than the set value and the cycle of T ₁ is longer, T ₁ -T ₂ is longer, and when the number of rotations is higher than the set value and the cycle of T ₁ is shorter.
T ₁ -T ₂ becomes short and a pulse signal proportional to the period of T ₁ is generated, converted into a voltage value inversely proportional to the rotation speed by using the low pass filter 18 shown in FIG. The signal is output to the signal amplification circuit 14.

Next, the phase system will be described. When the phase of the disk 9 shown in FIG. 1 is frame-locked to the external composite synchronizing signal b, the motor 10 has to make one revolution at a cycle of T ₄ = 525 / _HD .

Since T ₄ is equal to twice the cycle of the vertical synchronizing signal d, the phase error detecting circuit 12 outputs the vertical synchronizing signal d output from the synchronizing signal separating circuit 11 and the pulse-like signal output from the rotating phase detecting circuit 8. The phases of the signals are compared to detect the lead or lag of the rotation phase. The detected phase error signal g is converted into a voltage value and output to the signal amplification circuit 14. Using the above conditions as an expression, the relationship between the rotational speed R of the motor 10 and the horizontal synchronizing signal c is R = 1 / T ₄ = _HD / 525. Period T ₁ of the thus FIG. 2 (A) is the _{T 1 = 1 / R · Z} = 525 / HD · Z ...... (1). On the other hand, from the above, T ₂ = mT ₃ , so T ₂ = m / _HD
N.

When the rotational speed of the motor is converted into a voltage value from the phase error signal g using a low-pass filter or the like as described above, if the proportional constant is A, the speed voltage V _S is It is represented by. Therefore, by substituting the values of T ₁ and T _{2 into} the equation (2), It turns out that it has nothing to do with _HD . That is, even when the frequency of the external synchronization signal changes, the motor rotates in synchronization with the external synchronization signal.

Since this external synchronizing signal is an NTSC type external composite synchronizing signal in this embodiment, the above N, Z, and m can be specifically determined as follows. ^{N = 910, m = 2 13} , Z = 50, except Z is a constant determined by the FG attached to the motor.

In the above description, of the external composite synchronizing signal b, the horizontal synchronizing signal c is used as the reference of the motor rotation speed control system, and the vertical synchronizing signal d is used for the rotation phase control system. It is also possible to use the vertical synchronizing signal d as a reference for both the rotation phase control system and the rotation speed control system.

The frequency stability of the motor control device of this embodiment is further improved by setting the constant of the integrating circuit 2 shown in FIG. 1 to a value at which the jitter component contained in the external synchronizing signal is sufficiently removed.

FIG. 3 shows another embodiment in which the synchronizing signal changeover switch 24 and the internal synchronizing signal generating circuit 25 are provided. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 3, 23 is an external synchronizing signal output section for outputting the external synchronizing signals a ₁ and a ₂ , and 25 is an internal synchronizing signal generating circuit 25 for generating the synchronizing signal j. An external synchronization signal generation circuit 26 detects the presence or absence of the external synchronization signal a ₁ and outputs a detection signal k to the synchronization signal changeover switch 24. The sync signal changeover switch 24 switches between the external sync signal a ₂ and the internal sync signal j output from the internal sync signal generation circuit 25 based on the detection signal k, and outputs the switched signal l to the sync signal separation circuit 22.

In addition, 19 is a rotation speed error detection circuit, 20 is a frequency multiplication circuit,
Reference numeral 21 is a rotation phase error detection circuit.

With the above configuration, the motor 10 can rotate in synchronization with the internal synchronization signal even when the synchronization signal generation circuit is not provided outside. Further, by configuring the internal synchronization signal generation circuit 25 as a VCXO, it is possible to configure a motor control device with variable rotation speed even when no external synchronization signal generation circuit is provided.

EFFECTS OF THE INVENTION As described above, according to the present invention, the rotation of the motor can be easily synchronized with the synchronization signal of a wide range of frequencies input from the outside. Further, even if there is no external synchronization signal generator, the internal synchronization signal generation circuit allows the motor to rotate in synchronization with the internal synchronization signal, which is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a block diagram showing a motor control device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of essential parts of a speed error detection circuit according to an embodiment of the present invention, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a block diagram showing a motor control device provided with an internal synchronization signal generating circuit and a synchronization signal changeover switch in the example, and FIG. 4 is a block diagram showing a conventional motor control device. 7 ... Rotation speed detection circuit, 8 ... Rotation phase detection circuit, 9
...... Disk, 10 ...... Motor, 12 ...... Phase error detection circuit, 14 ...... Signal amplification circuit, 15 …… Driving circuit, 17 …… Frequency multiplication circuit, 19 …… Rotation speed error detection circuit, 20 …… Frequency Multiplier circuit, 21 ... Rotation phase error detection circuit, 22 ... Sync signal separation circuit, 24 ... Sync signal selector switch, 25 ... Internal sync signal generation circuit, 26 ... External sync signal detection circuit, 56
...... Speed error detection circuit.

Claims (4)

[Claims] 1. A rotation speed detecting means for outputting a signal of a frequency proportional to a rotation speed of a motor, a reference signal generating means for outputting a signal of a frequency serving as a reference of the rotation speed of the motor, and the rotation speed detecting means. Rotation speed error detection means for comparing the output of the reference signal generation means with the output of the reference signal generation means, and a rotation phase of the disk from a synchronization mark provided on the disk mounted on the motor. And a rotational phase error detecting means for comparing an external synchronizing signal serving as a reference of the rotational phase of the disk with an output signal of the rotational phase detecting means, and outputting a signal corresponding to the error. A signal amplification means for amplifying an addition signal obtained by adding the output of the rotation speed error detection means and the output of the rotation phase error detection means, and the output of the signal amplification means And a motor driving means for rotating the serial motor, motor controller, characterized in that said reference signal generating means constituting the frequency of the external synchronization signal frequency converting means for haploid integral multiple or an integer fraction. 2. An external synchronization signal detecting means for detecting the presence / absence of an external synchronization signal, an internal synchronization signal generating means, and a switch means for switching the output of the internal synchronization signal generating means and the external synchronization signal. 2. The motor control device according to claim 1, wherein when the absence of the external synchronizing signal is detected by the signal detecting means, the switch means switches to the internal synchronizing signal generating means. 3. The rotation phase detecting means detects the rotation phase of the disk by detecting a mark attached to a motor.
A motor control device according to the item. 4. The rotation speed error detecting means generates a measurement pulse by counting a fixed number of pulses of the output of the reference signal generating means in synchronism with any of the edges of the output of the rotation speed detecting means to generate the rotation speed. The motor control device according to claim 1, wherein a difference between the output of the detection means and the measurement pulse is detected.