JPH01300469A - Disk player - Google Patents

Abstract

PURPOSE:To execute the motor control corresponding to the various kinds of disks by changing an FG pulse to be impressed on a comparator circuit by a disk loaded in the player. CONSTITUTION:When the player is loaded with the disk D, the FG pulse (a pulse having a period corresponding to a spindle motor 1 in r.p.m.) corresponding to this disk D is supplied to the comparator circuit 16 by a switching means 10, so as to control the rotation of the spindle motor 1 to coincide with the period of a clock pulse. Now, the number of the FG pulses per revolution of the spindle motor 1 is different among others in plural kinds corresponding to a reproducible disk D, and when the period of each FG pulse coincides with the period of the clock pulse, the spindle motor 1 is settled in its r.p.m. so as to coincide with one of disks D in r.p.m. By this method, the disk D loaded by the switching means 10 is decided, and when its corresponding FG pulse is supplied to the comparator circuit 16, the revolution control can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a disc player, and in particular,
This invention relates to a disc player that can play several types of discs with different controlled rotational speeds.

B)) Prior Art In recent years, so-called compatible disc players that can play various discs such as video discs and compact discs have been developed. In this type of disc player, the number of revolutions varies depending on the disc to be played, so the spindle motor must be controlled appropriately for each disc.

One example of a spindle motor control device is one that focuses on the FG pulse of a spindle motor.

That is, a pulse (FG pulse) having a period corresponding to the rotation speed of the spindle motor is compared with a reference pulse having a predetermined period, and the rotation of the spindle motor is controlled so that the two match.

(c) Problems to be Solved by the Invention In a multi-disc player that plays multiple types of discs as described above, it is necessary to provide separate motor servo circuits because it is necessary to control each spindle motor accordingly. . However, providing separate motor servo circuits in this manner increases the cost of the player and also poses many technical problems. Therefore, the present invention is capable of controlling the motors of various disks with a single motor servo circuit.
It is an object of the present invention to provide a disc player having a motor servo circuit of this type.

B) Means for Solving the Problems In view of the above problems, the present invention receives FG pulses of a spindle motor that rotationally drives a disk, and controls the rotation of the spindle motor so that the period of the FG pulses becomes a predetermined period. In a disk player that performs control, several types of different numbers of FGs are used for one rotation of the spindle motor.
A pulse generation circuit that outputs pulses, a clock pulse generation circuit that outputs pulses at a reference frequency, a comparison circuit that compares the frequency of the received pulse and the clock pulse, and a comparison circuit that determines the type of disc loaded in the player. , among several types of FG pulses output from the pulse generation circuit,
The configuration includes a switching circuit that selectively supplies a predetermined FG pulse to the comparison circuit.

(E) Operation When a disc is loaded in the player, the switching means supplies the FG pulse corresponding to the disc to the comparator circuit, and the spindle is set so that the period of this FG pulse and the period of the clock pulse match. The rotation of the motor is controlled. Here, the number of the FG pulses per one rotation of the spindle motor is different from one another depending on the disc that can be played by the player, and when the period of each FG pulse matches the period of the clock pulse, The number of revolutions is set to match the number of revolutions of one of the discs to be reproduced.

Therefore, if the switching means determines which disk is attached to the ship layer, and the corresponding FG pulse (based on this determination) is supplied to the comparator circuit, the comparator circuit will detect synchronization between the FG pulse and the reference pulse. Then, the rotational speed of the disk can be controlled well.

(f) Examples Hereinafter, examples of the present invention will be explained with reference to the drawings. In this embodiment, a motor control circuit in a disc player capable of playing compact discs and video discs will be described.

In FIG. 1, +11 is a spindle motor, and a turntable (2) is pivotally mounted on the spindle shaft. (
31 Press the disk 0 placed on the turntable (21) onto the turntable (2) using a clamp bar.

+41 +51 are the first and second sensors, which are placed on the predetermined circumference of the lower surface of the turntable (2) and have the first and second protrusions +6) (7+ surrounding surfaces facing each other and receiving the reflected light. Time,
Outputs an H level signal. Such a protrusion 161 (71 is formed of a light reflecting member), and this protrusion (61+71F
(9) Notches are formed at a predetermined pitch on the surface facing the two sensors (41+5). In other words, the first protrusion (6) has 60 notches at a constant pitch. Second
Forty notches are formed in the protrusion (7) at a constant pitch. Therefore, when the turntable (2) rotates once, 60 sensors are detected from the first sensor (4), and 60 sensors are detected from the second sensor (5).
40 pulses are output from. (81 (91 is the first and second sensor (41+51) that detects the rise of the output and outputs a pulse of a constant width.
The G pulse output circuit is selectively connected to the FG counter circle depending on the state of the switch circuit αα. Here, the switch circuit a-O+ is switched in state by the detection output of the LD/CD detection circuit (121), that is, the detection circuit U detects that the disc mounted on the turntable (2) is a laser disc. If it is detected that there is a compact disc, the first FG pulse output circuit (8) is connected to the F'G kakunta [111, while if it is detected that it is a compact disc, the second FG pulse output circuit (9) is connected to Connect the FG counter (1υ).

The method for detecting a disc by the LD/CD detection circuit (121) is, for example, by looking at the size of the disc mounted on the turntable (21) and detecting the size of the disc electrically, mechanically, or optically. There are methods such as detecting the

(131 is a clock counter, which receives and counts the clock from the oscillator ■ which outputs a reference clock of 1800 Hz. (151 is a timing generation circuit, which sends a control signal to the FG counter (111 and clock counter α&) every second. The FG counter (1υ) and the clock counter (131) are reset in response to the control signal, and simultaneously supply the count values immediately before reset to the comparator circuit σe, respectively.

Therefore, the count value of FG pulses counted by the comparator circuit (in 161, the old FG counter) is 1800 per second.
The size is compared based on the number of items. Specifically, comparison circuit α
The comparison in 6) shows that the count value of the FG counter circle is 1 above.
Is it within ±20% based on 800?
20% larger or -20% smaller.
This is commonly done, and when it is greater than +20%, a control signal is applied to the brake circuit 1n to brake the spindle motor il+, and when it is less than -20%, a control signal is applied to the accelerator circuit (il+) to brake the spindle motor il+. accelerate. On the other hand, F
When the count value of the G counter fill is within ±20% of the reference value of 1800, a control signal is applied from the comparison circuit ←6) to the second control circuit a9 to control the spindle motor (1). However, the first control focusing on the FG pulse is switched to the second control focusing on the reproduction signal from the disk.

Next, the operation of this embodiment configured as above will be explained. As mentioned above, this embodiment relates to a motor control circuit in a disc player capable of playing compact discs and video discs. Here, it is assumed that both the compact disc and the video disc are rotated at a constant linear velocity, and the rotation speed of the compact disc is 2700 to 1800 r, pm, and the rotation speed of the video disc is 1800 to 60 or. It is controlled so that it becomes p, m. Also, since information is recorded on each disc from its inner circumference, each disc has the fastest rotational speed during playback, i.e. 270 Or, p, m, and 1800 r.
, p, m.

Now, when a video disc is inserted into the player, this is determined by the LD/CD detection circuit uz,
A control signal is supplied to the switch circuit (101). In response, the switch circuit (101) connects the output of the first FG pulse output circuit (8) to the input of the FG counter 1ull. However, at this time, the turntable (2) is not driven, no pulse is output from the first FG pulse output circuit (8), and therefore the FG counter (il
The count value of l is zero, so the comparator circuit applies a control signal to the accelerator circuit 0&, causing the accelerator circuit (181 to apply a drive signal to the spindle motor 111).

In this manner, the spindle motor (1) is activated, and the rotation of the turntable (2) and disk 0 proceeds.

As the turntable (2) and disk 0 continue to rotate,
Accordingly, the count value of FG counter l111 increases,
The count value of the clock counter 1131 approaches 1800. Here, the count value of FG counter ttn is 180
When it reaches near 0, the first FG pulse output circuit (8) outputs 60 pulses per rotation of the turntable (2), so the turntable (2) outputs 18 pulses per second.
00+60-500 rotations, so turntable (2) is 60X60-1800 repam
This means that it is rotating at . Therefore, the FG counter (
The count value of 111 is the count value of clock counter U.
When the rotation speed is 800, the motor control at the time of disk startup is achieved, but in this embodiment, since the rotation speed of the disk changes from moment to moment, after that, the specific It is impossible to control the motor by pulling it down to a rotation speed of . Therefore, when the count value of the FG counter U falls within ±20% of the reference value of 1800, the second
I am trying to switch to control.

Such second control is performed by the second control circuit α9 as described above, and for example, it focuses on the synchronization signal among the signals reproduced from the disc, and controls the output cycle of the synchronization signal to be maintained at a predetermined cycle. Various types of control are possible, such as controlling the spindle motor (1).

Next, when a compact disc is inserted into the player, the discrimination is performed by the LD/CD detection circuit (121), and a discrimination signal indicating this is supplied to the switch circuit (101). In response to such a signal, the output of the second FG pulse output circuit (9) is connected to the input of the FG counter (111).Hereafter, as in the case of the video disc described above, the count value of the FG counter U is connected to the clock counter (131). The spindle motor is controlled by motor 1 until it reaches within ±20% of the count value, ie, 1800, and then switched to motor control by the second control circuit (19).

Note that here, the count value of the FG counter fil) is 1800.
Calculating the number of rotations of the turntable (2) when the turntable (2) reaches the vicinity, the second FG pulse output circuit (9) outputs 40 pulses for each rotation of the turntable (2), so it is 1800. ÷40ζ45[re I)-s]=2700
(r, p, m], therefore, it is close to 2 700 [r, p, m], which is the initial rotation speed of the compact disc.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment and can be modified in various ways. For example, in the above embodiment, the turntable (
2) The lower surface iC has a configuration in which two protrusions and a sensor are arranged, but instead of arranging the second protrusion (7) and the first sensor (5) on the lower surface of the turntable (2) as shown in FIG. A frequency dividing circuit (20) is arranged in the first FG pulse output circuit (20).
It is also possible to adopt a configuration in which the output from 8) is frequency-divided. In such a case, the configuration of the bottom surface of the turntable (2) can be simplified, and the FG can be changed by simply changing the division ratio of the frequency dividing circuit (201).
The number of pulses can be set freely, so that the FG pulses can be flexibly adapted to the type of disc loaded in the player. Furthermore, instead of providing a switch circuit, the division ratio of the frequency dividing circuit may be changed depending on the type of disk.

(g) Effects of the Invention As described above, according to the present invention, motor control can be performed in accordance with various discs by simply changing the FG pulse applied to the comparator circuit depending on the disc mounted in the player. Therefore, it is possible to simplify the circuit configuration and reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention, and FIG.
The figure is a circuit block diagram showing another embodiment. il+... spindle motor, 141f51... first and second sensor, +61171... first and second
Projection, 181f91...first and second FG pulse output circuit, (fil-...switch circuit, (17J...
- LD/CD detection circuit, (16)...comparison circuit,...branch circuit.

Claims (1)

[Claims] (1) FG of the spindle motor that rotates the disk
In a disk player that receives a pulse and controls the rotation of the spindle motor so that the cycle of the FG pulse becomes a predetermined cycle, one of the spindle motors
A pulse generation circuit that outputs several different numbers of FG pulses with respect to rotation, a clock pulse generation circuit that outputs pulses at a reference frequency, a comparison circuit that compares the frequency of the received pulse and the clock pulse, and a player. and a switching circuit that discriminates the type of disk mounted on the disc and selectively supplies a predetermined FG pulse to the comparator circuit from among several types of FG pulses output from the pulse generating circuit. disc player.