JP2002150762A - Disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the emission of strobolight which is synchronized to disk rotation and is applied on a level surface so as to visualize letters, etc., on the level surface even during the disk rotation in a disk device in which a conventional disk rotating motor is used. SOLUTION: An address detection circuit 8 detects absolute time information from a disk 2. A microcomputer 9 calculates the number of disk revolution from the detected absolute time information and generates a pulse light of the strobolight 3. A pulse signal outputted from the microcomputer 9 is inputted into a light driving circuit 10 and controls the light of the strobolight 3. The light of the strobolight which is applied on the level surface of the disk is reflected and is emitted to the outside through a filter of a cover 4 and, thereby, the state of slow rotation to such an extent that letters and pictures, etc., which are drawn on the level surface can be visualized can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device capable of recognizing characters and pictures displayed on a label surface of a disk even when the disk is rotated, and more particularly to an optical disk device such as a CD on which music data and the like are recorded. Things.

[0002]

2. Description of the Related Art CDs on which music data is recorded have become widespread, and various types of CD players, such as portable portable players, exist as devices for reproducing such CDs. In some of such CD players, a transparent portion is provided on a cover for covering the upper surface of the disc so that the mounted disc can be visually recognized from the outside. The user mounts the disc from the transparent portion. In addition to being able to confirm that the CD is the album of which artist and which song, by reading the characters and pictures displayed on the label surface of the disc, it is possible to recognize the song. . Further, the label surface may be provided with an illustration or the like that can be visually enjoyed, and such an illustration can be enjoyed without removing the disc from the apparatus.

[0003] However, characters and the like drawn on the label surface are visible when the disk is not rotating and not played back, but are not visible during playback because the disk rotates at high speed. . In order to avoid such inconveniences, a light illuminating the upper surface of the disk is provided so that characters and the like drawn on the label surface can be visually recognized even during disk reproduction, and the light emission of the light is synchronized with the rotation of the disk. Japanese Patent Laid-Open No. 6-34255 discloses a technique in which characters are visually stationary.
No.2, Shokai 63-191499, Heikai 2-8419
0).

[0004] However, the technique disclosed in the above-mentioned documents is intended to detect a signal synchronized with the rotation of the disk.
The spindle motor is provided with rotation detecting teeth for detecting the number of rotations, a photodiode or a reed switch is provided, or a magnet is provided on the back surface of the turntable to detect rotation by a Hall element. However,
Providing the spindle motor with the rotation detecting teeth, the photodiode, and the reed switch requires a special motor provided with such components, and a general-purpose motor cannot be used, which leads to an increase in cost. Also, if a magnet is provided on the turntable and a Hall element is provided at a position opposite to the magnet, the number of parts will increase accordingly, and the number of steps for mounting such parts will increase, leading to an increase in cost. Becomes

[0005]

As described above, a general-purpose motor cannot be used to obtain a signal synchronized with the disk rotation so that characters on the label surface can be visually recognized while the disk is rotating. There are problems such as an increase in points and man-hours, and a resulting increase in cost. Therefore, an object of the present invention is to solve such a problem.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a disk apparatus for reproducing information recorded on a disk by rotating a disk placed on a turntable, based on a reproduction position on the disk. Rotation control means for controlling the rotation, light-emitting means for irradiating light on the upper surface of the loaded disc, address detection means for detecting an address recorded on the disc, and detection of the rotation cycle of the disc from the detected address And a light emission control means for controlling light emission of the light emitting means based on the rotation cycle detected by the rotation cycle detection means. The address detection means detects the current reproduction position on the disk by reading the address, and the rotation cycle detection means detects the rotation cycle of the disk at the current reproduction position, and substantially detects the rotation of the disk based on the detection signal. The light emission of the synchronized light emitting means is controlled. Therefore, there is no need to use a special motor equipped with rotation detecting teeth, photodiodes, reed switches, etc., and use a general-purpose motor to strobe light or the like so that characters and the like on the label surface can be visually recognized during disk rotation. The light emission of the light emitting means can be controlled, and the number of parts and man-hours can be reduced, thereby reducing the cost.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a CD player to which the present invention is applied. Above the disk 2 mounted on the turntable 1, a strobe light 3 is provided so as to irradiate the label surface of the disk with strobe light according to the disk rotation cycle. Further above, a cover 4 is provided so as to cover the disk. The portion of the cover facing the upper surface of the disk is formed by a filter. Such a filter has such characteristics that it is difficult to transmit light from the outside of the cover to the inside, and easily transmits light to the outside from the inside of the cover. Therefore, almost only the strobe reflected light reflected from the label surface of the disk is transmitted through the filter, so that characters and the like drawn on the label surface can be easily recognized from the outside during disk reproduction.

At a position facing the recording surface of the disk 2, there is provided an optical pickup 6 for irradiating the disk recording surface with laser light to reproduce recorded information. A motor 5 for rotating the disk 2 is connected to the turntable 1. Here, the motor 5 is a general-purpose motor without a special mechanism for detecting rotation, and is controlled so that the disk is rotated at a constant linear speed based on a synchronization signal reproduced from the disk. . Optical pickup 6
Move in the radial direction of the disk so as to follow the track when reproducing the disk.

Next, the operation at the time of reproducing a disc will be described. Information recorded on the disk 2 is transmitted to an optical pickup 6
And the reproduced signal is input to the RF amplifier 7. In the RF amplifier 7, the signal reproduced by the pickup 6 is subjected to IV conversion, and an RF signal and a focus / tracking error signal (not shown) are passed through an arithmetic circuit.
Respectively. RF output from RF amplifier 6
The signal is input to the address detection circuit 8, and the absolute time information (address) is obtained by reading the subcode.
The RF signal output from the RF amplifier is subjected to signal processing such as EFM demodulation and CIRC decoding, and is reproduced as an audio signal (not shown).

The absolute time information detected by the address detection circuit 8 is input to the microcomputer 9. The microcomputer 9 calculates the current rotational speed of the disk from the absolute time information. When the rotation speed of the disk is calculated, the microcomputer 9 outputs a pulse signal (one pulse per rotation) according to the rotation speed. The pulse signal output from the microcomputer 9 is input to the light drive circuit 10 and the strobe light 3
Is turned on and off once per disk rotation. The strobe light irradiated on the disc label surface is reflected and emitted to the outside through the filter of the cover 4. As described above, the filter is designed to easily transmit light from the inside to the outside, so that only the reflected light from the disc label surface of the strobe light according to the disc rotation cycle is emitted from the cover. As a result, characters and pictures drawn on the label surface can be rotated slowly enough to be visually recognized.

FIG. 2 is a flowchart showing a process of calculating the rotation speed from the absolute time information in the microcomputer 9 and generating a strobe light lighting pulse.
The absolute time information detected by the address detection circuit 8 is read in the microcomputer (S1), and the length of the track (scanning distance) from the inner circumference of the disk is calculated based on the read absolute time information and the linear velocity. (S2). Next, the product of the scanning distance and the track pitch is obtained. Since this is equivalent to the area of a circle having the current scanning position of the pickup as a radius, the radial distance of the current scanning position of the pickup is calculated from this. Is performed (S3). After the radial distance is calculated, the rotational speed of the disk at the current scanning position is obtained based on the calculated distance and the linear velocity (S4).
Then, a lighting pulse for emitting the strobe light is generated based on the determined disk rotation speed (S5).

In the above embodiment, the rotation speed of the disk is always calculated from the read absolute time information, and the lighting of the strobe light is controlled based on the calculation result. Since the cycle of the lighting time changes only by about 0.5 msec with respect to the movement of, it is not efficient to always perform the calculation in consideration of the load on the microcomputer.

Therefore, instead of always calculating the number of rotations of the disk from the read absolute time information, the absolute time information detected by the address detection circuit is extracted at intervals such that the rotation speed does not greatly change. The current disk rotation speed is calculated from the absolute time information obtained, a pulse signal corresponding to the rotation speed is output, and the output of the pulse signal is output until the rotation speed is calculated based on the absolute time information to be extracted next. It may be maintained.

FIG. 3 shows another embodiment. 1 in that it has a ROM 31 connected to the microcomputer 29. In the above-described embodiment, the calculation is performed each time to calculate the disk rotation speed in the microcomputer from the absolute time information detected from the disk. However, this is tabulated here and stored in the ROM 31. . Since the microcomputer 29 can obtain the corresponding disk rotation speed from the read absolute time information simply by referring to the table in the ROM 31, there is no need to perform an operation for calculating the rotation speed, and the load on the microcomputer is reduced. Is done.
Further, a table of the pulse period for the absolute time information may be used.

FIG. 4 shows a microcomputer 49 provided with a delay processing means 51 for delaying a pulse signal generated by referring to a calculation or a table for a predetermined time.
The operator can set a predetermined delay amount from the operation unit 52, and according to the set delay amount, the delay processing unit 5
1 delays the pulse signal for lighting the strobe light. By continuously changing the delay amount by the operation unit 52, it is possible to change the rotation speed of characters and the like on the label surface and display the rotation. Therefore, by changing the amount of the change, it becomes possible to completely stop the characters on the label surface or change the rotation speed and the rotation direction. Can be performed.

[0016]

As described above, according to the first aspect of the present invention, the rotation control means for controlling the rotation of the disk based on the reproduction position on the disk, and the light emitting means for irradiating the upper surface of the mounted disk with light. Address detection means for detecting an address recorded on the disk, rotation cycle detection means for detecting a disk rotation cycle from the detected address,
Light emission control means for controlling light emission of the light emission means based on the rotation cycle detected by the rotation cycle detection means.

As described above, the address recorded on the disk is read, the current rotation period of the disk is obtained based on the read address, and a light emission control signal substantially synchronized with the current rotation period is supplied. There is no need to use a special motor with teeth, photodiodes, reed switches, etc., and a light emitting means such as a strobe light can be used with a general-purpose motor so that characters and the like on the label surface can be visually recognized during disk rotation. Light emission can be controlled, and the number of parts and man-hours can be reduced, thereby reducing costs.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a CD player according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation in the microcomputer.

FIG. 3 is a diagram illustrating a configuration of a CD player according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a CD player according to a third embodiment of the present invention.

[Explanation of symbols]

 2,22,42 Optical disk 3,23,43 Strobe light 4,24,44 Cover 6,26,46 Pickup 8,28,48 Address detection circuit 9,29,49 Microcomputer 10,30,50 Write drive circuit

Claims (1)

[Claims] 1. A disk drive for rotating a disk placed on a turntable to reproduce information recorded on the disk, wherein a rotation control for controlling the rotation of the disk based on a reproduction position on the disk. Means, light emitting means for irradiating the upper surface of the disc with light, address detection means for detecting an address recorded on the disc, and rotation cycle detection means for detecting a rotation cycle of the disc from the address And a light emission control means for controlling light emission of the light emission means based on the rotation cycle detected by the rotation cycle detection means.