JPH07244858A - Data-recording/reproducing apparatus - Google Patents

Abstract

PURPOSE:To protect an objective lens from dusts and foreign articles when a pickup is at a home position and to quickly move the pickup from the home position to a start position where recording/reproducing of data is started. CONSTITUTION:A driving force-transmitting means such as pulleys 3, 6, a belt 7, etc., is interposed between a rotary driving shaft 5 of a motor 4 and a spindle shaft 2 of a turntable 1. A predetermined vacant space is secured at an opposite side to a surface of the turntable 1 where a recording medium is loaded. An objective lens 9 is arranged to face to the turntable 1 at a home position of a pickup 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording / reproducing information by emitting a light beam from an objective lens carried by a pickup onto a disc-shaped recording medium such as an optical disc. Concerning the dustproof measures of the objective lens.

[0002]

2. Description of the Related Art When an optical disc represented by a compact disc (so-called CD) is loaded in an information recording / reproducing apparatus, the inner circumference of the optical disc is placed on the turntable and clamped, and then the turntable is driven by a motor. It is rotatably driven to rotate integrally with the optical disc, and a light beam is emitted from a pickup, which is also called a carriage, toward a program area of the rotating optical disc so that information can be recorded and reproduced. An objective lens is carried on the optical path of the pickup in order to narrow this light beam to a minute spot on the optical disc, but this objective lens is exposed outside the pickup so as to face the loaded optical disc. Therefore, in order to maintain the reliability for a long period of time, some dustproof measure is required for the objective lens. That is,
In an information recording / reproducing device in which no special dustproof measures are taken for the objective lens of the pickup, dust inside the device easily falls onto the objective lens when the optical disc is not loaded, and it adheres to the optical disc. Since the foreign matter that has been used may fall onto the objective lens during loading, there is a high risk that dust or foreign matter will be accumulated on the objective lens and obstruct the transmission of the light beam after a long period of time. It will not be possible to record and play back correctly.

Therefore, as disclosed in Japanese Patent Laid-Open No. 3-207030, a dustproof cover capable of covering an objective lens of a pickup and a lever, a gear or the like for driving the dustproof cover in conjunction with the pickup are conventionally provided. An information recording / reproducing device provided with a cover drive mechanism so that the objective lens is covered with the dust-proof cover when the pickup is located at the home position, which is also the standby position when the device is stopped, at the outer peripheral end of its movement range. A device has been proposed.

[0004]

By the way, in the above-mentioned conventional proposal, in order to avoid contact with the loaded optical disc, the space for installation of the dustproof cover and the cover drive mechanism should be equal to or more than the radius of the optical disc from the rotation center of the turntable. Although a remote place is selected, in order to cover the objective lens with the dustproof cover, the home position of the pickup must also be set on the outer peripheral side of the loaded optical disc. However, when the recording operation or the reproducing operation is started, the pickup is set in a predetermined position near the turntable in advance so that the objective lens faces the innermost peripheral portion of the program area of the optical disc (for example, the lead-in track of the CD). Since it is necessary to move to the recording / reproducing operation start position), if the home position of the pickup is set on the outer peripheral side of the optical disc, the movement distance of the pickup from the home position to the recording / reproducing operation start position becomes large, Therefore, there is a problem that the time required from the command of the start of the recording / reproducing operation to the actual start of the operation becomes long and the responsiveness deteriorates.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to protect an objective lens of a pickup from dust and foreign matters, and to perform a recording / reproducing operation of the pickup from a home position. An object of the present invention is to provide an information recording / reproducing device that can be quickly moved to a start position.

[0006]

In order to achieve the above-mentioned object, the present invention provides a turntable on which an inner peripheral portion of a disk-shaped recording medium such as an optical disk is mounted and which is integrally rotated. A motor for rotating the turntable and a pickup having an objective lens and movable in the seek direction are provided, and a light beam is emitted from the objective lens toward the program area of the rotating disk-shaped recording medium. In an information recording / reproducing apparatus for recording / reproducing information by rotating the rotary drive shaft directly connected to the motor, the axis of the rotary drive shaft is horizontally displaced from the center of rotation of the turntable, and between the rotary drive shaft and the turntable. A driving force transmitting means is provided between the objective lens and the turntable so that the objective lens faces the turntable at the inner peripheral edge of the moving range of the pickup.

Further, in order to achieve the above-mentioned object, while adopting a usual structure in which a rotary drive shaft directly connected to the motor is used as a spindle shaft of the turntable, a distance between the turntable and the motor is increased. The width may be set so that the pickup can be inserted, and the objective lens may be set to face the turntable at the inner peripheral end of the moving range of the pickup.

[0008]

As described above, the motor, which normally has its rotation center aligned with that of the turntable, can be horizontally displaced,
If the distance between the turntable and the motor is widened, it is possible to secure a vacant space of a predetermined size in which the pickup can be inserted on the side opposite to the recording medium mounting surface side of the turntable, and the objective lens is placed in this vacant space. If the housed state is the pickup's home position, then the turntable facing the objective lens at a close range functions as a dustproof member to cover the lens, and from this home position to the recording / reproducing operation start position. The moving distance of the pickup becomes extremely short.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a main portion of a CD player according to an embodiment of the present invention, and FIG. 2 is a plan view of the portion shown in FIG.

In these figures, reference numeral 1 is a C (not shown).
A turntable for mounting the inner peripheral portion of D and rotating integrally, 2 is a spindle shaft of this turntable 1, 3
Is a first pulley fixed around the spindle shaft 2, 4 is a motor for rotationally driving the turntable 1, 5 is a rotary drive shaft directly connected to the motor 4, 6
Is a second pulley fixed around the rotary drive shaft 5, 7 is a drive belt wound around the first and second pulleys 3 and 6, and 8 is driven by a motor (not shown). A pickup capable of reciprocating along the direction of arrow A, an objective lens 9 carried by the pickup 8 and exposed to the outside, and a guide rail 10 for guiding the reciprocating movement of the pickup 8.

That is, this CD player has a motor 4
Of the rotary drive shaft 5 is displaced in the horizontal direction (lateral direction) from the center of rotation of the turntable 1 (the shaft center of the spindle shaft 2), and the drive force of the rotary drive shaft 5 causes the first and second pulleys to move. It is adapted to be transmitted to the spindle shaft 2 via 3, 6 and the drive belt 7, and by shifting the motor 4 in the horizontal direction in this way, on the side opposite to the CD mounting surface side of the turntable 1, An empty space of a predetermined size in which the pickup 8 can be inserted is secured. The home position of the pickup 8 is a state in which a part of the pickup 8 including the objective lens 9 is inserted into this empty space, where the objective lens 9 is the turntable 1.
And are facing each other at close range. That is, FIG.
As shown in FIG. 5, the radius of the turntable 1 is R1, the distance between the objective lens 9 and the rotation center of the turntable 1 when the pickup 8 is at the home position is r, and the diameter of the exposed portion of the objective lens 9 is d. Then, the value of r + d is set to be smaller than R1. Further, at the start of the reproducing operation, it is necessary to move the pickup 8 from the home position to a predetermined reproducing operation starting position so that the objective lens 9 faces the lead-in track of the innermost peripheral portion of the program area of the loaded CD. However, since this lead-in track is irradiated with the light beam from the objective lens 9 just outside the turntable 1, if the distance from the center of rotation of the CD to the lead-in track is R2, then R2>R1> r + d. The relational expression holds.

Next, the operation of the CD player thus constructed will be briefly described.

When a CD (not shown) is loaded into the CD player, the inner circumference of the CD is placed and clamped on the turntable 1, and then the turntable 1 is
Since it is rotationally driven by the motor 4 via the rotary drive shaft 5, the pulleys 3, 6, the drive belt 7, the spindle shaft 2, etc.,
The CD rotates integrally with the turntable 1, while the pickup 8 waiting at the home position moves to the reproducing operation start position so that the objective lens 9 faces the lead-in track of the CD. The pickup 8 irradiates the program area of the rotating CD through the objective lens 9 while moving in the seek direction from the reproduction operation start position to the minute spot, and records from the change in the reflected light. The signal can be read. It should be noted that the lead-in track of a CD usually has a control code indicating a music number, a playing time and the like recorded therein.

As described above, in this embodiment, the driving motor 4 is horizontally displaced with respect to the turntable 1, and driving force transmitting means such as the pulleys 3 and 6 and the driving belt 7 are provided between the both 1 and 4. By interposing, an empty space that can be used as a home position for the pickup 8 is secured on the side opposite to the CD mounting surface side of the turntable 1,
There, since the turntable 1 facing the objective lens 9 at a close distance functions as a dustproof member for covering the lens 9, there is no need to separately provide a dustproof member or a drive mechanism therefor, and the objective lens 9 has a simple structure. Can be protected from dust and foreign matter. Moreover, when the home position of the pickup 8 is set in the vicinity of the turntable 1 as in the present embodiment, the moving distance of the pickup 8 from this home position to the reproduction operation start position is extremely short, so that the reproduction operation is started. The time required from when the command is issued to when the operation is actually started can be greatly reduced.

FIG. 3 is a side view of the essential parts of a CD player according to another embodiment of the present invention, in which parts corresponding to those in FIGS.

That is, in this embodiment, while adopting a usual structure in which the rotary drive shaft 5 directly connected to the motor 4 is used as the spindle shaft 2 of the turntable 1, the length of the shaft 5 (2) is slightly lengthened. By doing so, the space between the turntable 1 and the motor 4 is made wide enough to allow the pickup 8 to be inserted, and therefore, as in the above-described embodiment, an empty space on the side opposite to the CD mounting surface side of the turntable 1 is provided. Can be used as the home position of the pickup 8, and the objective lens 9 is covered by the turntable 1 at this home position.

In each of the above-mentioned embodiments, a CD player has been described, but other information recording / reproducing apparatus for optically recording / reproducing information using a disc-shaped recording medium other than a CD may be used. Needless to say, the present invention is applicable.

[0019]

As described above, according to the present invention, the pickup can be inserted on the side opposite to the recording medium mounting surface side of the turntable by shifting the motor in the horizontal direction and slightly lengthening the rotary drive shaft. Since the home position of the pickup is a state in which an empty space of a predetermined size is secured and the objective lens is housed in this empty space, the turntable facing the objective lens at a close range at this home position. Can be made to function as a dustproof member for covering the lens, so that the objective lens can be protected from dust and foreign matter with a simple structure and reliability is enhanced, and the loaded disc shape The home position of the pickup is set on the inner circumference side of the recording medium. And can be moved quickly to the recording reproduction operation start position an excellent effect that the response is enhanced.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a CD player according to an embodiment of the present invention.

FIG. 2 is a plan view of a portion shown in FIG.

FIG. 3 is a side view of essential parts of a CD player according to another embodiment of the present invention.

[Explanation of symbols]

 1 Turntable 2 Spindle shaft 3,6 Pulley 4 Motor 5 Rotation drive shaft 7 Drive belt 8 Pickup 9 Objective lens

Claims (2)

[Claims] 1. A turntable for mounting an inner peripheral portion of a disk-shaped recording medium to rotate integrally, a motor for rotationally driving the turntable, and an objective lens in a seek direction. Equipped with a movable pickup,
In an information recording / reproducing apparatus that emits a light beam from the objective lens toward a program area of a rotating disc-shaped recording medium to record and / or reproduce information, the axis of a rotary drive shaft directly connected to the motor Is horizontally displaced from the rotation center of the turntable, and driving force transmitting means is interposed between the rotation drive shaft and the turntable, and the objective lens is turned at the inner peripheral end of the moving range of the pickup. An information recording / reproducing apparatus characterized by being set so as to face a table. 2. A turntable for mounting an inner peripheral portion of a disk-shaped recording medium to rotate integrally, a motor for rotationally driving the turntable, and a connection between the motor and the turntable. A rotary drive shaft driven by the motor, and a pickup having an objective lens and movable in the seek direction. A light beam is emitted from the objective lens toward the program area of the rotating disk-shaped recording medium. In an information recording / reproducing apparatus that ejects and records and / or reproduces information, the interval between the turntable and the motor is set to a width that allows the pickup to be inserted, and the inner peripheral end of the movement range of the pickup is set. An information recording / reproducing apparatus, wherein the objective lens is set to face the turntable.