JPH0192960A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the recording density by moving an information recording medium and a driving means driving the medium in response to the location of the head with respect to the radial direction of the information recording medium relatively in the radial direction of the information recording medium to make the relative linear velocity between the head and the information recording medium. CONSTITUTION:A drive subject to servo control into a constant speed by a control circuit is driven at a constant speed. In driving a head motor M2 by the control circuit, a screw 4 fixed incorporatedly with the head motor M2 is driven and an arm 3 screwed to the screw 4 and guided linearly by a guide rod 5 is driven straight-forward in the direction of A-A'. Thus, steel balls 2a, 2b held freely turnably in a hole 3a of the arm 3 are moved on the shaft of a drum 1 in the direction of A-A' and the head H supported fixedly to the arm 3 is moved by the same quantity in the same direction as the steel balls 2a, 2b. Thus, the relative linear velocity of the head with respect to the outer circumference and the inner circumference of the information recording disk medium is made constant thereby improving the information recording density of the information recording medium.

Description

Detailed Description of the Invention [Field of the Invention] The present invention relates to recording and reproducing information on a rotationally driven information recording medium by a recording and/or reproducing head that sequentially moves in the direction of the rotation radius of the information recording medium. The present invention relates to an information recording/reproducing device that performs/or reproduction.

[Prior art]

Information is recorded and reproduced on a disk-shaped information recording medium (hereinafter referred to as a disk) using a constant angular speed, which is performed at a constant rotational speed regardless of the position of the recording and/or reproducing head in the radial direction of the disk. method (hereinafter referred to as rCAV method)
) and isolinear velocity method (abbreviated hereafter), in which the rotational speed of the disk is changed according to the radial position of the disk so that the relative linear velocity with the recording and/or reproducing head is constant. rCLV method). In both types, a bearing 3 is fixed to a printed circuit board P on which a control circuit is configured as shown in FIG. is fixed. The printed circuit board P has the magnet 2
A coil 4 is disposed opposite to the coil 4, and current is supplied to the coil 4 from a control circuit to rotate the turntable l, thereby forming a type of motor. A disk mounting surface is formed on the surface of the turntable 1 opposite to the printed circuit board P side, and the disk D is fixed to the mounting surface and information is recorded/reproduced by a head H (an optical head in this figure). will be held. Here, the rotation control of the turntable 1 is performed by CA
Both the V method and the CLV method are electrically controlled by a control circuit.

[Problem that the invention is trying to solve] For this reason, CLV
The CAV method has a simple control circuit, but the recording density is restricted at the inner circumference of the recording area, and the recording density cannot be increased sufficiently. Optical recording requires a high-output laser, which has the disadvantage of significantly increasing costs.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional devices, and to maintain a constant relative speed between the recording and/or reproducing head at the outer circumferential portion and the inner circumferential portion of a disk-shaped information recording medium with a simple configuration. The object of the present invention is to provide an information recording and reproducing device that can substantially improve its recording density.

The above object of the present invention is to provide an information recording medium that is rotationally driven.
In an information recording and reproducing apparatus that records and/or reproduces information using a recording and/or reproducing head, the information recording medium and the information recording medium are arranged in a manner corresponding to the position of the head in the rotation radius direction of the information recording medium. This is achieved by keeping the relative linear velocity between the head and the information recording medium constant by moving a driving means for rotationally driving the medium in the direction of the rotation radius of the information recording medium.

〔Example〕

FIG. 1 is a schematic sectional view showing an embodiment in which the present invention is applied to an optical disk device, and FIG. 2 is a plan view seen from the XX direction of FIG. 1.

In FIG. 1, 1 is a cylindrical drum fixed to a drive motor Ml and rotatably provided on a frame 9;
The center is arranged perpendicular to the extension line of the rotation center of the plate 6. 2a and 2b are steel balls that are pressed between the drum 1 and the plate 6 and transmit the rotational force of the drum 1 to the plate 6 by frictional force, and are inserted into the hole 3 of the arm 3.
There are two rotatably arranged fittings in a. Incidentally, the friction force is between the drum l and the first steel ball 2a, and between the first steel ball 2a and the second steel ball 2b.

The force is sequentially transmitted from the drum l to the plate 6 by the contact surfaces of the second steel ball 2b and the plate friction surface 6c.

3 is an arm that rotatably holds steel balls 2a, 2b in holes 3a at one end, engages the optical head H at the other end, and is held by a guide rod 5 and a screw 4 so as to be movable in a straight line; are fitted, and are threadedly engaged with the screw 4, and the rotation of the screw 4 moves straight in the A-A' force direction.

At this time, the optical head H and the steel balls 2a and 2b are simultaneously moved by the same stroke. At this time, the steel ball is moved by the drum l.
The drum L is arranged so that its surface moves parallel to the axis of the drum L. 4 is threadedly engaged with the arm 3, and the arm 3 is connected to A.
One end is fixed to the head motor M2 by a screw for moving in the -A' direction, and the other end is rotatably held by the frame 9. Reference numeral 5 denotes a guide rod fitted with the arm 3, one end of which is fixed to the frame 9, moves in a straight line with the arm 3 in cooperation with the screw 4, and is held at a predetermined position. 6 consists of a mounting surface 6a for mounting and holding the disk D, a center shaft 6b for positioning the disk D, a shaft 6d forming a rotation center axis, and a friction surface 6c for contacting the steel ball 2a and transmitting frictional force. The plate is rotatably held by the frame 9 via a bearing 8 fitted into the shaft 6d, and is configured to be movable by a small amount in the axial direction. A disc spring 7 is incorporated in a part of the plate 6 and is arranged so as to come into contact with the bearing 8, and presses the steel balls 2a and 2b between the drum 1 via the friction surface 6C of the plate 6. 8
is a first bearing that rotatably holds the shaft 6d of the plate 6 relative to the frame 9; 9 is a frame that holds this mechanism. IO is a second bearing that is fitted into the frame 9 and holds the drum 1 rotatably. Ml is a drive motor that is a disk rotation drive source, and is fixed to the frame 9.

M2 is a head motor that rotates the screw 4, fixes the screw 4, and is fixed to the frame 9. In the above configuration, the drive motor M1, which is servoed to a constant rotation by a control circuit not shown, rotates at a constant rotation. Therefore, the drum l fixed to the motor M1 rotates at a constant rate. Since the steel ball 2a is pressed against the surface of the drum 1 by the spring pressure of the disc spring 7 via the plate 6 and the steel ball 2b, the rotational force of the drum 1 is applied via the steel balls 2a, 2b and the friction surface 6c. The signal is transmitted to the plate 6, and the plate 6 rotates around the axis 6d.

Here, a control circuit (not shown) controls the head motor M2.
When the head motor M2 is driven, the screw 4, which is integrally fixed with the head motor M2, rotates and engages with the screw 4, and the arm 3, which is guided in a straight line by the guide rod 5, moves into the first position.
It is driven straight in the direction A-A'.

Therefore, the steel balls 2a and 2b rotatably held in the hole 3a of the arm 3 move on the axis of the drum l in the direction A-A', and the head H fixedly held on the arm 3 also moves in the direction A-A'. It will move the same amount in the same direction as the balls 2a and 2b.

At this time, the initial positions of the steel balls 2a, 2b and the head H are set from the center of rotation of the plate 6 to the steel ball 2a.

2b and the distance from the center of rotation of the plate 6 to the position where the light beam of the head H is projected onto the disk D (that is, the information recording/reproducing position) (R1 and the distance shown in FIG. 3). By setting r+) to the same size,
The circumferential speed at point a and point 0 in Figure 3 are the same, and even if the arm 3 moves in the A-A' direction, for example from point a to point b in Figure 3, point a and The peripheral speed at point b is the same.

Therefore, the circumferential speeds at point C and point d in FIG. 3 are also the same.

FIG. 3 is an explanatory diagram for explaining the above-mentioned reason in more detail, and the explanation of the same reference numerals as in FIGS. 1 and 2 will be omitted.

In Fig. 3, Dl is the external dimension of the drum 1, and point a is the steel ball 2b.
The initial position is defined as a position where the friction surface 6c of the plate 6 contacts the friction surface 6c of the plate 6 at a distance of radius R1 from the rotation center of the plate 6.

b is a position where the steel ball 2b has moved from a and is in contact with the friction surface 6c at a position of radius R2. C is disk D
The innermost recording periphery is defined as the position where the light beam is projected at a distance of radius r1 from the center of rotation of the plate 6 on the recording surface. d is a radius r of the recording position from C due to the movement of the head H.
2 represents the projection point of the light beam at position 2. e represents the contact position between the steel ball 2 and the drum 1.

If the diameter of drum 1 is Dl and its rotation speed is Nrp□,
The peripheral speed V of the drum at the 0 point on the drum surface is V= yr D
It is expressed as 1N/min.

The circumferential velocity V at eight points on the plate surface is V, =2 yr R1*n&==V, where na is the rotational speed of the plate 6.

Also, when the steel ball moves from R1 to R2, if the circumferential velocity at point b is vb and the number of rotations of the plate is J, then V
, = 2 yr R2 nb = V, and point a and b
The circumferential speed of the point remains constant even when the rotation radius changes from R1 to R2.

On the disk surface, the circumferential velocity v0 at point 0 means that the steel ball position is R1
It is related to the number of revolutions n of the plate when the steel ball is at the position R2, and the peripheral speed vd at point d is related to the number of revolutions nb of the plate when the steel ball is at the position R2. The fact that the speeds of the inner and outer circumferences above are constant means that Vo and V at point 0 and point d should be v0=v4te. Therefore, it is necessary to satisfy the condition that V0=Vd by assuming that they are equal.

Here, R2=R1+ΔRΔR is the amount of radial movement r2
= R2・i = (R1+ΔR)i = iR1+
In order to change the radius from rl to r2, it is necessary to move the optical head via a variable magnification mechanism such as a lever mechanism that has a magnification of the radius ratio i to the amount of radial movement on the steel ball side. However, this makes the mechanism complicated, so r1=R, r2=R
It was set to 2. This has made it possible to maintain a constant value using simple mechanical means.

In the above embodiment, the steel ball and head are moved by the same amount of movement using one arm 3, but as pointed out in the detailed explanation above, the amount of movement of the steel ball and head is The effect of the first embodiment can be obtained by applying a coefficient and moving the steel ball with a lever, etc., or by moving the steel ball and the head with separate motors using servos at a rotation ratio of i without using a lever. can get.

FIG. 4 is a schematic sectional view showing another embodiment of the present invention, in which the same members as in FIG. 1 are given the same reference numerals and detailed explanations are omitted. Reference numeral 11 denotes a frame that rotatably supports the plate 6 on which the disk D is placed and is movable in the radial direction of the disk D (in the BB' direction).

As described above, in this embodiment, the disk is moved in the radial direction instead of moving the steel ball and the head, so that the same effects as in the first embodiment can be obtained.

In this embodiment, a disk rotation mechanism of an optical recording/reproducing device is mentioned, but this may be any device that records/reproduces information by rotationally driving a rotary record carrier. It is not limited to recording/reproducing devices.In addition, although a disk-shaped information recording medium is used in this embodiment, any information recording medium with a circular information recording section may have a card-like outer shape or a sheet-like outer shape. However, it is clear that any form falls within the scope of the present invention.

〔Effect of the invention〕

As explained above, the present invention provides a conventional disc-shaped information recording/reproducing device, in which the information recording medium and the driving means for rotationally driving the information recording medium correspond to the position of the head in the rotation radius direction of the information recording medium. 1) It is possible to keep the relative linear velocity between the head at the outer circumference and the inner circumference of the disk-shaped information recording medium constant with a simple configuration. can.

2) This improves the information recording density of the information recording medium.

It has the following effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment in which the present invention is applied to an optical disk device, FIG. 2 is a plan view of the device shown in FIG. FIG. 4 is a schematic diagram showing another embodiment of the present invention; FIG.
The figure shows a conventional disc-shaped information recording/reproducing device.

Claims (1)

[Claims] (1) In an information recording and reproducing apparatus that records and/or reproduces information on a rotationally driven information recording medium using a recording and/or reproducing head, the position of the head in the rotation radius direction of the information recording medium Correspondingly, the relative linear velocity between the head and the information recording medium is increased by relatively moving the information recording medium and a driving means for rotationally driving the information recording medium in the direction of the rotation radius of the information recording medium. An information recording/reproducing device characterized by keeping constant.