JPS62154239A - Optical type information recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a device by which the access time of an optical head is quick, and also a skew mechanism can be executed satisfactorily by a simple constitution, by inclining the rotary shaft of a recording medium by a prescribed angle from the vertical direction in accordance with the angle of deflection of the recording medium. CONSTITUTION:The vicinity of the outside peripheral surface of a disk-shaped recording medium 31 is deformed to an umbrella type having the angle of deflection A of about 0.2 deg. by the change with the lapse of time and dead weight. In this state, the rotary shaft 33 of a driving motor 32 is provided by being inclined to about 0.1 deg. of about half of the angle of deflection A (0.2 deg.) of the disk-shaped recording medium 31, in the vertical direction, namely, in the direction of the optical axis B of an optical head 34. Accordingly, an inclination C1 in the direction of the optical axis B of the disk-shaped recording medium 31 on a turntable 30 installed to the rotary shaft 33, and the optical head 34 also becomes about 0.1 deg.C. Also, the part deformed to an unbrella shape in the vicinity of the outside periphery can adjust the inclination in the direction of the optical axis B of the optical head 34, to about 0.1 deg., and the orthogonal relation of the optical axis B of the optical head 34 and the disk-shaped recording medium 31 can be maintained in a state that the drop of a reproducing signal is scarcely generated.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an optical system having a skew mechanism (light @ top tilt f!A structure) that maintains the optical axis of an optical head and an optical recording medium in an orthogonal relationship. This article relates to an information recording and reproducing device.

(Prior Art) In this type of information recording device and ejection, for example, in an apparatus 1lillC using a disk-shaped recording medium, the orthogonal relationship between the optical axis of the optical head and the disk-shaped recording medium (hereinafter referred to as disk) When a shift occurs, information from adjacent tracks leaks, resulting in a so-called crosstalk phenomenon. As described above, the orthogonal relationship between the optical axis of the optical head and the disk may deviate due to, for example, the disk deforming into an umbrella shape due to aging, or the disk rotating shelf tilting due to a change in the shape of the deck part of the device. can be mentioned.

In addition, when crosstalk occurs, the relationship between the disk tilt and the reduction in the reproduced signal is as shown in Figure 3.
The crn disk tilts in an umbrella shape by about 0.2° due to aging and chalk. Due to this K, the student signal is N A =
At 0.5, it decreases by about 0.5 dB.

Therefore, as shown in Figure 4, there is a disk tilt detector that automatically detects crosstalk and always maintains an accurate orthogonal relationship between the optical axis of the optical head and the disk to prevent crosstalk. was proposed.

That is, in FIG. 4, an objective lens 3 is provided for converging a recorded information reading light beam whose optical axis 1 is .H on the recording surface 2 of the recording disk. On the other hand, a detection auxiliary beam light source 4 is provided to detect a deviation in the orthogonal relationship between the optical axis 1 and the recording surface 2, and this auxiliary beam is irradiated onto the recording surface 2 through the objective lens 3. The reflected light is configured to enter the pair of light receiving elements 5 and 6 via the objective lens 3 again. Here, if the recording surface 2 is perpendicular to the optical axis 1, the auxiliary beam is reflected in a direction symmetrical to the optical axis and returned to a position symmetrical to the light source 4 and the optical axis 1, as shown by a solid line. On the other hand, if the recording surface is inclined as shown by the dashed line or broken line, the auxiliary beam is reflected as shown by the broken line or broken line.

Therefore, light receiving elements 5 and 6 are provided for these reflected beams as shown in the figure, and the light receiving outputs thereof are supplied to a differential amplifier 7 and output for detection.

This detection output is subtracted from the reference signal 9 in the subtracter 8, and the skewed rock si is calculated using this subtraction output.

By driving the optical axis, the orthogonal relationship between the optical axis and the recording surface is separated.

As the conventional skew mechanism 10, the mechanism shown in FIG. 5 has been used.

That is, when the motor 11 rotates, the gear 12 connected to the motor 11 rotates the gear 18 to which the pin 17 is attached via the gears 13, 14, and 15 degrees 16. Then, a mechanism (
(not shown) is provided. Further, the optical head 19 is
It is movable on the rails 20° 21 in the &-8' directions via the rollers 22 and the bearing holes 23, and is further rotatable in the b-b' directions about the Km rod 24. Therefore, if the optical head 19 is always pressed down by a spring (not shown) attached to the receiving member 25, the rotation of the pin 17 will cause the optical head 19 to −
By rotating in the b' direction, the optical axis of the optical head 19 can be tilted.

(Problem to be Solved by the Invention) However, the above-mentioned skew mechanism
This solves the problem that the xlk of the one-gen head 19 itself is heavy because it is disposed on the optical head 19 itself, and the access time of the optical head 19 in the a-a' force direction becomes slow.

The present invention was made for the purpose of solving the above-mentioned problems of the conventional example, and it is an object of the present invention to provide an optical 11r information recording/writing device in which the access time of the optical head is fast and the skew mechanism can be satisfactorily performed with a simple configuration. It is something to do.

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides an optical recording and reproducing apparatus that records or reproduces information by rotating a recording medium relative to an optical head. , the gist is that the rotation axis of the recording medium is tilted at a certain angle in the vertical direction in correspondence with the deflection angle of the recording medium.

(Embodiment 1flJ) The present invention will be described in detail below with reference to one embodiment shown in the drawings.

FIG. 1 is a perspective view showing the main parts of an optical information recording/reproducing apparatus according to the present invention. In this figure, numeral 30 is a turntable serving as a mounting base for a disk-shaped recording medium 31, and the turntable 30 is attached to a rotating shaft 33 of a drive motor 32 such as a spindle motor. 34 is an optical head for recording or reproducing information on the disk-shaped recording medium 31, and 35 is an objective lens. Reference numeral 36 denotes a horizontally arranged guide rail, along which the optical head 34 can freely move.

At this time, near the outer peripheral surface of the disk-shaped recording medium 31,
Due to aging and its own weight, it deforms into an umbrella shape with a deflection angle A of about 0.2°. In the above state, the rotation shaft 33 of the drive motor 32 rotates toward the disk-shaped recording medium 3 in the vertical direction, that is, in the direction of the optical axis B of the optical head 34.
It is arranged at an angle of about 0.1°, which is approximately half of the deflection A (0.2°) of 1.

Therefore, the turntable 3 installed at rotation 1ItH33
Light 1 from the optical head 34 and the disk-shaped recording medium 31 on the
11] The stiffness C8 in the B direction also has a 0.1 degree goodness.

In addition, the overlap that has been deformed into an umbrella shape near the outer periphery is also removed by the optical head 34.
The inclination of the light with respect to the B direction can be set to about 0.1°, and the original axis B of the optical head 34 and the disk-shaped recording medium 3
1 can be maintained in a state where the Nyu signal does not deteriorate at all.

Furthermore, as shown in FIG. 2, the disk-shaped recording medium 37, which has been deformed into an umbrella shape with a bending angle of about 0.1° near the outer peripheral surface due to aging, is placed on a turntable with the deformed portion facing upward. 30, the leading end of the disk-shaped recording medium 37 is bent downward by about 250 μm.

In other words, this deflection is approximately 0.1° in angle, resulting in a substantially flat disk-shaped recording medium 37 without deformation. Further, the rotation @33 of the drive motor 32 is caused by the rotation of the optical head 34.
As described above, it is arranged at an angle of about 0.1° with respect to the direction of the optical axis B. Therefore, the inclination C3 of the disk-shaped recording medium 37 on the turntable 30 mounted on the rotation shaft 33 and the optical head 34 in the direction 411B can be adjusted to 0.1 part 8 degrees, and the optical head 34 can be adjusted to 8 degrees. Axis B and -f4
The orthogonal relationship with the disk-shaped recording binding body 37 can be maintained in a state where the playback signal does not deteriorate as much as possible.

(Effects of the Invention) As explained above, the optical information recording and reproducing apparatus according to the present invention has a configuration in which the rotation axis of the recording medium is tilted at a certain angle from the vertical direction in accordance with the deflection angle of the recording medium. The optical axis of the optical head and the recording medium can be maintained in an orthogonal relationship that hardly causes a drop in the reproduced signal, and the skew mechanism can be eliminated from the optical head.

Therefore, it is possible to significantly increase the @ value of the optical head, making it possible to speed up the access time, and furthermore, the skew mechanism can be configured more conveniently. play.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the cost part of the optical information recording device according to the present invention, FIG. 2 is a cross-sectional view showing another embodiment of the same device, and FIG. The fourth figure is a schematic diagram showing the disk tilt detection mechanism, and the fifth figure is a perspective view showing the S2 portion of the skewed rice porridge in the conventional arrangement. 30... Turntable, 31.37...r disk-shaped recording medium, 32... Drive motor, 33... Rotating shaft, 34... Optical head, A... Deflection angle, B...
Optical axis, C□, C2...tilt. Agent Patent Attorney Akira Yamashita Half cylinder 1, 2, 3 and 5

Claims (2)

[Claims] (1) In an optical information recording/reproducing device that records or reproduces information by rotating a recording medium relative to an optical head,
An optical information recording/reproducing device characterized in that the rotation axis of the recording medium is tilted at a certain angle from the vertical direction in correspondence with the deflection angle of the recording medium. (2) Claim 1, wherein the certain angle is approximately half the angle for deflection of the recording medium.
The optical information recording and reproducing device described in .