JP2715689B2 - Optical disk master recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk master recording apparatus (hereinafter also referred to as "cutting machine") for optically recording information on a recording medium such as a glass master coated with a resist or the like by using a laser beam.

[0002]

2. Description of the Related Art In order to manufacture a compact disk (CD) widely used as a music medium or the like, a master disc in which pits are cut as information signals is prepared in advance. The cutting machine used is used.

[0003] The optical system of a general cutting machine is
As shown in FIG. 8, the laser beam 103 emitted from the light source 101 is condensed on the master 107 on the turntable 106 via the reflection mirrors 104a, 104b, 104c and the condenser lens 105, so that the laser beam 103 is emitted onto the master 107. Cutting a predetermined information signal. In this case, Master 1
In order to record the signal spirally or concentrically on 07,
A feed mechanism for moving either the turntable 106 or the condenser lens 105 in the radial direction of the master 107 with high accuracy is required.

Therefore, conventionally, a screw feed mechanism has been used. As shown in FIG. 9, the screw feed mechanism includes a servomotor 108 with an encoder, and a high-precision speed reducer 110 connected to a motor output shaft 108a of the motor 108 via a coupling 109a. The output shaft 110a is connected to the screw portion 112a of the screw nut feed mechanism 112 via the clutch 111a to form a steady feed mechanism. The timing belt 11 is disposed between the pulley of the clutch 111a and the pulley of the other clutch 111b.
3 and a motor 114 is connected to the clutch 111b to form a fast-forward mechanism.

[0005] Further, since the surface of the master 107 rotated by the turntable 106 at the time of cutting changes the distance H to the condensing lens 105, the condensing lens 105 corresponds to the surface fluctuation. A focusing mechanism for displacing the beam 103 in the direction of the optical axis of the beam 103 to constantly focus the beam 103 on the master 107 is required.

Therefore, conventionally, a lens vertical mechanism for coping with the thickness of the master, a lens focusing mechanism for coping with surface deflection, and a focusing optical system for controlling these are provided. The former generally includes a combination of a single-axis linear guide mechanism (for example, a roller guide mechanism or an Arimizo mechanism) with a motor and a screw feed mechanism, a coil provided in a lens movable section supported by a spring, and a fixed section, A so-called moving coil type driving mechanism comprising a magnet and a yoke is employed. The latter generally includes a light source section such as a helium neon (HeNe) laser and a focus detection optical system (for example, a skew method or an astigmatism method).

For example, as shown in FIG. 10, a conventional focusing mechanism and an optical system transmit a laser beam emitted from a laser
05, the light is reflected by the glass master 107, passes through the condenser lens 105 again, enters the focus detection optical system 116, and detects a defocus. The lens barrel 117 of the condenser lens 105
Is supported by a spring 125 in a movable state.
Is provided with a coil 118, and a lens driving mechanism 121 including a so-called voice coil is constituted by a magnet 119 and a yoke 120 sandwiching the coil 118, and a current for correcting a focus error signal of the focus detection optical system 116 is applied. This absorbs the runout of the master 107. Further, the lens driving mechanism 121 is configured by
In order to move several mm in the optical axis direction of
Between the lens drive mechanism 121 and the screw nut mechanism 123
Is provided with a one-axis moving mechanism 124 for
The variation in thickness of 7 is corrected.

[0008]

However, in the above-described conventional optical disk master recording apparatus, the turntable is fed by a screw nut feed mechanism. The characteristic screw precision for each pitch, which is a characteristic, appears in the cutting as a pattern, and this causes so-called gear marks that also appear on the final formed disc. Also, if a system that incorporates a lens drive mechanism in this feed mechanism is adopted,
The moving load had to be reduced in weight and increased in rigidity as much as possible.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is characterized in that a laser beam is converged by a condenser lens.
After beam shaping, condensed light is focused on a circular turntable
Spiral or concentric recording of signal on recording master rotating with
Optical disk master recording apparatus,
Says that the lens drive mechanism is supported only by the static pressure air bearing
In addition, the lens drive mechanism is turned by a linear motor.
To move in the radial direction of the optical disk.
A recording device was constructed. Claim 2 is a side in the traveling direction of the feed mechanism.
A lens drive mechanism is provided on the surface. Claim
3 is a movable part including a condenser lens in the lens driving mechanism.
Is supported on the body of the lens drive mechanism by a helical spring.
It is characterized by having been done.

[0010]

[Function] The lens drive mechanism is supported by a static pressure air bearing
The lens drive mechanism in the radial direction of the turntable.
Moved by ammo. Therefore, the frictional resistance when the lens driving mechanism is moved by a very small distance and when the lens driving mechanism is started can be made extremely small, and a gear mark does not occur as in the case where the screw nut feeding mechanism is used. Sending
Since the lens drive mechanism is provided on the side of the moving mechanism in the traveling direction,
Almost uniform pressure on the lens drive mechanism due to static pressure air bearing
In addition, it can be stably supported. Focusing of the lens drive mechanism
The movable part including the lens is driven by a helical spring.
The movable range of the lens is expanded because it is supported by the main body
Variations in the thickness of the master can be sufficiently absorbed.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view of an optical disk master recording apparatus to which the present invention is applied, FIG. 2 is a front view of the apparatus, FIG. 3 is a perspective view of a state where a lens drive mechanism is attached to a feed mechanism of the apparatus, and FIG. FIG. 5 is a perspective view showing another state of the lens driving mechanism attached to the feed mechanism of the apparatus, FIG. 5 is a plan view of a lens movable section of the apparatus, FIG. 6 is a half sectional view of the lens movable section, and FIG. FIG. 5 is a diagram illustrating a displacement amount of a part.

A helium cadmium laser (HeCd laser) light source 2 serving as a laser light source and an optical unit for shaping and controlling the laser light emitted from the laser light source 2 are provided on a stone surface plate 1 with a high-performance small vibration isolator. 3 and brushless not shown
Turntable 4 rotated by a motor and static pressure air
A moving mechanism comprising a bearing 5 and a linear motor 6 disposed at the bottom of the hydrostatic air bearing 5 is provided. A moving optical section 7 including a condenser lens is formed by the hydrostatic air bearing 5 and the linear motor 6 constituting the moving mechanism. Feeding is performed in the radial direction of the turntable 4.

As described above, by using a helium cadmium laser as the recording laser light source, the size of the entire apparatus can be reduced. Further, static-pressure feed mechanism of the movable optical unit 7
By performing with the air bearing 5 and the linear motor 6,
There is no so-called gear mark generated when the screw nut feed mechanism is used.

The focusing mechanism of the moving optical section 7 must move in the radial direction on the turntable 4 so as to project in a direction perpendicular to the moving direction of the guide 5a of the hydrostatic air bearing 5. Is attached to the slider 5b. Further, the moving optical unit 7 includes a lens driving mechanism 8.
Is provided. The lens driving mechanism 8, by providing the moving direction side of the slider 5b as shown in FIG. 3, the static pressure air bearing 5 compared to the case of providing the distal end of the moving direction of the slider 5b as shown in FIG. 4 Is supported by the force obtained in all directions of the blown air flow (arrows), the moment M which falls forward in the movement direction due to the weight of the lens drive mechanism 8 does not occur, and the movement is started without being caught. Rigid feed becomes possible.

As shown in FIGS. 5 and 6, the lens driving mechanism 8 has a coil 1 mounted above a lens barrel 11 of a condenser lens 10.
3, a so-called voice coil is constituted by the magnet 14 and the yoke 15 sandwiching the coil 13.
The entire movable portion 16 is supported by a spiral spring 12 (gimbal spring). Spiral spring 12
7, the movable range of the lens is widened, as shown in FIG. 7, the thickness variation of the master D placed on the turntable 4 can be absorbed, and other components are not required, and the moving is possible. The weight of the optical unit 7 can be reduced. Further, by using a semiconductor laser as the light source of the focus optical system, both weight and volume can be significantly reduced as compared with the case where a conventional helium neon laser is used, and further weight reduction can be achieved.

[0016]

As described above, the optical disc of the present invention is used.
The master disc recorder uses only a static pressure air bearing for the lens drive mechanism.
And the lens drive mechanism to a linear motor.
The light travels more in the radial direction of the turntable.
Since the disk master recording device was configured, the lens drive mechanism
Resistance when moving a small distance and starting
Can be made extremely small and using a screw and nut feed mechanism
No gear mark is generated. Of feed mechanism
Since a lens drive mechanism is provided on the side in the traveling direction, static pressure air
The pressure from the bearing is almost uniformly applied to the lens drive mechanism,
I can support it. Condenser lens of lens drive mechanism
The movable part including the main body of the lens drive mechanism by a helical spring
The movable range of the lens is widened and the thickness of the master
It is possible to sufficiently absorb only variations.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical disk master recording apparatus to which the present invention is applied.

FIG. 2 is a front view of the device.

FIG. 3 is a perspective view of a state in which a lens drive mechanism is attached to a feed mechanism of the apparatus.

FIG. 4 is a perspective view showing another state in which the lens driving mechanism is attached to a feed mechanism of the apparatus.

FIG. 5 is a plan view of a lens movable unit of the apparatus.

FIG. 6 is a half sectional view of the lens movable section.

FIG. 7 is a diagram showing a displacement amount of the lens movable portion.

FIG. 8 is a configuration diagram showing an optical system of a general cutting machine.

FIG. 9 is a schematic plan view of a conventional feed mechanism.

FIG. 10 is a schematic front view of a conventional lens driving mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stone surface plate, 2 ... Helium cadmium laser, 3 ... Optical part, 4 ... Turntable, 5 ... Static pressure air bearing , 6 ... Linear motor, 7 ... Moving optical part, 8 ... Lens drive mechanism, 1
2. Spiral spring.

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuyuki Negishi 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside of Victor Company of Japan, Ltd. (56) References 2-308428 (JP, A) Real opening Hei 2-335337 (JP, U)

Claims (3)

(57) [Claims] A laser beam is shaped by a lens provided in a lens driving mechanism and then condensed to form a circular turntable.
An optical disc master recording apparatus for recording a signal spirally or concentrically on a recording master rotating on a cable , wherein the lens drive mechanism is a static pressure air bearing.
In addition to supporting the lens drive mechanism with a linear
Move in the radial direction of the turntable
Master optical disc recording apparatus characterized by was Unishi. 2. The optical disk master recording apparatus according to claim 1, wherein a lens driving mechanism is provided on a side surface of the feed mechanism in the traveling direction. 3. The recording apparatus according to claim 1, wherein a movable portion of the lens driving mechanism including the condenser lens is supported by a main body of the lens driving mechanism by a helical spring.