JPH0266732A - Optical pickup - Google Patents

Abstract

PURPOSE:To always vertically keep the optical axis of an optical pickup for the recording surface of an optical recording medium by respectively an upper lower direction fixed bearing and an upper lower direction movable bearing at the receiving position of a guide rail for the optical pickup. CONSTITUTION:When the receiving position of a guide rail 33 for an optical pickup 36 in an upper lower direction movable bearing 51 is moved in the upper and lower direction, the optical pickup 36 is chilled in the upper and lower directions with the receiving position of the guided rail 33 in an upper and lower direction fixed bearing 42 as a center. Consequently, the optical axis of the optical pickup 36 can be always made vertical for the recording surface of a signal in an optical recording medium 31 in the vicinity to which the convergent ray is irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical pickup used in an optical recording/reproducing device such as a video disc player or a compact disc player.

[Conventional technology]

For example, an optical disc, which is a recording medium used in a video disc player, may bend into an umbrella shape due to its own weight or changes over time, so that the optical axis of an optical pickup may not be perpendicular to the optical disc. In this case, aberrations such as coma aberration occur in the spot shape of the convergent light irradiated onto the optical disc, and signals recorded on tracks adjacent to the track where the reproduced signal is recorded are mixed into the reproduced signal. so-called crosstalk may occur.

Therefore, in the past, for example, as shown in FIG.
In addition to the guide rail 14 that guides the lens in the radial direction, a device is used in which the tilt angle, opening, and direction of the optical axis can be adjusted.

That is, the spin motor 12 that falls on the guide rail 14
The side end portion is rotatably supported by a support portion 16 via a rotation shaft 15 . Further, a rank 17 is attached to the other end of the guide rail 14, and a pinion gear 18
The driving force of the motor 19 is transmitted through the motor 19.

An optical pickup 13 is slidably supported on the guide rail 14 and is moved in the radial direction of the optical disc 11 by being driven by a drive means (not shown).

With this configuration, the optical pickup 13 can be tilted together with the guide rail 14 by driving the motor 19, so that the optical axis of the optical pickup 13 can be aligned with the signal on the optical disk near the area where the convergent light is irradiated. It was possible to always keep it perpendicular to the recording surface.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 160844/1984, an optical pick amplifier in which the direction of the optical axis can be adjusted by tilting only the optical block provided inside is also used. There is.

This type of optical pink amplifier 21 is provided with an optical block 22 that is rotatable via a support shaft 26 inside, as shown in FIG. 12, for example. Also, light pink up 2
1 is supported by a guide rail 24 via rollers 23, 23, and is movable in the radial direction of the optical disc 25.

The optical block 22 provided inside the optical pink amplifier 21 is provided with a protrusion 27 extending in the radial direction of rotation. This protrusion 27 is connected to the gear 2 as shown in FIG.
It is engaged with a radial elongated hole 28a formed at 8. The gear 28 is rotationally driven by a motor 30 via a pinion gear 29.

That is, when the gear 28 is rotated by being driven by the motor 30, the protrusion 27 of the optical block 22 that engages with the elongated hole 28a moves in the vertical direction. Therefore, since the optical block 22 can be tilted around the spindle 26, the optical axis of the optical block 22 that enters the optical pink amplifier 21 is aligned with the signal recording surface of the optical disk near where the convergent light is irradiated. On the other hand, it was always possible to keep it vertical.

(Problem to be Solved by the Invention) However, in the configuration as shown in FIG. Therefore, a recording/reproducing device or the like using the optical pickup 13 becomes larger.

In addition, along with the optical pickup 13, the guide rail 14
Since the movable shaft 19, the rack 17, and the pinion gear 18 are required to generate and transmit large driving force. Therefore, the size of the device becomes larger, and the power consumption also increases.

On the other hand, in the configuration shown in FIG. 12, for example, as shown in FIGS. 14 and 15, the optical block 22 is located near the inner circumference of the optical disc 25 and when it is located near the outer circumference. So, the distance between the optical disk 25 and the optical block 22! changes.

By the way, in order to converge the convergent light irradiated onto the optical disc 25 into a spot shape, it is necessary to move an objective lens (not shown) in the focus direction according to the distance between the optical disc 25 and the optical block 22. Therefore, as described above, by moving the optical block 22 in the radial direction of the optical disk 25, the distance between the optical disk 25 and the optical block 22! At least this distance if changes significantly! It is necessary to move the objective lens by more than the amount of change in .

For this reason, there are significant restrictions in designing the optical block 22, such as the need to increase the operating range of the actuator for moving the objective lens.

Furthermore, an optical block 22 is provided inside the optical pickup 21.
In order to provide this and tilt only the optical block 22, the optical pickup 21 will be constructed from a double housing. Therefore, the weight of the optical pickup 21 as a whole increases, the movement of the optical pickup 21 in the radial direction of the optical disk 25 becomes slow, and the access time becomes longer.Furthermore, the optical pickup 21 becomes larger.
Again, there is a problem in that the recording/reproducing apparatus using the optical pickup 21 becomes bulky.

[Means to solve the problem]

In order to solve the above problem, the optical pickup according to the invention of claim 1 is provided with an optical pickup that is slidably provided on a guide rail and that records and reproduces signals by irradiating convergent light onto an optical recording medium. The pickup is provided with a vertically fixed bearing in which the receiving position of the guide rail relative to the optical pickup is fixed at least in the vertical direction, and a vertically movable bearing in which the receiving position of the guide rail relative to the optical pickup is movable in the vertical direction. It is characterized by

In order to solve the above problem, the optical pickup according to the invention of claim 2 is provided with an optical pickup that is slidably provided on a guide rail and that records and reproduces signals by irradiating convergent light onto an optical recording medium. In the pickup, the receiving position of the guide rail with respect to the optical pickup is fixed in the vertical direction, while the guide rail direction movable bearing is movable in the direction of the guide rail, and the receiving position of the guide rail with respect to the optical pickup is moved in the vertical direction. It is characterized by being provided with a vertically movable bearing.

[For production]

According to the structure of claim 1, if the receiving position of the guide rail relative to the optical pickup in the vertically movable bearing is moved in the vertical direction, the optical pickup can be moved around the receiving position of the guide rail by the vertically fixed bearing. Tilt vertically. Therefore, the optical axis of the optical pickup can always be perpendicular to the signal recording surface of the optical recording medium in the vicinity of which the convergent light is irradiated.

Moreover, at a position protruding from the outer edge of the optical recording medium,
Since there is no need to provide a driving means or the like for tilting the optical pickup, a compact recording/reproducing apparatus or the like can be constructed. In addition, since it is only necessary to tilt the optical pickup without tilting the guide rail, etc., the required driving force is small, and the driving device and driving force transmission device can be downsized. Power consumption can also be kept low.

Furthermore, since the entire optical pickup is tilted, there is no need to double the housing, and the weight of the optical pickup can be reduced. Therefore, the speed at which the optical pickup moves in the direction of the guide rail can be increased and the access time can be shortened.

According to the structure of claim 2, the optical pickup of the optical pickup is moved by moving the guide rail direction movable bearing in the direction of the guide rail and moving the vertical direction movable bearing in the vertical direction to tilt the optical pickup. It is possible to adjust both the angle formed between the axis and the signal recording surface of the optical recording medium near which the convergent light is irradiated, and the distance between the optical recording medium and the optical pickup.

Therefore, similarly to the invention of claim 1, without increasing the size of the recording/reproducing device or increasing the access time,
The optical axis of the optical pickup can be always perpendicular to the signal recording surface of the optical recording medium in the vicinity where the convergent light is irradiated, and the convergent light irradiated onto the optical recording medium can be shaped into a spot. Since the amount of movement of the objective lens in the focus direction to condense the light can be kept small, the degree of freedom in design increases, such as being able to set the operating range of the actuator small, for example.

〔Example〕

An example used in an optical recording/reproducing apparatus as an embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

As shown in FIG. 1, for example, an optical disk 31, which is a recording medium, is mounted on a turntable 32a formed integrally with the rotation 1jhl+ of a spin motor 32, and is driven to rotate. Below the optical disc 31, as shown in FIGS. 2 and 3, there is a guide rail 33 having a circular cross-sectional shape and a rectangular cross-sectional shape in the radial direction of the optical disc 31 (hereinafter referred to as the radial direction). Guide rails 34 and 35 are provided.

An optical system unit 37 is installed in an optical pickup 36 that moves in the radial direction along the guide rails 33 to 35 and records and reproduces signals by irradiating the optical disc 31 with convergent light. The optical system unit 1-37 includes an objective lens 37 and an objective lens 38 for condensing convergent light to be irradiated onto the optical disc 31 into a spot shape, and an objective lens 38 in the direction of the optical axis of the optical system unit 37 (hereinafter referred to as the focus direction). It consists of an actuator (not shown) that moves the

On the spin motor 32 side of the optical pickup 36,
A bearing support member 41 is provided that can move forward and backward in the radial direction with respect to the optical pick amplifier 36. A guide rail 33 is provided at the end of the bearing support member 41 on the spin motor 32 side.
A bearing 42 is provided which is slidably supported by the bearing 42 .

That is, the bearing 42 acts as a vertically fixed bearing in which the receiving position of the guide rail 33 relative to the optical pickup 36 is fixed at least in the vertical direction, that is, in the focus direction, and the receiving position of the guide rail 33 relative to the optical pickup 36 is fixed at least in the vertical direction, that is, in the focus direction. While being fixed in the vertical direction, it is movable in the direction of the guide rail 33, that is, in the radial direction, and acts as a movable bearing in the guide rail direction.

Furthermore, the bearing 42 is such that the receiving position of the guide rail 33 relative to the optical pickup 36 is also fixed in a direction perpendicular to the radial direction and the focus direction (hereinafter referred to as the tangential direction).

A sliding pin 43 that is slidably supported by the guide rail 34 is provided at the end of the bearing support member 41 on the guide rail 34 side. A plate-shaped locking member 44 is provided at the end of the bearing BJ support member 41 on the side opposite to the guide rail 34 . On the other hand, the main body of the optical recording/reproducing apparatus includes a U-shaped regulating member 45 having abutting portions 45a and 45b that abut against the locking member 44 to regulate movement of the bearing support member 41 in the radial direction. It is provided.

A worm wheel gear 51 is rotatably provided on the opposite side of the optical hookup 36 from the spin motor 32. This worm wheel gear 51 has a long hole 51a formed in the diametrical direction, and receives the guide rail 33 at a position eccentric from the center of rotation. The motor 5 is connected to the worm wheel gear 51 via the worm gear 52.
As shown in FIGS. 4 and 5, the guide rail 33 functions as a vertically movable bearing in which the receiving position of the guide rail 33 relative to the optical pink-up 36 moves vertically. Elongated hole 51 formed in the worm wheel gear 51
a, and the bearing hole 42a formed in the bearing 42,
The cross-sectional shape of the portion in contact with the guide rail 33 is formed to form a quadratic curve.

A sliding contact member 55 having a leaf spring 54 attached to its tip is provided on the guide rail 35 side of the optical pickup 36 opposite to the spin motor 32.
The guide rail 35 is sandwiched between the guide rail 35 and the leaf spring 54 to restrict movement of the optical pickup 36 in the tangential direction.

In the above configuration, when recording and reproducing signals on the optical disc 31, the optical pickup 36
Driven by a drive means (not shown), the guide rails 33-
35 in the radial direction, and irradiates a predetermined area on the optical disc 31 with convergent light.

By the way, the optical disc 31 may bend in its entire shape due to its own weight or changes over time. In such a case, the worm wheel gear 51 is rotated in the direction indicated by the arrow A, for example, by driving the motor 53. Then, the receiving position of the guide rail 33 in the elongated hole 51a of the worm wheel gear 51 moves upward with respect to the optical pickup 36, as shown in FIG. A straight line passing through the contact position with 34 and the center of the bearing 42 is the rotation axis,
It rotates in the direction shown by arrow B.

By rotating the optical pickup 36 in this manner, even if the optical disc 31 is bent, the optical axis of the optical system unit 37 in the optical pickup 36 can be set to record signals on the optical disc 31 in the vicinity where the convergent light is irradiated. It can always be perpendicular to the surface.

Therefore, it is possible to prevent aberrations such as coma aberration from occurring in the spot shape of the convergent light irradiated onto the optical disc 31, so that, for example, in a reproduced signal, a track adjacent to the track where the signal is recorded can be It is possible to reliably prevent the occurrence of so-called crosstalk, in which signals recorded on the

Here, the elongated hole 5 formed in the worm wheel gear 51
1a and the bearing hole 42a formed in the bearing 42 are both formed so that the cross-sectional shape of the portion in contact with the guide rail 33 forms a quadratic curve, so even when the optical pickup 36 is tilted, , smooth movement of the optical pickup 36 in the radial direction is not hindered.

On the other hand, even if the optical disc 31 is bent due to its own weight or changes over time, the following operations are performed to prevent the optical disc 31 and the optical pickup 36 from being bent.
The distance from the optical system unit 37 does not change significantly.

That is, the bearing support member 41 is as shown in FIGS.
As shown in FIG. 2 , it moves as the optical pickup 36 moves toward the outer circumference of the optical disc 31 . However,
When the locking member 44 comes into contact with the contact portion 45a of the regulating member 45 provided on the main body of the optical recording/reproducing apparatus, even if the optical pickup 36 further moves toward the outer circumference of the optical disc 31, the bearing support member 41 As shown in FIGS. 6(C) to 6(e), the locking member 44 remains in the position where it contacts the contact portion 45a.

In this case, as shown in FIG. 7, the distance between the bearing 42 and the worm wheel gear 51, that is, the rotation radius when the optical pickup 36 tilts,
It changes according to the amount of movement of 6. Therefore, especially near the outer periphery of the optical disc 31 where the deflection is large, the optical axis of the optical system unit 37 is made perpendicular to the signal recording surface of the optical disc 31 near the surface where the convergent light is irradiated. Along with the tilt operation of the optical pickup 36,
The optical system unit 37 moves greatly in the vertical direction, and the distance between the optical disc 31 and the optical system unit 37 is kept almost constant.

Further, when the optical pickup 36 moves toward the center of the optical disc 31, the locking member 44 engages the contact portion 45 of the regulating member 45, as shown in FIGS. 6(f) to (j).
b, and the optical pick amplifier 36 also contacts the optical disc 3.
1, the distance between the bearing 42 and the worm wheel gear 51 becomes smaller. Therefore, the radius of rotation when the optical pickup 36 tilts becomes small, and as shown in FIG. In addition, optical pickup 3
Even if the optical disc 6 tilts a little, the distance between the optical disc 31 and the optical pickup 36 does not change significantly.

Therefore, the amount of movement of the optical system unit 37 in the focus direction for condensing the convergent light irradiated onto the optical disk 31 into a spot shape can be kept small, so that, for example, the operating range of the actuator can be set small. , there is a large degree of freedom in design.

In this embodiment, the receiving position of the guide rail 33 relative to the optical pick amplifier 36 is moved in the vertical direction by rotating the worm wheel gear 51 in which the elongated hole 51a is formed. For example, as shown in FIG.
The bearing L3 member 61 on which the bearing L3 member 1a is formed may be provided so as to be slidable in the tangential direction, or a bearing similar to the bearing 42 provided on the support member 41 may be provided directly in the focusing direction. It may be provided so that it can be moved.

Furthermore, the optical pickup 36 is not limited to being restricted in the focus direction and the tangential direction by the guide rails 34 and 35; for example, as shown in FIG. 42, 42, and may be configured to be regulated by two guide rails 33, 33 having a circular cross-sectional shape.

Furthermore, in this embodiment, an example was explained in which the mechanism for driving the bearing support member 41 forward and backward is simplified by moving the bearing support member 41 forward and backward in accordance with the movement of the optical pink amplifier 36 in the radial direction. For example, by providing a drive means dedicated to driving the bearing support member 41 forward and backward,
It may be possible to control the movement of the bearing support member 41 so that the variation in the distance between the optical disk 31 and the optical system unit 37 is minimized.

[Effect of the invention] As described above, the optical pickup according to the invention of claim 1 is slidably provided on the guide rail, and records and reproduces signals by irradiating convergent light onto an optical recording medium. In the optical pink-up, there are two types of bearings: a vertically fixed bearing in which the receiving position of the guide rail relative to the optical pickup is fixed at least in the vertical direction, and a vertically movable bearing in which the receiving position of the guide rail relative to the optical pickup is movable in the vertical direction. This is the configuration provided.

This allows the optical axis of the optical pink amplifier to always be perpendicular to the optical disk surface in the vicinity of where the convergent light is irradiated, reduces power consumption, and reduces access time. Shorten it, and furthermore, optical pi-2
This has the effect that a recording/reproducing device using the cup can be made smaller.

As described above, the optical pink-up according to the invention of claim 2 is an optical pink-up that is slidably installed on a guide rail and performs reliable recording and reproduction by irradiating convergent light onto an optical recording medium. In the up-down, the receiving position of the guide rail with respect to the optical pickup is fixed in the vertical direction, while the guide rail direction movable bearing that can move in the direction of the guide rail and the receiving position of the guide rail with respect to the optical pickup are ``1''.
This configuration includes a vertically movable bearing that can move downward.

As a result, the optical axis of the optical pickup is always perpendicular to the optical disk surface near where the convergent light is irradiated, similar to the optical pink-up according to the invention of claim 1. In addition, it is possible to reduce the size of recording/reproducing devices using optical pickups, etc., and furthermore, it is possible to reduce the amount of movement in the focus direction of the objective lens in order to converge the convergent light irradiated onto the optical disc into a spot shape. This has the effect of increasing the degree of freedom in design, such as being able to keep the operating range of the actuator small, and also making it possible to downsize the recording/reproducing device, etc.

[Brief explanation of the drawing]

1 to 8 show an embodiment of the present invention, in which FIG. 1 is a perspective view showing optical pink-up, FIG. 2 is a plan view of the same, FIG. 3 is a side view of the same, and FIG. Figure 4 is the same front view, Figure 5
The figure is a front view showing the tilted state of the optical pickup, and FIGS. 6(a) to 6(N) are explanatory diagrams showing the advancing and retreating states of the bearing support member at each stage when the optical pickup moves in the radial direction. FIG. 7 is an explanatory diagram showing a state in which the optical pickup is tilted near the outer periphery of the optical disc, and FIG. 8 is an explanatory diagram showing a state in which the optical pink-up is located near the center of the optical disc. FIG. 9 and FIG. 10 each show other embodiments,
Fig. 9 is a side view showing an optical pickup in which one bearing member with a long hole formed in an oblique direction is provided slidably in the tangential direction, and Fig. 10 is a side view showing two bearing members having a circular cross-sectional shape. FIG. 2 is a perspective view showing an optical pickup configured to be regulated in a focus direction and a finite direction by a guide rail. FIG. 11 shows a conventional example, and is a front view of an optical pickup. 12 to 15 show other conventional examples, in which FIG. 12 is a front view showing an optical pickup, FIG. 13 is a side view of the same, and FIG. 14 is an optical pickup near the center of an optical disk. FIG. 15 is an explanatory diagram showing a state in which the optical pickup is tilted near the outer periphery of the optical disc. 31 is an optical disk (optical recording medium), 33 to 35 are guide rails, 36 is an optical pickup, 42 is a bearing (vertical fixed bearing, guide rail movable bearing), and 51 is a worm wheel gear (vertical movable bearing). . Figure (a) Figure (b) Figure (C) Figure (d) Figure (e) Figure (f) Figure (9) Figure (h) b Figure (i) Figure 6 ( j)

Claims (1)

[Claims] 1. In an optical pickup that is slidably provided on a guide rail and records and reproduces signals by irradiating an optical recording medium with convergent light, the receiving position of the guide rail with respect to the optical pickup is at least An optical pickup comprising: a vertically fixed bearing that is fixed in the vertical direction; and a vertically movable bearing that allows the receiving position of a guide rail relative to the optical pickup to move in the vertical direction. 2. In an optical pickup that is slidably provided on a guide rail and records and reproduces signals by irradiating an optical recording medium with convergent light, the receiving position of the guide rail relative to the optical pickup is fixed in the vertical direction, while the receiving position of the guide rail is fixed in the vertical direction. 1. An optical pickup comprising: a guide rail movable bearing that can move in the direction of the guide rail; and a vertically movable bearing that can move the guide rail receiving position relative to the optical pickup in the vertical direction.