JPS6326843A - Supporting device for convergence lens - Google Patents

Abstract

PURPOSE:To obtain the effect of a pneumatic damper by providing a guide wall leading the air flow from an intake in a case to both ends of a supporting frame in a racking direction near the supporting frame. CONSTITUTION:A hollowed enclosure-shaped cover 6 whose lower face is opened is covered to an actuator base 1, and the cover 6 and the actuator base 1 constitute the case 7 containing the component on the base. An intake 71 taking an air flow caused by the rotation of an information recording disk 9 is provided to the case 7 and the guide wall 72 driving the air flow into two and leading the divided flows to both end faces 23, 23 of the lens supporting frame 2 in the tracking direction is provided to the case 7. The guide wall 72 consists of a channel shaped inner wall 73 and a couple of outer walls 74, 74 arranged symmetrically to the outside of the inner wall 73.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a support device for a condenser lens in an optical pickup that accesses an information recording medium.

(Prior art and its problems) Fig. 4 shows a condensing lens support device of a conventional optical pickup, in which an actuator moves in the tracking direction of the information recording disk (9), that is, in the radial direction of the disk. A lens holding frame (2) is attached to four wire springs (12) implanted in a support plate (11) on the pace (1), and is swingably supported.

A condensing lens (3) and a pair of permanent magnets (4) (4) are attached to the holding frame (2), and each permanent magnet (4) (4)
By energizing the coil blocks (5) (5) placed on the actuator base (1) facing the , the light is focused integrally with the holding frame (2) by the magnetic force acting between the magnet and the coil. The tracking direction is controlled by driving the lens (3).

In order to solve the problem of primary resonance of the spring, the wire spring (12) is equipped with a rubber tube (13) as shown in Fig. 5.
) to provide a damper effect.

However, the wire spring (12) has a diameter of about 0.2m+a.
Due to troubles such as accidentally bending the wire spring when wrapping the thin rubber tube (13), there was a problem in manufacturing that the yield was poor.

(Means for Solving the Problems) In view of the above, the present invention discloses a support device for a condenser lens that can obtain a damper effect by utilizing the air flow generated when an information recording disk rotates. It is.

The present invention provides a cover (6) for an actuator base (1).
Cover the case (7) with the base (1) and cover (6).
The case (7) is provided with an intake port (71) for the air flow generated by the rotation of the information recording disk (9), and the air flow flowing into the case from the intake port (71) is
It is constructed by providing guide walls (72) close to the holding frame (2) that guide the holding frame (2) to both ends in the tracking direction.

(Operation and Effect) Airflow generated by the rotation of the information recording disk flows in from the air intake port (71) of the case, is divided into two by the guide wall (72), and is directed to both ends of the lens holding frame (2) in the tracking direction. By applying wind pressure to the air, this can create an air damper effect.

(Example) In the following description, the front side refers to the side facing the rotational direction of the information recording disk, and refers to the left side in the drawings.

In FIG. 1, a support plate (11) is provided on the rear upper surface of a substantially rectangular actuator pace (1) that is disposed so as to be movable in the tracking direction of the information recording die ff1 (9) shown by arrow A. Wire springs (12) are provided horizontally protruding forward at the four corners of (11), and the free ends of each wire are connected to the lens holding frame (2).

The lens holding frame (2) floats above the actuator pace (1) and can swing in the tracking direction and the focus direction shown by arrow B by the deflection of the spring (12).

The lens holding frame (2) has a condensing lens (3) attached to the center thereof, and a pair of permanent magnets (4) (4) attached to both the front and rear surfaces.

Furthermore, support pieces (21) (21) to which the tips of the springs (12) are attached protrude from both sides of the holding frame (2) in the tracking direction.

The lens holding frame (2) is formed symmetrically in the tracking direction along a line passing through the center of the condenser lens (3) and the center of the support plate (11) and parallel to the spring (12).

The actuator pace (1) has the above magnets (4) (4)
A pair of coil blocks (5H5) are arranged facing each other.

As is well known, each coil block (5) includes a focus coil (51) that drives the holding frame (2) in the focus direction;
and a tracking coil (
52).

A hollow housing-like cover (6) with an open bottom is placed over the actuator space (1), and the cover (6) and the actuator space (1) form a case (7) that accommodates the components on the base. It consists of

The feature of the present invention is that the information recording disk (7) is attached to the case (7).
) to accommodate the air flow generated by the rotation of the
71), and divides the air flow into two parts within the case to connect both end surfaces (23) (23) of the lens holding frame (2) in the tracking direction.
23) is provided with a guide wall (72) that guides the user toward.

The airflow intake (71) is opened in the center of the front of the cover (6).

The guide wall (72) includes a U-shaped inner wall (73) and a pair of outer walls (74) arranged symmetrically on the outside of the inner wall.
It consists of

Inside! (73) surrounds the front coil block (5) of the pair of coil blocks (5), has both U-shaped ends close to both sides of the holding frame (2), and has its tip connected to the front magnet (4). ) is bent inward to the side.

A convex portion (75) is formed at the center of the front surface of the inner wall (73) to divide the incoming airflow into two.

Each outer wall (75) (75) has an air flow intake (71)
The lens holding frame (2) bends along the inner wall from near the
) extends on both sides, with an inner wall (73) and an outer wall (74) (7
A flow path (76) (77) facing both sides of the holding frame (2) in the tracking direction is formed between the flow path (76) and
) (77) is close to the holding frame (2).

An air escape port (79) is provided on the top surface of the cover (6) at a position corresponding to the condenser lens (3).

However, the airflow generated by the rotation of the information recording disk,
Air flows in through the air intake port (71) of the cover (6), branches into two channels (76) and (77), and applies equal wind pressure to both sides of the lens holding frame (2> in the tracking direction). .

When the holding frame (2) approaches one of the channels (76), resistance is created to the outflow of air from the channel, the air pressure near the outlet of the channel increases, and a force pushing back the holding frame (2) acts. do.

On the other hand, in the other channel (77), the holding frame (
2) moves away, the passage widens, and air flows out smoothly.

The holding frame (2) is pressed to the opposite side by the pushing force of the air, and a phenomenon similar to that described above occurs.

The above operation is repeated to attenuate the vibration.

FIG. 3 is a bottom view showing another embodiment of the cover (6), in which a guide wall (72) similar to that described above is formed on the cover itself.

Note that the present invention is not limited to the above embodiments, and various changes can be made within the scope of the claims.

[Brief explanation of drawings]

Fig. 1 is an oblique view of the condensing lens support device, Fig. 2 is an explanatory diagram showing the air flow within the support device, Fig. 3 is a bottom view showing another embodiment of the cover, and Fig. 4 is a conventional one. Example slope diagram, 5th
The figure is a front view showing a part of a conventional wire spring in cross section.

Claims (1)

[Claims] 1. In a focusing lens support device for an optical pickup, a lens holding frame (2) is swingably mounted on an actuator base (1) via a spring (12), and a focusing lens is fixed to the holding frame. , a cover (6) is placed over the actuator base (1), and the base (1) and the cover (6) constitute a case (7), and the information recording disc (9) is placed in the case (7).
) is opened, and the airflow flowing from the intake port (71) is divided into two parts in the case on both sides in the tracking direction of the holding frame (2). A support device for a condensing lens formed by bringing a guiding wall (72) close to a lens holding frame (2).