JP2549862B2 - Optical pickup support device in optical information reader - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an optical pickup supporting device in an optical information reading device, and more specifically, a compound spring supporting an optical actuator for irradiating a recording surface of a recording medium with a spot light is offset at the supporting position, and a vibration damping effect is provided. The present invention relates to an optical pickup support device which is improved.

[Prior art]

In the optical information reader, an information recording medium such as a video disc or a disc such as a digital audio disc has an information signal recorded on its surface. When reproducing such a disc, the disc is rotated at a predetermined number of revolutions, spot light is irradiated in a track shape, and a change in the intensity of the reflected light or the transmitted light is converted into an electric signal to obtain an original information signal. It is something to play. In reproducing this disc, the irradiation light must be accurately focused on the recording surface of the disc, and for this reason, it is necessary to control the position in the direction perpendicular to the recording surface of the optical system, that is, the focus direction (focus servo). And
Further, since the irradiation light must always accurately track the recording track, it is necessary to control the irradiation light in the radial direction of the disk, that is, the tracking direction (tracking servo). Therefore, in the optical pickup support device of the information reading device, a support mechanism that movably supports an optical actuator that irradiates the disc recording surface with spot light for reading information in the focus direction and the tracking direction, and a focus error signal and a tracking error. A driving device that drives the optical actuator in the focus direction and the tracking direction according to the signal is provided. And, in the support mechanism that supports the optical actuator,
A suspension mechanism using a spring is used, and a mechanism that uses an electromagnetic force of a magnet and a coil is used for a drive device that drives an optical actuator. The structure of a conventional optical pickup supporting device is shown in FIGS. 7 (a) and 7 (b). In FIGS. 7A and 7B, reference numeral 1 is an optical actuator that includes an optical system such as an objective lens and irradiates the recording surface of the recording medium with spot light. A composite spring 2 is attached to the upper and lower ends (left and right ends) of the optical actuator 1, and is attached and fixed to the fixing portion 3 via the composite spring 2. Further, a magnetic circuit unit 4 is provided in the fixed portion 3 so as to face the optical actuator 1, and the magnetic circuit unit 4 is a drive device for driving the optical actuator 1 so as to change the optical actuator 1 vertically and horizontally. . As shown in FIG. 8, the composite spring 2 has a plurality of springs 2a to 2d set as one set by etching a plate-shaped spring material, and a dumping agent is filled between the springs 2a to 4d. , Has a vibration damping effect. Then, in the above-described optical pickup supporting device, the optical actuator 1 supported by the pair of composite springs 4 is driven by the magnetic circuit unit 4 in the focus direction and the tracking direction.

[Problems to be Solved by the Invention]

As described above, when the composite spring 2 used in the supporting mechanism of the conventional optical pickup supporting device is driven and changes, relative displacement does not occur between the individual springs 2a to 2d constituting the composite spring 2. Therefore, there is a problem that the vibration damping effect cannot be obtained even if the dump agent is filled between the springs.

[Means for solving problems]

Therefore, the present invention is intended to provide a structure for imparting a high vibration damping effect to a composite spring supporting an optical actuator. For that purpose, an optical actuator for irradiating a recording surface of a recording medium with spot light and a support for the optical actuator are provided. And a magnetic circuit unit that drives the optical actuator in the focus direction and the tracking direction.The composite spring is composed of a plurality of springs filled with a dumping agent, and is offset at its supporting position. It is characterized by being present.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In FIGS. 1 (a) and 1 (b), reference numerals 1, 3, and 4 indicate the seventh
It is the same as the conventional configuration described in FIGS.
The optical actuator, fixed part and magnetic circuit unit are shown respectively. Reference numeral 20 denotes a compound spring, and as shown in FIG. 2, a plurality of springs 20a to 20e are made into a set by etching a plate-shaped spring material, and a dumping agent is filled between the springs 20a to 20e. It is configured to be. Further, the composite spring 20 is configured such that the starting points and the ending points of the springs 20a to 20e are offset from each other, and are offset at the support position. The springs 20a to 20e have the same length and are arranged parallel to each other. The composite spring 20 configured in this way has one end fixed to the fixing portion 3,
The optical actuator 1 is supported in the air by attaching the other ends to the optical actuator 1. Next, the operation of the optical pickup supporting device using the compound spring 20 will be described. 3 (a) and 3 (b) are views showing the configurations of the compound spring 20 and the conventional compound spring 2 when the optical actuator 1 is displaced in the tracking direction,
In addition, FIGS. 4A and 4B are diagrams showing a mode when the displacement is similarly made in the focus direction. In addition, FIG. 3 (a), (b) and FIG. 4 (a),
The compound springs 20 and 2 shown in (b) are the individual springs 20a, 20b,
20c and 2a, 2b, 2c are shown as three. As is clear from FIGS. 3 (a) and 4 (a), according to the configuration using the compound spring 20 in which the supporting position is offset in the optical pickup supporting device, each spring 20a constituting the compound spring 20. Since 20c causes a relative change between the springs,
The dump agent filled between the springs 20a to 20c acts, and the damping of vibration can be extremely increased. On the other hand, in the conventional composite spring 2, in each form, the intervals between the springs 2a, 2b, 2c are only parallel, so that the dumps filled between the springs 2a, 2b, 2c There is almost no action of the agent. As described above, the composite spring 20 is configured to drive the optical actuator 1 in the tracking direction and the focus direction.
Both have a vibration damping effect. In addition, in the above-described embodiment, the spring that constitutes the composite spring 20.
Although the case where five of 20a to 20c are used has been described, this can be a plurality of two or more. Also composite springs
In 20, the structure that offsets the support position is
The present invention is not limited to the above-described embodiment, but as shown in FIG. 5, both ends may be bent in an L shape and the springs 20a to 20c may be independently arranged. With such a configuration, each spring 20a to 20c can be used as a power supply line of the optical actuator 1. 6 (a) and 6 (b) show a specific example of an optical pickup supporting device using this composite spring.

【The invention's effect】

As is clear from the above description, the optical pickup supporting device in the optical information reading device of the present invention is composed of a plurality of springs in which the composite spring supporting the optical actuator is offset at the supporting position, Even if the optical actuator is driven in both the direction and the focus direction, it has a high vibration damping effect in both directions.

[Brief description of drawings]

1 (a) and 1 (b) are a plan view and a side view showing an embodiment of an optical pickup supporting device according to the present invention, and FIG. 2 is a plan view of a compound spring used in FIGS. 1 (a) and 1 (b). FIGS. 3 (a) and 3 (b) show the configurations of the compound spring of the present invention and the conventional compound spring when the optical actuator is displaced in the tracking direction, and FIGS. 4 (a) and 4 (b) are The figure which shows the form of the compound spring of this invention when the optical actuator is displaced to the focus direction, and the form of the conventional compound spring, FIG. 5 is a top view which shows the modification of the compound spring of this invention, FIG. 6 (a),
FIG. 7B is a plan view and a sectional view showing another embodiment of the optical pickup supporting device according to the present invention using the compound spring shown in FIG. 5, and FIGS. FIG. 8 is a plan view and a cross-sectional view showing the pickup supporting device, and FIG. 8 is a plan view of the composite spring used in FIGS. 7 (a) and 7 (b). 1 ... Optical actuator, 2 ... Compound spring, 2a-2d ...
Spring, 3 ... Fixed part, 4 ... Magnetic circuit unit, 20 ...
Compound springs, 20a-20e ... springs

Claims (1)

(57) [Claims] 1. An optical actuator for irradiating a recording surface of a recording medium with spot light, a composite spring for supporting the optical actuator, and a magnetic circuit unit for driving the optical actuator in a focus direction and a tracking direction, The optical pickup support device in an optical information reading device, wherein the composite spring is composed of a plurality of springs filled with a dumping agent and is offset at its support position.