JPS6159636A - Object lens driving device - Google Patents

Abstract

PURPOSE:To make the increase of the number of turns of coils unnecessary to simplify the winding process by equalizing gaps between outside peripheral surfaces of the first and the second coils, which drive an object lens in the focus direction and the tracking direction respectively, and a pair of magnets. CONSTITUTION:The first coil 9 is wound around a bobbin 25 of a supporting member of an object lens 8, and the second coil 10 is wound around a bobbin 29, and the same magnetic poles of a pair of magnets 11 are allowed to face the lens 8, and the lens 8 is driven in the focus direction and the tracking direction. Since gaps between outside peripheral surfaces of coils 9 and 10 and magnets 11 are equalized, the magnetic loss of the coil 9 is reduced, and the driving force is increased though the number of turns is not increased, and therefore, the winding process is simplified considerably to improve the productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to reading recorded information on a disc-shaped recording information medium (disc) using an objective lens.

The present invention relates to an objective lens drive device attached to an optical information recording/reproducing device that writes new information onto a disk.

In general, optical information recording and reproducing devices are configured to optically read recorded information on a disk or write new information to the disk by using an optical element to make a laser beam enter an objective lens. ing.

By the way, in this optical information recording/reproducing device, the objective lens is moved by one direction in the focus direction so as to follow the surface runout of the disk, and the objective lens is moved one direction toward the focus direction to follow the one-rack runout that occurs in the radial direction due to eccentricity when the disk rotates. Since it is necessary to drive the objective lens in the 1-racking direction in order to obtain the desired results, an objective lens driving device is provided to drive the objective lens with high sensitivity.

Conventionally, there are objective lens driving devices for this dish as shown in FIGS. 3 to 56. That is, 1 shown in FIGS. 3 and 4 is the main body of an optical information recording and reproducing device. Reference numeral 2 denotes an objective lens driving device attached to the main body 1, and is configured as described below. A pair of leaf springs 3 have one end attached to the main body 1, and are connected by a connecting member 4 so as to be simultaneously driven in the focus direction F by magnetic force and elastically deformed. A pair of temporary springs 5 which are simultaneously driven in the tracking direction T by electromagnetic force and are elastically deformed are attached to the connecting member 4. This leaf spring 5 is attached to the main body 1 integrally with the leaf spring 3 via a connecting member 4, and intermediate members 6, 6 are respectively attached to the main body 1 side. Each intermediate member 6 is attached to opposing side surfaces of an objective lens support member 7, and an objective lens 8 is attached to the objective lens support member 7.

The objective lens 8 is provided on the outer peripheral surface of the objective lens support member 7.
A first coil 9 for driving the lens in the focus direction F is wound to form a rectangular parallelepiped as shown in FIG. Further, on the outer circumferential surface of the first coil 9, four second coils 10 are formed by bending at 90 degrees to drive the objective lens 8 once in the tracking direction T, and project outward.

In the figure, a pair of magnets 11 forming a magnetic circuit are installed on the left and right outer sides of the first coil 9 and the second coil 10 via a yoke 12 attached to the main body 1. Each magnet 11
The same magnetic pole is connected to the first coil 9. While facing the second coil 10, the distance G1 from each magnetic pole to the outer peripheral surface of the first coil 9. The second coil IO is arranged so as to maintain a distance G2 to the outer circumferential surface of the second coil IO. Note that 13 is a way 1 balance member attached to the objective lens support member 7, and 14 is a disk.

□ By the way, in such an objective lens drive device, the second
Since the coil 10 is attached to the outer peripheral surface of the first coil 9,
The interval G1 is formed to be larger than the interval G2. Therefore, the magnetic loss of the first coil 9 becomes larger than that of the second coil 10. Therefore, in order to prevent a decrease in driving force, the number of turns of the first coil 9 has to be increased, resulting in an increase in weight and size, and it has been necessary to increase the current used. In addition, since the second coil 10 is attached from the corner of the first coil 9 so as to face both sides, the second coil 10 has a shape bent at 90 degrees. Therefore, there is a problem that not only is production time-consuming and productivity is low, but also there is a risk of wire breakage.

Furthermore, in order to install the second coil 10 so as to maintain the spacing G2 without contacting the magnet 11, a highly accurate assembly process is required, which causes the problem of varnish 1-up.

Purpose This invention was made in view of the above-mentioned problem, and its purpose is to prevent an increase in the number of turns of each coil by forming the same distance from the outer peripheral surface of the first coil and the second coil to the magnet. In addition, the object of the present invention is to provide an objective lens driving device that improves productivity by simplifying the winding process.

Structure In order to achieve the above object, the objective lens driving device according to the present invention has the following features:1. ＆′? i have a long time. That is, a first coil for driving the objective lens in the focusing direction is wound around the objective lens support member to which the objective lens is mounted, and a second coil for driving the objective lens in the trunking direction is wound around the outer peripheral surface of the first coil. A coil is attached, and a pair of magnets with the same magnetic poles are placed outside the first coil and the second coil, and an objective lens driver II attached to the optical information recording/reproducing device is attached. In the IJ device, the objective lens support member around which the first coil is wound.

A pair of frame members around which the second coil is wound in a direction perpendicular to the first coil can be taken out so as to sandwich the objective lens, and from the outer peripheral surfaces of the first coil and the second coil to the magnet. It is constructed by forming the intervals of 9 to have the same interval. and.

With this configuration, nF+J of the winding process of each coil
In addition to improving productivity by increasing the number of coils to three parts, we are also trying to prevent a decrease in the driving force of the coil.

Example The present invention will be explained below based on the drawings.

FIGS. 1 and 2 are diagrams showing an embodiment of the present invention.

In this embodiment, the same reference numerals are used for the same parts and members as in the conventional example described above, and the explanation thereof will be omitted.

In each figure, the reference numeral 20 denotes an objective lens drive device according to the present invention, which is constructed as follows. That is, reference numeral 21 denotes a pair of hinge members of the objective lens driving device 20, which are arranged at a distance of R1i from each other, and both ends of which are respectively attached to the main body 1 of the optical information recording/reproducing device. The spring members 21 are formed in the same shape so as to be elastically deformed when driven in the 1-racking direction T by electromagnetic force.

Further, an objective lens support member 22 is disposed inside the wing member 21.21. The objective lens support member 22 is provided with a mounting part 23 for mounting the objective lens 8 and a mounting part 24 for mounting the balance member 13, and the first coil 9 is wound between these mounting parts 23 and 24. A bobbin 25 is formed. On the main body 1 side of the objective lens support member 22, a pair of magnets 11 are installed with the same magnetic poles facing the objective lens 8 and spaced apart from both sides of the objective lens support member 22 at equal intervals. The first coil 9 is wound around the bobbin 25 so that the outer peripheral surface facing each magnet 11 is maintained at an equal distance from the magnet 11.

Further, on the spring member 21 side of the objective lens support member 22, a second coil IO is attached to a frame portion, l, 4' 2
2G has a mounting part 27 mounted on the objective lens support part +A'22 and a mounting part 28 mounted on the wing part Vi21, and these mounting parts 27. A bobbin 29 for winding the second coil 10 in a direction orthogonal to the first coil 9 is formed between the coils 28 and 28 .

In this frame member 2G, attachment portions 27 and 28 are attached to the objective lens support member 22 and the spring portion 21, respectively. Further, the second coil 10 is wound to a high degree before being attached to the objective lens support member 22, or after being attached to the objective lens support member 22. Each of the second coils 10 is wired so that current flows in the same direction, and each outer peripheral surface on the magnet 11 side is installed so as to maintain the same position as the outer peripheral surface of the first coil 9. Furthermore, the distance from each outer peripheral surface to the magnet 11 can be made closer to the magnet 11 as necessary. The closer the object is, the more the sensitivity when driving the objective lens 8 can be improved.

Next, the effect will be explained.

When the objective lens 8 is driven in the focus direction F of the disk 14, a current in the opposite direction flows through the portion of the first coil 9 facing the magnet 11, as shown in FIG. Therefore, electromagnetic force in the same direction acts on the first coil 9, driving the objective lens 8 in the focus direction F. In this case, the first
Since the distance from the outer circumferential surface of the coil 9 to the magnet 11 is the same as the distance from the outer circumferential surface of the second coil 10 to the magnet 11, the magnetic loss of the first coil 9 is reduced. The driving force increases and the sensitivity improves without increasing the number of turns or increasing the power used. Also,
When the objective lens 8 is driven in the 1-racking direction T, currents in the same direction flow in the portions of each second coil 10 that face the same magnet 11, as shown in FIG. Therefore, an electromagnetic force in the same direction acts on the second coil 10, and the objective lens 8 is driven in the 1-racking direction T.

In this case, since the second coil 10 is wound around the bobbin 29 of the frame portion 26, the winding process is simplified, productivity is improved, and the risk of wire breakage is also reduced.

Effects As explained above, the present invention winds the first coil around the objective lens support member, FA, and winds the second coil around the pair of frame members attached to the objective lens support member. Since the distance from the outer circumferential surface of the second coil to the magnet is the same, the winding process for each coil can be simplified more easily than in the past. Therefore, other processes are also simplified and productivity is not only significantly improved, but also an accident of disconnection of the second coil is prevented. Furthermore, since the distance from the outer peripheral surface of each coil to the magnet is the same, there is no need to increase the number of turns of the coil or to increase the power for the coil in order to increase the driving force of the objective lens. Moreover,
Since this distance allows the magnet to be approached, the sensitivity can also be improved in the combination C in which the objective lens is driven in the direction of the focus direction and the 1-ranking direction.

[Brief explanation of drawings]

1 and 2 show an embodiment of the objective lens driving device according to the present invention, FIG. 1 is a partially cutaway plan view, FIG. 2 is a partially cutaway side view, and FIG. 3 is a partially cutaway side view. 5 to 5 do not show conventional examples, FIG. 3 is a partially cutaway side view, FIG. 4 is a partially cutaway plan view, and FIG. 5 is a perspective view of the first coil and the second coil. be. 2.20... Objective lens drive type, 8... Objective lens, 9... First coil. 10...Second coil, 11...Magnet, 22...
...Objective lens support member, 26...Frame member. Figure 1 Figure 2 Figure 4 Figure 4 Figure 5

Claims (1)

[Claims] A first coil for driving the objective lens in the focus direction is wound around the objective lens support member on which the objective lens is attached,
A second coil for driving the objective lens in the tracking direction is attached to the outer peripheral surface of the first coil, and a pair of magnets are installed outside the first coil and the second coil with the same magnetic poles facing each other. In addition, in the objective lens driving device attached to the optical information recording and reproducing device, the objective lens support member around which the first coil is wound,
A pair of frame members in which the second coil is wound in a direction perpendicular to the first coil are attached so as to sandwich the objective lens, and the distance from each outer circumferential surface of the first coil and the second coil to the magnet is An objective lens driving device characterized in that: are formed at equal intervals.