JPH08235614A - Information reader - Google Patents

Abstract

PURPOSE: To obtain an information reader in which the optical axis of an objective lens and that of a light source are adjusted easily. CONSTITUTION: Conductor arrangement faces of focusing coils 13A, 13B are provided with a first conductor part and a second conductor part which are nearly parallel to a medium face and which are separated from each other, and conductor arrangement faces of tracking coils are provided with a third conductor part 20 and a fourth conductor part 21 which are nearly vertical to the medium face and which are separated from each other. It is constituted that magnetic fluxes whose polarities are opposite to each other are directed to the first conductor part and the second conductor part and that magnetic fluxes whose polarities are opposite to each other are directed to the third conductor part and the fourth conductor part. In addition, the first, second, third and fourth conductor parts are faced respectively with faces of permanent magnets 12A, 12B, and at least the first conductor part and the second conductor part are arranged between a first virtual plane which comes into contact with the end part of the third conductor part on the side close to the medium face and which is parallel to the medium face and a second virtual plane which comes into contact with the end part of the fourth conductor part on the side away from the medium face and which is parallel to the medium face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved information reading device.

[0002]

2. Description of the Related Art JP-A-59-201240 discloses
Focusing coil having a lens (reference numeral 27) for irradiating a recording medium with convergent light and a conducting wire arranging surface perpendicular to the medium surface of the recording medium (appearing surface generated by arranging a plurality of coil conducting wires in close contact) (Reference numeral 32) and the tracking coil (reference numeral 33) support (arm 30,
A permanent magnet (reference numeral 55a, 55b) fixed to a bobbin 51) and having a surface facing the conductor array surface with a gap and perpendicular to the medium surface is arranged to perform focusing drive and tracking drive. At this time, the coil is in the surface direction of the surface of the permanent magnet (the “surface direction” is the direction perpendicular to the medium surface in the case of focusing drive, and in the case of tracking drive, as shown in FIG. 4 of the above publication). When the optical head is viewed in the direction of the optical axis of the lens, the surface of the permanent magnet is an arc centered on the axis of the shaft 34, so that the surface of the permanent magnet should move substantially along the circumference of the shaft 34. The information reading device configured as described above is described. However, the technique disclosed in this publication has a larger magnetic flux because it directs the magnetic flux only to one of the two conductive wire portions formed on the left and right of the conductive wire arranging surface of the tracking coil substantially perpendicular to the medium surface. Tracking driving force cannot be obtained,
There is a drawback that it is not possible to expect an efficient tracking drive force.

[0003]

As a technique for solving such a drawback, there is a technique disclosed in Japanese Utility Model Laid-Open No. 59-66926. In the conductor arrangement plane of the tracking coil (reference numeral 28) of FIG. 4 of the publication, there are two conductor portions of the coil (vertical portions 28a and 28b of the drive coil of FIG. 4) which are substantially perpendicular to the medium surface. Then, magnetic fluxes of opposite polarities are directed to the respective conductor portions. However, this publication does not describe how to incorporate a focusing coil to drive focusing.

On the other hand, the following technique is described in Japanese Utility Model Laid-Open No. 59-107726. The support (reference numeral 2) is provided with four wires (10a, 10b, 10) on the base (reference numeral 11) so that the lens (reference numeral 1) is guided in the focusing direction (reference numeral F) and the tracking direction (reference numeral T).
c, 10d). The focusing coil (reference numerals 8 and 9) and the tracking coil (reference numeral 7) are fixed to the support. Furthermore, focusing driving is performed by directing magnetic fluxes of opposite polarities to the two conducting wire portions, that is, the upper conducting wire portion and the lower conducting wire portion, which are parallel to the medium surface of the focusing coil (reference numerals 8 and 9). ing.

However, in the technique disclosed in the above publication, the coil moves in the direction perpendicular to the magnetic pole surface of the permanent magnet (T direction in FIG. 3) during tracking drive, so that the coil may collide with the magnetic pole surface. There is a drawback that the coil is easily damaged. As a solution to these drawbacks, there is a technique disclosed in JP-A-58-118037 shown below. A lens (reference numeral 1) for irradiating the recording medium with convergent light and a plane for arranging the coil wire perpendicular to the medium surface of the recording medium (first
A focusing coil (reference numeral 7) having the coils 6 and 7 in FIGS. 3 and 6 and a tracking coil (reference numeral 6) are a support body (holding body 2 and an auxiliary plate integrally fixed to the holding body 2). 5 is also included in the support). A surface (a permanent magnet 10a in FIG. 3;
Permanent magnets (reference numerals 10a, 10a ', 10) having 0a', 10b, 10b 'facing the coils 6, 7)
b, 10b ') are arranged. Here, in focusing drive and tracking drive, the coil is substantially along the surface direction (x direction or z direction) of the surface (“almost along” is a direction substantially parallel to the extending direction of the surface). Meaning) It is designed to move. The focusing coil has a first conductive wire portion substantially parallel to the medium surface (a coil conductive wire portion substantially parallel to the upper medium surface near the medium surface of the flat coil 7 in FIG. 1a) and a second conductive wire portion (FIG. 1). a of the flat coil 7 and a conducting wire portion substantially parallel to the lower medium surface far from the medium surface), and the tracking coil is a third conductive wire portion substantially perpendicular to the medium surface (the flat coil 6 of FIG. 1a). Of the first conductor portion and a fourth conductor portion (a conductor portion of the flat coil 6 shown in FIG. 1a which is perpendicular to the right medium surface of the flat coil 6). The magnetic fluxes having mutually opposite polarities are directed to the two conductor portions, respectively. On the other hand, magnetic fluxes of opposite polarities are directed to the third conductor portion and the fourth conductor portion, respectively, and the first, second, third, and fourth coil conductor portions are respectively arranged on the surface. It is arranged to face each other.

Here, the focusing coil (reference numeral 7)
And the tracking coil (reference numeral 6) are arranged so as to be substantially L-shaped. Here, an elastic member made of a spring or rubber is connected between the support and the base on two side surfaces perpendicular to the y-axis among the four side surfaces of the substantially cubic structure of the support body. On the other hand, a trapezoidal prism (reference numeral 17) is arranged on the side surface of another support perpendicular to the x-axis, and a tracking coil (reference numeral 6) having a conductor array surface perpendicular to the side surface and the medium surface on the other side surface. Is fixed. Therefore, the focusing coil (reference numeral 7) has to be fixed to the bottom surface of the support body.

Assuming that the focusing coil is fixed to the side surface of the support body, the support body (reference numeral 2) is y in the arrangement structure of the elastic members (reference numerals 3 and 3) as shown in FIG.
There is a risk of turning around the axis during focusing drive. In the arrangement of the focusing coils as disclosed in Japanese Patent Application Laid-Open No. 58-118037, the size of the support in the focusing direction becomes large, which is not suitable for thinning the information reading device, and the weight of the support becomes large. There is a drawback that good responsiveness of focusing drive and tracking drive cannot be expected.

An object of the present invention is to provide an information reading device that solves the above drawbacks.

[0009]

In the information reading apparatus of the present invention, a lens for irradiating a recording medium with convergent light and a conductor array surface perpendicular to the medium surface of the recording medium (a plurality of coil conductors are arranged in close proximity to each other). A focusing coil and a tracking coil having an external surface (though not necessarily visible) caused by the above, are fixed to a support, and are opposed to the conductor array surface with a gap and are perpendicular to the medium surface. Is disposed, and the coil moves substantially along the surface direction of the surface during focusing drive and tracking drive (“move substantially along the surface direction”).
Means that the moving direction of the coil is approximately parallel to the plane direction of the surface of the magnet within the moving range of the coil for a short distance during focusing drive or tracking drive. In the information reading device configured so as to exclude the configuration in which the coil moves toward the first direction), a first conductor portion and a second conductor portion that are substantially parallel to the medium surface and are separated from each other are provided on the conductor arrangement surface of the focusing coil. And a third conductor portion and a fourth conductor portion which are substantially perpendicular to the medium surface and are spaced apart from each other on the conductor arrangement surface of the tracking coil. And magnetic fluxes having opposite polarities to the second conductor portion, and magnetic fluxes having opposite polarities to the third conductor portion and the fourth conductor portion, respectively. The first, second, third, and fourth conductive wire portions respectively face the surface and are parallel to the medium surface and are separated from each other by a first virtual plane and a second virtual plane, The coil was sandwiched in a contact state ("sandwiched in a contact state" means that "a coil conductor closest to the medium surface and a coil conductor farthest from the medium surface are both in contact with each other") At this time, at least the first conductor portion and the second conductor portion are arranged between the first virtual plane and the second virtual plane.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1A to 1E show a first embodiment of the pickup and carriage actuator of the present invention. The movable portion main body 1 having a substantially rectangular parallelepiped shape is provided with a communication hole 2 vertically extending therethrough at the center thereof. PENCOM INT
An optical head 3 called an ERNATIONAL model 60 is attached to the upper surface of the movable portion main body 1 at its flange portion 4 in such a manner that it is loosely fitted in the communication hole 2. A hollow coil support cylinder 6 is externally fitted to the rising portion 5 of the optical head 3, and a lens holder 7 having the same diameter is connected to the lower end of the coil support cylinder 6. The lens holder 7 is made of an aluminum material, and an objective lens 8 is fixed to the lower end of the lens holder 7. The outer surfaces of the coil support cylinder 6 and the lens holder 7 are shown in FIGS.
As shown in Fig. 2, each two wires 9A, 9B, 10A, 1
OB is fixed, and each end of the wire is fitted and fixed to the wall surface of the communication hole 2.

Inside the movable portion main body 1, there are provided rectangular parallelepiped internal spaces 11A and 11B orthogonal to the communication hole 2, and a pair of magnetic circuits 12A and 12B are installed in the space. The magnetic circuit 12A (12B) is composed of upper and lower permanent magnets and a non-magnetic material sandwiched between them. Focusing coils 13A and 13B and tracking coils 14A and 14B are fixed to the side surface of the coil support cylinder 6 as shown in FIGS. 1 (a), 1 (b) and 1 (c). The focusing coils 13A and 13B are wound along the circumferential direction of the coil support cylinder 6. The tracking coils 14A and 14B are formed by overlapping a part of two coils wound in a square shape, and the shape thereof is shown in FIG. 1 (d).

Guide rollers 17A to 17A are provided in a portion where the corner where the side surface of the movable body 1 and the upper surface or the lower surface intersect is cut off.
17D is fixed. These guide rollers 17A to 17D
Is in contact with the inclined surfaces of the prismatic guide members 18A and 18B extending along the moving direction of the movable portion main body 1, and smoothly guides the movement of the movable portion main body 1. Next, the operation of this embodiment will be described. Focusing coils 13A, 13
B, the positional relationship between the tracking coil 14B and the magnetic circuit 12B is shown in FIGS. 1 (d) and 1 (e). Actually, the focusing coils 13A and 13B and the tracking coil 14
As shown in FIG. 1 (c), A and 14B are fixed so as to be superposed on the surface of the coil support cylinder 6. Coil 14
In order to make it easier to see the positional relationship between B, 13A and 13B and the magnetic circuit 12B, they are shown separately in FIGS. 1 (d) and 1 (e).

In order to perform tracking, when a current is passed through the tracking coil 14B in FIG. 1 (d), the directions of the magnetic field and the current are reversed in the coil portions 20 and 21, so that a force in the same direction is generated and the objective The lens 8 is shown in FIG.
To move in the tracking direction indicated by the arrow. Next, focusing is performed by focusing coil 13 in FIG.
When currents are applied to A and 13B in opposite directions, the magnetic fluxes from the magnetic circuit 12B that traverses the coils are also in opposite directions, and as a result, forces in the same direction are generated and the objective lens 8 is moved to the position shown in FIG.
It is moved in the focusing direction indicated by the arrow (e). In both cases of tracking and focusing described above, the magnetic flux 22 generated from the magnetic circuit 12B is as shown in FIG.
As described above, the upper N pole is crossed across the coil at a right angle, the coil is moved downward along the coil support cylinder 6, and then the coil is turned rightward to pass through the coil and return to the lower S pole. Although this description has been made for the magnetic circuit 12B, the same operation is performed for the magnetic circuit 12A side, and the direction of the current is set so that the directions of the generated forces are the same on the magnetic circuit 12A side and the magnetic circuit 12B side. do it.

FIGS. 2A and 2B show a structure in which the wires 9A, 9B, 10A and 10B of FIG. 1A are used as leaf springs, and the deformation of the wires for supporting the lens holder 7 and the coil support cylinder 6 is shown. Here is an example. Generally, since the movable range of focusing and tracking is about 10: 1, the length ratio of the focusing leaf spring 26 to the tracking leaf spring 27 joined thereto is 10: 1 in FIG. 2 (A). Further, in FIG. 3B, the leaf springs have the same length and the thickness ratio is 10: 1.

FIG. 3 shows an embodiment of the pickup optical system. This optical system is PENCOMINTERNATION
It is an optical system of AL model 60. The light beam emitted from the laser 28 is collimated by the collimator lens 29, passes through the hologram 30, and is focused on the recording medium by the objective lens 8 in the actuator 31. The reflected light from the recording medium passes through the objective lens 8 again, and the hologram 3
The detector 3 is deflected by 0 and collimator lens 29 is used.
Focused on 2.

Further, the entire pickup section is lightweight,
If a sufficient frequency response characteristic can be obtained, the tracking coil may be removed and the carriage coil may also be responsible for the tracking function. The shape of the recording medium is not limited, and may be, for example, a card shape.

[0017]

According to the information reading apparatus of the present invention, a lens for irradiating a recording medium with convergent light and a focusing coil having a conductor array surface perpendicular to the medium surface of the recording medium and a tracking coil are fixed to a support. A permanent magnet having a surface facing the conductor array surface with a gap and perpendicular to the medium surface is arranged so that the coil moves substantially along the surface direction of the surface during focusing driving and tracking driving. In the configured information reading device, the conducting wire arrangement surface of the focusing coil has a first conducting wire portion and a second conducting wire portion that are substantially parallel to the medium surface and are separated from each other, and the conducting wire arrangement of the tracking coil. The surface has a third conductor portion and a fourth conductor portion that are substantially perpendicular to the medium surface and are spaced apart from each other, and the third conductor portion and the fourth conductor portion are provided in the first conductor portion and the second conductor portion. The magnetic fluxes of opposite polarities are directed respectively, and the magnetic fluxes of opposite polarities are directed to the third conducting wire portion and the fourth conducting wire portion, respectively. 4, each of the conductive wire portions faces the surface, is in contact with an end of the third conductive wire portion on the side closer to the medium surface, and is parallel to the medium surface; At least the first conductive wire portion and the second conductive wire portion are arranged between a second imaginary plane that is in contact with the end of the fourth conductive wire portion on the far side and is parallel to the medium surface. Therefore, the present invention has an advantage that stable tracking drive can be expected as compared with the prior art disclosed in Japanese Patent Laid-Open No. 58-118037.

[0018]

According to the information reading apparatus of the present invention, a lens for irradiating a recording medium with convergent light and a focusing coil having a conductor array surface perpendicular to the medium surface of the recording medium and a tracking coil are fixed to a support. A permanent magnet having a surface facing the conductor array surface with a gap and perpendicular to the medium surface is arranged so that the coil moves substantially along the surface direction of the surface during focusing driving and tracking driving. In the configured information reading device, the conducting wire arrangement surface of the focusing coil has a first conducting wire portion and a second conducting wire portion that are substantially parallel to the medium surface and are separated from each other, and the conducting wire arrangement of the tracking coil. The surface has a third conductor portion and a fourth conductor portion that are substantially perpendicular to the medium surface and are spaced apart from each other, and the third conductor portion and the fourth conductor portion are provided in the first conductor portion and the second conductor portion. The magnetic fluxes of opposite polarities are directed respectively, and the magnetic fluxes of opposite polarities are directed to the third conducting wire portion and the fourth conducting wire portion, respectively. When the tracking coil is sandwiched in contact with a first virtual plane and a second virtual plane, which are parallel to the medium surface and are spaced apart from each other, Since the first conductor portion and the second conductor portion are at least arranged between one virtual plane and the second virtual plane, the present invention has the following effects. .

Positioning of the optical head member (hologram unit) of the present invention and the objective lens in the direction perpendicular to the optical axis of the light beam emitted from the optical head member and the optical axis of the objective lens, and the objective lens. The alignment of the objective lens and the optical head member in the optical axis direction has the advantage of being extremely simple.

[Brief description of drawings]

1 (a), (b), (c), (d) and (e) are diagrams showing an embodiment of the present invention.

2A and 2B are modified examples of an elastic support member.

FIG. 3 is a diagram illustrating an optical system of the present invention.

[Explanation of symbols]

 1 movable part main body 3 optical head 6 coil support cylinder 7 lens holder 13A focusing coil 14B tracking coil

Claims (1)

[Claims] 1. A lens for irradiating a recording medium with convergent light, a focusing coil having a conductor array surface perpendicular to the medium surface of the recording medium, and a tracking coil are fixed to a support, and a gap is provided on the conductor array surface. A permanent magnet having a surface facing each other and perpendicular to the medium surface is arranged, and the coil is moved substantially along the surface direction of the surface during focusing driving and tracking driving, A first conductor portion and a second conductor portion, which are substantially parallel to the medium surface and are spaced apart from each other, are provided on the conductor arrangement surface of the focusing coil.
And a third conductor portion and a fourth conductor portion which are substantially perpendicular to the medium surface and are spaced apart from each other on the conductor arrangement surface of the tracking coil. And magnetic fluxes having opposite polarities to the second conductor portion, and magnetic fluxes having opposite polarities to the third conductor portion and the fourth conductor portion, respectively. The first, second, third, and fourth conductive wire portions respectively face the surface and are in contact with the tracking coil by a first virtual plane and a second virtual plane that are parallel to the medium surface and are separated from each other. An information reading device, wherein when sandwiched, at least the first conductor portion and the second conductor portion are arranged between the first virtual plane and the second virtual plane.