JPS60182027A - Optical focusing position shifter - Google Patents

Abstract

PURPOSE:To decrease number of coils to be used and also to improve the utilizing efficiency of a current flowing to the coils by arranging two coils each formed with channel-shape oppositely at a gap of a magnetic circuit. CONSTITUTION:The two coils are formed as U-shape respectively and they are fitted to a bobbin 4. It is supposed that a direction of a magnetic field is 13 and a direction of a current is 11, then a magnetomotive force 14 in the track direction (y direction) is obtained and the track control is attained. In this case, all currents in Z direction contribute to the driving force, and since the same driving force with the same number of turns of the coils as a conventional method is obtained, the inductance is decreased by the share of decrease in the number of coils. The burden on the control circuit is relieved with the smaller inductance and current consumption at a high frequency is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a system for irradiating light onto the Tinuku surface, which is a source of all information, and detecting the reflected light, such as an optical Dinuku device. The present invention relates to the structure of a coil for controlling the track position.

Recently, I read information optically Jll! ? 9, and devices for performing male penetration, such as digital audio discs and magneto-optical discs, have begun to be prototyped or put into practical use. However, the information 'fi (bits) recorded on a Tinuku is extremely small, and accurate reading and writing cannot be carried out unless constant control 17 is taken to prevent track deviations of the optical disc due to eccentricity of the disk.

Generally, when performing position control, there is a detection unit that detects the deviation from the desired position (i position), a calculation unit that generates a signal to move the control logarithm according to the amount of deviation, and a calculation unit that actually detects the control target. A drive device rt is required to move it.By the way, in the case of optical dinuks, etc. 1. As a drive device, there are 11 methods of driving using an insulating Z force using a combination of a magnetic circuit and a coil.The present invention This is related to the 41.1 structure of the magnetic circuit and coil for track position control in this drive device, and is intended to reduce the number of coils used and increase the efficiency of using the current flowing through the coil. The details of the present invention are explained below along with the drawings.
Give a detailed explanation.

The method of configuring the magnetic circuit and coil for track control drive is as follows.
Fuokanu control 1! Although various proposals have been made, including a combination with TK+suke, the example shown in Figure 1 is a typical configuration. Figure 1 (α) is a plan view showing the structure of the magnetic circuit and coil 2, where the y direction is the track direction and the second direction is the fork direction (that is, the Dinuk plane is perpendicular to the z axis). (b) Chill with the front view of the rice.2
magnets2. A magnetic circuit is formed by the sand wire 3, and a π-direction Ω magnetic field 13 is generated. Four coils 1 are attached to the bobbin 4 in the gaps of this magnetic circuit. coil 1
is wound as shown in Figure 1 (-) to form 3-? As a result, current flows in opposite directions at both ends. @1 In Figure (cL), assume that the polarity of the magnet is in the direction indicated by the symbols N and S in the figure, and consider the case where currents 1.1 and 12 are passed through the coil. Current 11 is shifted in the y direction by magnetic field 13. magnetic force of 14
Therefore, it is possible to drive in the track direction [V direction]. However, in this case, the current 12 that does not intersect with the magnetic field 13 does not contribute to the driving force, resulting in poor efficiency, the number of coils increases, and the inductance also increases accordingly. In addition, Fig. 1<a> is shown in Fig. 2.
An example is shown in which the protruding portion of the coil is bent, but this is also exactly the same in terms of efficiency.

Therefore, the present invention aims to reduce the number of coils from four to two, and to increase the driving efficiency.

Figure 3 shows the actual result 1. (There are 11 examples, two coils are each formed into a U-shaped shape as shown in Figure PI3), and they are made into a bobbin/4 shape as shown in Figure 3(a). Give 9 to . Figure 1 (
Similar to α), the direction of the magnetic field 13 as shown in Figure 3 Ca)
Assuming the current direction 11, a magnetic force 14 in the track direction (V direction) is obtained and nl track control can be performed. In this case, the currents in both directions will all be involved in the driving force, so the same driving force can be obtained with the same number of coil turns as the conventional example shown in Figure 2R1 and Figure 2.
The inductance can also be reduced by reducing the number of coils. If the inductance is small, the burden placed on the control circuit is light (and the current consumption at high frequencies can also be reduced.And above all, the productivity of the invention is improved by reducing the number of coils). It can be said that the value is strong.

In addition, the present invention can be applied to any type of magnetic circuit as long as the necessary magnetic field can be obtained, and furthermore, it can be applied to any type of magnetic circuit as long as the necessary magnetic field is obtained. Let's add the following and explain that it does not apply to any case where t is applied, such as when moving .

[Brief explanation of the drawing]

Figure WJ1 is a diagram showing the configuration of a magnetic circuit and coil for conventional track control IN operation, Figure 1 (cL) is a plan view showing the configuration thereof, Figure 1 (b) is a front view thereof, 1st (
C) is a plan view showing how to wind the coil. FIG. 2 is a plan view showing a conventional embodiment similar to FIG. 1(G). Fig. 3 is an example of the present invention, Fig. 3 (@) is a plan view showing the structure of the magnetic circuit and the coil, and Fig. 3 (b) is a perspective view showing how to wind and bend the coil. be. 1°, coil 21 in the conventional example. Magnet 31. Magnetic material 4. Bobbin +1, +2°. The symbol 13° indicates the direction of the current flowing through the coil. , the symbol 146° indicating the direction of the six-circle field. . The symbol 21° indicates the direction of magnetic force. 0 Coil in the present invention Applicant: 10 Iko Electronics Industry Co., Ltd. Representative Patent Attorney Mogami Mu SI'J1i',','I(a)713]
! ``ζ1(b) '-:; ] Figure (c) Continued from page 1 0 Inventor: Seiji Hoshi At Kameido Company, Koto-ku, Tokyo 0 Inventor Yasuhiro Takemura At Kameido Company, Koto-ku, Tokyo

Claims (1)

[Claims] 1. A light source, a means for converging the light emitted from the light source, a disk which is an information storage medium irradiated with 1% light (61f), and a focusing means (i"iii). The light focusing position is i'H1
An optical focusing position moving device comprising means for detecting f'L between a desired track position of a second disc and a means for directing the focused light to the desired track position, The means for guiding the 01r flux light to the desired track position uses a magnetic force generated by passing a current through a coil inserted into a gap between a magnetic circuit made of a magnet and a magnetic body and a fii + magnetic distribution circuit. The optical focusing position moving device is characterized in that the nil coil is two coils each formed into a U-shape and facing each other at a gap between the anchor circuits. ``In the optical focusing position moving method according to claim 1, the means for guiding the focused light to the desired trunk position is characterized by being accomplished by moving the entire optical system. 3. In the optical focusing position moving method according to claim 1, the means for guiding the focused light to the desired track position is configured to move an objective lens. J: 5 formation 3
An optical focusing position moving device characterized by: