JPH01303035A - Frequency generator for motor - Google Patents

Abstract

PURPOSE:To facilitate assembling of a thin and precise device, by securing a reflection board to the magnetized face of a polarized magnet constituting a rotor corresponding to a light emitting/receiving element fixed to a stator substrate. CONSTITUTION:A polarized thin disc magnet 2 is fitted to the ring 1a, having C-shaped cross-section, of a rotor 1 supported rotatebly. A reflection disc 5 having alternating light reflecting sections 5a and light absorbing sections 5b is adhered to the magnetized face 2a of the magnet 2. A stator winding 3 connected with the electric wiring section 4a of a stator substrate 4 is faced with the magnetized face 2a. An optical element 6 comprising a light emitting element and a light receiving element is fixed to the stator winding 3 in order to detect light reflected from the reflection board 5. By such arrangement, thin, highly accurate and easily assemblable products can be mass produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a frequency generator for a motor used in equipment such as a tape recorder with its rotation speed controlled.

Conventional technology When a motor is used in equipment such as a tape recorder, it is common to control the number of rotations. It is necessary to provide a number detection means. The rotational speed detection means is desired to be capable of highly accurate detection, downsized, and easy to manufacture (mass production), and various means have been proposed and adopted. Among them, from a precision standpoint, a frequency generator (which generates an AC voltage proportional to the rotation speed of the mortar)
The FG (hereinafter referred to as FG) has the highest detection ability, and one method is to rotate a reflector plate with a light-reflecting surface with a pattern that reflects and absorbs light together with the rotor of the motor, and emits light. The optical FG, which generates an alternating current voltage by arranging the receiving/emitting surface of an optical element having a detecting/receiving/emitting surface facing a light reflecting surface, has the advantage of not being affected by the electrical effects of electronic devices such as tape recorders. It is widely adopted.

3.\-7 An example in which a conventional optical FG is applied to a planar opposed motor will be described below with reference to the drawings.

FIG. 4 is a vertical sectional view of the conventional example, and FIGS. 5 and 6 are
5 is a plan view seen from the entrance direction and the B direction in FIG. 4. FIG.

In FIG. 4, a rotor 1 is rotatably supported by a holding means (not shown).

Reference numeral 2 denotes a disk-shaped rotating magnet, which is fixed to the rotor 1 and has a polarized magnetized surface 2a. A fixed winding 3 is disposed facing the magnetized surface 2d, fixed to the stator board 4, and connected to the electrical wiring section 4a of the stator board 4. Reference numeral 5 denotes a reflecting plate, which is fixed to the surface 1b opposite to the fixed surface 1a of the disc-shaped rotating magnet 2 of the rotor 1, and has a reflecting portion 5a that reflects light and an absorbing portion 5b that absorbs light arranged alternately. It has a reflective surface 5C. Reference numeral 6 denotes an optical element, which has a light receiving/emitting surface 6c having a light emitting part 6d for emitting light and a detecting part 6b for detecting light, and a holding means (not shown) such that the light receiving/emitting surface 6c faces the reflective surface 5c. It is fixed to the stator board 4 by. A connection line γ connects the emitting section 6a and the detecting section 6b of the optical element 6 to the electrical wiring section 4d of the stator board 4.

Next, the operation of the conventional optical FG configured as described below will be explained.

A motor drive circuit (not shown) continuously generates a rotational force in a desired direction between the disc-shaped rotating magnet 2 and the fixed winding 3, thereby continuously rotating the rotor 1 and the reflecting plate 5. As a result, the reflecting part 5a and the absorbing part 5b of the reflecting plate 6 alternately face the light receiving/emitting part 6C, and the optical element 6 generates an alternating current voltage, and the rotational speed of the rotor 1, that is, the motor, can be detected based on the frequency of this alternating voltage. .

Problems to be Solved by the Invention However, although the conventional optical FGs shown in FIGS. 4, 5, and 6 are excellent in terms of accuracy, they have problems in terms of miniaturization and mass production. In other words, in terms of miniaturization, the thickness H of the motor is reduced because the optical element 6, reflection plate 5, rotor 1, disc-shaped rotating magnet 2, fixed winding 3, and stay board 4 are all arranged in series. (Fig. 4) The issue of increased thickness 57,-7 The problem with mass production is that the fixed winding 3, which requires electrical wiring, and the optical element 6 are arranged on different planes. The problem was that a three-dimensional connection had to be made between the two.

The present invention solves these conventional problems and provides an excellent motor frequency generator that is small and mass-produced.

Means for Solving the Problems In order to solve the above problems, the Mori frequency generator of the present invention is configured to reflect light on the magnetized surface of the disk-shaped rotating magnet so that the reflection surface of the reflection plate faces the fixed winding. The plate is fixed, and the optical element is fixed to the stator substrate so that the light receiving and emitting surface of the optical element faces the reflecting plate.

According to the present invention, with the above-described configuration, the optical element is not arranged in series with other parts, but is arranged in parallel with the fixed winding, so that the thickness of the motor or the thickness of the optical element can be reduced. In addition to being much thinner and more compact, the fixed winding, which requires electrical wiring, and the optical element are arranged on the same plane, which facilitates connection and improves mass productivity.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the present invention, and FIGS. 2 and 3 are plan views seen from the entry direction and B direction of FIG. 1. In this embodiment, the same parts and parts are given the same numbers as in the conventional example described above.

In FIG. 1, a rotor 1 is rotatably supported by a holding means (not shown).

Reference numeral 2 denotes a disk-shaped rotating magnet, which is fixed to the rotor 1 and has a polarized magnetized surface 2a. 3 is a fixed winding disposed facing the magnetized surface 2a, fixed to the stator board 4, and connected to the electrical wiring section 4a of the stator board 4. Reference numeral 5 denotes a reflecting plate, which is fixed to the magnetized surface 2d of the disc-shaped rotating magnet 2, and has a reflecting part 6a that reflects light and an absorbing part 5b that absorbs light arranged alternately on the surface facing the fixed winding 3. It has a reflective surface 5c. Reference numeral 6 denotes an optical element, which includes a light emitting/receiving part 6 having a light emitting part 6d for emitting light and a detecting part 6b for detecting light.
C, and is fixed to the stator substrate 4 so that the light receiving and emitting surface 6C faces the reflecting surface 5C, and the emitting section 6d and the detecting section 6b are connected to the electrical wiring section 4d of the stator substrate 4.

The operation of the optical FG configured as described above is the same as the explanation given for the conventional example, but the optical element 6 is not arranged in series with other components and is connected to the fixed winding 3. Since the motor is arranged in parallel, the Ω thickness of the motor is reduced by the thickness of the optical element 6, allowing for miniaturization, and the fixed winding 3 and the optical element 6, which require wiring, are arranged on the same plane. This facilitates connection and improves mass productivity.

/ Effects of the Invention As described above, in the frequency generator for a motor of the present invention, the reflection plate is fixed to the magnetized surface of the disc-shaped rotating magnet so that the reflection surface of the reflection plate faces the fixed winding, and the optical element Since the optical elements are fixed to the stator board so that the receiving and emitting surfaces of the As a result, the thickness of the motor is thinned by the thickness of the optical element, making it possible to make the motor more compact.The fixed windings, which require electrical wiring, and the optical element are placed on the same plane, making connection easier and improving elemental efficiency. will improve.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIGS. 2 and 3 are plan views seen from directions A and B in FIG. 1, and FIG. 4 is a longitudinal sectional view of a conventional example. 1 and 6 are plan views seen from directions A and B in FIG. 4. 2... Disc-shaped rotating magnet, 2a... Magnetized surface, 3...
・Fixed winding, 4... Stator board, 5...
Reflector, 6... Optical element. Name of agent: Patent attorney Toshio Nakao and one other person
Jumping to the Kaden-system: ; 1 : : : Oh, if it's an island, ku Otsu□

Claims (1)

[Claims] A disc-shaped rotating magnet having a polarized magnetized surface, a fixed winding disposed opposite to the magnetized surface of the disc-shaped rotating magnet, and a fixed winding that holds the fixed winding and is electrically A stator board for wiring, an optical element having a light receiving/emitting surface for emitting and detecting light, and a reflecting plate having a light reflecting surface provided with a pattern for reflecting and absorbing light, The reflecting plate is fixed to the magnetized surface of the disk-shaped rotating magnet so that its surface faces the fixed winding, and the reflecting plate is fixed to the stator substrate so that the light receiving and emitting surface of the optical element faces the reflecting plate. A motor frequency generator characterized by having a fixed optical element.