JPS6314284B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reflective encoder that converts a rotational displacement amount, which is an analog signal, into a digital signal.
The aim is to provide a miniaturized reflective encoder.

FIG. 6 shows a conventional example of this type of reflective encoder.

Reference numeral 21 denotes an encoder plate, which has reflective protrusions 2 arranged in parallel over the entire circumference.

Reference numeral 3 denotes an index slit, which is made up of slits 4 corresponding to the reflective protrusions 2 arranged in parallel.

Reference numeral 5 denotes a light emitting element which irradiates the rotating encoder plate 21 with projected light through the slit 4 and takes the reflected light from the reflective protrusion 2 into the light receiving element 6 through the slit 4 again. The rotational position of the encoder plate 21 and, by extension, the rotational speed of the motor connected to the encoder plate 21 can be measured by the number of times the reflected light is received in this manner.

However, in the conventional reflective encoder as shown in FIG. The drawback was that it was bulky in both directions. Further, since the reflective protrusions 2 of the encoder plate 21 and the index slits 3 provided corresponding to the reflective protrusions 2 form a fan-shaped arrangement, it becomes difficult to form them if the inner periphery becomes dense and small. It also had the disadvantage of poor accuracy because it was not possible to obtain a large number of .

This invention aims to eliminate the above-mentioned drawbacks, and its gist is to provide an inner cylindrical coil 11 and an outer cylindrical coil 12 formed by coil wires 1 of equal length that are closely arranged in parallel. This is a reflective encoder in which one end of each coil wire 1 of a coil unit 16 is fitted and combined, and the overlapping portions are successively joined to form an electrically closed loop.

Incidentally, in order for the coil wires 1 of the inner cylindrical coil 11 and the outer cylindrical coil 12 to form one continuous electrically closed loop as described above, it is necessary to satisfy the following conditions. That is, the coil wires 1 forming the inner cylindrical coil 11 and the outer cylindrical coil 12 are both made of the same number and arranged in parallel on the cylindrical surface without overlapping, and the inner cylindrical coil 11 and the outer cylindrical coil 12 are When mating, it is necessary that each coil wire 1 of the outer cylindrical coil 12 overlaps with each coil wire 1 of the inner cylindrical coil 11 in the radial direction at each end.

When the coil wire 1 is twisted in opposite directions to form the inner cylindrical coil 11 and the outer cylindrical coil 12, and when these are combined and fitted, the coil wire 1 of the inner cylindrical coil 11 is Cylindrical coil 1
The two coil wires 1 are not arranged point-symmetrically, but are fitted so that the coil wires 1 are shifted by one length at one end.

Also, conventionally, the inner cylindrical coil 11 and the outer cylindrical coil 1
In order to join two coil wires 1 that overlap in the radial direction, a bonding material 32 is generally spread between the coil wires 1 that overlap in the radial direction, and the bonding is carried out by melting and joining using a laser beam or the like. Such a coil unit 16 has recently been used in electric razor motors and the like.

The present invention will be described below based on an illustrative embodiment.

What is shown in FIGS. 1 to 5 is an embodiment of the present invention.

A circular support plate 1 is attached to one end of the coil unit 16.
4 is attached, and a rotating shaft 1 is attached to the center of the support plate 14.
5 is inserted and fixed.

This coil unit 13 is fitted into, for example, a cylindrical yoke 17 and a magnet 18 is inserted therein to be used as a rotor of a cup-shaped coreless motor.

The light emitting unit has an index slit 3 arranged corresponding to the outer peripheral surface of the end portion of the coil unit 16.
A light emitting element 5 and a light receiving element 6 are arranged outside the index slit 3 so as to face it.

The light emitted from the light emitting element 5 is reflected by the coil wires 1 arranged closely in parallel forming the upper end of the outer periphery of the rotating coil unit 16 via the index slit 3, and is reflected back to the index slit 3. 3
The light is received by the light receiving element 6 via. In this way, rotational displacement is detected by measuring the number of times the light receiving element 6 receives the reflected light when the index slit 3 and the end of each coil wire 1 meet. Since there is an insulating layer between the coil wires 1,
The amount of light received by the light receiving element 6 changes each time it moves to an adjacent coil wire 1, and thereby the number of times the light is received can be measured.

As mentioned above, the reflective encoder according to the present invention uses one end of the coil wire 1 forming the coil unit 16, which is the rotor of the coreless motor, as a reflective surface, so it is not necessary to provide a separate encoder plate. It can be made smaller without being bulky. Furthermore, since the encoder plate is not separately assembled to the rotor or rotating shaft, the accuracy of the encoder is also good. Furthermore, since the index slits 3 are arranged around the outer periphery of the coil unit 16, the intervals between the slits 3 can be formed with a sufficient margin, and as a result, the detection accuracy is improved.
In the above embodiment, the outer periphery of the upper end of the coil unit is used as a reflective surface, but it goes without saying that the end face of the upper end may also be used as a reflective surface.

[Brief explanation of the drawing]

1 to 5 are diagrams showing one embodiment of the present invention, in which FIGS. 1 to 3 are perspective views, FIG. 4 is a schematic vertical sectional view, FIG. 5 is a schematic cross sectional view, and FIG. The figure is a perspective view showing a conventional example.

Claims (1)

[Claims] 1. Inner cylindrical coil 11 and outer cylindrical coil 12 formed by coil wires 1 of equal length arranged closely in parallel are fitted and combined, and the overlapping parts are sequentially joined to form an electrically closed loop. A reflective encoder in which one end of each coil wire 1 of a coil unit 16 is used as a reflective surface.