JPH05302836A - Encoder having eight-pole magnetized ball - Google Patents

Abstract

PURPOSE:To obtain a means, which can measure any direction in front or rear and right or left and can measure minute sizes. CONSTITUTION:The spherical surface of an eight-pole magnetized ball 1 is divided into eight regions of the cubic triangle shape having the solid angle of 90 deg. with two points in the direction of the diameter as the centers. Each region is magnetized so that the region has the different magnetic polarity from the neighboring region (N pole or S pole). The magnetized ball 1 is rotatably supported. A yoke 2 having a pair of tips 2a and 2b, which face to each other with a gap, is arranged so that the tips 2a and 2b are close to the ball 1. A detecting coil 3 is wound around the yoke 2. An induced-voltage detecting means, which detects the pulse-shaped induced voltage generated in the detecting coil 3 by the rotation of the ball 1, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoder having an octupole magnetized ball, and more particularly to an encoder having an octupole magnetized ball for detecting a displacement amount by utilizing a magnetic pole change caused by rotation of the octupole magnetized ball. Regarding

[0002]

2. Description of the Related Art For example, there are planimeters and mice as encoder-type tools for measuring the lengths and intervals of lines on a drawing, both of which are operated by moving them on a plane. Basically, the planimeter decelerates the rotation of the measuring wheel brought into contact with the surface by an appropriate number of gears (usually the reduction ratio is 1/50 to 1/100), and displays it on the scale plate with a pointer. Has become.

Further, the mouse is generally provided with a rotatable track ball having elasticity and a rotatable small diameter roller pressed against the ball. Then, when the ball is rotated while being pressed against the paper surface or the desk surface, the roller engaged with the ball also rotates, and the displacement amount is detected by the rotation of the roller.

[0004]

However, because of its structure, the planimeter can measure only in a fixed direction, and the mouse is too large in shape to measure minute dimensions. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide means capable of measuring in any of front, rear, left, and right directions and capable of measuring a minute dimension. .

[0005]

The above-mentioned object is to achieve the object of the present invention.
This is achieved by an encoder with polar magnetized balls.
That is, in the encoder of the present invention, the surface of the magnetic ball is divided into eight sections of a solid triangle having a solid angle of 90 ° centering on two points in the diameter direction, and each section has a magnetic pole (N-pole) different from that of the adjacent section. An 8-pole magnetized ball magnetized to S pole) is rotatably supported, and a yoke having a pair of opposed tips with a gap is arranged so that the tips are close to the ball. A detection coil is attached to the iron, and induction voltage detection means for detecting a pulsed induction voltage generated in the detection coil by the rotation of the ball is provided.

The octupole magnetized ball, which is a major feature as a constituent element of this encoder, has a spherical surface equally divided into eight sections.
Each section is magnetized to the N pole or the S pole, and the boundary of the section and its vicinity are magnetically neutral. Therefore, when this ball is pressed against the surface and rotated, the magnetic poles change at the pair of tips of the yoke according to the number of rotations of the ball (corresponding to the distance moved on the surface). A pulsed magnetic induction voltage is generated in the. By counting the pulse voltage by the induced voltage detecting means, the moving distance of the ball, that is, the length of the line segment or the like on the drawing can be measured.

[0007]

EXAMPLES An encoder equipped with an 8-pole magnetized ball according to the present invention will be described below based on examples. FIG. 1 shows a cross-sectional view of a main part of an encoder according to the embodiment. This encoder has a pencil shape, and the pencil case 10
The front end of is formed in a holder 11 that rotatably supports the octupole magnetized ball 1. The holder 11 has a concave curved surface having a diameter slightly larger than the diameter of the ball 1, and rotatably holds the ball 1 accommodated therein. Further, the lower end of the holder 11 is open, and the ball 1 is opened from this opening.
The ball 1 appears in a protruding shape so that the ball 1 can easily roll along the surface 30 such as the drawing.

A perspective view of the octupole magnetized ball 1 is shown in FIG.
The upper hemispherical view of the ball shown in FIG. 2A is shown in (b) of the same figure, and the lower hemispherical view thereof is shown in (c) of the same figure. As can be seen from FIG. 2, the octupole magnetized ball 1 is, for example, a steel ball, and the spherical surface has a solid angle 90 about two points in the diameter direction.
It is equally divided into eight sections (portions sectioned by dotted lines) of a solid triangle of °, and each section is magnetized to the N pole or the S pole so that each section has a magnetic pole different from that of the adjacent section. In the upper hemisphere 1a and the lower hemisphere 1b of the ball, FIG.
From (c), the north pole and the south pole are located in point symmetry, and the upper and lower hemispheres have different magnetic poles. By arranging the magnetic poles in this way, all sections are adjacent to each other.
It has a different polarity than the one section.

In the case 10, a yoke 2 is arranged on the upper portion of the ball 1, and the yoke 2 has a pair of tips 2a and 2b with an appropriate gap. The tips 2a and 2b are located close to the ball 1 and directly above the diameter thereof. A detection coil 3 is wound around and attached to the yoke 2, and both ends of the coil 3 serve as lead wires 4 and are drawn out to the upper part of the case 10. The induced pulse voltage generated in the detection coil 3 by the rotation of the magnetized ball 1 is sent to the induced voltage detecting means (not shown in FIG. 1) via the lead wire 4.

Further, in this embodiment, the yoke 2'having a pair of tips 2a ', 2b', the detection coil 3'wound around the yoke 2 ', and the coil 3'just like the above. Lead wires 4 ′ led out from both ends are arranged in the case 10. And, a pair of tips 2a ', 2 of the yoke 2'
b'is shown in FIG. 3 (a schematic view seen from the holder 11 side, the ball 1
(Not shown) is located immediately above the ball 1 and is adjacent to and adjacent to the pair of tips 2a and 2b of the previous yoke 2 at right angles. In this way, two detection mechanisms are provided, and when the number of detection mechanisms is only one, if the tips 2a and 2b accidentally trace the boundary line (non-magnetic pole portion) between the N pole and the S pole of the ball 1, This is to avoid the inconvenience that the magnetic field does not change at all, the induced pulse output is not obtained, and the target measurement is not performed.

The induced pulse output from the above-mentioned two detection mechanisms is inputted to the induced voltage detecting means. FIG. 4 shows a circuit section equipped with the induced voltage detecting means. The circuit unit 20 calculates the number of rotations of the ball 1 based on the result of the pulse counter 21 that counts the number of pulses of the pulse voltage due to magnetic induction, and the movement of the ball 1 based on the rotation speed and the outer peripheral dimension of the ball 1. A calculation unit 22 for calculating the distance, and a reference time pulse generation unit 23 for calculating the moving speed based on the moving distance / time. The results such as the moving distance and the moving speed obtained by the calculation unit 22 are displayed on the display unit (for example, liquid crystal display) 25. The circuit unit 20
Is built in the upper part of the case 10, and the display unit 25 is the case 1
It is set in place of 0.

Next, the operation of the encoder will be described. As shown in FIG. 1, the surface 3 of the drawing or the like to be measured.
The ball 1 is pressed against 0 and the holder 11 is pressed in this pressed state.
When (Case 10) is moved in the direction of arrow A, the ball 1
Moves on the surface 30 while rotating in the direction of arrow B. Then, at the tips 2a and 2b of the yoke 2, the N pole of the ball 1 that was initially close to is moved away, the nonmagnetic band between the N pole and the S pole is crossed, and then the next S pole is approached. An electromotive force is induced in the detection coil 3 by the change of the magnetic pole from the N pole to the S pole. The same thing occurs at the tips 2a 'and 2b' of the yoke 2 '. Therefore, if the magnetic pole change is repeated, a pulse voltage corresponding to the change is generated in the detection coils 3, 3 ′, and this pulse voltage is sent to the circuit unit 20 through the lead wires 4, 4 ′. As described above, in the circuit section 20, the pulse counter 21 counts the number of pulses, respectively, and based on this, the moving distance and the moving speed are calculated by the calculating section 22, and the result is displayed on the display section 25.
Displayed in. Of course, even if the encoder is moved in a direction other than the arrow A direction, the same operation is performed.

Here, the manufacture of the octupole magnetized ball 1 will be briefly described. First, the surface of a magnetic ball (steel ball) is divided into eight sections of a solid triangle with a solid angle of 90 ° centering on two points in the diametrical direction, and a pole that generates a magnetic field of N pole or S pole in each section. The magnetic fields of N poles or S poles are generated from the respective poles so that each section has a magnetic pole different from that of the adjacent section, and each section may be magnetized to the N pole or the S pole at once.
By doing so, it becomes possible to magnetize one magnetic body with eight poles. It should be noted that the magnetic balls may be those capable of magnetizing at least the surface thereof, and the balls may be clogged or hollow.

The above embodiments are merely examples of encoders, and can be applied to various devices as encoders. For example,
"Memory pen" filed by the applicant earlier (Japanese Patent Application No. 4-18
No. 854) is provided with a writing means, a handwriting detection means for detecting a locus of characters, figures, etc. drawn by the writing means, and a storage means for storing the handwriting of the detected characters, figures, etc. in the case body. However, the detection mechanism of FIG. 1 and the circuit of FIG. 4 can also be used as the handwriting detection means. In this case, the ball diameter is very small (diameter 0.4 to 0.5
If it is set to about (mm), a writing feeling similar to that of a ball-point pen can be obtained, it becomes easier to draw characters and figures with the pen, and it is possible to detect the length of written handwriting and to detect the writing speed. Become.

[0015]

As described above, in the encoder of the present invention, eight sections on the spherical surface have different magnetic polarities (N
An eight-pole magnetized ball magnetized to have a pole or a south pole is rotatably supported, and a pulsed induced voltage generated in the detection coil due to a change in magnetic pole due to the rotation of the ball is detected by the induced voltage detecting means. Therefore, the measurement accuracy is high, the measurement direction is not trapped, and even if a ball having a small diameter is used, a minute dimension can be measured. Further, by using a ball having a small diameter, it is possible to provide a highly accurate planimeter having an operability and a shape similar to, for example, an ordinary ballpoint pen as an encoder.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an encoder according to an embodiment of the present invention.

2 is a perspective view, an upper hemisphere view, and a lower hemisphere view of an octupole magnetized ball used in the encoder shown in FIG. 1. FIG.

FIG. 3 is a schematic view of the encoder case shown in FIG. 1 when viewed from the holder side.

FIG. 4 is a block diagram for explaining a circuit configuration of the encoder shown in FIG.

[Explanation of symbols]

 1 8 pole magnetized ball 2 Yoke 2a, 2b Yoke tip 2a ', 2b' Yoke tip 3, 3'Detection coil 20 Circuit part (induced voltage detection means)

Claims (1)

[Claims] 1. The surface of a magnetic ball is divided into eight sections of a solid triangle having a solid angle of 90 ° centering on two points in the diametrical direction, and each section has a magnetic pole characteristic (N pole or S pole) different from that of an adjacent section.
Poles) are rotatably supported by an 8-pole magnetized ball, and a yoke with a pair of opposing tips with a gap is arranged so that the tips are close to the balls. An encoder provided with an 8-pole magnetized ball, further comprising a detection coil, and an induction voltage detecting means for detecting a pulsed induction voltage generated in the detection coil by the rotation of the ball.