Rotary encoder

A method of manufacturing an encoder mechanism of a rotary encoder,

• the rotary encoder including:
• a shaft;
• and
• the encoder mechanism that holds the shaft in a rotatably inserted state and detects a rotation direction and a rotation angle of the shaft;
• wherein
• the encoder mechanism includes:
• a substrate that rotatably holds the shaft;
• an insulator portion and resistor portions provided on one surface of the substrate and alternately provided in the rotation direction of the shaft;
• a rotor attached to the shaft so as to be integrally rotatable with the shaft;
• and
• a slider that is attached to the rotor and alternately contacts the insulator portion and the resistor portions in a sliding manner by rotation of the shaft;
• and
• the insulator portion includes a base material made of a resin, spherical silica, and
• a fluororesin filler;
• and
• the method comprising:
• a step of preparing an insulating material including the base material made of a resin, spherical silica, and a fluororesin filler;
• a step of providing an electrode portion on one surface of the substrate so as to extend in a rotation direction of the shaft;
• a step of applying the insulating material on the electrode portion to form the insulator portion so that the electrode portion is exposed intermittently in a circumferential direction;
• and
• a step of applying a resistor material on the electrode portion exposed from the insulator portion to form the resistor portions;
• wherein
• in the step of preparing the insulating material, a second fluororesin filler having an average particle diameter of about 0.5 μm or more and about 10 μm or less, the spherical silica, and the base material are kneaded to produce a first fluororesin filler having an average particle diameter of about 50 nm or more and about 800 nm or less by crushing the second fluororesin filler.

A rotary encoder comprising:

• a shaft;
• and
• an encoder mechanism that holds the shaft in a rotatably inserted state and detects a rotation direction and a rotation angle of the shaft;
• wherein
• the encoder mechanism includes:
• a substrate that rotatably holds the shaft;
• an insulator portion and resistor portions provided on one surface of the substrate and alternately provided in the rotation direction of the shaft;
• a rotor attached to the shaft so as to be integrally rotatable with the shaft;
• and
• a slider that is attached to the rotor and alternately contacts the insulator portion and the resistor portions in a sliding manner by rotation of the shaft;
• the insulator portion includes a base material made of a resin, spherical silica, and a fluororesin filler;
• and
• the base material is an epoxy resin.