Patent ID: 8746061

Claim:
A liquid level detecting apparatus, comprising a resistance plate that has a plurality of conductive segments provided on an insulating substrate, and a resistor electrically connected with the plurality of conductive segments; and a sliding body that includes a contact that contacts different ones of the plurality of conductive segments in response to the sliding body sliding in accordance with change of a level of a liquid surface, wherein the plurality of conductive segments are provided on the insulating substrate at approximately equal intervals, wherein the contact of the sliding body has a flat and round shaped top portion which contacts with the conductive segments and comes into surface contact with top portions of the plurality of conductive segments when the contact slides on the plurality of conductive segments, wherein a diameter a of the flat and round shape top portion of the contact satisfies 0.5<α [mm]<0.6, when the width W of the conductive segment is 200 [μm], and an interval D of neighboring conductive segments is 200 [μm], wherein the flat and round shaped top portion of the contact of the sliding body includes: a flat top, located at a top of the contacting portion, the flat top including a contacting surface that contacts the conductive segments and comes into surface contact with top portions of the plurality of conductive segments when the contact slides on the plurality of conductive segments; and a multi-angled side surface extending from the contacting surface of the flat top to a surface of the sliding body, the multi-angled side surface including a peripheral portion and an extensional portion, the peripheral portion extending from the contacting surface of the flat top to the extensional portion at a first angle, the extensional portion extending from the peripheral portion to the surface of the sliding body at a second angle.