JPS6444814A - Detecting element of origin of magnetic head for magnetic encoder - Google Patents

Abstract

PURPOSE:To obtain a detecting element whose pulse width is unvaried even when the relative directions of movement of a scale and a magnetic head are varied to be normal and reverse mutually, whose amplification rate is low and whose high-speed responsiveness is excellent, by a method wherein four blocks each comprising magnetoresistance (MR) elements in the number of (n) [(n) is a plus integer] are disposed in parallel geometrically. CONSTITUTION:Blocks B1-B4 each comprising MR elements in the number of (n) are disposed in parallel sequentially. Respective ends of the blocks B1 and B3, the other end of B3 and one end of B2, the other end of B2 and one end of B4, and the other ends of B4 and B1, are connected together to form first to fourth connection elements L1-L4. A supply voltage is impressed between the connection elements L2 and L4 and first and second output signals are taken from the connection elements L1 and L3 respectively. These two signals are added up, amplified 2 and converted 3 into a rectangular one, and thus an origin signal of a rectangular wave is obtained at an output terminal 4. The pulse width of this signal is unvaried even when the direction of an origin position detection pattern 1a turns reverse.