| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an encoder of high-resolution, having a simple structure. <P>SOLUTION: The encoder 300 includes: a rotating disk 310; optical element arrays 311 to 314 comprising slits or reflective plates equidistantly provided on the rotating disk; light emitting parts 321 to 324 irradiating the optical element arrays with light; and light receiving parts 371 to 374 receiving the light from the individual optical elements of the optical element arrays and outputting rectangular light receiving signals. The n (n is an integer of 2 or more) pieces of the optical element arrays having distances from the center of the rotating disk different from one another are arranged in n arrays along the circumference. The n sets of the optical element arrays include identical number m (m is an integer of 2 or above) optical elements. The n sets of the light emitting parts and light receiving parts are arranged, corresponding to the n sets of the optical element arrays. The n set of optical element arrays and the n sets of the light emitting parts and light receiving parts are arranged so that the phases of n light receiving signals generated at the n sets of light receiving parts are sequentially shifted by π/n, where the phase difference of one period of the individual light receiving signals is defined as 2π. <P>COPYRIGHT: (C)2011,JPO&INPIT |
