SLIT PLATE AND ROTARY ENCODER USING IT

PROBLEM TO BE SOLVED: To provide a slit plate with which erroneous detection hardly occurs and no malfunction occurs in the output of an encoder, and to provide a rotary encoder using the slit plate. SOLUTION: In a slit provided with a thin belt-like reinforcing bridging section, a width B of the slit near the bridging section is made broader than the widths B0of the slit at both end sections in the circumferential direction by ΔB so that the quantity of the light transmitted through the broadened portion of the slit may not become smaller than that of the light transmitted through both end sections of the slit in the circumferential direction. The rotary encoder uses the slit plate. COPYRIGHT: (C)2004,JPO