Optical type rotary encoder

Abstract

Abstract PURPOSE:To make a light receiving apparatus compact by admitting transmission lights through a main signal slit section and those through a sub slit section into a single lens with a light receiving element composed of a refractive index distribution type lens whose refractive index decreases parabolically to the periphery from the maximum on the center axis. CONSTITUTION:In a light projection element 11, one end of an optical transmission fiber 14 is connected to one end face of a refractive index distribution type lens 12 whose lens length is set at 1/4 pitch to match optical axes thereof, a similar refractive index distribution type lens 13 is connected to the other end thereof 14 and a light source 15 such as light emitting diode is arranged opposite to the lens 13. Light from the light source 15 enters the refractive index distribution type lens 13 to be focused, is transmitted through the optical fiber 14 and made parallel light with the lens 13. The diameter of the lens 13 is so selected that the parallel light 16 emitted from the lens 13 passes through both of a main signal slit section 5 and a zero signal slit section 6 on a rotary disc 2.

Inventors

• 👤 Katsushige Nakai
• 👤 中井　克滋
• 👤 Takashi Kishimoto
• 👤 隆 岸本

Bibliographic Details