JP2583307B

PURPOSE:To simultaneously read the magnetic pattern and optical dark-and-light pattern of the same place of a recording medium by forming the magnetism detecting gap section of a magnetic sensor of a light transmissive material and providing an optical detecting device to the gap section. CONSTITUTION:An optical detecting device 3 is constituted of a light emitting element 5, light receiving element 6, and optical fibers 7 optically connecting both elements with each other. The device 3 is constituted to lead the light of the element 5 to a transparent magnetism detecting gap section 2 by means of an optical fiber 7a for incident path and the reflected light of the incident light from a recording medium F to the element 6 through an optical fiber 7b for reflected path. Moreover, the device 3 projects the light of the element 5 on the recording medium F so that the light can pass through the medium F and reads the optical dark-and-light pattern of the medium F from the transmitted light received by the element. Glass or a transparent plastic material can be used for the light transmissive material forming the gap section 2.