Sound reproduction device for talking books

摘要

A sound reproducing device is disclosed for reproducing sound recorded on an optical sound track, having a manually movable wheeled vehicle with means provided for regulating its speed along such track, a light source substantially restricted to red and infrared light mounted on the vehicle for directing light onto such track, a plurality of light conduit means for transmitting light, the conduit means having input ends mounted on the vehicle and arranged in a substantially linear array transverse to the track for permitting manual movement of the source and the input ends along the optical sound track so as to receive light from the source incident upon a strip of the sound track. The conduit means have output ends arranged in a compact array and a maximum linear dimension substantially less than the length of the linear array. The device further includes photosensor means positioned to receive light from the output ends of the light conduit means and capable of providing an electrical signal substantially proportional to the intensity of the light thus received, amplifier means to receive the electrical signal from the photosensor means and for amplifying the signal, and loudspeaker means to receive the amplified electrical signal from the amplifier means for producing output sound responsive to the signal as the vehicle is moved along the optical sound track. The arrangement facilitates the reproduction of sound from a sound track having a width greater than the maximum widthwise dimension of the photosensor means thereby facilitating alignment of the light conduit means with the sound track and providing a relatively substantial signal to noise ratio.