Apparatus for adapting multi-line telephone instrument for use by the blind

摘要

Apparatus for providing auditory and tactile recognition of a light signal associated with a line-selector pushbutton of a multi-line telephone instrument. A photocell is provided for sensing the light signal. An oscillator generates a sine wave voltage which is amplified and applied to excite a piezoelectric crystal into vibration in response to activation of the photocell. An auxiliary pushbutton is disposed in alignment with the line selector pushbutton so that manual depression of the auxiliary pushbutton actuates the line selector pushbutton. Vibration of the crystal in response to the light signal acts upon the auxiliary pushbutton to impart the vibration thereto so that the presence of a light signal is sensed by vibration of the auxiliary pushbutton.