Optical accelerometer

Claim 1

An optical accelerometer device that serves as a transducer for providing an electrical signal, which is proportional to the magnitude of the acceleration on the device in the direction of its axis of sensitivity, comprising: a. a housing having inside surfaces of light absorbing quality; b. a light source mounted at one end of said housing along the axis of sensitivity; c. a seismic mass having a light reflective surface thereon facing said light source, suspended within said housing along said axis of sensitivity some distance from said light source; d. means for suspending said seismic mass and reflective surface which will translate the reflective surface under action of inertial forces created by acceleration along the axis of sensitivity; e. a pair of photocells mounted at said one end of said housing, one on each side of said light source, and having electrical leads therefrom passing through the wall of said housing; f. light from said light source being reflected by the reflective surface on said seismic mass onto said photocells for directly generating a signal proportional to the amount of light absorbed by each photocell; g. acceleration in the direction of the axis of sensitivity causing the reflective surface on said seismic mass to translate so that the amount of light reflected onto each of the photocells changes, the change in the output of the two photocells being proportional to the acceleration on the device, the light collecting surfaces of said photocells being shaped such that the electrical output is a linear function of the applied acceleration.