The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1976
Filed:
Jan. 15, 1975
Russell Peter Smith, Christchurch, NZ;
Other;
Abstract
A sensory aid for the blind in which a frequency swept ultra-sonic carrier signal is generated and radiated as acoustic energy from a head set and reflected acoustic energy is received by two spaced apart receiving transducers which feed a two channel receiver. The receiving transducers have divergent polar lobes which in combination with the polar lobe of the transmitting transducer simulate the characteristics of a normal human auditory system. The carrier signal is multiplied with each received signal to produce respective beat frequency signals each of which have a frequency and level which is dependant on the range and direction respectively of the source of reflection with respect to the user. The gain of both channels is controlled synchronously by controlling the level of the carrier signal multiplied with each received signal. The range of gain control can be increased by feeding the transmitting transducer with the controlled level carrier signal.