Acoustic encoding apparatus

In a keyboard having at least two keybuttons, a device for providing a signal representative of the keybutton which is activated, which device comprises:

• a member for transmitting vibratory energy, said member having a midpoint;
• means activated by said keybuttons for imparting vibratory energy to said member at a different location for each keybutton, at least a pair of said locations being symmetrically disposed about said midpoint;
• means for detecting said transmitted energy at two spaced apart points and having the outputs thereof coupled to
• means for providing a signal representative of the difference in time of arrival of said transmitted vibratory energy at said detection means, said symmetrically-disposed pair of locations yielding identical differences in time of arrival, and means coupled to the detecting means at one of said two points and operable to modify said representative signal in response to detection of transmitted energy by the detecting means at said one point, whereby a unique signal is obtained for each keybutton activated.

An apparatus for a keyboard having at least two depressible keys, the apparatus operable to generate a unique code representative of each key, comprising:

• an elongated member for transmitting acoustic energy, said elongated member having a midpoint defining first and second halves of the member;
• a striker corresponding to each said key and spaced along said elongated member in symmetric pairs about said midpoint, each said striker being adapted to impact said member and induce acoustic energy therein in response to depression of the corresponding key and the induced acoustic energy forming separate wave fronts travelling in diverging directions;
• means operatively connected to said elongated member for transducing said wave fronts into a leading and following signal with an elapsed time therebetween, each symmetric pair producing equal elapsed times;
• and
• means connected to said transducing means to generate therefrom said unique code representative of each key, said code generating means including discriminating means providing a different code in response to production of said leading signal by strikers along said first of the halves of the member.

In a keyboard having at least two keybuttons, a device for providing a signal representative of the keybutton which is activated, which device comprises:

• a member for transmitting vibratory energy, said member having a midpoint,
• a plurality of means activated by said keybuttons for imparting vibratory energy to said member, said means being disposed along said member about said midpoint with at least one of said plurality on an opposite side thereof, and each said means being at a discrete distance from said midpoint;
• means for detecting said transmitted energy at two spaced apart points in a temporal sequence determined by location of said activating means relative to said midpoint, said detecting means having respective outputs coupled to
• means for providing a signal representative of the difference in time of arrival of said transmitted vibratory energy at said detecting means, whereby a unique signal is obtained for each keybutton activated, said signal providing means operating independently of said sequence.

An apparatus for generating signals representative of a mechanical motion comprising:

• a member for transmitting vibratory energy, said member having a midpoint;
• a plurality of means for imparting vibratory energy to said member, each selectively activatable in response to said mechanical motion, said means being disposed adjacent said member with each being at a discrete distance from said midpoint and at least one of said plurality being on an opposite side of said midpoint,
• means for detecting said transmitted energy at two spaced apart points in a temporal sequence determined by location of said activating means relative to said midpoint, said detecting means having respective outputs;
• means connected to said outputs for providing a signal representative of the difference in time of arrival of said transmitted vibratory energy at said detecting means, whereby a unique signal is obtained upon each selective activation of one of said plurality of means, said signal providing means being operative irrespective of said sequence.