Proximity detecting device

A proximity detecting device for detecting the presence of an object or human body part within a target area, said device comprising in combination:

• (a) a first circuit having a first coil for producing a magnetic field, said first circuit including a low voltage source and means for electrically connecting said first coil across said low voltage source to develop the magnetic field and for disconnecting said low voltage source from said first coil to collapse the magnetic field and to generate an electromotive force;
• (b) a second circuit for producing a pulse in response to the electromotive force developed by said first circuit, said second circuit including a second coil magnetically coupled to said first coil for producing said pulse upon collapse of the magnetic field and means for emitting a further pulse into the target area in response to said pulse produced by said second coil;
• and
• (c) a receiver for detecting the presence of said further pulse emitted from said emitting means into the target area.

A proximity detecting device for detecting the presence of an object in a target area, said device comprising in combination:

• (a) a low voltage power source;
• (b) a circuit for generating electrical pulses and supplying them to a light emitting diode (LED) in order to emit light pulses into the target area;
• (c) a receiver for receiving the light pulses emitted from said LED and directed towards the target area;
• (d) a first circuit containing a primary coil and switching means for connecting said primary coil for a period of time to said low voltage power source to accumulate a predetermined amount of magnetic energy in said primary coil;
• and
• (e) a second circuit containing said LED and a secondary coil magnetically coupled to said primary coil to transform the accumulated magnetic energy into one of said electrical pulses each time upon opening said switching means.

An active proximity detecting device for detecting the presence of an object in a target area, said device comprising in combination:

• (a) a low voltage power source;
• (b) a first circuit having a primary coil and a switching means for connecting said primary coil to said low voltage power source to accumulate a predetermined amount of magnetic energy in said primary coil;
• (c) a second circuit having a secondary coil magnetically coupled to said primary coil to transform the accumulated magnetic energy by mutual induction into a high electrical current pulse flowing through the LED (upon actuation of said switching means and an LED energized by the electrical pulse) to emit a light pulse upon opening said switching means to disconnect said primary coil from said low voltage power source;
• (d) a receiver for receiving in the alternative the light pulse directly from said LED or the light pulse reflected from the object;
• and
• (e) a microprocessor coupled with said first and second circuits for controlling the operation of said LED and said receiver.

A proximity detection device for detecting the presence of an object in a target area by generating a high amplitude short duration current pulse from a low voltage power source to energize an LED for emitting a light pulse, said device comprising:

• (a) a transformer having a primary coil and a secondary coil;
• (b) switching means for periodically connecting the low voltage power source with said primary coil for a first period of time to accumulate a predetermined amount of magnetic energy in said primary coil during the first period of time and for transforming the accumulated magnetic energy by mutual induction into a high amplitude current pulse in said secondary coil upon opening said switching means, said mutual induction having a duration of a second period of time which second period of time is less than the first period of time;
• (c) conductor means for conducting the current pulse to the LED to energize the LED and emit a high energy short duration light pulse;
• (d) a receiver for receiving the light pulse directly or in the alternative as a light pulse reflected from the object and for generating an output signal responsive to the received light pulse;
• and
• (e) a microprocessor responsive to the output signal for controlling operation of said switching means and said receiver.