Non-contact type transmission system for transferring data electromagnetically

A data receipt device that receives data by electromagnetic induction comprising:

• a receiving circuit that receives data having a voltage defined related to a first threshold;
• a bias circuit that raises said voltage of said received data by a predetermined voltage to produce a sum voltage;
• and
• a judging circuit that judges whether said voltage of said data indicates high or low by comparing said sum voltage with a second threshold that is equal to or larger than said first threshold,
• wherein said receiving circuit includes a coil that produces an electromotive force upon receiving said data from said transmitting circuit, and
• wherein said bias circuit includes a diode that is connected to said coil in series to increase said electromotive force by a forward voltage of said diode.

A data transmission system including a first device and second device communicating with each other, said first device having a power supply that provides electric power for said second device using a magnetic field,

• wherein said power supply comprises
• an oscillator that generates an oscillation signal;
• a magnetic field preparing circuit that prepares said magnetic field;
• a current supplying circuit that supplies a current to said magnetic field preparing circuit according to said oscillation signal;
• a detecting circuit that detects a halt of generating said oscillation signal by said oscillator;
• and
• a switching circuit that turns off said current supplying circuit upon detecting said halt,
• wherein said oscillation signal includes a plurality of first pulses, wherein said detecting circuit includes
• a generating circuit that generates a second pulse that permits said switching circuit to keep said current supplying circuit turned on, in response to each first pulse;
• and
• a smoothing circuit that smoothes said second pulses;
• and
• wherein said switching circuit turns off said current supplying circuit in an absence of said smoothed second pulses.

A device that communicates by electromagnetic induction, comprising a power supply,

• wherein said power supply includes
• an oscillator that generates an oscillation signal;
• a magnetic field preparing circuit that prepares said magnetic field;
• a current supplying circuit that supplies a current to said magnetic field preparing circuit according to said oscillation signal;
• a detecting circuit that detects a halt of generating said oscillation signal by said oscillator;
• and
• a switching circuit that turns off said current supplying circuit upon detecting said halt,
• wherein said oscillation signal includes a plurality of first pulses,
• wherein said detecting circuit includes
• a generating circuit that generates a second pulse that permits said switching circuit to keep said current supplying circuit turned on, in response to each first pulse;
• and
• a smoothing circuit that smoothes said second pulses;
• and
• wherein said switching circuit turns off said current supplying circuit in an absence of said smoothed second pulses.

A data receipt method used for a data receipt device receiving data by electromagnetic induction comprising:

• receiving a data having a voltage defined related to a first threshold;
• increasing said voltage of said received data by a predetermined voltage to produce a sum voltage;
• and
• judging whether said voltage of said data indicates high or low by comparing said sum voltage with a second threshold that is equal to or larger than said first threshold,
• wherein said increasing includes raising said voltage of said received data by said predetermined voltage defined by said first threshold and said second threshold.

A power supplying method used for a device that communicates by electromagnetic induction comprising:

• generating an oscillation signal that includes a plurality of first pulses;
• using a current supplying circuit to supply a current according to said oscillation signal;
• preparing a magnetic field using said current;
• first detecting a halt of said generating of said oscillation signal;
• and
• using a switching circuit to turn off said supplying said current upon detection of said halt,
• wherein the step of first detecting a halt of said generating of said oscillation signal comprises generating a second pulse that permits said switching circuit to keep said current supplying circuit turned on in response to each first pulse, and smoothing said second pulses, and
• wherein said switching circuit turns off said current supplying circuit in an absence of said smoothed second pulses.