Data communication apparatus

A data communicating apparatus for performing a data transmission of serial data between a first device and a second device, wherein

• said first device comprises
• (a) an oscillator which has a first coil arranged on a surface which can face said second device;
• (b) transmission pulse generating means for continuously generating a transmission pulse signal of a first or second duty ratio, for switching said first and second duty ratios in correspondence to a transmission data signal upon data transmission, for giving the transmission pulse signal to said oscillator, and thereby for intermittently causing oscillation of said oscillator in accordance with said first or second duty ratio;
• (c) a first resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said oscillator and includes a second coil arranged on the surface that can face said second device;
• (d) a timing control circuit for providing a signal which causes said transmission pulse generating means to provide said transmission pulse signals to said oscillator;
• (e) reception gate signal generating means connected to said timing control circuit for receiving said timing control signal and for generating a reception gate signal having a timing corresponding to the cessation of oscillation of said oscillator;
• (f) a first detecting circuit connected to said first resonance circuit through a switch controlled by said reception gate signal in order to enable said first detecting circuit to detect an electromagnetic induction signal obtained in said first resonance circuit for a time when said reception gate signal is given from said reception gate signal generating means;
• (g) a sample and hold circuit for sampling an output of said first detecting circuit at a predetermined timing of the reception gate signal;
• and
• (h) a first comparator for comparing a signal held by said sample and hold circuit with a predetermined level,
• and said second device comprises:
• (i) a second resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said oscillator of said first device and includes a third coil arranged on a surface that can face said first device;
• (ii) a second detecting circuit for detecting a signal obtained in said second resonance circuit;
• (iii) a second comparator for reproducing a transmission pulse signal received by said first device and received by said second resonance circuit by comparing a detection output of said second detecting circuit with a predetermined threshold level;
• (iv) a data demodulating means for demodulating a transmission data signal represented by the first and second duty ratios of said transmission pulse signal on the basis of an output of the second comparator upon data reception from said first device;
• (v) memory control means for writing/reading a transmission data signal in/out of a memory;
• and
• (vi) reverberation control means which has switching elements connected between said second resonance circuit and ground and which upon receiving transmission data read out of memory from said memory control means controls a reverberation caused in said second resonance circuit by turning on/off said switching elements in correspondence to transmission data at the timing of the cessation of the oscillation of said oscillator on the basis of transmission pulse signal derived from said second comparator upon data transmission to said first device.

An oscillator comprising:

• a parallel resonance circuit comprising resonance elements including a first type of resonance element and a pair of series connected second type of resonance elements;
• a transistor whose first terminal is connected to one electrical end of said parallel resonance circuit, the other electrical end of which is connected to a first terminal of a voltage source, said transistor including a second terminal coupled to a mid-point of said series connected second type of resonance elements and to a second terminal of said voltage source and having a base coupled to a bias source, said oscillator being used in a data communicating apparatus to transmit a signal by intermittently executing an oscillation;
• a switching element for opening or closing said resonance circuit provided between said first type of resonance element and said series connected second type of resonance elements of said resonance circuit;
• and wherein the oscillation is intermittently controlled by operation of said switching element.

An oscillator comprising:

• a parallel resonance circuit comprising resonance elements;
• an oscillation device connected to said resonance circuit such that said resonance circuit affects the oscillation frequency of said oscillation device, said oscillator being used in a data communicating apparatus to transmit a signal by intermittently executing an oscillation;
• and
• a switching element for opening or closing a connection path between at least two resonance elements wherein the oscillation of said oscillator is intermittently controlled by operation of said switching element.

A data communicating apparatus for performing a half-duplex transmission of serial data, which comprises a first device and a second device, wherein said first device comprises:

• (a) an oscillator which has a first coil arranged on a surface which can face said second device;
• (b) transmission pulse generating means for generating a transmission pulse signal of a predetermined period having a first or second duty ratio in correspondence to a transmission data signal upon data transmission and a predetermined third duty upon data reception, and for giving the transmission pulse signal of the predetermined period to said oscillator to cause said oscillator to intermittently oscillate n accordance with the duty ratio provided by said transmission pulse generating means;
• (c) a resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said oscillator and which includes a second coil arranged on the surface that can face said second device;
• (d) a timing control circuit for providing a signal which causes said transmission pulse generating means to provide said transmission pulse signals to said oscillator;
• (e) reception gate signal generating means connected to said timing control circuit for receiving said timing control circuit signal and for generating a reception gate signal having a timing corresponding to when the oscillation of said oscillator is stopped;
• (f) a detecting circuit switchingly connected to said resonance circuit for detecting an electromagnetic induction signal obtained in said resonance circuit for a time when said reception gate signal of said reception gate signal generating means switchingly connects said detecting circuit to said resonance circuit;
• (g) a sample and hold circuit for sampling an output of said detecting circuit at a predetermined timing of the reception gate signal;
• and
• (h) a comparator for comparing a signal held by said sample and hold circuit with a predetermined level.

A data communicating apparatus for performing a half-duplex transmission of serial data which compromises a first device and a second device wherein said second device comprises:

• (i) a resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said first device and which includes a coil arranged on a surface that can face said first device;
• (ii) a detecting circuit for detecting a signal obtained in said resonance circuit;
• (iii) a comparator for reproducing a transmission pulse signal received by said resonance circuit and transmitted by said first device by comparing a detection output of said detecting circuit with a predetermined threshold level;
• (iv) a data demodulating means for demodulating a transmission data signal represented by the first and second duty ratios of said transmission pulse signal on the basis of an output of the comparator upon data reception from said first device;
• (v) memory control means for writing/reading a transmission data signal in/out of a memory;
• and
• (vi) reverberation control means which has switching elements connected between said resonance circuit and ground and which upon receiving transmission data from said memory control means controls a reverberation that is caused in said resonance circuit by turning on/off said switching elements in correspondence to transmission data at the timing of the cessation of the oscillation of said oscillator on the basis of reception of a transmission pulse signal having a third duty ratio which is derived from said comparator upon data transmission to said first device.

A data communicating apparatus for performing a data transmission of serial data between a first device and a second device, wherein said first device comprises:

• (a) an oscillator which has a first coil arranged on a surface that can face said second device;
• (b) transmission pulse generating means for continuously generating a transmission pulse signal of a first or second duty ratio, for switching said first and second duty ratios in correspondence to a transmission data signal upon data transmission, for giving the transmission pulse signal to said oscillator, and thereby for intermittently causing oscillation of said oscillator in accordance with said first or second duty ratio;
• (c) a resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said oscillator and includes a second coil arranged on the surface that can face said second device;
• (d) a timing control circuit for providing a signal which causes said transmission pulse generating means to provide said transmission pulse signal to said oscillator;
• (e) reception gate signal generating means connected to said timing control circuit for receiving said timing control signal and for generating a reception gate signal having a timing corresponding to the cessation of said oscillator;
• (f) a detecting circuit connected to said resonance circuit through a switch controlled by said reception gate signal in order to enable said detecting circuit to detect an electromagnetic induction signal obtained in said resonance circuit for a time when said reception gate signal is given from said reception gate signal generating means;
• (g) a sample and hold circuit for sampling an output of said detecting circuit at a predetermined timing of the reception gate signal;
• and
• (h) a comparator for comparing a signal held by said sample and hold circuit with a predetermined level.

A data communicating apparatus for performing a data transmission of serial data between a first device having an oscillator and a second device, wherein said second device comprises:

• (i) a resonance circuit which has a resonance frequency that is substantially equal to an oscillating frequency of said oscillator of said first device and which includes a coil arranged on a surface that can face said first device;
• (ii) a detecting circuit for detecting a signal obtained in said resonance circuit;
• (iii) a comparator for reproducing a transmission pulse signal received by said resonance circuit and transmitted by said first device by comparing a detection output of said detecting circuit with a predetermined threshold level;
• (iv) a data demodulating means for demodulating a transmission data signal represented by the first and second duty ratios of said transmission pulse signal on the basis of an output of the comparator upon data reception from said first device;
• (v) memory control means for writing/reading a transmission data signal in/out of a memory;
• and
• (vi) reverberation control means which has switching elements connected between said resonance circuit and ground and which upon receiving transmission data read out of memory from said memory control means controls a reverberation caused in said resonance circuit by turning on/off said switching elements in correspondence to transmission data at the timing of cessation of the oscillation of said oscillator on the basis of the transmission pulse signal derived from said comparator upon data transmission to said first device.