Communication system and transmitter

A communication system comprising:

• a transmitting AC coupling element;
• a first transmission line comprising one end connected to the transmitting AC coupling element;
• a transmission circuit connected to an other end of the first transmission line and configured to transmit a transmission signal;
• a receiving AC coupling element coupled to the transmitting AC coupling element using AC coupling;
• a second transmission line comprising one end connected to the receiving AC coupling element;
• and
• a reception circuit connected to an other end of the second transmission line and configured to receive a reception signal via the receiving AC coupling element and the second transmission line,
• wherein the reception circuit comprises a hysteresis circuit having a hysteresis in input and output characteristics, the hysteresis circuit configured to compare the reception signal with a first threshold voltage and a second threshold voltage, the second threshold voltage being lower than the first threshold voltage, and configured to output output data according to the comparison result,
• the reception signal comprises a transmitted signal and a reflected signal, the transmitted signal being the transmission signal reached to the reception circuit without being reflected, the reflected signal being the transmission signal reached to the reception circuit after being reflected, and
• a delay time Td1 of the first transmission line and a delay time Td2 of the second transmission line are set so that, in an input of the reception circuit, a timing when the transmitted signal becomes the first threshold voltage or more, or the second threshold voltage or less is different from a timing when an absolute value of an amplitude of the reflected signal becomes maximum.

A transmitter configured to perform communication with a receiver, the receiver comprising a receiving electrode, a second transmission line comprising one end connected to the receiving electrode, and a reception circuit connected to an other end of the second transmission line and configured to receive a reception signal via the receiving electrode and the second transmission line, the transmitter comprising:

• a transmitting electrode capacitively coupled to the receiving electrode;
• a first transmission line comprising one end connected to the transmitting electrode;
• and
• a transmission circuit connected to an other end of the first transmission line and configured to transmit a transmission signal,
• wherein characteristic impedances of the first transmission line and the second transmission line are greater than an output impedance of the transmission circuit.

A transmitter configured to perform communication with a receiver, the receiver comprising a receiving AC coupling element, a second transmission line comprising one end connected to the receiving AC coupling element, and a reception circuit connected to an other end of the second transmission line and configured to receive a reception signal via the receiving AC coupling element and the second transmission line, the reception circuit comprising a hysteresis circuit having a hysteresis in input and output characteristics, the hysteresis circuit configured to compare the reception signal with a first threshold voltage and a second threshold voltage, the second threshold voltage being lower than the first threshold voltage, and configured to output output data according to the comparison result, the transmitter comprising:

• a transmitting AC coupling element coupled to the receiving AC coupling element using AC coupling;
• a first transmission line comprising one end connected to the transmitting AC coupling element;
• and
• a transmission circuit connected to an other end of the first transmission line and configured to transmit a transmission signal,
• wherein the reception signal comprises a transmitted signal and a reflected signal, the transmitted signal being the transmission signal reached to the reception circuit without being reflected, the reflected signal being the transmission signal reached to the reception circuit after being reflected, and
• a delay time Td1 of the first transmission line and a delay time Td2 of the second transmission line are set so that, in an input of the reception circuit, a timing when the transmitted signal becomes the first threshold voltage or more, or the second threshold voltage or less is different from a timing when an absolute value of an amplitude of the reflected signal becomes maximum.