Patent ID: 7446571

Claim:
A data transmission system comprising: a first electronic equipment connected to a first power supply and a second electronic equipment connected to a second power supply; a cable for connecting the first and second electronic equipment so as to transmit signals therebetween; and a digital data transmitting circuit having an open drain type output section provided on the first electronic equipment, an input section provided on the second electronic equipment and connected to an internal circuit provided on the second electronic equipment, and a signal transmission line provided on the cable for connecting between the output section and the input section; wherein a pull-up type resistor and a driving circuit are provided on the signal transmission line, between both ends thereof, at a position closer to the output section than to the input section; and an output signal from the output section is inputted to the driving circuit by way of the signal transmission line, and outputted from the driving circuit, and thereafter inputted to the input section by way of the signal transmission line.