Patent ID: 9674474
Date: 2017-06-06
CPC Classifications: G09G,H04N

Claim:
1. A video transmission system, the system comprising: a first device; a second device; and a third device, wherein the first device receives an uncompressed video signal from the second device through a first HDMI (High-Definition Multimedia Interface) cable and transmits the received uncompressed video signal to the third device through a second HDMI cable, wherein the first HDMI cable has a first bi-directional communication line for transmitting a CEC (Consumer Electronic Control) message and a first EDID (Extended Display Identification Data) line for transmitting a first EDID, wherein the second HDMI cable has a second bi-directional communication line for transmitting a CEC message and a second EDID line for transmitting a second EDID, wherein the first device provides a first HPD (Hot Plug Detect) signal to the second device through the first HDMI cable and receives a second HPD signal from the third device through the second HDMI cable, wherein when the first device confirms that both the second device and the third device have a predetermined bi-directional communication function by exchange of particular CEC messages with at least one of the second device communicating through the first bi-directional communication line and the third device communicating through the second bi-directional communication line, the first device activates the predetermined bi-directional communication function between the second device and the third device, wherein when the second HPD (Hot Plug Detect) signal from the third device is set to an “L” level after activating the predetermined bi-directional communication function between the second device and the third device, the predetermined bi-directional communication function between the second device and the third device is deactivated, wherein the first device, until activating the predetermined bi-directional communication function between the second device and the third device, does not transfer a message from the second device to the third device, wherein the second device is a video signal reproduction device that reproduces and outputs the video signal, and wherein the third device is a display device which displays a video based on a video signal transmitted to the third device.