System and method for transmitting a video signal from a transmitter to a receiver and reading and writing edid

Abstract

The present invention relates to system and method of reading and rewriting EDID in a video transmission system includes a transmitter transmitting a video signal and a receiver receiving the video signal that the transmitter transmitted which are connected to each other through digital interface, the method includes a reading step where the transmitter reads the EDID of the receiver through the digital interface; a first transmitting step where the transmitter transmit the video signal to the receiver on the basis of the EDID which the transmitter read; a second transmitting step where the receiver transmits a first message related to the EDID of the receiver; and a third transmitting step where the receiver transmits a second message related to the EDID of the receiver; wherein the transmitter, which received the first message from the receiver, does not read the EDID of the receiver until the second message is received.

What is claimed is: 
     
         1 . A video transmitting system, in which a transmitter device to transmit a video signal and a receiver device to receive the video signal transmitted by the transmitter device are connected through a digital interface, the digital interface having a CEC interface to transmit CEC messages including a Header and an Op Code,
 wherein the receiver device includes an EDID recording part to record an EDID indicating the performance of the receiver device,   wherein the transmitter device reads the EDID of the receiver device through the digital interface, and transmits the video signal to the receiver device based on the read EDID,   wherein when the receiver device prohibits the transmitter device to read the EDID, the receiver device transmits a first one and a second one of the CEC messages regarding the EDID reading of the receiver device to the transmitter device, and the transmitter device is prohibited to read the EDID of the receiver device after the transmitter device receives the first one of the CEC messages, until the transmitter device receives the second one of the CEC messages from the receiver device, and   wherein when the receiver device prohibits the transmitter device to read the EDID and resets contents protection, the receiver device transmits a third one of the CEC messages regarding the contents protection processing of the receiver device to the transmitter device, and the transmitter device starts a process of contents protection when the transmitter device receives the third one of the CEC messages from the receiver device.