I was sitting watching my HD TV and was just thinking of who invented it and what was the first brand that made it.

HD TV was not "invented" by any one individual, but rather was the work of several companies who came together in the early 90's under the auspices of the FCC to develop a single standard for high def TV signals. Those early contributors incuded Zenith, Philips, General Instruments, AT&T Labs, Sarnoff Labs, and MIT, all of whom had done preliminary work using various technologies.

Most modern digital advances come about this way, through collaboration between players who meet to develop a common set of standards based on preliminary work done separately. Examples include WiFi, BlueTooth, and interface connectors such as USB and HDMI.

It's really a technological extension of computer LCD screens.

It's really a technological extension of computer LCD screens.

It's a LOT more than that. It's like saying that Compact Discs are a technological extension of vinyl records. I assume you're referring to progressive scanning (used with PC displays) - but remember that HDTV encompasses interlace as well as progessive scannning, and at several different resolutions, and encompasses both analog and digital transmission schemes.