The TX-40CXW684 has a maximum display resolution of 4K Ultra HD. That's over four times the display resolution of the most frequently found HD type of Full HD. 4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
A 4K Ultra HD HD type is actually the best display resolution across all mid-size TVs that have been around for a similar time to the TX-40CXW684.
An HD Ready HD type is the worst display resolution across similar types of TV.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
We think you might also be interested in some of the alternative 4K Ultra HD TVs currently available including cheaper televisions such as the Samsung UE48JU6445.