What causes a red glow covering almost all of my tv screen? I have Hitachi rear projection LCD tv?

It is a circled-shape and covers almost all of the tv screen. All the images within this circle area have a red glow to them, especially when it is against a white or black background. Normal TV screen should be black when there is no video signal to it. Instead, this TV has a patch of red glow. It is not the TV lamp as i replaced it with a new lamp twice.