Definition: The Screen Door Effect is an LCD artifact that is mostly associated with LCD video projectors. The image projected by an LCD projector is made up individual pixels. These pixels are separated by black (non-lit) borders. As you increase the size of the projected image (or decrease the resolution on same size screen) the individual pixel borders are more likely to become visible, thus giving the appearance of viewing the image through a "screen door". To eliminate this effect, an increasing number of manufacturers use various technologies to decrease the visibility of the non-lit pixel borders.