Image display device and image projector apparatus
An image display device used for an LCD projector provided with a periodic structure of pixels arranged in a matrix and a substrate supporting the pixels, modulating light entering from an entrance surface in pixel units, and emitting the same from an exit surface. A phase shift structure for randomly changing the phase of the light is formed on a surface of the substrate. The phase shift structure has a relief structure formed, for example, by etching the surface of the substrate through which light passes to random depths. Therefore, occurrence of high-order diffracted light caused by the periodic structure of very fine pixels is prevented, and accordingly the amount of 0th order light inherently required is increased.
1. An image display device used for an image projection apparatus having a periodic structure of pixels arranged in a matrix and a substrate supporting said plurality of pixels,
and a phase shift structure formed over a surface of said substrate for randomly changing the phase of a light as the light passes therethrough in order to reduce a high-order diffracted light.
2. An image display device as set forth in claim 1 , characterized in that said phase shift structure comprises a relief structure formed by etching a surface of said substrate to random depths.
3. An image display device as set forth in claim 1 , characterized in that said phase shift structure comprises a relief structure formed by depositing a dielectric transparent film over a surface of said substrate to random thicknesses.
4. An image display device as set forth in claim 1 , characterized in that said phase shift structure is formed using photolithography.
5. An image display device as set forth in claim 1 , characterized in that said phase shift structure has a relief structure such that there are substantially no changes in height in areas which oppose the portion of a pixel through which the light passes.
6. An image display device as set forth in claim 1 , characterized in that a micro-lens structure is further formed over a surface of said substrate for converging said light toward said pixels.
7. An image projection apparatus comprising a light source, a display panel, and an expansion projection optical system arranged in that order along an optical axis;
said display panel having a periodic structure of pixels arranged in a matrix and a substrate supporting said plurality of pixels, and
a phase shift structure formed over a surface of said substrate for randomly changing the phase of a light as the light passes through it.
8. An image projector apparatus as set forth in claim 7 , characterized in that a micro-lens structure is further formed over a surface of said substrate for converging said light toward said pixels.
9. An image display device used for an image projection apparatus having a periodic structure of pixels arranged in a matrix and a substrate supporting said plurality of pixels,
and a phase shift structure formed over a surface of said substrate for randomly changing the phase of an incoherent light as the light passes therethrough.
10. An image display device as set forth in claim 9 , characterized in that substantially all of the light passing through an individual pixel experiences substantially the same amount of phase shift.