Micromirror elements, package for the micromirror elements, and projection system therefor
US6962419B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 2001 |
| Grant date | Nov 8, 2005 |
| Priority date | — |
| Expiry date | Jan 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/16195
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the collection optics, in the present invention, micromirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, is not however, orthogonal to any substantial portion of sides of the individual micromirrors in the array. Orthogonal sides cause incident light to diffract along the direction of micromirror switching, and result in light ‘leakage’ into the ‘on’ state even if the micromirror is in the ‘off’ state. This light diffraction decreases the contrast ratio of the micromirror. The micromirrors of the present invention result in an improved contrast ratio, and the arrangement of the light source to micromirror array in the present invention results in a more compact system. Ano…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.