Browse Prior Art Database

Single Panel Full-color Projector with Two-zoned DMD

IP.com Disclosure Number: IPCOM000013636D
Original Publication Date: 2000-Mar-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 3 page(s) / 59K

Publishing Venue

IBM

Abstract

Disclosed is a full color projection system that provides a good color matching for two-zoned digital micromirror device (DMD) projector, which provides increased brightness since twice as many lumens can be projected within the full color image.

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Single Panel Full-color Projector with Two-zoned DMD

Disclosed is a full color projection system that provides a good color matching for two-zoned digital micromirror device (DMD) projector, which provides increased brightness since twice as many lumens can be projected within the full color image.

The DMD is monolithically fabricated by CMOS-like process over a CMOS memory. Each light switch has an aluminum mirror that can rotate around the hinge locating on the diagonal. Each mirror can reflect light in one of two directions, depending on the state of the underlying memory cell. Rotation of the mirror is accomplished through electrostatic attraction produced by voltage difference developed by the mirror and the underlying cell. With the memory cell in ON state, the mirror rotates +10 degrees. In this state, the mirror will reflect the incident light to the projection lens. This light will form an "ON" pixel on the screen. With the memory cell in OFF state, the mirror rotates -10 degrees. In this state, the mirror will reflect incident light -40 degrees from the optical axis. This light will be absorbed. In the two-zoned DMD technique, mirrors are divided into two zones. In the right zone, hinges direction is +45 degrees, and in the left zone, hinges direction is -45 degrees (Fig-2).

A schematic optical layout of this invention is illustrated in Fig.-1.The white light from lamp [1] is collimated into parallel beam by parabola mirror [2] and then focused on the dichroic mirror wheel [5] by condenser lens [4]. The dichroic mirror wheel [5] is a red, green and blue, dichroic mirror system that spins at 60 Hz, for example, to give 180 color fields a second. The light transmitted through the dichroic mirror wheel [31] will be one of three primary colors, and condensed by condenser lenses [10a] and [12a], then reflected by mirror [13a] and incidents to the right zone of Two-Zoned DMD [21] from the right-bottom di...