Patent ID: 6719427
Filing Date: 2004-04-13
Classification: G03B

Abstract:
A projection display apparatus comprising:a light modulator used as image forming means; and a projection optical system for projecting and displaying an image, wherein gradation is represented by varying ON-time in the temporal axis during one frame period of said light modulator, and the ON-time is used by at least three light components, wherein said three light components comprises a first light component to make the light reflect or transmit maximally, a second light component to make the light reflect or transmit minimally, and a third light component to make the light reflect or transmit intermediately, and wherein said light modulator is a reflective device including a micromirror, and said gradation is performed by controlling said micromirror to at least three reflection angles including a first reflection angle in which the amount of light reflection to the projection optical system is the maximum; a second reflection angle in which the amount of light reflection to the projection optical system is the minimum; and a third reflection angle between the first reflection angle and the second reflection angle in which the amount is between the amount for the first reflection angle and the amount for the second reflection angle.