Proposal of interferometric display device driven by electrostatic force

摘要

A new display device based on a micro-Fizeau interferometer (IDD: Interferometric Display Device) is proposed and trially manufactured. The mirror is suspended by leaf-springs so that it may move vertically when driven by a dc voltage - electrostatic force. The optical path difference between the half mirror and the bottom substrate is adjusted by the voltage, resulting in the optical interference. Contrast in the IDD can be changed by the voltage, and color can be displayed in the case of white light source. A 300micrometer-square half mirror made of SiO2 and Si substrate electrode/mirror is used for the construction of the IDD. A 4 X 4 array of the IDD is fabricated by using a bonding technique. An interferometric pattern is observed at a driving voltage of 200V dc. The frequency response of the device is confirmed more than 100Hz. The display quality is not sufficient at present because of the deformation of the half-mirror, however, it has a potential for lower driving energy and higher integrity of the pixels.