Yun G., Hong S., Ko E., Koo H., Park S.

Recently, display devices become lighter and slimmer and the size of an image screen is the important issue in the development of display devices. Furthermore, display devices with a large screen are required to represent high resolution as high definition TV images are widely spread out. There are several display devices such as plasma display panel (PDP), liquid crystal display (LCD), projection with micro devices for digital light processing (DLP) and others with a large screen and high resolution. Among those, the DLP projection device realizes an image on a screen through pixels generated by micro mirrors each of which moves independently on the digital micro-mirror device (DMD) chip. The number of pixel which depends on those of mirrors determines the resolution of the device and thus, it should be increased in order to enhance the resolution of the device in DLP projection. However, it has some technical problems and leads to increase in cost. Therefore, a new methodology with existing DMD chip is required for high resolution of DLP projection device. For this purpose, Texas Instruments proposed a smooth picture mechanism by which the resolution of DLP projection device is visually made double. First, the shape of micro mirrors is changed from square to diamond type. Second, pixels are repeatedly multiplied in the vertical direction. Consequently, the resolution of the DLP projection device is visually doubled. In this work, we propose a transmission-type pixel enhancement actuator (PEA) for pixel doubling of DLP projection device which employs the above smooth picture mechanism, where mechanical characteristics and the driving methodology are explained.