Mikromercek dizini tabanlı şeffaf ve yüksek kazançlı projeksiyon ekranları

Tablet computers and smart phones have increased the mobility of the users but small screen size has been a major limitation for the productivity of the users. Mobile projectors, called pico-projectors, are emerging technologies and can project images to any distance and size from a tiny display engine that can be embedded in mobile computers and phones. While pico-projectors can overcome the screen size limitation, they are limited in brightness due to battery operation and laser safety concerns. The aim of this research was to develop reflective and transparent novel screen technologies that can provide high-efficiency and high-brightness when used together with laser scanning based pico-projectors. Such screens are needed in augmented reality displays, head-up displays, and head-mounted projection displays. When an image is projected on ordinary surfaces, such as walls or a piece of paper, the light is scattered onto the entire hemisphere. We developed special micro-structured screens that concentrate the scattered light only around the user?s eyes. As the projected energy is concentrated into a smaller area, the brightness of the image is increased and the screen has a gain compared to ordinary surfaces. Three different screen technologies have been developed that use microlens array (MLA) based diffusers: a single MLA screen, a dual MLA screen and a rotated MLA screen. The single MLA screen has a gain of 3 and it was designed for automotive head-up display applications. Due to its unique index matched structure the screen provides excellent transparency and high brightness at the same time. The dual MLA screen is an opaque screen with a gain of 9. It concentrates the diffused light more efficiently compared to the single MLA due to the telecentricity of the microlenses. A novel rotated MLA provides the highest gain of all the screens. It is designed specifically for a given application such that every pixel on the screen is reflected towards the user due to the rotation of the microlenses. It can provide gains on the order of 100.