A switched emissive transparent display with controllable per‐pixel opacity

Abstract

An emissive transparent display with per-pixel opacity employs rapid synchronized switching of a transparent display and transparent backlight between content with a scattering luminous backlight, and masks with a clear unlit backlight. A 144 fps transparent LCD panel is used in conjunction with a transparent backlight and controllably diffusive smartglass screen. The display is capable of producing opaque emissive content on a transparent field for novel display and compact spatial augmented reality applications.Author Keywords transparent display; opaque; emissive; switching; transparent backlight ObjectiveMany futuristic display concepts from action and sci-fi movies involve transparent displays with colorfully emissive yet opaque content; we have interest in physically creating such displays. Such a display would also be useful in allowing synthetic characters to be placed amongst physical objects a real-world scene, i.e. a compact Pepper's Ghost. In these cases, the ability to control opacity in a transparent display is important, otherwise the content or character would be also appear semi-transparent and low contrast against bright busy background environments.Practical implementation of such a display is difficult since each pixel of such a display would need not only a color, e.g. R: red, G: green, B:blue components, and emissive luminance/brightness, e.g. R,G,B= [0, 1, ... , 255], but also an absorption/opacity, e.g. α= [0,1, ..., 255]. This would be considered a color transparent emissive display with real-world optical alpha (or per-pixel variable transparency). Current displays' pixels control only two out of the three variables. For example, the pixels of a transparent LCD panel vary color and opacity, but not emissive luminance; LCD panels to not generate their own light. Similarly, transparent OLEDs may vary color and luminance, but do not control opacity; OLEDs do not modulate background light. As a result, content displayed on current transparent displays are low-contrast and semi-transparent. We need pixels that can vary in color, luminance and opacity (e.g.RGBα), and the display must be able to accept such four data component signals (or six data component with an independent alpha channel for each color channel). Typical video signals have only three data components (RGB).Since common displays are only able to control two out of the three desired variables of luminance, color and opacity, we temporally multiplex opaque-emissive content (color and luminance) and transparency with absorbing masks (color and transparency). We employ rapid synchronized switching of a transparent LCD display and transparent backlight between displayed content with scattering-luminous backlight, and displayed mask with a transparent -nonluminous backlight states. To implement this scheme, a 120 fps (or greater) transparent LCD panel can be used in conjunction with a variety of transparent backlights. BackgroundWe have previously presented displays which can control each pixel's color, luminance, and opacity...