Timothy Large

Collimated light from a waveguide for a display backlight

We report light collimation from a point source without the space normally needed for fan-out. Rays emerge uniformly from all parts of the surface of a blunt wedge light-guide when a point source of light is placed at the thin end and the sources position determines ray direction in the manner of a lens. A lenticular array between this light-guide and a liquid crystal panel guides light from color light-emitting diodes to designated sub-pixels thereby removing the need for color filters and halving power consumption but we foresee much greater power economies and wider application.

Fabrication of Novel Transparent Touch Sensing Device via Drop-on-Demand Inkjet Printing Technique

UNLABELLED A novel transparent touch sensor was fabricated with a drop-on-demand inkjet printing technique on borosilicate glass and flexible polyethylene terephthalate (PET) substrates. Conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PEDOT PSS) and dielectric poly(methylsiloxane) were deposited on a desired area to form a capacitive touch sensor structure. The properties of the printed sensors (optical transparency, electrical resistance and touch sensing performance) were investigated with varying PEDOT PSS printing passes. A novel transparent touch sensor fabricated with an all-inkjet-printing method is demonstrated for the first time. This process holds industrially viable potential to fabricate transparent touch sensors with an inkjet printing technique on both rigid and flexible substrates for a wide range of applications.

20.4: Image Quality in Flat Projection Wedges

We report a flat projection display with a 20 mm thick screen, 14″ diagonal, brightness of 5000 cdm−2 and resolution of ∼600×800 pixels. The display is made of off-the-shelf PMMA and uses an unmodified video projector with only keystone predistortion. Optical modeling predicts XGA resolution on a 20 mm thick screen with a diagonal of 50″, brightness of 500 cdm−2 and contrast the same as for conventional projection.

Image capture via a wedge light-guide with no margins

We report the capture of images via a wedge light-guide without the margin for fan-in needed heretofore. While this lets one look out of a slim panel as if it were a periscope, half the power is lost and resolution is degraded by aperture diffraction. Volume gratings may resolve these drawbacks at certain wavelengths and we consider how these might be extruded.

A novel see-through screen based on weave fabrics

See-through screens (STS) have found important applications in remote collaboration systems to enhance non-verbal communication and gaze awareness. Existing STS designs often sacrifice the display quality significantly, rendering low-contrast images that discount the overall user experience. In this paper, we present a novel see-through screen solution based on weave fabrics. Such fabrics are known to be acoustically transparent and used to build professional projection screens for Hollywood studios. We place a cam-era immediately behind the screen and synchronize it with a 120Hz projector to perform time-multiplexing display and video capture. By focusing the camera at the user 4–5 feet away from the screen, the image of the weave fabric will be severely blurred. We present the imaging principle of the setup, and derive image processing techniques to enhance the quality of the captured video. The overall system is low cost, has much better display quality than existing systems, and can be used to build wall-size see-through screens for various applications.

71.4: Invited Paper: Imaging via Backlights

We have used a wedge light guide to capture images in front of an LCD as if from a point deep behind. We have also used it to illuminate an LCD so as to be visible to only one viewer. These two features offer the prospect of a digital window.

16.2: Backlight for ViewSequential Autostereo 3D

We have demonstrated a backlight which emits collimated light whose direction can be scanned through 16°. Combined with a high frame rate LCD, this lets us display stereo 3D with no need for glasses.