Time-Sequential Working Wavelength-Selective Filter for Flat Autostereoscopic Displays

Abstract

A time-sequential working, spatially-multiplexed autostereoscopic 3D display design consisting of a fast switchable RGB-color filter array and a fast color display is presented. The newly-introduced 3D display design is usable as a multi-user display, as well as a single-user system. The wavelength-selective filter barrier emits the light from a larger aperture than common autostereoscopic barrier displays with similar barrier pitch and ascent. Measurements on a demonstrator with commercial display components, simulations and computational evaluations have been carried out to describe the proposed wavelength-selective display design in static states and to show the weak spots of display filters in commercial displays. An optical modelling of wavelength-selective barriers has been used for instance to calculate the light ray distribution properties of that arrangement. In the time-sequential implementation, it is important to avoid that quick eye or eyelid movement leads to visible color artifacts. Therefore, color filter cells, switching faster than conventional LC display cells, must distribute directed light from different primaries at the same time, to create a 3D presentation. For that, electric tunable liquid crystal Fabry-Pérot color filters are presented. They switch on-off the colors red, green and blue in the millisecond regime. Their active areas consist of a sub-micrometer-thick nematic layer sandwiched between dielectric mirrors and indium tin oxide (ITO)-electrodes. These cells shall switch narrowband light of red, green or blue. A barrier filter array for a high resolution, glasses-free 3D display has to be equipped with several thousand switchable filter elements having different color apertures.Keywords: fast switchable wavelength-selective elements; autostereoscopic image splitter; color filter barrier array; computational display; Fabry-Pérot color filter; on-off filter mode

Quantum dot materials for improved autostereoscopic color filter display designs

“…This means that the resolution alternates horizontally with the visible color and the selected color filter strip width F. For uniform color resolution across the entire 3D display, the width of the color filter stripes must be small or a time‐sequential procedure must be implemented in which the filter strips change their color. We have published studies on the width of color stripes in as well as on the time sequential design case in de la Barré et al . However, to test these assumptions, it will be sufficient to examine pattern designs with static color barriers.…”

“…Common LCDs with LED backlighting use a broad illumination spectrum that is not efficiently applicable for stereoscopic wavelength selective image splitter in 3D displays . This assessment for stereoscopic displays also applies to autostereoscopic 3D displays.…”

“…Even the use of improved display materials is not enough. Therefore, in de la Barré et al ., it was verified that the barrier effect is not sufficient for autostereoscopic displays (ASDs) by using subtractive filters of subpixels. In contrast, quantum dot LED or QLED spectra with their narrow band characteristic are a promising candidate for such an ASD with a color filter splitter.…”

“…Different arrangements of such combinations of RGB‐display and color filter barrier have been simulated with in‐house software and, therefore, enabling several new design approaches to be developed. From an experimental setup with current display technologies, it is possible to differentiate requirements for the materials required …”

“…For the first time, wavelength based color filters for stereoscopic multiview ASDs were investigated by Grasnick at the beginning of this century. The practical work of Grasnick and others showed the color splitting approach continued to remain unsatisfactory in the area of ASD applications. The principal reasons for this are the display materials used.…”