A new paradigm of digital projection is on the horizon, based on innovative emissive screen that are made fully transparent. It can be readily applied and convert any surface to a high image quality emissive digital display, without affecting the surface appearance. For example, it can convert any glass window or windshield to completely see-through display, with unlimited field of view and viewing angles. It also enables a scalable and economic projection display on a pitch-black emissive screen with black level and image contrast that rivals other emissive displays such as plasma display or OLED.
Front digital projection (FDP) displays have the features of being portable,
economical and scalable for large size displays. Unfortunately, existing FDP technologies
suffer with poor image contrast in well-lighted environments, due to the "black-level"
issues of the conventional white diffusive screens. More powerful projectors can be
applied to enhance contrasts by increasing the brightness, at the expenses of significantly
increased cost, weight, power consumption, and viewer eye fatigue due to the bright
In this joint paper, we demonstrate an innovative full color, high contrast front
projective display system on a black emissive screen (BES). It comprises of a novel
transparent fluorescent screen on pitch-black substrate, and a digital image projector with
optic output that excite the fluorescent screen. The fluorescent layered screen is
comprised of at least 3 layers of RGB emissive materials, which are made in fully
transparent form. The "excitation" projector is based on DLP® projector platform, where a
UHP lamp is filtered by a color filter wheel which sequentially excites the RGB emissive
layers resulting in RGB emissions from the screen.
This display combines the best of both worlds of front projection and emissive display
technologies. Like projection displays, it is scalable and economic at large displays, the
screen has no pixel structure and can be manufactured using a roll to roll method. Like
emissive displays (e.g. plasma or field emission displays with phosphor screen), the
quality of the emissive images on black back-plate is superior, with large viewing angles
and superior contrasts in any environments. The new projection display can favorably compete with existing flat panel displays and other projection displays.
In this paper, Sun Innovations demonstrates an innovative emissive
projection display (EPD) system. It is comprised of a fully transparent fluorescent
screen with a UV image projector. The screen can be applied to glass windows or
windshield, without affecting visible light transmission. The UV projector can be
based on either a DLP (digital light processor) or a laser scanner display engine. For
a DLP based projector, a discharge lamp coupled to a set of UV filters can be
applied to generate a full color video image on the transparent screen. UV or blue-ray
laser diodes of different wavelengths can be combined with scanning mirrors to
generate a vector display for full windshield display applications. This display
combines the best of both worlds of conventional projection and emissive display
technologies. Like a projection display, the screen has no pixel structure and can be
manufactured roll to roll; the display is scalable. Like an emissive display (e.g.
plasma or CRT), the quality of the image is superior, with very large viewing angles.
It also offers some unique features. For example, in addition to a fully transparent
display on windows or windshields, it can be applied to a black substrate to create
the first front projection display on true "black" screen that has superior image
contrast at low projection power. This fundamentally new display platform can
enable multiple major commercial applications that can not be addressed by any of
the existing display technologies.
We present a two-step two-frequency up-conversion (TSTF-UC) fluorescent material based crossed-beam display (CBD) apparatus. 3D voxels are addressed by two IR laser beams, which are driven by fast acousto-optic light deflectors (AOLD). The compact scanning system can cover a display volume of 100mmx100mmx100mm. Initial demonstration was carried out with a piece of 0.5-mol % Er<sup>3+</sup>-doped ZBLAN glass (23mmx23mmx17mm). It was found that the 3D image brightness dropped dramatically when refresh rate was increased. Also “ghost” voxels appeared with increasing refresh rate. A simplified rate-equation analysis was performed to address the issues.