Thin metallized viscoelastic layers coated by a mirror electrode and addressed by an active matrix are
proposed for ue in schlieren-optical light-valve projection systems for high-definition television (HDTV).
Previously, the deformation behavior of such viscoelastic spatial light modulators (VSLMs) was analyzed
extensively by use of the theories of electrostatics, linear viscoelasticity, and plate bending. In the meantime,
most of the theoretical results could be qualitatively confirmed by interferometric deformation measurement.
Of the many predictions derived from the theoretical treatment, only the deformation patterns to
be expected with one bright line and with two bright lines separated by a dark line are demonstrated here.
Furthermore, the number of grating periods per picture element as well as the ratio of electrode width and
grating period are discussed in view of resolution limits. In addition, three concepts of full-color schlierenoptical
projection systems for the above reflective VSLMS are described and compared. All three systems
contain a light source, three spatial light modulators (one for each primary color), and a projection lens.
The first concept is based on a very small light source and a correspondingly small stop; in the second
concept, mirror bars as in the well-known Eidophor projector are employed; and parallel light is assumed
in the third concept.
A high-brightness liquid crystal light valve (LCLV) projector, in which three
amorphous Si TFT-addressed LCLVs are used, has been developed for laroe screen
displays. By using a newly developed polarization converter, about twice the
brightness has been realized compared to using a conventional sheet polarizer.
The polarization converter principle is to efficiently convert an unpolarized
light from a light source into a linearly polarized light, used to illuminate a
twisted nematic LCLV. The LCLV has 240 x 756 pixels in the 4.3 inch diagonal area.
High-brightness full-color images with 120 ft-L brightness have been obtained,
when projected onto a 5.0 gain 80 inch diagonal screen using a 300W Xenon arc lamp.
Full-color, large screen display systems can enhance military applications that
require group presentation, coordinated decisions, or interaction between decision
makers. The technology already plays an important role in operations centers,
simulation facilities, conference rooms, and training centers. Some applications
display situational, status, or briefing information, while others portray instructional
material for procedural training or depict realistic panoramic scenes that are
used in simulators. While each specific application requires unique values of
luminance, resolution, response time, reliability, and the video interface, suitable
performance can be achieved with available commercial large screen displays.
Advances in the technology of large screen displays are driven by the commercial
applications because the military applications do not provide the significant market
share enjoyed by high definition television (HDTV), entertainment, advertisement,
training, and industrial applications.
This paper reviews the status of full-color, large screen display technologies
and includes the performance and cost metrics of available systems. For this discussion,
performance data is based upon either measurements made by our personnel or
extractions from vendors' data sheets.
A review of the components and technology used to produce large color raster Images using
lasers as a light source is given, with an analysis of the tradeoffs that must be made.
1. Faithful color reproduction. Whereas the tristimulus model suggests that a wide
range of three primary colors might be used, wavelength choices for the red and
blue seem to be critical in this application.
2. Perceived versus measured brightness. It seems that the brightness of scanned
laser light Images depends upon conventional perceptive variables such as contrast
ratio, color purity, and luminosity: and not upon the special quality of the laser
light itself, the scanning technique, or the coherence. Laser speckle can be
considered strictly as a contrast ratio enhancement. Practical guidelines for
planning installations are given, and the relationship between lumens and watts
in laser projectors is clarified.
3. Laser choice. There are few laser light sources that meet both tristimulus and
power requirements. While some pulsed lasers can be used, full color displays now
require continuous wave lasers that have several lines in the visible part of the
A full-color projection display system, using CRT driven Liquid Crystal
Light Valves (LCLV5), is specifically designed to withstand the rigorous
environmental requirements of surface ship applications. The projection system
is designed to allow the Navy to upgrade its current monochromatic displays to
full-color capability. The projector contains three optical subsystems: the
arc-lamp housing, the fluid-filled prism, and the relay projection lens.
Illumination is provided by a 750-watt xenon arc lamp that is prealigned and
prefocused inside a replaceable module. The fluid-filled prism polarizes the
arc-lamp light and separates it into the red, green, and blue primary colors.
The projector contains three LCLV5 (one for each primary color). Images are
reflected off the light valves and relayed back though the prism to a single
projection lens. The wide-angle projection lens directs the image to a 42-inch
square projection screen. Image registration is achieved by both dynamic
digital--orrection circuitry and by screen sensors that provide feedback to the
projector's analog deflection drivers.
TRU-LYTE Systems, Inc. is developing an HDTV display that will exceed displays in the large screen
display (LSD) market. Due to the present design and manufacturing techniques of LCDs, ELs, and
CRTs there are limitations with LSD applications. One of the possible solutions is a hybrid of fiber
optic technology and transmissive active matrix LCDs. In this design, multiple LCD modules are
coupled with an equal number of fiber optic modules. These modules are designed so that strands of
fiber optics are placed in a coherent manner from a rear panel to a predetermined spaced front panel.
An image projected onto the rear panel will result in an enlarged image being displayed on the front
panel. Imageboard modules would then be manufactured using this design of the building block
method. The determining factors would include the desired output intensity, size restrictions, and cost
factors. Research has also developed a technology that allows for consistent wide-angle viewing of the
image displa'ed by the optical fibers. Applications for this product range from HDTV to stadium
HDTV (known as Hi-Vision in Japan), with its ability to provide through high-
definition pictures on a large screen display advanced psychological effects such as
sensations of reality and a visual impact unobtainable in conventional television,
is the television system of the next generation.
In Japan, daily one-hour experimental broadcasting was initiated in June 1989
using the BS-2 broadcast satellite, and regular service is scheduled to begin via
the BS-3 satellite to be launched in 1990. To this end, a home-use receiver using
VLSIs has already been developed. Moreover, HDTV is currently being applied in such
diverse areas as film production, printing and publishing, medicine, and art
The HDTV system handles approximately five times the information of
conventional television. As a result, a large screen display capable of maintaining
stable resolution greater than twice that of conventional displays is essential to
the full realization of HDTV's vast potential.
This paper will first discuss HDTV's basic parameters, concentrating on the
psychovisual effects, and explain some preferable display characteristics from this
psychovisual point of view. It will then discuss the technical problems in
developing such a display, and final ly describe the current state of HDTV display
Three dimensional displays using binocular disparity techniques are widely used. Binocular stereoscopic images can produce
a mismatch of distance between plane of focus (accommodation) and plane of fixation (convergence) of the observe?s eyes.
The viewing distance, i.e. plane of required focus, is generally greater when looking at a large screen than when look at a
small display. In this study the fusional ranges of the binocular three dimensional image are compared when viewing a large
screen (75inch,projection type TV display) at a distance of 350cm and when observing a small display (2linch CRT) at a
distance of 100cm. We found that the fusional range was more extended on the larger screen than the smaller display.
Accommodative responses were measured when looking at the 3D image. Accommodation does not remain in the plane of the
display but changes to the stereoscopic distance of the 3D image fixated by the observer. The changes required when using a
longer viewing distance were smaller than those measured with an a short viewing distance. These results suggest the longer
viewing distance reduces an unnatural feeling of viewing 3D images due to the mismatch of distance between the planes of
accommodation and convergence.
Accommodation response time was measured after looking at stereoscopic 3D images. Far-to-near response time was
longer than before viewing these images. The results showed that the viewing stereoscopic 3D images provided the observer's
visual system with different type of stimuli from these experienced in normal viewing.
In the last two or three years electro-stereoscopic display
systems using large liquid crystal panels have become commonplace.
These devices change the polarization characteristics of
the light emitted by the display at video field rate so that
passive eyewear employing polarizers may be used. The size of
such displays is limited because liquid crystal factories aren't
set up to handle panels larger than 19 inches in diagonal. In
addition, the present product is costly to manufacture and larger
panels would be even more costly.
The new battery powered CrystalEyesTM product uses wireless
eyewear with active liquid crystal lenses, having a fiftieth of
the area of the larger panels. The eyewear receives information
from an infrared emitter, allowing the lenses to occlude in
synchronization with the field rate. There is no size limitation
with regard to the display screen, and the clumsy tethering
cable of prior active eyewear has been eliminated. Moreover, the
cost of the new product is considerably lower than that of the
large liquid crystal panels, and the performance is superior.
Large screen television displays have been developed for use in stadiums, aircraft simulators,
and large auditoriums. Electronic display of these images will become even more widespread
with the introduction of high definition television. Consumer applications of HDTV require a
large (about 3' x 5 1/3') bright display at a relatively low cost. This paper will discuss the
properties of commercially available large screen television displays and evaluate the options
for the new technologies that could satisfy the requirements of the future applications.
A stereoscopic projection system for displaying 3-D video
information has been constructed using Liquid Crystal Light Valves
(LCLV5) . Presently most stereoscopic displays of video imagery use a
single CRT with a liquid crystal or PLZT shutter1'2 or use two CRT5 with
orthogonally polarized outputs3. The advantage of the first method is
only one CRT is needed and image convergence is not a problem. However,
whether passive or active glasses are used for the field-sequential
viewing, ghost images are formed due to the finite phosphor decay time1.
A dual CRT projector 3-D display has the advantage that passive glasses
can be easily employed with virtually no ghost images. The luminous
output of the projector, though, is reduced by half during the initial
In a Liquid Crystal Light Valve projector the output light is
linearly polarized in normal operation. Therefore a two-projector 3-D
stereoscopic system using LCLVs can be realized which has very low
intensity ghost images, high luminous output, and can be viewed with
passive glasses. This paper discusses some potential configurations of
such a projector and how a newly developed LCLV with improved time
response makes real-time 3-D imaging using this technology possible.
In recent years, LCDs have drawn the attention of persons who present data such
as sentences and patterns on the screen. This paper describes a new type of the
device for projection using the LCD. CITIZEN has developed a multi-pixel,
high-density and small-sized liquid crystal cell, using the Chip on Glass method.
Driver ICs are directly connected to glass substrates. CITIZEN has developed a
small liquid crystal display device, which is located between the light source and
the lens of a conventional slide projector so that an image on the LCD is projected.
The likely performance envelope and architecture for satellite
cinema systems are derived from simple practical assumptions. A
case is made for possible transatlantic cooperation towards
establishing a satellite cinema standard.
After over ten years experience with the domed cinema and planetarium medium, I began this study as a way o+ broadening my own base of knowledge as well as hopefully creating an input vehicle to manufacturers of the various needs of end users. This study is based on information received from various manufacturers mixed with my own experience. I would like to believe it is the next development in this rapidly changing medium. I wish to stress that at this time this concept is still experimental, yet I believe similar projects will occur within the next five to ten years if not sooner.