Sxrd technologies, Vertically aligned liquid crystal system, Thin liquid crystal cell gap – Sony SRX-R220 User Manual
Page 9: Short response time, Reliable imaging device
9
SXRD Technologies
In addition to their extreme resolution and high contrast, the
SXRD devices used in the SRX series projectors have the
following remarkable technological features:
Vertically Aligned Liquid Crystal
System
In every type of projector system, displaying absolute black
is a major issue in order to achieve a high contrast ratio.
In other words, the contrast ratio of a projector depends on
how effectively the light from the source can be blocked so it
does not leak through the imager.
All Liquid Crystal Display (LCD) devices control the amount
of light to be projected by applying an electric field to the
liquid crystal gap. In typical LCD devices, black is produced
when an electric field is applied across the liquid crystal cell
gap. However, molecules near the surface of the glass
substrate may not be accurately controlled due to the
influence of the alignment film. This is not an issue for
bright images. However, when displaying dark images, light
may tend to leak from the LCD device, since the molecules
near the surface are less accurately controlled. This results
in a creamy black instead of a deep black.
The SXRD device does not exhibit these characteristics. This
is because the Vertically Aligned Liquid Crystal system
displays black when
the electric field is
not applied and
because all
molecules are in the
correct alignment,
the polarized light
alignment is also
optimized. The
direct result is a far
deeper black level,
leading to a high
contrast ratio.
Thin Liquid Crystal Cell Gap
Another important enabling factor of high contrast is the
SXRD device’s ultra-thin cell gap of less than 2 micrometers.
In conventional Vertically Aligned Liquid Crystal systems, a
thin cell gap could not be achieved. Sony has overcome this
difficulty through the use of Sony’s innovative planarization
technology in the silicon backplane structure and an
advanced Silicon wafer-based assembly process.
The SXRD device also adopts a structure that does not use
“spacers”. These are columns found in conventional
reflective liquid crystal devices to maintain a constant gap
between the liquid cell floor and the top of the device.
Spacers tend to both scatter and reflect light, which can
impair high-contrast pictures. In the spacer-less SXRD
device, these artifacts are no longer seen.
Short Response Time
The thin cell gap structure in SXRD devices also contributes
to an ultra-fast response time of 5 milliseconds. The SXRD
device reacts promptly to an instantaneous change of picture
content, enabling it to display a smooth motion.
Consequently, the SRX-R220 and SRX-R210 virtually
eliminate motion blur; a particularly significant benefit for
visual content that includes fast-moving objects.
Reliable Imaging Device
The SRX-R220 and the SRX-R210 use a high-power, bright
lamp. As a result, special attention has been paid to the
reliability of the SXRD device. The inorganic materials
utilized for the alignment layer of the SXRD device are
resistant to deterioration or deformities that could occur due
to the intense heat and light generated by the powerful lamp
system.
High-Density Pixel Pitch 8.5 µm
• 4 x Full-HDTV (4096 H x 2160 V pixels)
SXRD Cross-Section view
Thin Cell Gap (2.0 µm) Space-less
• Short response time < 5 msec
• High Device Contrast ratio 4000 : 1
Light
Inorganic
Alignment Layer
• High reliability
Vertically Aligned Liquid Crystal
Glass Substrate
Silicon Backplane
Narrow Inter-Pixel
Spacing (0.35 µm)
• High fill factor 92 %
• High reflectivity
Aluminium Pad
SXRD Cross-Section view