This article was posted on 12/01/1999.
Device can replace many conventional glass or plastic
components in an extremely low-profile package
An electrically switchable lens operates at speeds far greater than the human
eye can detect. It is presented as the first diffractive lens to offer
full-color capability in a compact package.
A new category of optical device, called an application-specific integrated
lens (ASIL), has been introduced by
. The device, an electrically switchable diffractive lens, can replace many
conventional glass or plastic optical components.
The device consists of several layers of polymer-dispersed liquid crystal that
can switch its optical properties at speeds far greater than the human eye can
detect. Each layer is tuned to a specific color range, providing flicker-free
sequential control of red, green, and blue.
The material can be optimized to operate from the near ultraviolet, at around
400 nm, out to the near infrared, at around 1,600 nm. ASILs can be configured
as either reflective or transmissive elements.
These attributes allow ASILs to enhance many applications where size is
critical. For example, the ASIL can reduce the size of the optics in full-color
microdisplays for such applications as high-definition television, business
projectors, computer monitors, and next-generation miniature handheld devices
for wireless Internet access. Until now, the benefits of microdisplays have
largely gone untapped because of the complexity of the illumination and
magnification of the image.
In addition, conventional refractive glass and plastic lenses are bulky.
Standard diffractive lenses resolve these space and weight constraints, but are
unsuitable for color displays because they can handle only monochromatic light.
Able to replace bulky conventional optics, an ASIL is a polymer-dispersed
liquid-crystal electrically switchable lens that can switch its optical
properties at speeds far greater than the human eye can detect.
The ASIL avoids bulk by encapsulating the prescriptions of multiple lenses in a
miniature solid-state package. When creating an ASIL, the manufacturer
calculates the optical characteristics, which are then computer generated and
holographically recorded using proprietary software tools and assembly
processes. Any single holographic layer of a multilayer ASIL may be switched
clear momentarily, allowing the next stacked layer's optical properties to
In addition to imaging applications, ASILs can also be implemented as spectral
filters. It is thus possible to create switchable, color-selective backlight or
ambient-light diffusers and color filters for direct-view or projector
applications. For more information, contact Mike Adams of DigiLens at
408-737-1100, ext. 257, e-mail him at email@example.com, or visit
--Alix L. Paultre