Design of LCOS Microdisplay Backplanes for Projection Applications

Chapter 1 : Welcome to “Display World” CH1 - 25
Chapter 1 : Welcome to “Display World”
T
he target of this book is to describe some of the issues concerning the design of
liquid-crystal-on-silicon (lcos) micro-display backplanes. This first chapter
introduces the research topic in more detail. An lcos micro-display backplane
comprises a special chip. Its behavior is much that of a programmable slide.
Essentially, it is an electro-optical device; lcos micro-displays are often referred to
as light valves: electrical signals steer the modulation of a beam of light in a few
million points. It is useful to place the lcos display case in a broader context and to
try to assess the following questions: is this particular system the display system that
will conquer our houses, is it meaningful to spend research resources to such a
subject and which are the basic principles behind display operation?
The first paragraph of this chapter recalls three essential facts about human vision;
three facts that are fundamental to understand the operation of most display systems.
The second paragraph briefly mentions economical aspects and gives an indicative
value of the "real world" market. After all, what's the practical interest in research on
displays?
The third paragraph is entitled “application specific displays”. It is indeed justified –
to some degree – to state that each display type fits a particular application. A
classification attempt is made to help distinguishing between the several display
technologies, applications, etc, etc. Subsequently, the text focuses on examples of
liquid-crystal-on-silicon (lcos) projection architectures. Finally, a glance at the
anatomy of an lcos micro-display backplane wraps up this chapter and by then
provides more insight in the meaning of the thesis’s title… Welcome to display
world!
1.1 How we see colored, moving images
The first paragraph recalls three facts about human vision, essential to understand
the operation of any display system.
Today’s state of evolution is marked by exchanges of increasingly massive
quantities of information. In this respect, display systems play a prominent role in
everyday communications. But how did mankind come to invent display systems?
Let’s look at some historical facts: some 200 years BC, the famous Aristote noted
how the sun’s image remained visible for a while, after turning his eyes away from
it! Around 1650 the ‘magic chamber’ shows up; it is not clear whether it should be
attributed to Athanasius Kircher or Christiaan Huygens. Later, amongst other
discoveries in optics, Joseph Plateau (°1801-†1883) studied ‘phenomena of image
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