SEMINAR on

SEDSEDA d a r s h .S

COMMON DISPLAY TECHNOLOGIES :

AN OVERVIEW

Cathode Ray Tube

Earliest displays

A specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface

Later RGB colour model for displays in colour monitors

Affected by external fields

Bulky , high power consumption and heat production

Liquid Crystal Display

Displays thinner than (CRT) technology.

LCD’s consume much less power

Work on the principle of blocking light rather than emitting it.

LCD has a grid of conductors with pixels located at each intersection in the grid. A current is sent across two conductors on the grid to control the light for any pixel.

Slow response time

Less viewable angle

Difficulty in producing dark and grey colours

Plasma

”Technology Today” , also in development

Electrical pulse excite a pixel

Wider angle view than LCD

Power consumption higher than LCD

Complexity

Cost greater than LCD

Fragile technology : quite easy to damage

PC connectivity less common since it is developing

Buzz into SED ??SED ??

Wider angle view !!!!Lower cost !!!!Superior picture quality !!!!Less complexity in overall terms !!!!

“ “ SURFACE CONDUCTION SURFACE CONDUCTION ELECTRON EMITTER DISPLAY ”ELECTRON EMITTER DISPLAY ”

Combine CRT into LCD technology.Millions of miniature CRTs, called

surface-conduction electron emitters (SCEs) embedded in surface.

“High quality picture in low centimeter thickness”

Only 3cm thickness

Inside SED @@

sv

how SED works ??

An SED-TV has millions of these SCE s arranged in a matrix , and each one controls the Red, Green or Blue aspect of one pixel of the picture. Rather than directing electrons to create the image one row at a time, the matrix activates all the SCE s needed to create the picture virtually simultaneously

SCE MATRIX

One SCE pixel

One SCE pixel

In short……............……............………………………………tied together

When the SED-TV receives a signal,,

a) Scans the signal

b) Decides what to do with the red, green and blue aspect of each pixel

c) Activates the necessary SCE s, which generate electrons that fly through the vacuum to the screen

Comparison between different technologies

Prototype models developed

Developed by Canon

Beneficial Features

Sharp resolution and fast response(1ms) and only 3cms in thickness

Excellent colour and contrast potential

Relatively inexpensive production cost

180º Viewing angle.

Extremely low power consumption

Lower cost than LCD or PLASMA

It can be used in Mobile device display

Snaps from sed tv’s

Challenges

Unknown (though optimistic) life expectancy

Potential for screen burn-in : but expected to overcome due to phosphor development

Currently prototype only expected soon

References:

Document-United States Patent 7548017 engadgetHD Nanotechnology, Transactions on Volume 7, Issue 4,

July 2008. Audioholics www.cnet.com www.newtechnologyworld.com

By A d a r s h

Questions