PLASMA
DISPLAY
MONITOR
RASTOR
VS RANDOM
SCAN
INTERLACING
AND NONINTERLACING
PLASMA DISPLAY MONITOR
WHAT IS PLASMA?
Plasma is often called the "Fourth State of Matter", the other
three being solid, liquid and gas. A plasma is a distinct state of
matter containing a significant number of electrically charged
particles, a number sufficient to affect its electrical properties and
behavior.
Plasma is a substance similar to gas in which a certain portion of
the particles are ionized .
INTRODUCTION

A plasma display is the most advanced technology based display
devices (as they are not at all bulky when compared to CRTs).

Provide a very good quality of picture which is sharp from every
angle.

They have a slim profile & can be wall mounted.

They have got high refresh rates and a faster response time,
contributing to superior performance.

The weight of a plasma display monitor that is, on average about
40% to 50% of the weight of a CRT-based monitor of similar
screen size.
INSIDE THE DISPLAY

A plasma display monitor is
composed of a front plate with
pairs of display electrodes and a
rear plate which contains address
electrodes.

In the front plate the electrodes
are covered with a glass layer
called the Dielectric Layer. A
magnesium oxide coating, called
the Protective Layer, is applied to
this glass layer.
IMAGE FORMATION
The display electrodes are
arranged in horizontal rows along
the screen and the address
electrodes are arranged in vertical
columns. The vertical and
horizontal electrodes form a basic
grid.
 Within each cell, there are actually
three sub cells, one containing a
red , another a blue , and a green
phosphor. To generate color
shades, the perceived intensity of
each RGB color must be controlled
independently .
 To ionize the gas in a particular
cell, the plasma display's computer
charges the electrodes that
intersect at that cell.




When the intersecting
electrodes are charged, an
electric current flows through
the gas in the cell .
The current creates a rapid
flow of charged particles,
which stimulates the gas
atoms to release ultraviolet
photons.
The released ultraviolet
photons interact with
phosphor material coated on
the inside wall of the cell..
When an ultraviolet photon
hits a phosphor atom in the
cell, one of the phosphor's
electrons jumps to a higher
energy level. When the
electron falls back to its
normal level, it releases
energy in the form of a
visible light .
What actually happens inside the
cell?
RANDOM vs RASTER SCAN

When operated as a randomscan display unit, a CRT
directs the electron beam
only to the parts of the screen
where a picture is to be
drawn.

In raster scan, the beam
sweeps horizontally left-toright at a steady rate, then
blanks and rapidly moves
back to the left, where it turns
back on and sweeps out the
next line (flyback).
Random displays have high
resolutions
Smooth lines are produced as
the electron beam directly
follows the line path
Random-scan system's are
generally costlier


Decreasing memory costs
have made raster systems
popular.

Random scan systems are
designed to draw all the
component lines of a picture
30 to 60 times each second

Refreshing on raster scan
displays is carried out at the
rate of 60 to 80
frames/second

Picture definition is stored as
a set of line drawing
commands in an area of
memory referred to as refresh
display file.

Picture definition is stored in
a memory area called the
refresh buffer/frame buffer.




Raster displays have less
resolution
Lines produced are ziz-zag as
the plotted values are discrete
INTERLACING
Interlaced scan refers to one of two common methods for
"painting" a video image on an electronic display screen by
scanning or displaying each line or row of pixels.
This technique uses two fields to create a frame. One field contains
all the odd lines in the image, the other contains all the even lines
of the image .
NON-INTERLACED DISPLAY
It is the opposite phenomenon of Interlacing. In this all the lines
of frame are scanned in one pass.
For higher resolution the non-interlaced display creates a better
image as compared to Interlaced display. The scanning is done
line by line in continuous fashion in non-interlaced display.