PLASMA DISPLAY PLASMA DISPLAY MONITORMONITOR

RASTOR VS RASTOR VS RANDOM SCANRANDOM SCAN

INTERLACING AND INTERLACING AND NON-INTERLACINGNON-INTERLACING

PLASMA DISPLAY PLASMA DISPLAY MONITORMONITOR

WHAT IS PLASMA?WHAT IS PLASMA?

Plasma is often called the Plasma is often called the ""Fourth State of Fourth State of MatterMatter", the other three being solid, liquid and ", the other three being solid, liquid and gas. A plasma is a distinct state of matter gas. A plasma is a distinct state of matter containing a significant number of electrically containing a significant number of electrically charged particles, a number sufficient to affect its charged particles, a number sufficient to affect its electrical properties and behavior. electrical properties and behavior.

Plasma is a substance similar to gas in which a certain portion of the particles are ionized .

INTRODUCTIONINTRODUCTION A plasma display is the A plasma display is the most advanced technologymost advanced technology

based display devices (as they are not at all bulky based display devices (as they are not at all bulky when compared to CRTs).when compared to CRTs).

Provide a very Provide a very good qualitygood quality of picture which is sharp of picture which is sharp from every angle. from every angle.

They have a They have a slim profileslim profile & can be wall mounted. & can be wall mounted.

They have got high They have got high refresh ratesrefresh rates and a faster and a faster response timeresponse time, contributing to superior , contributing to superior performance.performance.

The weight of a plasma display monitor that is, on The weight of a plasma display monitor that is, on average about 40% to 50% of the weight of a CRT-average about 40% to 50% of the weight of a CRT-based monitor of similar screen size.based monitor of similar screen size.

INSIDE THE DISPLAYINSIDE THE DISPLAY

A plasma display A plasma display monitor is composed of a monitor is composed of a front plate with pairs of front plate with pairs of display electrodesdisplay electrodes and a and a rear plate which contains rear plate which contains address electrodes.address electrodes.

In the front plate the In the front plate the electrodes are covered electrodes are covered with a glass layer called with a glass layer called the the Dielectric LayerDielectric Layer. A . A magnesium oxidemagnesium oxide coating, called the coating, called the Protective Layer, is Protective Layer, is applied to this glass applied to this glass layerlayer..

IMAGE FORMATIONIMAGE FORMATION The display electrodes are The display electrodes are

arranged in horizontal rows along arranged in horizontal rows along the screen and the address the screen and the address electrodes are arranged in vertical electrodes are arranged in vertical columns. The vertical and columns. The vertical and horizontal electrodes form a basic horizontal electrodes form a basic grid. grid.

Within each cell, there are Within each cell, there are actually three sub cells, one actually three sub cells, one containing a red , another a blue , containing a red , another a blue , and a green phosphor. To and a green phosphor. To generate color shades, the generate color shades, the perceived intensity of each RGB perceived intensity of each RGB color must be controlled color must be controlled independently .independently .

To ionize the gas in a particular To ionize the gas in a particular cell, the plasma display's cell, the plasma display's computer charges the electrodes computer charges the electrodes that intersect at that cellthat intersect at that cell. .

When the intersecting When the intersecting electrodes are charged, an electrodes are charged, an electric currentelectric current flows flows through the gas in the through the gas in the cell .cell .

The current creates a rapid The current creates a rapid flow of charged particles, flow of charged particles, which stimulates the gas which stimulates the gas atoms to release atoms to release ultraviolet photons.ultraviolet photons.

The released ultraviolet The released ultraviolet photons interact with photons interact with phosphor material coated phosphor material coated on the inside wall of the on the inside wall of the cell.. When an ultraviolet cell.. When an ultraviolet photon hits a phosphor photon hits a phosphor atom in the cell, one of the atom in the cell, one of the phosphor's electrons phosphor's electrons jumps to a higher energy jumps to a higher energy level. When the electron level. When the electron falls back to its normal falls back to its normal level, it releases energy in level, it releases energy in the form of a the form of a visible light .visible light .

What actually happens inside What actually happens inside the cell?the cell?

RANDOM vs RASTER SCANRANDOM vs RASTER SCAN When operated as a When operated as a

random-scan display random-scan display unit, a CRT directs the unit, a CRT directs the electron beam only to electron beam only to the parts of the screen the parts of the screen where a picture is to where a picture is to be drawn. be drawn.

In raster scan, the In raster scan, the beam sweeps beam sweeps horizontally left-to-horizontally left-to-right at a steady rate, right at a steady rate, then blanks and then blanks and rapidly moves back to rapidly moves back to the left, where it turns the left, where it turns back on and sweeps back on and sweeps out the next line out the next line (flyback)(flyback). .

Random displays have high Random displays have high resolutions resolutions

Smooth lines are produced Smooth lines are produced as the electron beam as the electron beam directly follows the line pathdirectly follows the line path

Random-scan system's are Random-scan system's are generally costliergenerally costlier

Random scan systems are Random scan systems are designed to draw all the designed to draw all the component lines of a picture component lines of a picture 30 to 60 times each second 30 to 60 times each second

Picture definition is stored Picture definition is stored as a set of line drawing as a set of line drawing commands in an area of commands in an area of memory referred to as memory referred to as refresh display file. refresh display file.

Raster displays have less Raster displays have less resolution resolution

Lines produced are ziz-Lines produced are ziz-zag as the plotted values zag as the plotted values are discreteare discrete

Decreasing memory Decreasing memory costs have made raster costs have made raster systems popular. systems popular.

Refreshing on raster Refreshing on raster scan displays is carried scan displays is carried out at the rate of 60 to out at the rate of 60 to 80 frames/second 80 frames/second

Picture definition is Picture definition is stored in a memory area stored in a memory area called the refresh called the refresh buffer/frame buffer. buffer/frame buffer.

INTERLACINGINTERLACING Interlaced scan refers to one of two common Interlaced scan refers to one of two common

methods for methods for "painting""painting" a video image on an a video image on an electronic display screen by scanning or electronic display screen by scanning or displaying each line or row of pixels. displaying each line or row of pixels.

This technique uses two fields to create a frame. This technique uses two fields to create a frame. One field contains all the One field contains all the odd linesodd lines in the image, in the image, the other contains all the the other contains all the even lineseven lines of the of the imageimage . .

NON-INTERLACED DISPLAYNON-INTERLACED DISPLAY It is the opposite phenomenon of Interlacing. In It is the opposite phenomenon of Interlacing. In

this all the lines of frame are scanned in one this all the lines of frame are scanned in one pass.pass.

For higher resolution the non-interlaced display For higher resolution the non-interlaced display creates a better image as compared to Interlaced creates a better image as compared to Interlaced display. The scanning is done line by line in display. The scanning is done line by line in continuous fashion in non-interlaced display.continuous fashion in non-interlaced display.