Introduction

Recently, more and more plasma displays are marketed. They have wide screens, comparable to the largest CRT displays, but they are only about 15cm thick. The basic idea of a plasma display is to illuminate tiny colour fluorescent lights (called pixels) to form an image. Each pixel is made up of three subpixel cells with different fluorescent lights -- a red light, a green light and a blue light. By varying the intensities of these three colors, A full range of colors are produced in each pixel. Then the image is formed when these pixels light up.

Plasma Display

TianHua Zhang

Inside the display

Plasma An electrically neutral, highly ionized gas compose

d of ions, electrons, and neutral particles. Xenon and neon atoms are used in plasma displays.

These atoms release ultraviolet light photons, which are invisible to the human eye. But these UV photons can excite visible photons.

Inside the display

photoluminescent phosphors

Red(Y,Gd)BO3:Eu+3

GreenZn2SiO4:Mn+2

BlueBaMgAl10O17:E+2

How Atoms light up

How Display work

The intersecting electrodes are charged (with a voltage difference between them), 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 UV photons.

How Display work

UV photons are invisible, which interact with phosphor material coated on the inside wall of the cell. The phosphors give off colored light when they are excited.

How Display work

By varying the pulses of current flowing through the different cells, the control system can increase or decrease the intensity of each subpixel color to create hundreds of different combinations of red, green and blue. This process can be done thousands of times in a small fraction of a second for each pixel in turn.

Some Comparisons (CRT)

They are bulky. In order to increase the screen width in a CRT set, you also have to increase the length of the tube (to give the scanning electron gun room to reach all parts of the screen). The image is not as bright as LCD and plasma display.

CRTs give off electric, magnetic and electromagnetic fields. There is considerable controversy as to whether any of these pose a health hazard, particularly magnetic fields.

Some Comparisons (LCD)

Display size is limited by the quality-control problems faced by manufacturers. to increase display size, manufacturers must add more pixels and transistors. As they increase the number of pixels and transistors, they also increase the chance of including a bad transistor in a display. about 40 percent of the panels that come off the assembly line. The level of rejection directly affects LCD price.

Limited viewing angle.

Plasma display

Advantages1.Large screen size (up

to 60 in. diagonal)2.Thin form factor (< 4

in.)3.Full color with good

color purity4. Fast response time for

excellent video capability

5. Wide viewing angle (>160o , all directions)

6. Insensitive to ambient temperatures

Disadvantages1. Low luminance for

outdoor applications (non-sunlight readable)

2. Low contrast in high ambient light

3. High power consumption and heat generation

4. Short panel lifetime due to phosphor degradation

5. Latent image (Image sticking)

References

1. Betsui, Keiichi., F. Namiki., Y. Kanazawa and H. Inoue. 1999. High-resolution Plasma Display Panel (PDP).

2. http://electronics.howstuffworks.com/plasma-display.htm

3. http://mass.micro.uiuc.edu/publications/papers/77.pdf4. http://en2.wikipedia.org/wiki/LCD