(F E D)(F E D)FIELD EMISSION DISPLAYFIELD EMISSION DISPLAY

DEEPAK GUPTADEEPAK GUPTA

EC 3EC 3rdrd YR. YR.

08001310340800131034

PLAN OF PRESENTATION

WHAT

WHEN APPS. HOW ADV. CHARACTERISTICS

FEDFED

FED is such a display that works FED is such a display that works a bit like a cathode-ray tube, a bit like a cathode-ray tube, except that electrons are except that electrons are emission procedureemission procedure

Instead of one cathode emission Instead of one cathode emission spraying of electron through spraying of electron through number of hole is donenumber of hole is done

HISTORYHISTORY

In 1968, Charles A. "Capp" Spindt at In 1968, Charles A. "Capp" Spindt at the Stanford Research Institute had the Stanford Research Institute had the idea of fabricating a flat display the idea of fabricating a flat display using microscopic molybdenum using microscopic molybdenum cones singly or in arrays (FEA’s)cones singly or in arrays (FEA’s)

This development was the enabling This development was the enabling technology the concept for using technology the concept for using FEA’s in a matrix addressed display FEA’s in a matrix addressed display (FED)(FED)

Assembly of FED DeviceAssembly of FED Device

Field emission displays, electrons coming from millions of tiny microtips pass through gates and light up pixels on a screen.

This principle is similar to that of cathode-ray tubes in television sets. The difference: Instead of just one "gun" spraying electrons against the inside of the screens face, there are as many as 500 million of them.

FED PrinciplesFED Principles

CathodeCathode The cathode/back plate is a matrix of row and column traces. Each crossover lays the foundation for an addressable cathode emitters.

Each crossover has up to 4,500 emitters, 150 nm in diameter. This emitter density assures a high quality image through manufacturing redundancy, and long-life through low operational stress.

EmissionEmission

Emitters generate electrons when a small voltage is applied to both row (base layer) and column (top layer).

FED PACKAGINGFED PACKAGING

The field emission display screens The field emission display screens are comprised of a thin sandwich. are comprised of a thin sandwich. In this the back is a sheet of glass In this the back is a sheet of glass or silicon that contains millions of or silicon that contains millions of tiny field emitters which is the tiny field emitters which is the cathode. The front is a sheet of cathode. The front is a sheet of glass coated with phosphor dots, glass coated with phosphor dots, which is the anode. which is the anode.

FED CHARACTERISTICSFED CHARACTERISTICS

Comparing with the CRT displays Comparing with the CRT displays the field emission displays has the field emission displays has many advantages. many advantages.

They are:They are:

1.1. BrightnessBrightness

2. Speed2. Speed

3. Compact and lightweight3. Compact and lightweight

4. Display size4. Display size

5. Low driving voltage5. Low driving voltage

6. Wider viewing angle6. Wider viewing angle

7. High illumination7. High illumination

8. Colour Quality8. Colour Quality

FED advantagesFED advantages

Inherently high luminous efficiencyInherently high luminous efficiency No Response Time issuesNo Response Time issues CRT-like Colour GamutCRT-like Colour Gamut Lower Power ConsumptionLower Power Consumption

Cold Cathode EmissionCold Cathode Emission Distance between cathode and Distance between cathode and

screen ~0.2–5mmscreen ~0.2–5mm Flat Panel TechnologyFlat Panel Technology

Matrix Addressed – No DYMatrix Addressed – No DY Capital investment for Capital investment for

manufacturing VLS TV with manufacturing VLS TV with printable CNT FEDs - 1/10printable CNT FEDs - 1/10thth of of LCD LCD

Cost advantage over LCD could Cost advantage over LCD could be 40%be 40%

TechnologyTechnology LuminouLuminous s

EfficiencEfficiency (Lm/W)y (Lm/W)

CRT (at CRT (at 30KV)30KV)

33

PDPPDP 0.80.8

LCDLCD 33

OLED / OLED / PLEDPLED

55

FED at 8 KVFED at 8 KV 77

APPLICATIONAPPLICATION

This technology could produce This technology could produce affordable large displays in the affordable large displays in the 20 to 40-inch diagonal range 20 to 40-inch diagonal range suitable for TVs.suitable for TVs.

DRAWBACKSDRAWBACKS

a. Vacuum tubes do require maintenance.a. Vacuum tubes do require maintenance.b. Current FEDs often suffer from variation in b. Current FEDs often suffer from variation in

screen brightness across the display, and screen brightness across the display, and also within each pixel.also within each pixel.

c. Durability due to electrical discharge in the c. Durability due to electrical discharge in the small gaps everywhere in FED prototypes.small gaps everywhere in FED prototypes.

d. The killing problem was durability: the tips d. The killing problem was durability: the tips could not survive under severe conditions of could not survive under severe conditions of arcing (i.e. electrical discharge) due to the arcing (i.e. electrical discharge) due to the small gaps everywhere in FED prototypes.small gaps everywhere in FED prototypes.

Thank you ...Thank you ...