This is to know about LCD and LED screens and their functions,advantges,disadvantages and applications of LCD and LED screen.

1. LCD SCREEN AND LED SCREEN

2. LCD SCREEN
• The LCD screen was invented by JOSEPH A.CASTELLANO at year between
1880’s - 1960’s.
• The full form of LCD was LIQUID CRYSTAL DISPLAY.
• It is a flat panel display or other electronically modulated optical device
that uses modulating properties of liquid crystals.
• These liquid crystals do not emit light directly , instead using a backlight or
reflector.
• It is to produce or display the images in color or monochrome.
• LCD’s are available to display arbitary images that means as like in general
purpose computer display.

3. • It also displays with fixed images with low information content
which can
be displayed or hidden such as preset words , digits , seven
segment
display as in a digital watch.
• They use the same basic technology , except the arbitrary images
are
made up of a large number of small pixels while other displays
have
larger elements.
• EXAMPLE - Digital Wrist Watch, LCD Television, Calculators , etc.,

4. IMAGES OF LCD SCREEN

5. LCD DISPLAY OF DIGITAL WRIST WATCH

6. INTERNAL VIEW OF LCD SCREEN

7. GENERAL CHARACTERISTICS OF LCD
SCREEN
• Each pixel of an LCD display typically consists of a layer of
molecules
aligned between two transparent electrodes and also two
polarizing
filters.
• The axes of transmission of which are perpendicular to each other.
• Without the liquid crystal between the polarizing filters and when
the
light passing through first filter would be blocked by the second
polarizer.

8. ADVANTAGES OF LCD SCREEN
• Produces very bright images due to high peak intensity and
suitable
for environments that are brightly lit.
• Life span is about 50,000 – 1,00,000 Hours.
• Viewing Angle is possible upto 165 degree.
• Less power consumption.

9. DISADVANTAGES OF LCD SCREEN
• The cost of the LCD screen is very expensive.
• It has only limited and required viewing angles.
• Low quality of image.
• Slower response of time and operation.

10. APPLICATIONS OF LCD SCREEN
• They were used in wide range of applications : -
-Parking Meters
-Digital Watches.
-Digital Thermometers.
-Mobile Phones and Pagers.etc.,

11. LED SCREEN
• The LED screen was invented and developed by James P.
Mitchell.
• The full form of LED was LIGHT EMITTING DIODE.
• A LED display is a flat panel display which uses an array of led’s
as a pixels for video display.
• Their brightness allows them to be used outdoors when they are
visible in the sun for store signs and billboards.
• And also in recent years they have also commonly used in
destination signs on public transport vehicles and as well as in
variable message signs on highways.
• It is also for stage lightnings and for decorative purposes.

12. IMAGE OF LED SCREEN

13. IMAGE OF LED SCREEN

14. GENERAL CHARACTERISTICS OF LED
SCREEN
• For this type of purposes diodes are emitted with three
colours
which are RED , GREEN , BLUE ranges.
• They together form a cluster are placed next to each other
LED
screen
• The distance between adjacent pixels(pitch) determines the
resolution of the received image.

15. ADVANTAGES OF LED SCREEN
• It has high resolution and displays more quality images.
• It is immune or resistant towards surface contaminants like
dirt , grease and moisture, etc.,
• It is also durable and resistance towards scratches and
damages.

16. DISADVANTAGES OF LED SCREEN
• The disadvantage is that it only works when touched by
a conductive device.
• Some capacitive touches can cause erratic behavior
when it is
touched with more than one input.

17. APPLICATIONS OF LED SCREEN
• It is widely used in many applications .They are
- Offices and Call Centers
- In the Transportation Roads.
- In clubs , pubs ,party places , theatres.
- In mobile devices
- Digital scoreboards in the sports stadiums.
- In Traffic Management Areas.

18. THANK YOU