Is there any
different between LEDs used to produce an LED display? What
is the comparison between Nichia, Cree, Silan, Epistar and
others? Which is more recommended to achieve a good LED
Thats a big
question with a complex answer. As short as I can.
Nichia and Cree
are probably the best, and most expensive.
Next down in
terms of quality are Taiwanese chips, Everlight etc.
At the bottom of
the quality table are the low cost Chinese Chips - Silan
in price between the same display built with good quality
LED's compared to the lowest quality can be huge. A low cost
LED can reduce the price by as much as 60%.
From new there
will not appear to be much difference in appearance between
an expensive display and a low cost one. But very soon the
low cost one will start to have more failures, colours will
fade more unevenly and there may be spares supply issues
over the life of the display.
says that if you pay over 2 times more for the 'same thing'
that there has to be a quality tradeoff.
companies who claim to offer a good quality LED like Cree,
but will actually only buy the chip and then package it
themselves. It's a bit like buying a Mercedes car without an
engine and then getting the dealer to fit their own engine.
It will never be as good!
A good guide as
to the quality of the Screen manufacturer is to ask them
what LEd's they quote as standard. If it is a high quality,
high price LED then the screen manufacture is probably quite
good. If it is a low cost chip like Silan or other Chinese
brand then the screen itself is probably also not good
Many low cost
manufacturers use low cost chips as standard so they can
offer attractive prices. We have a saying. If it is low
cost, there must be a reason.
Tony Hui • It
comes down to which LED and manufacturer you should use:
Nischia LED can
last up to 10 yrs, I have expereinced in Hong Kong, but
through years of maintenance( manufacurer was from Taiwan)
the screen was barely acceptable in the last stage. The LED
at Time Square in HK is by Sony, after so many years the
quality is acceptable. I heard they were burning 5 % modules
at the same time and Sony has special device for adjusting
brightness before installation. (Sony does not produce LED
achieve half brightness in less than 3 years, Cree and
Taiwanese in 5 years and Nischia in 7-8 years. It also
depends on the manufacturer as mentioned above.
You are also
important, it is a one time business or a recurrent
business, It is very very expensive to find the right
supplier. Different supplier will supply different type of
Your client is
also important so if it is a one time job. You should buy
from a local agent who is not a trader. If you want to make
money in LED, you need to invest a lot, unless U work with a
specialist, because there are installation and operation
Artha Doyle •
Harry's points are right on the money.
Another way to
look at it is by identifying the purpose of the display. For
instance, advertising agencies wishing to sell space on the
screens might opt for a screen that uses Epistar Red and
Silan Green and Blue because it's a much cheaper alternative
than using Cree or Nichia. Using this as an option can give
an agency an ROI of a year or less (depending on the
location and amount of clients). As long as it can perform
for 3 years, they make a good profit and replace the screen
with a new one whilst moving the old screen to a 2nd tier
location or even selling it to a 3rd party.
If you are
thinking of going down the cheaper alternative, make sure
you buy from a reputable supplier and ask them for prices
including a 3-year warranty. They'll charge you more for it
but it might just be worth it when things start to go wrong
in the 2nd or 3rd year.
Hope that was
somewhat relevant :)
Marty Pisano •
No doubt that Harry and Artha are giving you good advice.
Let me add this.
LED diodes are
becoming a mature technology. While Cree and Nichia have a
long track record, the other factories are getting better
every day as well.
(MediaNow) has built over 20 LED displays using diodes from
all brands mentioned above. Our experience is that the diode
is affected from many factors including: digitizers, sending
and recieving cards, resyncers, scan cards, power supplies
and wiring. Therefore, to get the best performance from any
LED diode, make sure your sytem is properly configured and
The one key item
for getting long life from the diodes is to design the best
artwork that stays away from too much white and bright
(lumen) colors. White (as a color or background) demands the
most power pass-through and will take more from the life of
the diode than time will. Also, avoid running the LED signs
and displays 24/7. There are 8700 hours in a year. Every day
you reduce hours of operation will to the lifetime of any
LED chipset.. We keep the signs ON and take the color to
black overnight to extend the life of the diodes and power
consumption for our Clients.