winsonic MFC1705S-EN30C User Manual page 15

(2) Define of Lamp current uniformity : I
I
UNI
Lamp current uniformity I
(3) Lamp frequency which may produce interference with horizontal synchronous
frequency may cause line flow on the display. Therefore lamp frequency should be
detached from the horizontal synchronous frequency and its harmonics as far as
possible in order to avoid interference.
(4) Life time (Hr) is defined as the time when brightness of a lamp unit itself becomes
50% or less than its original value at the condition of Ta = 25 2 C and I
(5) Designing a system inverter intended to have better display performance, power
efficiency and lamp reliability.
They would help increase the lamp lifetime and reduce leakage current.
a. The measurement should be done at typical lamp current.
b. The asymmetry rate of the inverter waveform should be less than 10%.
c. The distortion rate of the waveform should be 2 with
- Inverter output waveform had better be more similar to ideal sine wave.
Fig. Wave form of the inverter
(6) If an inverter has shutdown function, it should keep its output for over 1 second
even if the lamp connector is open. Otherwise the lamps may not be turned on.
Panel Specification
I I
| −
Max Min
=
I
Max
I : Maximum lamp current
max
I : Minimum lamp current
min
should be less than 25%
UNI
I
p
I
UNI
|
× 100
Asymmetry rate
Distortion rate
-p
L
10% tolerance.
I I
| − |
p - p
× 100
I
rms
I I
p - p
| | |
or
I I
rms rms
= 7.5mArms
|