LQ104V1DG51 Datasheet, PDF (8/21 Pages) Sharp Electrionic Components – TFT LCD MODULE

LD13708-6
6-2. Backlight driving
The backlight system is an edge-lighting type with single CCFT (Cold Cathode
Fluorescent Tube). The characteristics of single lamp are shown in the following table.
Ta=25℃
Parameter
Symbol Min. Typ. Max. Unit
Remark
Lamp current
IL
3.5
6.0
7.0 mArms _{【Note1】}
Lamp power consumption
PL
－
2.8
－
Ｗ 【Note2】
Lamp frequency
FL
40
60
70 KHz _{【Note3】}
Kick-off voltage
Vs
－
－
1000 Vrms _Ta=25℃
－
－
1300 Vrms _{Ta =0℃【Note4】}
Lamp life time
LL 50000 _－
－
hour _{【Note5】IL=6.0mA}
LL 30000 _－
－
hour _{【Note5】IL=7.0mA}
【Note1】 Lamp current is measured with current meter for high frequency as shown below.
１
Module
3
１
Ａ
～
3
Ａ
～
Inverter
* 3pin is V ^LOW
【Note2】 At the condition of Y_L =350cd/m2
【Note3】 Lamp frequency may produce interference with horizontal synchronous frequency,and
this may cause beat on the display. Therefore lamp frequency shall be detached as
much as possible from the horizontal synchronous frequency and from the harmonics
of horizontal synchronous to avoid interference.
【Note4】The open output voltage of the inverter shall be maintained for more than 1sec; otherwise
the lamp may not be turned on.
【Note5】Since lamp is consumables, the life time written above is referencial value and it is not
guaranteed in this specification sheet by SHARP.
Lamp life time is defined that it applied either ① or ② under this condition
(Continuous turning on at Ta=25℃, IL=6/7mArms)
① Brightness becomes 50% of the original value under standard condition.
② Kick-off voltage at Ta=0℃ exceeds maximum value,(TBD) Vrms.
In case of operating under lower temp environment, the lamp exhaustion is accelerated and the
brightness becomes lower.
(Continuous operating under for around 1 month under lower temp condition may reduce the
brightness to half of the original brightness.)
In case of such usage under lower temp environment, periodical lamp exchange is recommended.
【Note6】The performance of the backlight, for example life time or brightness, is much influenced
by the characteristics of the DC-AC inverter for the lamp. When you design or order the
inverter, please make sure that a poor lighting caused by the mismatch of the backlight and
the inverter (miss-lighting,flicker, etc.) never occur. when you confirm it, the module should
be operated in the same condition as it is installed in your instrument.
【Note7】 It is required to have the inverter designed so that to allow the impedance deviation
of the two CCFT lamps and the capacity deviation of barast capacitor.