Casio KX-724B, Руководство по обслуживанию и список запасных частей

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TFT-LCD
Each picture element electrode is controlled by a transistor. To the gate electrodes, the
gate pulse is applied timesharing. VCOM voltage is applied to the common electrodes.
The above figure shows the operation of TFT-LCD. If the gate pulse is not applied to
the gate electrodes, the transistors do not operate even when the potential difference
is given between the common electrodes and source electrodes, and no effect is given
to the liquid crystal. If the gate pulse is applied to Y1, the transistorT1 is in operation
during a priod of t1, and voltage of source electrode of Va is applied to the LCD layer
of picture element A, then electric charges are stored in the picture element of A. After
the period of t1, T1 is turned off, and voltage in the LCD layer of A is held until next
gate pulse comes, but it drops little by little through off leak resistance of TFT and leak
resistance of LCD itself.
Y1
Y2
Y3
Ym
GND
Vy
Va
Vb
t1 t2 t3
X1
X2 X3 X4 Xn
Gate electrode
Picture
element A
Source electrode
TFT array substrate
Common substrate
Frame period
Selective period
Picture
element
A
Gate
pulse
T1
T2
T3 T4 Tn
Common
electrode
V COM
X1
Y3
Y2
Y1
t1
BACK LIGHT
The camera unit is equipped with a fluorescent light source to provide the back lighting
for its LCD. The normal service life of the backlight is approximately six years, when the
camera is used for about two hours a day.
The backlight is consumption items, so even under guarantee replace it under charge
basis.