Casio QV-30 Specifications download pdf (Page 14)

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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.

GND

t2 t3

X2 X3 X4 Xn

Gate electrode

Picture

element A

Source electrode

TFT array substrate

Common substrate

Frame period

Selective period

Picture

element

Gate

pulse

T3 T4

Common

electrode

V COM

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.

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Casio QV-30 Specifications Page 14