Casio IT-2000 Service Manual page 21

5.2.4 Backlight Control
Backlight is controlled by KBC.
Measure the amount of light with the light sensor.
When light amount falls below a certain amount backlight turns on. When light amount exceeds a certain
amount backlight turns off.
By having a certain amount of hysteresis it prevents the flickering of the backlight.
Backlight control is shown in Figure 5.2.4.
Figure 5.2.4 Backlight Control
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