Casio PX-780 Service Manual page 24

5-2. Power saving control
The following power saving functions are provided with this device:
1 Idle state
Saves power by making the CPU in the idle state when there is no executable event and the system and
applications are waiting for a next event. Peripheral devices are in operation.
2 CPU frequency control
CPU frequency can be switched between the setting to handle high-speed processing and the power
saving setting. This setting can be changed by the system library and the CPU frequency of "LOW:
200MHz" or "HIGH: 400MHz" can be selected. "LOW" for the normal state is the default.
3 APO (Automatic Power Off)
When there is no key input (keys or touch panel) for the specified period, this function automatically turns
OFF the power of the system. Allowing or prohibiting the APO function and setting of the time to invoke the
function can be changed by the software.
Basic set time is specified by using "Power management" on the control panel.
4 Dimmer control
When the device is battery operated and is left without any input by keys or touch panel (idle state), the
backlight automatically becomes "dimmer" to save power (automatic dimmer function only works when the
device is battery operated. When it is operated by an external power source, this function is not invoked).
* Inputting by keys or touch panel cancels the automatic dimmer function and returns the backlight to the
normal brightness.
* Setting of on/off of the automatic dimmer function (default setting is on), and the waiting time until the
automatic dimmer function is invoked can be changed by "Contrast & Brightness" on the control panel.
The brightness of the LED backlight when the automatic dimmer function is on can be changed (default
setting is on the third step). The setting of the LED backlight when the automatic dimmer function is on
cannot be brighter than the normal brightness setting when the device is battery operated.
5 ABO (Automatic Backlight Off)
When the device is turned on and is left without any input by keys or touch panel (idle state), the backlight
automatically turns "off" to save power (automatic backlight off works when the device is battery operated
and also when it is operated by an external power source).
* Inputting by keys or touch panel cancels the automatic backlight off and returns the backlight to the
normal brightness.
* Setting of on/off of the automatic backlight off (default setting is on), and the waiting time until the
automatic backlight off is invoked can be changed by "Contrast & Brightness" on the control panel.
When the device is battery operated and both the above-mentioned automatic dimmer function and
automatic backlight off function are set, the setting whose waiting time is shorter will be valid.
Example: When the automatic dimmer function is set at 1 minute and the automatic backlight off function
is set at 5 minutes.
g After 1 minute, the automatic dimmer function is invoked, and 4 minutes thereafter, the
automatic backlight off is invoked.
When the automatic dimmer function is set at 5 minutes and the automatic backlight off function
is set at 1 minute.
g After 1 minute, only the automatic backlight off function is invoked (in this case, the automatic
dimmer function is not invoked). If the device is under the bright light such as under the outside
light, the bright sensor detects the brightness and automatically turns off the backlight of the
screen. This reduces the power consumption when the device is used under the outside light.
* This automatic change function works when the intensity of the outside light reaches the certain
brightness level. This function works at the brightness detected at a 5-second interval which does not
react to rapid changes.
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