Operation Guide 2760 2761
5
About the Auto Light Switch
Turning on the auto light switch causes the face to illuminate, whenever you position
your wrist as described below in any mode. Note that this watch features a “Full Auto
LED Light”, so the auto light switch operates only when available light is below a
certain level. It does not illuminate the face under bright light.
Moving the watch to a position that is parallel to the ground and then tilting it
towards you more than 40 degrees causes illumination to turn on.
• Wear the watch on the outside of your wrist.
Parallel to
ground
More than
40
°
Warning!
• Always make sure you are in a safe place whenever you are reading the face
of the watch using the auto light switch. Be especially careful when running or
engaged in any other activity that can result in accident or injury. Also take
care that sudden illumination by the auto light switch does not surprise or
distract others around you.
• When you are wearing the watch, make sure that its auto light switch is turned
off before riding on a bicycle or operating a motorcycle or any other motor
vehicle. Sudden and unintended operation of the auto light switch can create a
distraction, which can result in a traffic accident and serious personal injury.
To turn the auto light switch on and off
In any mode (except when a setting screen is on the display), hold down D for about
two seconds to toggle the auto light switch on (
displayed) and off ( not
displayed).
• The auto light switch on indicator (
) is on the display in all modes while the auto
light switch is turned on.
Power Supply
This watch is equipped with a solar cell and a special rechargeable battery (secondary
battery) that is charged by the electrical power produced by the solar cell. The
illustration shown below shows how you should position the watch for charging.
Example:Orient the watch so its face is
pointing at a light source.
• The illustration shows how to position
a watch with a resin band.
• Note that charging efficiency drops
when any part of the solar cell is
blocked by clothing, etc.
• Normally, you should try to keep the
watch outside of your sleeve as much
as possible. Charging is significantly
reduced if the face is only partially
covered.
Solar cell
Important!
• Storing the watch for long periods in an area where there is no light or wearing it in
such a way that it is blocked from exposure to light can cause rechargeable battery
power to run down. Make sure that the watch is normally exposed to bright light
whenever possible.
• This watch uses a special rechargeable battery to store power produced by the solar
cell, so regular battery replacement is not required. However, after very long use, the
rechargeable battery may lose its ability to achieve a full charge. If you experience
problems getting the special rechargeable battery to fully charge, contact your
dealer or CASIO distributor about having it replaced.
• Never try to remove or replace the watch’s special battery yourself. Use of the wrong
type of battery can damage the watch.
• All data stored in memory is deleted, and the current time and all other settings
return to their initial factory defaults whenever battery power drops to Level 4 and
when you have the battery replaced.
• Turn on the watch’s Power Saving function and keep it in an area normally exposed
to bright light when storing it for long periods. This helps to keep the rechargeable
battery from going dead.
Dial and
Digital Display
A
(Charge soon alert)
Battery Power Levels
The battery level dial and digital display show you the current level of the rechargeable
battery’s power. The digital display also shows a recover indicator, which lets you know
when there is a large load being placed on the battery.
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Battery level dial
Recover indicator
Level
1
2
3
4
Function Status
All functions enabled.
All functions enabled.
Except for internal timekeeping
and the C indicator, all functions
and display indicators are
disabled.
All functions disabled.
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• The battery level dial shows the battery power level in all modes except for the
Stopwatch Mode. In the Stopwatch Mode, the battery level dial indicates elapsed
minutes.
• The flashing C indicator at Level 3 tells you that battery power is very low, and that
exposure to bright light for charging is required as soon as possible.
• When battery power is at Level 3, analog hand movement and time calibration signal
reception are disabled.
• At Level 4, all functions are disabled and settings return to their initial factory
defaults. Functions are enabled once again after the rechargeable battery is
charged, but you need to set the digital time and date, after the battery reaches
Level 3 from Level 4. You will not be able to set any of the other settings until the
battery reaches Level 2 after dropping to Level 4.
• Display indicators reappear as soon as the battery is charged from Level 4 to Level
3.
• Leaving the watch exposed to direct sunlight or some other very strong light source
can cause the battery level dial to temporarily show a reading that is higher than the
actual battery level. The correct battery level should be indicated after a few minutes.
• If you use the illumination or alarms a number of times during a short period, the
recover indicator (R) appears on the display and the following operations become
disabled until battery power recovers.
Illumination; Beeper tone; Coordination between digital and analog timekeeping;
Time calibration signal reception
After some time, battery power will recover and the recover indicator will disappear,
indicating that the above functions are enabled again.
• If the recover indicator appears frequently, it probably means that remaining battery
power is low. Leave the watch in bright light to allow it to charge.
Charging Precautions
Certain charging conditions can cause the watch to become very hot. Avoid leaving
the watch in the areas described below whenever charging its rechargeable battery.
Also note that allowing the watch to become very hot can cause its liquid crystal
display to black out. The appearance of the LCD should become normal again when
the watch returns to a lower temperature.
Warning!
Leaving the watch in bright light to charge its rechargeable battery can cause it
to become quite hot. Take care when handling the watch to avoid burn injury.
The watch can become particularly hot when exposed to the following
conditions for long periods.
• On the dashboard of a car parked in direct sunlight
• Too close to an incandescent lamp
• Under direct sunlight
Charging Guide
After a full charge, timekeeping remains enabled for up to about five months.
• The following table shows the amount of time the watch needs to be exposed to light
each day in order to generate enough power for normal daily operations.
• Since these are the specs, we can include all the technical details.
• Watch is not exposed to light
• Internal timekeeping
• Display on 18 hours per day, sleep state 6 hours per day
• 1 light operation (1.5 seconds) per day
• 10 seconds of alarm operation per day
• 5 times calibration reception per day
• Stable operation is promoted by frequent charging.
Exposure Level (Brightness)
Outdoor Sunlight (50,000 lux)
Sunlight Through a Window (10,000 lux)
Daylight Through a Window on a Cloudy Day
(5,000 lux)
Indoor Fluorescent Lighting (500 lux)
Approximate Exposure Time
5 minutes
24 minutes
48 minutes
8 hours
Recovery Times
The table below shows the amount exposure that is required to take the battery from
one level to the next.
• The above exposure time values are all for reference only. Actual required exposure
times depend on lighting conditions.
14 hours
71 hours
4 hours
20 hours
– – –
– – –
Outdoor Sunlight (50,000 lux)
Sunlight Through a Window
(10,000 lux)
Daylight Through a Window
on a Cloudy Day (5,000 lux)
Indoor Fluorescent Lighting
(500 lux)
Approximate Exposure Time
Level 4 Level 3 Level 2 Level 1
▲
▲
▲
1 hour
3 hours
5 hours
49 hours
▲
Exposure Level
(Brightness)
Reference
This section contains more detailed and technical information about watch operation.
It also contains important precautions and notes about the various features and
functions of this watch.
Auto Return Features
• If you leave the watch in the Recall, Alarm (except for the target alarm countdown
screen), or Hand Setting Mode for two or three minutes without performing any
operation, it automatically returns to the Timekeeping Mode.
• If you leave a screen with flashing digits on the display for two or three minutes
without performing any operation, the watch automatically exits the setting screen.
Scrolling
The B and D buttons are used in various modes and setting screens to scroll
through data on the display. In most cases, holding down these buttons during a scroll
operation scrolls through the data at high speed.
Initial Screens
When you enter the Dual Time or Alarm Mode, the data you were viewing when you
last exited the mode appears first.
Radio-controlled Timekeeping Precautions
• Strong electrostatic charge can result in the wrong time being set.
• Even when the watch is within the reception range of the transmitter, signal
reception will be impossible if the signal is blocked by mountains or other geological
formations between the watch and signal source.
• Signal reception is affected by weather, atmospheric conditions, and seasonal
changes.
• The time calibration signal bounces off the ionosphere. Because of this, such factors
as changes in the reflectivity of the ionosphere, as well as movement of the
ionosphere to higher altitudes due to seasonal atmospheric changes or the time of
day may change the reception range of the signal and make reception temporarily
impossible.
• Even if the time calibration signal is received properly, certain conditions can cause
the time setting to be off by up to one second.