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Casio Illuminator – What types of lighting Casio uses

Tags: Technology and concepts | Casio | Classic | Smart

14.12.2023 | 5 MIN

Illuminator, Super Illuminator, Afterglow, Neon or Auto Light. With Casio watches you will come across different types and functions of illumination, let's get a little overview on that.

Historical context

The first digital watch was the Hamilton Pulsar. They used LEDs to display the time. LEDs were extremely power-hungry, so the display was only possible when pressed and for a short period of time. However, they were the first to be able to display the time in this way even at night.

Casio introduced their digital watches not long after. The first Casiotron model came out in 1974. But it didn't get to a model with illumination until 1995, 3 years after Timex introduced the first Indiglo electroluminescent watch. One of the first Casio models to use EL was the DW-5600E, where the "E" just stood for electroluminescence. That's also why it's now known as the G-Shock Illuminator.

Casio G-Shock DW-5600E s elektro-luminiscencí.

Casio G-Shock DW-5600E with electro-luminescence.

And under the "Illuminator" designation we know the illumination even today. In Japan, Casio has a synonymous term "Foxfire". But Casio has been switching to LEDs in most cases for a long time now, which are more economical and environmentally friendly but we still find ELs in some digital watches today on purpose.

Illuminator – EL (Back electro-luminescent)

The advantage of electroluminescence is the even illumination of the entire display. Casio also uses this option in collaborations with various artists or companies, where the EL allows the image to be highlighted after lighting.

Elektroluminiscence umožňuje obrázky v pozadí. Např. u G-Shock DW-6900GDA-9ER.

Electroluminescence allows you to display images in the background. For example, in the G-Shock DW-6900GDA-9ER.

Among the disadvantages is the large battery load, this is also one of the reasons why Casio is switching to LEDs.

Electroluminescence also allows for a Flesh Alert function - a flash alert in combination with an alarm. So you can set the alarm for a specific time and the screen will flash alongside the beeping. Likewise, if you have the full hour signaling function turned on.

Modely s EL můžou mít funkci Flesh Alert. Poznáte ji i díky malé hvězdičce vpravo na displeji.

EL models can have a Flesh Alert function. You can also recognize it by the small star on the right of the display.

You can recognize the Flesh Alert function by the small star on the display and the function can be deactivated in the watch.

Super Illuminator – LED

To save battery power, Casio has started replacing the original EL with more modern LED technology. The small LED bulbs are most often two, where in ana-digi models one illuminates the dial, the other illuminates the display. In digital watches, older models or cheap Casios, you often see only one. The colour is usually white or green (e.g. on the F-91)

LED žárovička u F-91 je poměrně slabá.

The LED bulb on the F-91 is quite dim.

In the beginning, the LED lighting was not that effective and balanced. For example, the popular 2010 GA-100 had a problem with weak backlighting where the LED failed to illuminate the display and dial sufficiently.

LED dioda osvětlí číselník, digitální displej u GA-100 v noci ale moc nepřečtete.

The LED illuminates the dial  but the GA-100's digital display is virtually unreadable at night.

However new models usually already have a strong LED backlight where you can see both the hands and the display in the dark or evenly illuminate the entire display on digital models.

LED podsvícení u modelu GW-M5610U.

LED backlight on the GW-M5610U.

The higher-end Mudmaster models have such a strong backlight that it can serve as a small flashlight.

LED podsvícení u Mudmaster GG-B100.

LED backlight on the Mudmaster GG-B100. You can see the display, the dial and it even "recharges" the luminescence on the hands.

The light is always triggered within a button. On many models, it is even described on the dial (dial). But, for example, on the well-known G-Shock GA-100, the top right button for the light is labeled Reverse and you can't visually tell that it is associated with the light.

Then some models have a special front button for the light at the bottom of the case. For example, G-Shocks GA-700, GBA-800, GBD-800, Mudmasters or Rangemans.

Některé modely, zvláště některé G-Shocky, mají pro spuštění světla speciální čelní tlačítko v dolní části pouzdra. Typicky model G-Shock GA-700

Some models, especially some G-Shocks, have a special front button at the bottom of the case to trigger the light. Typically the G-Shock GA-700

There are several types of functions found on Casio backlights.

Neon Illuminator

On some models we can find UV or also Neon Illuminator, where most often the indices or hands are painted with a special coating, which is activated by lighting the UV LED. For example Gravitymaster GA-1000 used this option.

Neon Illuminator u Gravitymaster GA-1000.

Neon Illuminator on Gravitymaster GA-1000. The illumination activated a special coating on the indices and hands.


The afterglow function is automatic. Illumination with this feature does not turn off immediately when the button is released, but remains lit for a while afterwards. Usually the length of the afterglow can be set, most often for 1.5, 3 or 5 seconds. Most current G-Shocks have this feature.

Auto Light

The Auto Light function allows the light to be turned on by tilting the hand at a 40 degree angle. So if you look at the watch and tilt your wrist towards you, the watch will light up. The function can be switched on/off, usually by holding the light button for a minimum of 3 seconds. If Auto light is not turned off manually, it normally turns off automatically after 6 hours to save battery.

Full Auto Light

The full auto light feature allows the light to be activated by tilting the hand, but the watch has an ambient light sensor so this feature will not activate in sufficiently lit environments. The goal is battery saving, but it's definitely a user convenience. After all, you'll usually only appreciate the backlight in the dark, not during the day when there's enough light.

NeoBrite - photoluminescence

The last type of lighting in Casio is photoluminescence. That is a luminescent coating whic is not lit by battery power but "recharges" with light, natural or artificial.

The coating is most often found on the hands and indices of analogue or analogue-digital models. It is not used on purely digital watches.

Fotoluminiscence u Casio Edifice ECB-S100D-2AEF.

Photoluminescence on Casio Edifice ECB-S100D-2AEF.

The advantages include the fact that photoluminescence does not consume the battery but the luminosity is not very intense in basic models and gradually fades depending on the strength of the illumination. In the higher Master of G type collection, the intensity and endurance is stronger.

Luminiscence u Mudmaster GWG-2000-1A1ER.

Luminescence of the Mudmaster GWG-2000-1A1ER.