What Makes an LCD Sunlight Readable?

Have you ever been at the car wash in the late afternoon, struggling to read the instructions on the display at the pay kiosk? That may be because it was not a sunlight-readable LCD display.

What Makes a Display Readable in Bright Light?

There are two ways to get sunlight readability: 1) is to work with the sun, and 2) is to overpower the sunlight.

1) LCDs that Work With the Sun

Any character or graphic LCD (not TFT, we will get to that in a bit) that is “positive mode” will be sunlight readable. Positive mode displays will have dark letters on a light background.

Examples of positive mode displays:

Crystalfontz Positive Mode LCD - CFAG 128x64 Graphic LCD Display
Crystalfontz Positive Mode LCD – CFAG 128×64 Graphic LCD Display
Crystalfontz Positive Mode LCD - CFA633 Series of Character LCDs
Crystalfontz Positive Mode LCD – CFA633 Series of Character LCDs

With these modules, more light gives better readability.

Crystalfontz LCD Modules That Are Best for Reading in Sunlight or Bright Light

The links below will display lists of Crystalfontz modules that are best for sunlight conditions, ranked by price.

What About Transflective TFT Modules?

Included in the sunlight-readable category are transflective TFT modules.

In dark environments up through office lighting, the TFT backlight makes them visible by being brighter than the environment, like all TFT modules.

However, where regular (transmissive) TFT modules wash out in direct sunlight, a transflective TFT will use the sun to be more visible in brighter conditions.

The CFAF480640A-035T is an example of a transflective, sunlight-readable TFT.


Want to see “sunlight-readable” in action?

Here is a video that takes you from pitch black to full sunlight, showing how the CFAF480640A-035T compares to a normal (transmissive) TFT module:

2) Overpower the Brightness of the Sun

The other way of making a sunlight readable display is to overpower the sun’s considerable brightness.

One example of this approach is our high-brightness OLED modules:

These low-cost LCD replacement OLED modules can be read nicely in all lighting conditions, from complete darkness to direct sunlight.

There is also a similar approach with TFTs — using a very bright backlight to keep the display visible even when the sun is on it.


For any questions about Crystalfontz LCD product lines, what LCD is the best choice for your application, or any other questions (technical or availability), please contact our knowledgeable and friendly support staff via email, phone, or chat.