LogCase | E-Paper Smartphone Case

No, LogCase does not have a battery inside, and it works without one! LogCase's E-Paper module relies on our NFC Energy Harvesting technology.

Please check out our technology page for further details.

An E-Paper display is bistable, meaning once an image is written, it stays visible indefinitely without any additional power. The LogCase panel will hold your picture until you choose to refresh or overwrite it—there is no built-in timeout that erases the image after a set period.

Behind the scenes, the microcontroller and driver circuitry can enter a low-power sleep mode (or even switch off entirely) once the update is complete, but the charged pigment particles in the E-Paper layer remain locked in place. This lets the display consume virtually zero energy between updates. In practical terms, your image will stay perfectly legible for months or even years, only disappearing when you send a new image or perform a manual, precise operation.

No. The LogCase uses a reflective E-Paper display rather than an emissive LED or backlit LCD. E-Paper works by moving tiny charged particles within each pixel to form an image, and that image remains visible without any power until you choose to update it. This delivers paper-like contrast and excellent readability—even in bright sunlight—while consuming virtually no energy between updates.

Because it isn't backlit or driven at high refresh rates, E-Paper can't show continuous video or rapid animations like an LED/LCD. Instead, it excels at displaying static photos, text or graphics with razor-sharp clarity and minimal power draw.

The LogCase E-Paper panel itself contains only four pigments—black, white, red and yellow—so it cannot generate any additional pigments directly. While simple halftone or dithering techniques can soften transitions or create the illusion of shading between those four inks, the underlying colour gamut remains those exact four pigments.

However, our companion iOS app is specially configured to extend that palette through advanced eye-tricking techniques. Before sending an image to the E-Paper, the app analyses each target hue. It converts it into microscopic clusters of the available pigments, using error-diffusion dithering and spatial halftoning algorithms optimised for human visual perception. For example, to 'fake' green, the app lays down a fine matrix of yellow and black pixels; when viewed at normal reading distance, your eye integrates those dots into a convincing greenish tone. This approach can simulate a range of intermediate hues—greens, oranges and even subtle pastels—while preserving the ultra-low-power, high-contrast benefits of our reflective display.