How do EPD displays work?
The functioning of EPD (Electronic Paper Display) is based on the phenomenon of electrophoresis. Each display cell consists of a mixture of oil and water with suspended pigment particles. They are positioned between two parallel rows of electrodes, which allow for control over the display by directing the particles. By applying a positive or negative charge, the particles move up or down, creating the desired image.
Initially, EPD displays used only black and white pigments, which allowed for grayscale images (1-, 2-, 4-bit). However, there are now color variants available, such as the Advanced Color ePaper (ACeP) developed by E Ink. This solution incorporates four pigments—magenta, cyan, yellow, and white—within each display cell, resulting in images with a full range of colors (eight primary colors). Learn more about color options for e-paper displays here.
EPD displays in industrial applications
In addition to consumer electronics (e.g., popular e-readers), EPD displays are increasingly finding application in industrial settings, especially where energy efficiency is a crucial factor. The characteristics of EPD technology enable energy savings up to 111 times greater compared to LCD displays.
Examples of EPD display applications
EPD displays are used in various applications, including:
- Retail: price tags and labels
- Digital signage systems: advertising displays (notably, color options such as E Ink’s Gallery series)
- Transportation: timetables and schedules
- Medical field: medication dosage labels for patients
- Smart buildings: indoor navigation systems (e.g., the Incrediscope project developed by Unisystem and Visionect)
How to choose the right EPD display from our offering?
When selecting an EPD display, in addition to choosing the appropriate diagonal size, several factors should be taken into account, such as DPI, module type, interface, and temperature ranges.
DPI (Dots Per Inch)
DPI refers to the number of pixels per inch on the display. Higher DPI values indicate a higher image resolution. The DPI should be adjusted to suit the device’s purpose and the end user’s requirements.
Interface Options for EPD Displays
Our offering includes solutions that support the two most popular interfaces used in EPD displays:
- SPI: This interface enables high-speed data transmission and is recommended for most EPD display models.
- USB: This interface allows direct connection of the EPD display to a computer and is mainly used for prototyping or testing purposes.
Temperature Range for EPD Displays
Typically, the operating temperature range for EPD displays is specified from 0 to 50°C.
Although the temperature range is limited, it does not make the implementation of EPD displays impossible in outdoor devices (such as transportation timetables). However, additional elements like heaters or fans may be required to maintain a temperature that ensures the reliable operation of the electronics.
EPD Display Manufacturers
In our offering, we provide EPD displays from two companies: E Ink and DKE.