E-paper is one of those technologies that fall under our radar and yet have an immense impact on our everyday lives. The Melrose portfolio of e-paper products is constantly evolving in line with the technological advancements in this niche brought by E Ink, the inventor, pioneer, and global leader of this technology.
Read on to find out why ePaper is a technology that will find an increasing number of applications in the near future.
How does an ePaper work?
To answer these questions, we first need to explain how e-ink works. At the core of this technology, you’ll find small capsules filled with a clear fluid that includes tiny particles. An electronic paper display consists of millions of such capsules spread on a thin film. The particles inside the capsules can have different colors and electric charges.
Next, we place electrodes above and below the capsule film. When a positive or negative electric field is applied to an individual electrode, the particles with the corresponding charge move to the top or bottom of the capsule. This is how the surface of an e-paper display can display images.
The particles within an e-ink capsule can either be black or white in the most basic version of an e-paper screen. While the positive charge is carried by white particles, the negative charge is carried by the black ones. If the electric charge is negative, the negative black ink particles are repelled to the top of the capsule – that’s how they end up coloring the display surface black in that location.
Electronic paper display controllers
Our research and development team built three controllers to address the most common sizes of e-paper displays used in industrial applications:
- The first controller supports screens ranging in size from 7.8 to 11.3 inches, including medium-sized 9.7-inch panels.
- The second controller is for e-papers with a diagonal of 13.3″ – both BW (black and white version) and BWR (black, white & red).
- The last controller handles one of the largest e-paper displays on the market – 31.2″.
Modes of image refresh
Static applications with interactive components get to benefit the most from the e-paper technology. However, the challenge that engineers face here is the slow refresh rate of the images.
We solved this problem by showing data in a variety of modes that differ not only in frequency but also in mapping precision. Reducing the accuracy of the projection allows us to create a considerably smoother image as a result of such a solution. The controller enables both partial picture changes and flashless mode, making it a versatile solution that can be tailored to the demands of any application.
Animation on ePaper is now possible
Animation is a flashless mode that we can use to enable frequent and rapid content changes or displaying simple animations. Image quality and ghosting are reduced, and the response time is faster (120ms at 25°C). The animation mode currently works with black and white graphics.
Another supported mode is the DU4 mode, which is also flashless. In this waveform, each pixel in the 16-level grayscale is changed to a pixel in 4-level grayscale (0 – black, 5, 10, 15 – white). Thanks to the combination of fast reaction time and keeping the grayscale, it works well in antialiased texts – for example, restaurant menus.
ePaper in outdoor applications
Technological advancements made the use of e-paper displays outside of buildings possible. Since the density of the fluid in which capsules are submerged rises with low temperatures, the display might encounter issues with refreshing and altering the displayed image. Our EPDs use a method that allows e-paper screens to function well at -20°C.
Get your ePaper solution from Melrose
Our EPD offer matches the demands of every application since e-paper displays support various display sizes (from 7.9” to 31.2”), BWR/color, partial image upload, simple communication via SPI/USB interface, easy implementation in the end-device, and low power consumption.
The table below shows more details about each display mode:
| Mode | Global/Local | Grayscale mapping | Ghosting | Refresh time [ms] | Usage |
| INIT | Global | n/a | n/a | 2000 | Display initialization |
| DU | Local | 4-bit to 1-bit | Low | 260 | Monochromatic menu, text input |
| GC16 | Global | 4-bit | Very low | 480 | High-quality images |
| GL16 | Global | 4-bit | Medium | 480 | Text on white background |
| A2 | Local | 1-bit | Medium | 120 | Fast pages scroll at low contrast |
| DU4 | Local | 4-bit to 2-bit | Medium | 290 | Antialiased text on touch menu |
Get in touch with us to learn more about our ePaper technologies and get expert advice from our specialists.
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