Rdot is a company based in Sweden and they have just developed an e-paper display that they think is better than E Ink. The Rdot Display is an electrochromic display. It categorized as a reflective display – meaning that it reflects ambient light instead of using a backlight. All layers are screen printed on a plastic substrate. The display stack consists of organic layers including a plastic substrate, an electrochromic material, and an electrode for each segment. Additional layers such as graphical overlays, circuits, and barrier layers may be added if required.
Rdot mentions in one of their tech articles that “LCD displays need an active driver that varies the polarity of the voltage across the pixel in a frequency of about 60Hz. E Ink, on the other hand, doesn’t need any active control once the display has been updated, this feature is often referred to as bistability. Rdot is somewhere in between LCD and E Ink, once the display has been switched the controller can go idle for about 15 minutes (there exist versions that can be idle for up to 24 hours as well). After this time a small refresh pulse is required to maintain the state. For E Ink and Rdot, energy is only required during switching and updating while no energy is consumed during idle state. Typically, the energy required for a full switch on an E Ink display is about 4mJ/cm2. The corresponding number for the Rdot display is about 1mJ/cm2 with the addition of 0,25mJ/cm2 every 15 minutes. LCD continuously consumes about 6µW/cm2.”
It could be a few years before rdot’s displays reach the consumer market, the company’s products are in a qualification phase, with samples being tested by various partners. Founded in 2016, the company has managed to fund itself through grants, EU programs and government support. “We’ve closed quite some good deals with joint-development partners and we’ll try to avoid having to raise capital if we don’t need to, to favour an organic growth” CEO Felix Karlsson said discussing the company’s finances. “We may need some capital in a year or so to scale up our company, but we want to be more established before and find our right market. The startup also wants to collaborate with other printed and flexible electronics companies to design full flexible products.