Oxford startup wants to boost displays with micro-optics

March 22, 2018 // By Julien Happich
Founded in 2008, Oxford startup Optovate Ltd. has just come out of stealth, announcing a proprietary multiple-microLED transfer technology (in parallel from a wafer to a substrate) combined with a precision alignment method with a micro-optical array.

The company says the micro-LED together with the micro-optics could boost the brightness and light focus of micro-LED based backlights for LCDs, OLED displays but also for head-mounted Augmented Reality (AR) and automotive Head-Up-Displays (HUD).

One implementation of Optovate’s catadioptric
micro-optics for high dynamic range (HDR) LCD
backlights using mini-LEDs.

Prior to launching Optovate on their own funds, the founders were operating successful startup Ocuity Ltd. which focused on lenticular displays for autostereoscopic 3D displays, eeNews Europe learned in an interview with Optovate's Commercial Director, Paul May. In 2008, they sold Ocuity to Taiwanese LCD display manufacturer AU Optronics (AUO) to focus on microLEDs together with micro-optics.

"Ten years ago, the initial applications we were looking at were LED lighting, but then by 2010-2011, the market turned around microLEDs for displays and we saw enough interest to continue developing IP for the display market. We had built up a lot of the technology, the microLED transfer with the optics for directionality when we were working on lenticular displays" explained May.

"There is a general move towards the use of microLEDs for display backlighting, but using micro-optics brings extra efficiency and allows privacy-type applications. Directionality is definitely a benefit as well as energy efficiency".

MicroLEDs used in a HDR-LCD combine privacy
display operation with high efficiency.

By aligning an array of microLEDs underneath a thin precision micro-catadioptric optical array, Optovate maximises the light output of each microLED through refraction and reflection. Because the micro-catadioptric elements can be designed to yield different beam angles, an array of microLEDs can easily be configured so as to be switchable from a wide angle to a narrow angle of view (effectively switching between two intertwined microLED arrays).

"By concentrating the light output within a cone, we increase brightness by a factor of 2 to 3, and we could get a similar increase in brightness for OLEDs, lots of light is lost in the plane of the display and our micro-optics extract the light in a usable cone" May told eeNews Europe. Now Optovate clearly has the ambition to shrink its micro-optics to pixel sizes, which would be needed for OLED applications. "We can do small pitches, we can take this down to between 50 and 100µm using a master and micro-imprinting" confirmed May.