Xiaomi Phones’ New Lens: Wafer-Level Glass and Liquid Lens
PRNewswire: Xiaomi’s Redmi K40 Gaming Edition is the first mobile phone to incorporate a Wafer Level Glass (WLG) hybrid camera lens. The hybrid camera lens solution includes 1 glass + 5 plastic lens elements provided by AAC Optics, a subsidiary of AAC Technologies. AAC Optics made their initial investment into WLG 10 years ago (in Danish startup Kaleido) and has developed expertise to enable volume production of Wafer Level Glass (WLG) technology into the Smartphone, Automotive, and IoT markets.
The WLG lens is said to have a larger aperture, a 15% increase in light reaching the sensor, and 5% resolution improvement.
Analysts from China Securities International compare WLG lens with Himax and ams plastic wafer lenses:
“AAC has absorbed the Wafer Level Glass Lens (‘WLG’) technology from Kaleido. Unlike WLL offered by Himax (HIMX US, NR) and AMS AG (Heptagon), AAC’s WLG features pure glass, which could further improve lens’ optical performance including larger aperture, transmittance, refractive index as well as thermal stability and small form factor. In terms of process, WLL is manufactured through depositing an epoxy on wafer through a mask, whereas WLG is made through molding techniques on both sides of glass wafer. Therefore, the aspherical surface of WLL is made of epoxy whereas that of WLG is made of glass. Currently, AAC’s WLG is made on 2-inch wafers with 30–40 lens per wafer. When the process is upgraded to 4-inch wafer process, one wafer contains over 100 lens, it could boost production efficiency significantly compared to molding glass (currently processes 3 lens at a time at maximum) and enable mass production of hybrid lens.”
IMVE reports that “Xiaomi Mix uses a liquid lens from Swiss firm Nextlens, sister company to Optotune, which makes liquid lenses for industrial use. Nextlens said the camera system has focusing speeds measured in thousands of a second, and close focusing up to 3cm.”