LCD technology is currently widely used in VR head-mounted displays, combined with Fresnel lenses or Pancake lenses. The difference between VR headsets and regular displays lies in the distortion and motion blur caused by head movements. To address this issue, global refresh driving technology is needed to reduce the time of light source emission. The response time of traditional LCD screens is a major problem, but Fast-LCD technology uses new liquid crystal materials (ferroelectric liquid crystal materials) and overdrive technology to effectively improve the refresh rate. So what are the advantages of Fast-LCD compared to AMOLED?
Compared to OLEDs, Fast-LCD has several advantages. Firstly, in terms of cost, there are four main display and optical configurations: Fast-LCD with a Fresnel lens (low-end product configuration), Fast-LCD with a Pancake lens (mid-range product configuration), Fast-LCD with Mini LED backlighting and Pancake lens (high-end product configuration), and Silicon-based OLED with a Pancake lens (high-end product configuration). In 2022, the cost ratio of these four configurations was approximately 1:2.3:2.9:4.5, indicating that Fast-LCD has a significant cost advantage over Silicon-based OLED.
Secondly, in terms of resolution-PPI, mainstream VR devices currently use Fast-LCD screens with a refresh rate of 90-120Hz and a single-eye PPI (pixel density) of approximately 1000. OLED's PPI is less than 500, and even Sony's PS VR2 has a PPI of only 850, showing a significant gap compared to Fast-LCD.
Finally, Mini LED technology is another advantage of Fast-LCD. It replaces the traditional LCD surface light source with a point light source provided by small LED chips, and the addition of Mini LED backlighting can significantly improve the display effect of Fast-LCD, compared to traditional backlighting. Mini LED backlighting can not only greatly increase the overall brightness of the display screen to solve the problem of light leakage, but also effectively reduce the OD distance and reduce the overall thickness of the device. In addition, when combined with a fine Local Dimming partitioning scheme, it can achieve higher contrast. Moreover, due to the further maturity of Mini LED technology and the relatively small display area of VR, Mini LED backlighting + Fast-LCD still has a significant cost advantage compared to Silicon-based OLED.
Currently, the mainstream VR devices are equipped with Fast-LCD screens, with a refresh rate of 90-120Hz and a single-eye PPI (pixel density) of around 1000. While it falls short of the ideal parameters of a refresh rate of 120-240Hz and a single-eye PPI of 2000-4000, Fast-LCD screens are still the best overall VR screens currently available. For example, the best-selling VR headset on the market, Quest 2, uses a 5.46-inch Fast Switch LCD.