# High-Resolution Pixel LED Headlamps: Functional Requirement Analysis and Research Progress
## 3 Research Progress of High-Resolution Headlamps
### Existing Beam Diversity of High-Resolution Headlamps
Through the pixel pitch, the position accuracy of the edge of the glare area makes the area larger. The glare area reduces the visibility of the edge, making the entire spot relatively smooth. Experiments show that, if 0-100% is used to deactivate or activate certain pixels, the light beam will produce disturbing unevenness. In order to reduce this discomfort, the brightness and the unevenness can be made by smoothly shifting the edge pixels. There are fewer junctions between dazzle, which makes the driver more comfortable. The indicator on the road can achieve refined light distribution through a large number of pixels. [PERSON] et al. initiated the SIMPL project to combine micro LED technology with display optics technology [56]. Due to the same width and height ratio, the light source being developed or to be released is not suitable for wide vehicle beam patterns. The central brightness of the beam pattern of the system exceeds 60 k cd, and the light efficiency exceeds 30%. At the same time, research has found that the resolution required is 0.1, FOV is a 40\({}^{\circ}\) horizontal and 10\({}^{\circ}\) vertical beam pattern, the number of LEDs is 400 \(\times\) 100 LEDs, each LED needs to be isolated from pixel crosstalk, and the spacing between each LED is 40 \(\upmu\)m. The projection part is used in the imaging optics engineering of the camera industry to project a clear spot. SIMPL can change any luminous flux within the range of \(+\)\(-\)20\({}^{\circ}\) to achieve the low beam distribution required by ECE. The luminous flux is 315 lm, and the extended luminous flux is 500 lm. The high beam output luminous flux is 900 lm, and the extended luminous flux is 500 lm. The imaging system is designed using the imaging method in the camera. High-resolution LED pixel headlamps can reduce the dazzling of other road participants, optimize the light distribution to suit the driver's field of vision, and help improve safety. [PERSON] et al. proposed a pixel light source based on \"wafer process and forming silicon on GaN\" [57]. Pix LEDs are attached to a metal PCB and electrically connected by wire bonding. The chip has a total of 192 pixels, and the thermal characteristics are less than 1.3 k/w. Each chip is wire-bonded and packaged with silicone resin. The spacing between each LED is less than 20 \(\upmu\)m. The chip is characterized by its narrow shape. The dark area and the LES are relatively small, thus the pixel separation between each LED can be achieved without using a condenser lens. The heat dissipation is good, the contrast can reach 600, and the width is that of a single LED. It is 4 \(\times\) 17.5 mm, and the pitch is 20 \(\upmu\)m. The realization of high contrast is mainly by applying Si barriers between each LED pixel to suppress light diffusion. Compared with traditional headlamps, the corresponding light output can be realized by only switching the LEDs. The design flexibility is high, and customized design can be realized. At the same time, functions such as \"single chip multi-color\" may be added in the future to adapt to extreme weather and improve visibility. The multi-color function in a single chip has great potential for automotive applications. When the car detects that there is a car on the side of the road or on the opposite side, some of the lights will be turned off to prevent it from affecting other drivers. This technology also means that more information can be projected on the road, such as projecting guide lines or navigation suggestions on narrow roads. At the same time, it can also be used to warn the driver, providing a reminder of road conditions or construction sections ahead.