During driving, when encountering lane changes or turns, intelligent headlights can light up in a unique "turning" manner, clearly conveying the driving intent to the driver and other road users. The design of car lights is becoming increasingly novel and unique, not only possessing interactive capabilities like a conversation but also projecting images and even achieving turn illumination. Car manufacturers spare no effort in the design of car lights to attract consumers, making them like the "bright eyes" of the car. Projection unit, or PGU (Picture Generation Unit), is the core component of car projection lights, projection unit is generally composed of optical technologies such as laser, LCOS, or DLP.

LCOS Technology's Projection Unit

LCOS (Liquid Crystal on Silicon technology) is a display device based on liquid crystal and silicon technology, widely used in car projection units. The basic principle of LCOS displays is combining liquid crystal displays and silicon technology. Liquid crystal displays control light transmission and blocking by adjusting the direction of liquid crystal molecules and the polarization state of light to achieve display functions. Silicon, being a semiconductor material, has the characteristics of high-precision processing and manufacturing, which allow the production of high-density electronic components and circuits. In an LCOS display, the liquid crystal layer is placed on the surface of the silicon, and the backlight source is placed behind the liquid crystal layer. By adjusting the direction of liquid crystal molecules, the liquid crystal layer can control light transmission and blocking to display the required images and texts.

Generally, LCOS projection units consist of dichroic mirrors, a light source, LCOS chips, and projection lenses. There are three sets of LCOS projection units, each displaying the R, G, and B channels. Dichroic mirrors map different light sources to different LCOS units, and the controller controls the display or shutoff of a specific projection point on the LCOS according to the image sent from the application layer. Combining the advantages of liquid crystal displays and silicon technology, LCOS displays offer high resolution, high brightness, low power consumption, and high contrast, making them suitable for the display needs of car projection lights.

DLP Technology's Projection Unit

DLP (Digital Light Processing technology) is a digital optical display technology, invented by Texas Instruments in 1996. The basic principle of DLP displays combines micromirrors and a digital signal processor (DSP) to convert light signals into images. DLP displays use an array of digital micromirrors called a DMD (Digital Micromirror Device), where each micromirror can control the reflection direction of light at high speed to adjust the brightness and color of pixels by altering the reflection angle of light.

Generally, DLP technology projection units consist of DMD chips, mirrors, a color wheel, a light source, and projection lenses. When the projection units work, the color wheel rotates at a certain speed, and the light source produces RGB monochromatic light through the color wheel to the mirror, which then reflects the light source onto the DMD chip. Then, the DSP outputs the corresponding RGB color for the current point based on the image received from the application layer. DLP technology features fast response speed, vibrant colors, and high contrast. However, compared to other display technologies like LCD and LCOS, DLP technology has higher energy consumption and costs, requiring special optical designs to achieve optimal projection effects and is mainly applied in high-end luxury vehicles.

In the future, projection units will have broader applications and development prospects. With continuous technological advancement, projection units will become more intelligent and personalized. For example, through the integration with artificial intelligence and big data technologies, projection units can automatically adjust projection modes and effects based on different drivers' driving habits and preferences, providing a more personalized driving experience for drivers.