Analysis of Car Camera Lenses

A car camera's effectiveness heavily relies on its lens—up to 70% of optical parameters are attributed to it. Despite the comparatively lower cost than the COMS chip, the lens's performance remains paramount.

Lens Materials and Material Preference:

1. Lens Barrel Material: Typically made of metal or plastic, metal barrels offer superior quality, temperature resilience, but come with potential issues like metal powder production during screw twisting, posing risks to the COMS photosensitive area. Conversely, plastic barrels are less problematic but possess inferior quality indicators.

2. Lens Materials: Divided primarily into glass (G) and plastic (P), with glass lenses mostly spherical and crafted via glass grinding, while plastic lenses are mainly aspherical and produced through injection molding.

In-car camera lenses often favor glass due to its high temperature resistance, friction resistance, and surface hardness, although it tends to thicken the overall camera and incurs higher costs. In-vehicle cameras require high durability and thermal stability. According to the material, the lens of car camera can be made of glass and plastic. Glass lenses have high durability and scratch resistance, and better temperature performance, so they are more often used in high-end products. Plastic lenses are cheap, but the imaging effect is poor, and in the harsh environment of the car is easy to cause lens deformation, affecting the imaging quality. At present, taking into account the cost and performance, the mainstream manufacturers of car lenses are gradually starting to use glass-plastic hybrid lenses, part of the high-end lenses using all-glass program.

Emerging Trends in Car Camera Technology:

1. Eliminate Stray Light Ghosting, Improve Optical Imaging Stability

With the optimization and upgrading of the car camera process, the car camera shock resistance, wear resistance, high and low temperature resistance gradually improve the ability to picture quality is clearer. In order to control headlights and other positive light interference caused by ghosting stray light, in extreme temperatures or short-term rapid temperature changes to maintain the stability of optical imaging and effectively capture and distinguish the details of the object. In addition to improving the algorithms from the software, vehicle lens manufacturers are progressively improving car camera resistance to shock, wear, and temperature changes to ensure clearer picture quality and minimize stray light interference, notably in extreme temperatures.

2. Pixel Upgrade: 800W Pixel Camera

The core of vehicle camera perception is vision, and the resolution determines the level of vision. With the ADAS function on the perception of distance needs to improve, the perception of the content of the finer, higher resolution camera trend. For mainstream new energy vehicle enterprises, 120W to 200W lens is no longer enough to meet the use, the industry began to upgrade to 800W pixels.

3. Lens Process: Aspherical Lenses

Spherical lenses can lead to aberration problems, that is, from the center of the lens into the light and the edge of the lens into the light focus is not the same, resulting in blurred imaging problems. Spherical lenses require a combination of multiple lenses to minimize aberration.

Aspherical lenses are lenses composed of spherical and out-of-plane surfaces, and the problem of aberration is solved by changing the curvature of the lenses so that the light rays converge at a fixed focal point, and this can be achieved with only one lens. Therefore, aspherical lenses have the advantages of miniaturization, light weight and good imaging effect, and have become the best solution for high pixel vehicle lenses.

Plastic aspherical lenses are produced by injection molding, while glass aspherical lenses are produced by using high-quality optical glass and precision-controlled thermal molding technology.

4. Self-cleaning, Anti-fogging and Defrosting

Self-cleaning anti-fouling: Currently the mainstream manufacturers at least in the car camera lens surface plated with a layer of hydrophobic coating, on the one hand, can be effectively cleaned by spraying water and other means to remove dirt. Whenever encountered in rainy or snowy weather, the camera exposed to the outside of the car and even fogging frost problems.

Anti-fog defrost: the industry has two directions, one is through the coating, the outer surface of the lens plated hydrophobic film, the inner surface of the lens plated hydrophilic film; the second is the use of heating solutions, or the lens as a whole, or the lens surface to do a layer of transparent conductive film to achieve heating.

5. Night Vision Technology

In order to ensure driving safety, automotive ADAS function needs to realize all-weather operation as much as possible. The camera is through the light and algorithms to realize the perception of the surrounding environment, so in the lack of light, such as night driving, through the tunnel and other scenes, the need to enhance the camera's night vision capabilities. Currently, automotive night vision systems can be divided into three categories according to different imaging principles and lenses: microlight, near infrared and far infrared.

• Microlight: from the literal meaning of the understanding, is through the amplification of a small amount of visible light received, and ultimately the image will be captured and projected onto the corresponding display. Microlight and general camera imaging principle is the same, are through the visible light to realize night vision, but need a certain visible light environment.

• Near-infrared night vision: also known as active infrared night vision technology, refers to the work with a strong infrared emission source to irradiate the target, the use of infrared light reflected back from the target to get the image of the object. The working band is in the near infrared light of 800~1000nm.

• Far infrared night vision (thermal imaging system): also known as passive infrared night vision technology, mainly using the object itself emits infrared radiation to image, which is also known as thermal imaging. Thermal imaging system is based on the temperature difference between the target and the background of the formation of infrared emissivity differences, the use of radiation thermometry technology on the target point by point to determine the intensity of radiation, and the formation of thermal images of visible targets. Its theoretical operating band between 1-14um, but the general far-infrared night vision mainly use short-wave (3μm - 5μm) and long-wave (8μm - 14μm) these two.

Among them, the microlight night vision needs to be realized from CMOS and algorithm upgrading; while infrared night vision needs to be equipped with special infrared lenses to ensure the entry of infrared light. In addition, micro night vision can see color images, while infrared can not do color.

With the evolution of automotive intelligence, car lenses are advancing toward rapid sensing, deep recognition, and synchronized environmental interpretation. Solutions like structured light and TOF technology are becoming focal points for major car lens manufacturers, aiming to achieve superior depth of field measurement and enhanced environmental understanding.