Views: 0 Author: Site Editor Publish Time: 2023-06-08 Origin: Site
Under the trend of automated driving and personalization, important changes are also taking place in automotive lighting systems. Mainly manifested in two aspects: firstly, from the initial simple lighting, to the main medium used today for decoration, embedding brand characteristics, showcasing technical strength and design skills. Secondly, in today's booming development of autonomous driving, automotive lighting systems have become increasingly intelligent.
1、 Introduction
The Chinese automotive market is undergoing a series of reforms and transformations, and automotive lighting - a configuration that was originally intended for us to explore the road - is quietly undergoing qualitative changes because it is no longer just a beacon. Nowadays, with the evolution of LED, OLED, laser headlights and other products, various car companies are playing with their headlights. The performance of the headlights has become more powerful and the size has become smaller, thus gaining more possibilities in terms of styling.
2、 Lamp type
From basic halogen, advanced xenon headlights, to new power LEDs, and futuristic laser headlights, each has its own advantages and disadvantages. The choice of these four different headlight forms depends on the location of the vehicle model. Let's take a look at them separately：
A.Halogen headlights
Halogen headlights began in the 1970s, which is currently the most common type of headlight light source. Halogen lamps are actually upgraded versions of incandescent lamps used in daily life. The application of halogen group elements can increase the brightness of incandescent lamps by 1.5 times, while increasing their service life by 2-3 times. They are composed of a bulb and a reflecting bowl, and the large volume required for the reflecting bowl results in poor plasticity of the design. However, due to the cheap price of halogen lamps, It is still very suitable for some lower priced economy models.
B.xenon lamp
The xenon lamp broke the tungsten filament luminescence principle invented by Edison, filling a quartz tube with high-pressure inert gas - xenon gas, replacing the traditional filament, and stimulating xenon gas to emit light through high-voltage current. Compared to halogen lamps, xenon lamps have a higher color temperature. Currently, mainstream xenon lamps have a color temperature between 4200K and 6000K, and their light color is closer to the white light of the noon sun. They are composed of light bulbs, reflective bowls, and lenses. Compared to halogen lamps, xenon lamps have the advantages of high brightness and long lifespan, but the cost is relatively higher.
C. LED
LED was initially used for interior lighting in cars, but later gradually expanded to a wider range of applications such as headlights and combination taillights. The most typical application of LED in headlights is daytime running lights. Due to the small size of LED, it is convenient for free combination and secondary optical design. Therefore, LED can be used to form different shapes and line combinations, with a large design space and strong sense of technology.
In addition, compared to traditional light sources, LEDs also have better performance:
Firstly, it has a longer lifespan, faster start-up speed, and LED response time that can reach ns level. Therefore, when LED is applied to turn signal lights and high mounted brake lights, it can meet the emergency response needs of vehicles during driving and effectively reduce the occurrence of car accidents.
Secondly, LED headlights can prevent glare: The white LED light source has a color temperature of 5500K~6000K, which is closer to natural light (4800K~6000K) compared to xenon light sources (4000K), and has higher comfort. It has a greater advantage in avoiding light fatigue issues for drivers.
Thirdly, energy conservation and environmental protection. LED is a cold light source that converts electrical energy into light energy, so there is no pollution or excessive heat generated during the emission process.
D. OLED
The emergence of OLED provides a new design solution for automotive lighting systems. OLED is a highly plastic material with rich shapes, and has been applied in many concept cars.
OLED has two major advantages:
Firstly, it has the characteristic of self illumination, without the support of any light source system, and the thickness is only 1.4 millimeters. The future taillights can even be pasted on the rear of the car like stickers, without occupying space in the trunk, and have greater advantages in volume compared to ordinary LED products;
Secondly, compared to LED point light sources, OLED has the characteristics of surface light source and diffuse reflection, with uniform light quality and can achieve stepless dimming without casting any shadows. The lighting effect can be uniform, produce light and dark effects, and even dynamic effects. These two characteristics make OLED very suitable for making interior ambient lights and taillights.
Its disadvantage is its short service life, the material can only withstand a temperature of 80 degrees Celsius, and its price is high, so it has not been widely used in the car lamp market at present. OLED currently cannot achieve the same brightness as LED, and is generally only used for taillights, signal lights, and interior lighting.
E. Laser headlights
In addition to OLED, laser headlights will also be one of the future trends in the development of car lights. Compared to LED headlights, laser headlights have more advantages in technology: their smaller size, brighter lighting, and lower heat generation allow designers to redesign the vehicle body, leaving more space for aerodynamic layout, and adjusting the front suspension and engine positions appropriately to achieve the purpose of optimizing space.
The illumination level of a laser lamp is 1000 times that of an LED lamp, and its volume is reduced by 100 times compared to an LED lamp. The laser light source has an illumination distance of nearly twice that of an LED high beam, with a maximum illumination distance of up to 700 meters. Due to the straight nature of the laser, it can be finely controlled when dispersed without any excess light.
So, using laser headlights can broaden the driver's field of view and help make early hazard judgments, while facing towards the oncoming direction with a larger controllable range of lights, avoiding the potential danger caused by glare. Its disadvantage lies in poor beam divergence and narrow beam irradiation range. Generally, a hybrid method of LED and laser light sources is used to solve this problem, so it is not suitable for use as a low beam headlight in automobiles at this stage.
