Comprehensive Overview of In-Car Display Technologies: TFT-LCD, OLED, LCD, LED, Mini LED, Micro LED

OLED, or Organic Light Emitting Diode, is a type of organic light-emitting device that emits light through the injection and recombination of charge carriers. The light intensity is proportional to the injected current. Under the influence of an electric field, holes generated at the anode and electrons generated at the cathode move towards the hole transport layer and electron transport layer, respectively, and migrate to the light-emitting layer. When the two meet in the light-emitting layer, they produce excitons, which excite light-emitting molecules to emit visible light.

Compared to LCD, the advantages of OLED screens include the ability to display pure black, no light leakage, nearly infinite contrast, short response time, flexibility, low power consumption, and short response time.

LCD is one of the earliest in-car display technologies. Its working principle involves sandwiching a layer of liquid crystal material between two glass plates and controlling the arrangement of liquid crystal molecules by changing the electric field to control light. LCDs have advantages such as low power consumption, small size, and light weight, but their color reproduction and contrast are relatively low.

LCDs do not directly display images; they require color filters to create images. The color filter is composed of many pixel points, each containing sub-pixels of red (R), green (G), and blue (B). According to the basic concept of color theory, the three primary colors RGB can be combined in different proportions to create various colors seen in reality, and the combination of different colored pixel points forms the colored images we see.

Comparison of OLED and LCD

LED, or Light Emitting Diode, is a type of semiconductor solid-state lighting device that uses solid semiconductor chips as light-emitting materials. When a forward voltage is applied across the two ends, the carriers in the semiconductor recombine, causing photon emission and light generation. LEDs are made from compounds containing gallium (Ga), arsenic (As), phosphorus (P), and nitrogen (N), and can directly emit red, yellow, blue, green, cyan, orange, purple, and white light. Gallium arsenide diodes emit red light, gallium phosphide diodes emit green light, silicon carbide diodes emit yellow light, and gallium nitride diodes emit blue light. They can be classified into organic light-emitting diodes (OLED) and inorganic light-emitting diodes (LED) based on their chemical properties.

Mini LED refers to LEDs with a chip size of approximately 50-200μm, with the chip size and pitch falling between traditional small-pitch LEDs and Micro LEDs.

Mini LEDs segment the backlight layer into smaller blocks and perform zone dimming through LED chips, thereby improving the black-and-white contrast issues that have plagued LCDs, achieving display effects close to OLED while avoiding lifespan issues. Compared to traditional LEDs, Mini LEDs have numerous advantages, including saving substrate materials, improving image pixel granularity, achieving local dimming in smaller areas, and enhancing gray display performance at low brightness. The future demand for display technology is vast.

Micro LED integrates all the advantages of LCD and OLED, shrinking LED beads to the nanometer level. Micro LED displays have higher brightness, contrast, and color gamut, and longer lifespan. However, the manufacturing process of Micro LEDs is more complex and costs more.

Comparison of LED, Mini LED, and Micro LED

In-car display technologies are continuously evolving, and major automotive manufacturers are constantly developing new display technologies to meet the increasing demands of consumers for in-car displays. In the future, we have reason to believe that in-car displays will present clearer and more realistic visual effects, providing drivers with a more comfortable driving experience.