In the past few years, HUD has appeared more and more frequently in the public's view, which is also a trendy entrepreneurial direction inside the auto parts, and our store also has many HUD products.
HUD (head up display) this kind of program that allows the driver to not have to look down at the instrumentation, will be important information in front of the line of sight above the windshield, and in the future, with the configuration inside the MEB. In the future, with the configuration of MEB, it may be extended to more electric vehicles. Here is the disassembly of the old BMW TFT projection HUD system, for reference only.
- Windshield HUD disassembly
The windshield HUD works by projecting driving-related information onto a transparent medium in front of the driver.
From the overall interface, we can refer to a HUD made by Japan Seiki to BMW to break it down. From the overall structure, it mainly includes the main control PCB board, LED light source unit, display part and mirror part. In total, there are three PCB boards, the main control PCB, light source PCB and display adapter board.
1) LED light source part: LEDs need to provide bright enough light to enable the driver to see the projected image and information clearly, and a separate LED array board is designed here. Since the effect of the projection display is determined by the brightness of the projected light together with the brightness of the ambient light, the brightness of the LEDs here is required by enough. As shown below, this LED board is directly below the heat sink housing.
2) LCD screen display content is an important part of the entire projection, these contents through reflection to change the angle of the light source eventually imaged on the windshield, of course, this structure is shown below.
3) The last part is the control of the reflection structure, which is mainly through the DC motor to control the position, and the structure is also relatively simple.
Mirror control section
The overall structure, the HUD is a pure optical device, the automotive electronics part is a light source, screen and image display, the following reference through the motherboard of another mainland HUD, after doing the integration of the motherboard, the main cost or glass, etc.. The irregular curved surface of the windshield will allow direct projection to produce distorted images, in the design of the need to add an aspheric mirror to correct the image, here is completely optical knowhow.
2. HUD with integrated main board and LED board
Also to BMW supply HUD also has Conti, in the 2015 disassembly, the whole consists of the following components, mainly including.
LCD display unit, (1.8", 480 x 240 pixels), 40.8mm x 20.4mm viewing area, 85um x 85um pixel size Manufactured by Japan Display (ACX416AKN-E)
HUD housing, made of aluminum alloy; also projection window frame housing, concave mirror housing and flat mirror housing
Concave mirror, injection molded polycarbonate with silver plated coating
Main control board controller: with 83.3MHz CPU, 136KB SRAM / 160KB NOR flash memory; with I2C and 6 stepper motor controller
DC motor with integrated gearbox brushless DC motor
As shown above, the main control board mainly includes graphic control, main control communication and motor control.
System block diagram of HUD
The difference between the main board and the Japanese Seiki is the integration of the main board and the LEDB board, as shown on the main board below.
HUD main control panel and display
From the recent trend of new cars, the popularity of HUD is still growing quite fast, reducing costs on the one hand is the optical level of cost reduction, on the one hand is the electronic BOM cost reduction, from the future, by a master control unit to the need to display the content directly to the display is also really reasonable. Many automotive electronic components look and electronic-related, in fact, the electronic part of the ratio is very low, mainly electromechanical and materials.
Links to our store HUD sales