Facility and equipment information.
Name: Vehicle-mounted AR-HUD TFT sunlight backfill detection light measurement equipment solution.
Device type: KYF-TY01-03x0.4-3a-am1.5g-01
Equipment manufacturer: Keyingfa Electric Sunshine Backfill Detection Solar Simulator.
Optical indicators. 440-460nm@t>90%
520-540nm@t>90%
620-640nm@t>90%
400-425nm@t<1%
480-500nm@t<1%
560-600nm@t<1%
660-1100nm@t<1%
Technical parameters of the equipment.
Irradiation intensity: 800-1300W m
Band: 380nm 1100nm
Irradiation area: 300mm 400mm
Working distance: 900mm-1200mm from the light source to the measured object.
Light direction: left light, down light, right light (direction adjustment: electric control).
Spectral matching: 25%.
Collimation half-angle 1°
Spatial inhomogeneity: 2%;
Output power instability: 2%.
The power of the device is: 5-7kw
Liquid crystal display technology is becoming more and more mature, has become the mainstream of the current display market, because of its display quality, light appearance, long life cycle, is widely used in vehicles, mobile devices, computers, televisions, medical and outdoor display and other fields, with the continuous pursuit of high brightness, low power consumption and accurate display color of display equipment, as well as the rapid development of high-resolution display panels, RGB display products have become popular products in recent years.
Industry Background February** Dynamic Incentive Plan
Today's vehicles are becoming electrified, intelligent, and automated, but the communication between the vehicle and the driver is forever. The head-up display HUD is considered to be a way for the driver to communicate safely with the vehicle.
The HUD has become a common feature in automobiles, allowing it to visualize speed, engine speed, or other information hovering in the driver's field of vision, reducing distractions caused by looking down at the dashboard and improving driving safety.
With the improvement of market acceptance and display effect, major manufacturers have increased their weight in this field. After continuous R&D and technological breakthroughs, the automotive HUD has also been updated and iterated
A combined head-up display, which is mounted on a piece of transparent glass, and the optical image is reflected into this piece of glass by three refractions. 18-2.The position of 5 meters forms a virtual image that displays different information.
The windshield head-up display directly uses the windshield of the car as the display device, and the display effect is more integrated.
AR-HUD augmented reality head-up display system. When navigating, it can be displayed in combination with the actual road scene, which is more intuitive and vivid, and represents the future development direction of HUD.
Based on a 3D virtual display, it can be projected in front of the windshield, at which point AR technology will dynamically project according to the 3D position of the target.
At present, the mass-produced head-up display HUD for automobiles is gradually developing from windshield W-HUD to AR-HUD of augmented reality: from a simple information display screen, to an augmented reality (AR) effect with warning symbols generated at the actual road position.
According to the monitoring data of the Intelligent Vehicle Research Institute, in 2021, the number of new cars equipped with HUD (W AR) as standard in the Chinese market will be 109450,000 units, a year-on-year increase of 5796%。Among them, more than 50,000 AR HUDs have been installed in front of them. In 2021, the Chinese market also ushered in the first year of AR-HUD with the launch of new vehicles of independent brands such as Great Wall Mocha and Geely Xingyue L equipped with AR HUD. At the just-concluded 2022CES exhibition, AR-HUD has also become a new track for major manufacturers to compete for.
This is the beginning of a new era of augmented reality in automobiles and fundamentally changes the experience of navigation, entertainment, and autonomous driving. For AR-HUD, a complete closed-loop industrial chain will be formed in the future.
The overall structure of the HUD mainly includes the main control PCB board, LED light source, projection display and reflector, which is essentially an optical device. Projection unit (PGU) is the core barrier of HUD, and the selection of its technical route is also the core that determines the future industrial development route, which can be divided into three technologies: TFT-LCD, DLP and MEMS laser projection. At present, TFT-LCD is a mature mainstream solution, and the projection principle is LED backlight emitting light, and the electric field controls the rotation direction of the liquid crystal branch between the two substrates to change the direction of light travel and the color of the light.
W-HUD AR-HUD has always relied on the imaging principle of optical concave mirror to achieve the magnification of distance and visual size, and the biggest technical challenge of AR-HUD is the problem of high magnification distortion and dizziness caused by high magnification, and the problem of sunlight back-filling and burning the optical machine. To produce the same long virtual image distance (vid) distance with a smaller volume, the larger the magnification. The greater the magnification, the more severe the distortion of sunlight and halo.
With the continuous breakthrough of the technology using TFT optical machine, the problem of TFT solar backfilling is no longer a problem. Among them, it can be considered from the perspective of "removing part of the heat energy of the sun":
Sunlight radiation heat is divided into infrared and visible light according to wavelength, and is divided into S wave and P wave according to the polarization direction. The HUD only uses the S wave of visible light, so the optical path component only allows the S wave of visible light to pass through, and other infrared P waves, infrared S waves, and visible P waves are blocked by the optical path in the HUD, so that the heat energy of sunlight poured into the TFT is left 1 4, which greatly reduces the thermal shock.
Among them, the anti-sunlight backfill filter can achieve high transmittance in the visible light band through the RGB narrow-band filter, and at the same time cut off the near-infrared and ultraviolet wavelengths, achieving high photometric sensitivity and dynamic range.
Bolton Optoelectronic Process Test Center uses self-developed coating equipment and is equipped with self-developed RF ion source to assist in the coating through the test, and obtains RGB narrowband filters with high transmittance, high matching accuracy, high density and firmness, high and low temperature change wavelength without drift, and good durability in harsh environments, providing high-quality coating solutions for on-board AR-HUD TFT anti-sunlight backfilling.
Purpose of the experiment. In the event of solar influx, the energy convergence at the TFT end is reduced.
Experimental method: Shutdown state, install temperature test in the AA area of the TFT screen 2head, and then put the prototype in the sunlight to simulate the occurrence of solar influx, so that the energy of the TFT segment reaches the maximum energy, and the temperature of the TFT screen rises to the maximum.
Experimental procedure: Sunlight irradiance and sunlight influx in TFT case I
Experiment 1: No protection scheme.
TFT AA area nine point MAX temperature (°C) probe temperature max--18765°c
Data analysis: As you can see from the data and graphs, the maximum temperature of the 3 probes on the temperature sensor is 18765°C, TFT theoretical withstand temperature of 105°C, no protection scheme leads to TFT damage.
Experiment 2: No narrowband filtering scheme.
TFT AA zone nine o'clock MAX temperature (°C): probe temperature MAX - 19135°c
Data analysis: As you can see from the data and graphs, the maximum temperature of the 10 probes on the temperature sensor is 19135°, TFT theoretical withstand temperature is 105, the scheme is not feasible.