A well designed headlamp for a vehicle lighting system is very important as it provides drivers with safe and comfortable driving conditions at night or in dark places. With the advances of the semiconductor technology, the LED has become the fourth generation lighting source in the auto industry. In this study, we will propose a LED vehicle projector headlamp system. This headlamp system contains several LED headlamp modules, and every module of it includes four components: focused LEDs, asymmetric metal-based plates, freeform surfaces, and condenser lenses. By optimizing the number of LED headlamp modules, the proposed LED vehicle projector headlamp system has only five LED headlamp modules. It not only provides the low-beam cutoff without a shield, but also meets the requirements of the ECE R112 regulation. Finally, a prototype of the LED vehicle projector headlamp system was assembled and fabricated to create the correct light pattern.

A cylindrical rod composed of a uniform mixture of single-wall carbon nanotubes and alumina powders dissolved in paraffin was inserted in the center of a radio frequency cavity. The complex dielectric constant of carbon tubes at various frequencies was measured by a resistanceinductance-capacitance (RLC) meter and a microwave network analyzer. The cylindrical rod benefits the protection of the sample from adsorbing moisture and preventing the rod from filling with air, thus making accuracy experiment values. The real part and the imaginary part of the dielectric constants of single-wall carbon nanotubes are, respectively, increase and decrease in magnitudes as frequency increases satisfactorily in complying with the portray from the free electron Drude model.

This study presents a silicon-based pressure sensor with temperature compensation. The eight piezoresistors were designed on the polycrystalline silicon membrane and constructed by two concentric Wheatstone-bridge circuits to perform two sets of sensors. The sensor in the central circuit measures the membrane deflection caused by the combined effects of pressure and temperature, while the outer one measures only the deflection caused by the working temperature. From this arrangement, it is reliable and accurate to measure the pressure by comparing the output signals from the two concentric Wheatstone-bridge circuits. The optimal positions of the eight piezoresistors were simulated by simulation software ANSYS. The investigated pressure sensor was fabricated by the micro electro-mechanical systems (MEMS) techniques. The measuring performance and an indication of the conventional single Wheatstone-bridge pressure sensor is easily affected under variation of different working temperature and causes a maximum absolute error up to 45.5%, while the double Wheatstone-bridge pressure sensor is able to compensate the error, and reduces it down to 1.13%. The results in this paper demonstrate an effective temperature compensation performance, and have a great performance and stability in the pressure measuring system as well.

A multiplanar reflector was designed to enhance the application efficiency of light-emitting diode (LED) light sources that can be employed as LED-based dental lights. This study used a high-power LED developed by Nichia, that is, a single LED capable of providing a total luminous flux of 120 lm, as the primarily light source to design and develop an LED-based dental light. This LED complies with the international standards and regulations stipulated in ISO 9680:2007. The light spots produced by the prototype were rectangular, with a length of 200 mm and a width of 100 mm. These light spots achieved maximum illumination of 12,000 lux. The use of LEDs can reduce energy consumption from 50 W to 3 W, providing an energy saving of more than 90%.

The big advantage of LED is the flexible spectral design to make white light using different color mixing schemes. Recently, the color mixing of RGB LEDs is mostly done by sealing all three chips at single package and regulated the mix ratio of these three colors to produce the color of light. And, by changing the LEDs array alignment, RGB chips can achieve overlapping colors of light and create the fun of changing colors in light mixing. Therefore, the purpose of this study is to propose an innovative technique of light mixing. By applying the mechanism design, a RGB light mixing mechanism is produced. Each of the RGB LEDs lamp-type is installed on the couple link of the three mechanisms, respectively. By driving a crank makes the couple link and an output link to produce the relative motion, this will result in the fact that the RGB lamps can project lights on the same plane in order to obtain the color mixing. Unlike mixing technique by control system, this design generates light mixing and changes of color with the synchronized driving of three mechanisms, thus achieving the dazzling perception of single-color lights or mixing of multiple colors for creating ambience of a space.