Laser scanning head-up display (HUD) is an off-axis imaging virtual image display system. Its optical design inherited
the feature of head-up display architecture in a fighter. When it is applied to a car, its main optics is replaced by a mirror
to save space. Usually, a diffusion sheet or frosted glass is placed in front of a pico-projector to be an image screen, but
there will be an issue of lower sharpness of the image due to its low divergence ability for the incident beam. This study
proposes a pyramid-shaped micro-structure optical diaphragm to replace the above traditional diffusion films. Besides,
the relationship between the optical light path and microstructure in the HUD is also well described.
Collimation lenses for light-emitting diode (LED) light sources have been widely used in lighting engineering. In this study, a collimated LED light source was developed for a color liquid-crystal display backlight, which is driven using a two-field driving scheme to display color. A color-separation backlight that involves using the designed collimation modules possesses several advantages such as low volume, elimination of dye color filters, high feasibility with conventional ultraprecision machining processes, and a wide color gamut.
In this study, a collimated LED light source has been developed as a colorful liquid crystal display backlight, which is driven by a two-field driving scheme to display color. In each field, the angular rays of two colors from LEDs are collimated by a collimation lens, redirected by a light guide and converged by a cylindrical-lens array to map into corresponding sub-pixel positions for efficiently displaying color image. The simulation results of the backlight module and the corresponding experimental results will be discussed in detail.
Multiple chips are often bonded in a small single package of LED to obtain higher light flux output. However, the nonuniformity of light pattern always exists due to the high order collimating lamp, which uses the MCLED (Multi-chips LED) as the source. In this paper, the light pattern uniformity of lamp composed of four-in-one MCLED, whose thickness of phosphor layer and the length of lamp are respectively 0.1 mm and 10 mm, is simulated and analyzed. The ray tracing simulated by computer with varying the spacing of chips, concentration of phosphor, shape of lamp, and the corresponding uniformity of light pattern will be analyzed and discussed in detail.
In this paper, we proposed a new configuration of concentrator in solar PV system. A special optical system in the
concentrator used in focusing sun light to solar cell is proposed, the system compose of an aspherical surface and a
specific diffusing surface. The uniform-squared light pattern is obtained on the solar cell, the shape and size of light
pattern can be modulated by the parameters of the diffusing surface. In order to decrease the weight of the lens, the
concentrator in Fresnel lens type is built at last. Besides, the optical efficiencies formed by the aspherical concentrator
and Fresnel concentrator are about 92% and 77%, the concentrations are about 720mW/mm2 and 640mW/mm2, and the
acceptance angles are about 0.35° and 0.30°, respectively. The tolerances in assembling the component of the
concentrator are also discussed in detail.