平板显示技术比较及研究进展

平板显示因具有体积小、重量轻、功耗低、画质好等优点,已被广泛应用于电子仪表显示、车载显示、数码相机、智能手机、个人电脑、电视产品等领域之中。本文介绍了薄膜晶体管液晶显示(Thin Film Transistor-Liquid Crystal Display,TFTLCD)、有机发光二极管Organic Light Emitting Diode(OLED)显示、量子点发光二极管Quantum Dot Light Emitting Diode(QLED)显示及微发光二极管(Micro-LED)显示这几种平板显示技术的结构及原理。从结构、材料、性能、应用几方面对这几种平板显示技术进行了比较。最后给出了这几种平板显示技术的最新研究进展。LCD显示经过多年发展,技术成熟,成本低廉,仍然在显示市场占据主流地位。OLED显示技术摆脱了传统LCD的背光源,开创了自发光显示的未来发展方向。在相当一段时期内,LCD和OLED仍将会共存于市场中,相互竞争和补充。QLED显示和Micro-LED显示这两种显示技术,在理论上较OLED显示具有更好的颜色表现、更长的工作寿命等优势,具有非常广阔的发展前景,将为未来显示行业提供更多更好的选择。     

Visible Channeled Spectra of a Multilayer Wood Filter

The transmission factor of multilayer Wood filters containing quartz and rutile layers was simulated in order to avoid the experimental trials for obtaining optical filters with predicted transmission. The main refractive indices of uniaxial crystals—quartz and rutile—were interferometrically determined and Cauchy constants were obtained by simulation. The transmission factor of optical devices consisting of quartz and rutile layers was simulated using the Maple Program.     

Incidence angle dependence on structural and optical properties of UHV deposited copper nano layers

Copper nano-layers with different incident angles as vertical, 20 and 30 degrees, same 73.3 nm thicknesses, and same deposition rate, were deposited on glass substrates, at 373K temperature, under UHV conditions. Their nano-structures were determined by AFM and XRD methods. Their optical properties were measured by spectrophotometry in the spectral range of 300–1100 nm. Kramers–Kronig relations were used for the analysis of the reflectivity curves of Cu films to obtain the optical constants of the nano layers. Different incident angles show important effects on both structural and optical properties. The effective medium approximation was employed to establish the relation between structure zone model (SZM) and EMA predictions. By increasing incidence angle the separation of metallic grains increases, hence the volume fraction of voids increases. That is in agreement with AFM analysis. The predictions of Drude free-electron theory are compared with experimental results for dielectric functions of these nano layers. There is a good agreement between our optical results and Hangman's optical results for a bulk standard Cu sample.     

胆甾相液晶电控螺旋畸变导致的布拉格反射特性

研究了平面织构胆甾相液晶在垂直于螺旋轴方向施加电场后,引起螺旋畸变导致布拉格反射光强度变化特性,利用液晶矩阵光学,琼斯矩阵法与Matlab矩阵计算软件对有螺旋畸变情况下的布拉格反射光谱特性进行了分析和数值计算.从数值计算和实验结果可知,胆甾相液晶在其垂直螺旋轴方向施加不同电压电场时,布拉格反射光中心波长不随电压改变,而布拉格反射光强会随电压的增大而减弱.提出一种电致螺旋畸变模型,对实验结果和数值计算结果给出了合理的解释,认为利用电场改变胆甾相液晶螺距进而设计电控颜色变化液晶器件的原理是不可靠的.     

太阳光对液晶显示器件光学特性的影响

太阳光对液晶显示器件的影响主要表现在它对其液晶显示器件光稳定性和寿命的影响,从而引起液晶显示器件的迅速老化。通过用分光光度计测量经过不同时间太阳光辐照后液晶显示器件的光谱特性,研究长时间阳光辐照对液晶显示器件的光学性能的影响,分析其光学性能的变化。结果表明, B组普通计算器液晶显示器和C组电话液晶显示器两组液晶片的光学特性类似,品质较好;而A组台式计算器液晶显示器液晶片的老化问题明显比B, C两组严重,品质较差。液晶显示器件长时间受阳光辐照,液晶结构会相应发生变化,光学性能也发生相应变化,表现为液晶表面变黄发黑,其光谱透射特性明显下降。这与液晶材料及制作工艺有关。     

Industrial resin inspection for display production using automated fluid-inspection based on multimodal optical detection techniques

The large-scale liquid-crystal display (LCD) industry requires an accurate inspection system for identifying defects, as the LCD quality can be drastically degraded because of defects. In particular, the refractive index of LCD panels can be changed by internal micrometer-range substances, which form as a result of defectiveness and the insufficient solidification of industrial liquid resins. Intrinsically, the defect inspection of the raw materials must be performed prior to the LCD manufacturing process. Thus, optical coherence tomography (OCT) based automated fluid-inspection (AFI) methodology was introduced to demarcate and enumerate the defects in industrial liquid resins and the final product (LCD smartphone). The accuracy of the method was enhanced by implementing an intensity-detection algorithm. Subsequently, the optimal solidification rates of liquid resins were investigated using a fluorescence sensor-based ultraviolet hardening method to prevent the formation of defects between the internal layers of the LCD panel. Therefore, AFI can be implemented as an effective and cost-saving method in the smartphone industry for improving the quality of the final product.     

消除自由立体显示串扰的定向背光源设计

定向背光柱透镜光栅式多视点自由立体显示器的串扰和亮度均匀性问题是影响其广泛应用的主要因素之一.本文通过分析串扰产生的原因,根据偏轴光线的成像光学原理,推导出液晶显示屏光开关板列单元与柱透镜组成的偏轴光学系统的参数计算式.提出一种液晶显示屏光开关蝶形单元结构,设计了采用该蝶形单元的定向背光自由立体显示背光源模组.模拟仿真结果表明:所设计的定向背光自由立体显示背光源可消除自由立体显示的串扰;在视点平面90%观看区域的串扰度小于0.5%,光束10%峰值宽度的串扰面积比γ=0,光束90%峰值宽度比普通液晶单元结构的增大37%,改善了不同位置观看图像亮度变化大的问题.     

动态目标模拟器用视景仿真镜头光学设计

研究一种基于液晶光阀的动态光学目标模拟器用视景仿真镜头,给出了视景仿真镜头的设计实例。动态光学目标模拟器由内置液晶显示系统、视景仿真镜头、外置投影仪、计算机、电缆、调整机构组成。测试设备将命令发送到计算机,计算机根据接收的指令生成模拟地形图并控制液晶光阀将图像显示出来,液晶光阀位于视景仿真镜头的焦平面位置,视景仿真镜头对液晶光阀成像后形成平行光出射,可在有限距离上产生无限远效果模拟观测结果,光学敏感器接受模拟器的出射光线并成像完成模拟试验,视景仿真镜头采用二次成像的反远结构,同时为保证与液晶光阀出射光相互匹配,采用了远心光路的结构形式。视景仿真镜头的焦距f=-22.447 1 mm,视场角是对角线视场为45,有效视场为301.5301.5;全视场畸边＜1％,在Nyquist频率42.5 lp/mm处MTF＞0.45,系统长度325 mm;视景仿真镜头与敏感器镜头配合后在敏感器像面上的照度均匀性不小于95.4％。最后给出了视景仿真镜头的测试结果。     

空间目标光学特性模拟实验研究

 通过不同材料、形状的空间目标模拟实验测量,研究了几种简单形状目标和卫星缩比模型的光学特性。结果表明：光源 目标 探测器的位置对目标的光学特性起决定作用,对于球体和柱体目标来说,光源和探测器的相位角是影响接收到光辐射的主要因素,而对于立体状目标,它的光学特性则与特定的入射角和观测角有关;对静止卫星而言,其光学特性主要受太阳能电池板对地夹角和观测面积的影响。该研究有助于实际观测数据反演空间目标的姿态,便于对空间目标特性数据进行归类和分发。     

腕部手厥阴心包经区域光传输特性的蒙特卡罗模拟

基于腕部手厥阴心包经循行区域的解剖结构,建立了腕部手厥阴心包经和旁开非经络线区域组织光传输结构的简化模型,并利用蒙特卡罗模拟的方法分别模拟了光在腕部手厥阴心包经、相邻肌腱以及旁开非经络线上的光传输特性。模拟结果表明,光沿腕部手厥阴心包经呈优势传输,与本实验室之前实验所得的结果相一致。分别计算了三个模型中各层的光通量情况,计算结果表明,腕部心包经循行区域的光传输特性主要受该区域的底层结构和底层组织成分影响,光在底层结构中也是沿腕部心包经呈优势传输的,并且该优势传输的现象与腕部心包经底层的筋膜间隙结构有关。     

Features of light transmission through monolayer of structurally identical anisotropic domains with random azimuthal orientation

Multidomain layers consisting of identical or nearly identical optically anisotropic domains with random in-plane orientation, manifest mixed, partly regular and partly diffuse transmission. In this paper, a simple theoretical model allowing the estimation of the ratio of the scattered and nonscattered components of the transmitted light as well as the polarization state of nonscattered component from optical parameters of a single domain is proposed. In particular, this model describes well the phenomenon of spectral selectivity observed on domain structures consisting of homogeneous birefringent domains. The results of experimental investigations of optical properties of multidomain LC layers, supporting the validity of the proposed model, are presented.     

Application of an LM-neural network for establishing a prediction system of quality characteristics for the LGP manufactured by CO2 laser

The light guide plate (LGP) is a part of a backlight module, which evenly spreads light sources in a liquid crystal display (LCD) to eliminate total reflection. Light is transmitted into the LGP, where it is reflected, scattered, and refracted due to the microstructure, which allows light to uniformly enter the panel. Therefore, the design of an LGP micro-structure and processing mode is important for light transmission in an LCD. This study used a CO₂ laser to fabricate a polymethyl methacrylate (PMMA) LGP, applied a Taguchi orthogonal array to set up the experiment, and utilized the data to establish a prediction system. Backpropagation (BP) neural network and the Levenberg–Marquardt (LM) algorithm were integrated to establish a prediction system for LGP processing by CO₂ laser, with the controlling factor as the input parameter, and quality characteristics as the output parameters. After learning and training the network, the prediction error rate of the system was controlled within 5%, demonstrating good predictive validity.     

Optical properties of multilayered Period-Doubling and Rudin-Shapiro porous silicon dielectric heterostructures

To investigate the optical properties in quasi-regular porous-silicon-based dielectric Period-Doubling and Rudin-Shapiro multilayer systems, we study here the reflection of light from these structures. The Period-Doubling and Rudin-Shapiro structures are fabricated in such a way that the optical thickness of each layer is one quarter of 600 and 640 nm respectively. We find that porous silicon Period-Doubling dielectric multilayers could demonstrate the optical properties similar to the classical periodic Febry–Perot interference filters with one or multiple resonant peaks, but with an advantage of having total optical thickness much lesser than the periodic structures. Additionally, light propagation in porous silicon Rudin-Shapiro structures is investigated for the first time, both theoretically and experimentally. The reflectance spectra of the structures exhibit photonic band gaps centered at predetermined wavelengths. In both cases, numerical simulation of light transmission is performed using transfer matrix method.     

Phase Modulation Characteristics Analysis of Optically-Addressed Parallel-Aligned Nematic Liquid Crystal Phase-Only Spatial Light Modulator Combined with a Liquid Crystal Display

An optically addressed parallel-aligned nematic-liquid-crystal spatial light modulator (PAL-SLM) has been studied as a dynamic phase-only light modulation device. The phase modulation characteristics of the PAL-SLM using a liquid crystal display (LCD) as an addressing mask were investigated by analyzing diffraction efficiencies resulting from binary gratings projected from the LCD. A more than 2π phase-only modulation depth was achieved. The highest first-order diffraction efficiency of approximately 38% was also obtained; this is close to the theoretical limit. The experimental results of diffraction efficiencies depending on the phase modulation depth are in good agreement with the simulation for the system operation.     

加固机载TFT-LCD的温控技术研究

论述加固机载TFT-LCD设计中温度控制技术所涉及的问题，实现了机载TFT-LCD显示器在-43℃至71℃的范围内正常工作。在研究TFT-LCD特点的基础上,提出了利用ITO膜加热液晶模块以及采用加热丝加热背光源CCFL灯管的加热方式，设计了加热电路的方法，从而确保了机载TFT-LCD在低温环境下的启动和正常工作。基于热设计的基本方法，分析并提出了加固机载TFT-LCD高温工作时的散热解决方案。作为一个自动温控系统，扩展了机载TFT-LCD的工作温度范围。在实际设计中获得了满意的效果。     

Anomalous transmission of terahertz wave through one-dimensional lamellar metallic grating

The anomalous transmission through one-dimensional lamellar metallic gratings was investigated in terahertz (THz) regime. The extraordinary optical transmission (EOT) is identified to originate from two possible ways: coupling of incident light with waveguide resonances and coupling of surface plasmon polaritons (SPPs) at the upper and lower interfaces of metal grating. The dual effects of SPPs have been clarified in this study: (i) the excitation of SPP modes at each individual interface results in the weakness of the THz wave transmission; and (ii) the coupling of SPP modes at two interfaces of metal grating is attributed to enhancement of THz wave transmission. The enhanced transmission is dominated by the coupling of incident light with transverse waveguide resonances. Numerical simulation based on finite-difference time-domain (FDTD) agrees well with experimental results.     

新型自动立体显示背光板的光学设计

立体显示技术的研究主要是解决虚拟现实领域的三维视觉问题。自动立体显示是不需要配戴特殊眼镜的,使用一个二维平面空间显示屏显示至少一对满足双眼视差的立体图像。当人的双眼接受到具有视差的立体图像对时,在视网膜上形成视差像,经大脑神经系统的融合,从而产生深度感。提出了一种全新的实现自动立体显示的折射式方法,设计了基于此方法的一种新型折射式的、结构简单的、通过透射显示屏(如液晶显示屏)实现自动立体显示的背光系统。根据视差立体显示参量模型,建立了光学系统的结构参量以及分析了光学材料的性质对实现立体显示的影响,并运用先进的光学设计软件进行设计、模拟。     

Computational analysis of metamaterial–aluminum–silicon solar cell model

In this paper, the optical parameters of an improved waveguide structure for a more efficient silicon solar cell are studied. Despite its favorable electronic, physical, and chemical properties, silicon remains a poor absorber of light. The optical losses due to the reflection at the air/glass interface of the cell and the transmission at its back are other factors, which limit the cell conversion efficiency. Consequently, several mechanisms for light trapping capable to increase the collection of the incident photons as electrical current and to decrease the transmission loss, have been developed. In this context, we propose a multilayer waveguide structure in which the sunlight is guided by a metamaterial layer and the transmission loss is eliminated by an aluminum back reflector. The reflection and transmission coefficients are derived by using the Generalized Transfer Matrix Method. The application of the law of conservation of energy allowed the determination of the absorption coefficient. These optical parameters are examined for several angles of incidence for s-polarized light, p-polarized light and unpolarized light. Simulation results show a significant reduction of reflection and a complete suppression of transmission.     

A Color Holographic Reconstruction System by Time Division Multiplexing with Reference Lights of Laser

3D-TV systems by holography technique have been studied in the world. In this paper, we report a color holographic reconstruction system by time division multiplexing method with reference lights of laser. The method can reconstruct a color holographic image by switching reference lights of red, green and blue colors at certain intervals. We can observe a color holographic image using red and green lasers as the reference lights, a high minute liquid crystal display (LCD) panel as a spatial light modulator (SLM) and electro-shutters as the shuttering device of the laser lights in the optical system. This approach has some advantages. Namely, the structure of the optical system can be simple and the number of LCD panels in the optical system can be decreased.