Recently, the novel development of light guide is V-cut light guide which integrate the micro-prisms on the top and bottom surface of the light guide. Although the V-cut light guide can use the energy of light source efficiently, its uniformity is lower than the traditional scattering dots light guide. Therefore, the purpose of this study is to improve the low uniformity phenomenon of V-cut light guide. First, this study designs three micro-structures on the bottom surface of light guide, and analyzes the influences of shape and geometric parameters of each micro-structure on the luminous flux enhancement. Then, on the top surface of light guide, the micro-lens are modeled which includes the scattering characteristic of diffuser in order to improve the backlight uniformity. It can achieve the effect of diffuser does through the design of scattering micro-lens, so it can save the cost of diffuser. Finally, the integrated design of 7 inches light guide and diffusion structures was simulated by using commercial software LightTools, and the result shows that the backlight uniformity can achieve 90.6%.

LGP( Light Guide Plate) is the important part of the BLM(Back Light Modulus). It makes the BLM high illuminance and uniformity with leading light direction. LED(Light Emitting Diode) is the light source of the BLM. In this study there are V-Cut of the micro-structure applying on the LGP to discuss and research with optical simulation software TracePro. A 2.5 inch BLM with LED is building to analysis. First, the beginning side of the LGP has been studied with V-Cut. The purpose is making the distribution angel larger and upgrading brightness. Then, with the V-Cut micro-structure on the out-light surface and optical sheets get the largest light availability ratio. Finally, the reflect surface divides to five parts with different pitches design. The results show the good benefit by more uniformly light distribution and illuminance.

In this study, the optical simulation software Light Tools was executed to reduce the LED amount used by improving the performance of light guide plate of backlight module with LED illuminator. The improvement of the design including: 1.replacing the V-cut microstructures on the lower layer of the light guide plate by the micro-semispherical lens structures;2.replacing the diffusion film by the micro-semispherical lens structures on the upper layer of the light guide plate ; 3.adding the lateral microstructure on the light guide plate to reduce the dark-area phenomenon. The sizes of upper/lower microstructures, their spacings and the amount of LED were selected as the parameters and applying L18 orthogonal array to process the simulations firstly. Then integrating different kind of lateral microstructures to find the best uniformity, and obtain a set of parameters that could improve the performance of backlight module and then the amount of LED can be reduced. The results show that the uniformity of backlight module is over 88% without diffusion film which have overcome the requirement of 85% in traditional design with 2 diffusion films. This improvement not only reduces the cost from diffusion film, also removes the dark-area phenomenon. Additionally, the amount of LED is reduced to 45 from 48 that retrench about 7% of power. Energy and cost are saved simultaneously.

This master’s thesis describes the using of hollow light guides for inner-space lightning. The project describes the legislation requirements for the inner-space day lightning. The usages of hollow light guides are also discussed. Other goal of the project is to describe computer programs, which are modeling the function of hollow light guides. The practical part of the thesis is describing the process and the results of the measuring, which was done on a model of a family house with hollow light guides.

Microstructures are usually fabricated on the surface of optical sheets to improve the optical characteristics. In this study, a new fabrication process with UV (ultraviolet) laser direct writing method is developed to embed microstructures inside the glass. Then the optical properties of glass such as reflection and refraction indexes can be modified. Single- and multi-layer microstructures are designed and embedded inside glasses to modify the optical characteristics. Both luminance and uniformity can be controlled with the embedded microstructures. Thus, the glass with inside pattern can be used as a light guide plate to increase optical performance. First, an optical software, FRED, is applied to design the microstructure configuration. Then, UV laser direct writing with output power: 2.5~ 2.6 W, repetition rate: 30 kHz, wave length: 355nm and pulse duration: 15ns is used to fabricate the microstructures inside the glass. The effect of pattern dimension such as the pitch, the layer gap, and the number of layer on the optical performance is discussed. Machining capacity of UV laser is ranging from micron to submicrometer; hence various dimensions of dot, line width, and layers can be easily embedded in the glass by one simple process. In addition, the embedded microstructures can be fabricated less damage and contamination. Finally, the optical performance of the glasses with various configurations is measured by using Spectra Colorometer (Photo Research PR650) and compared with the simulated results.

Halogen lamps are mostly applied as a light source to the traditional lamp for medical treatment due to its proper color temperature, but it has its disadvantages such as ultraviolet rays and infrared rays which will be harmful to the patients and faculties in the hospitals under long-term exposure. Consequently, using light emitting diode(LED) as a new light source instead of the traditional halogen lamp will be the trend of the future. The purpose of this study is to design a projective LED dental lamp that can achieve the goals of 200mm¡Ñ100mm for light shape and 11000lux illuminance energy by using the optics simulation software, LightTools. Firstly, a single LED lamp module with a high focusing hollow tubular light guide structure was designed and developed comparing with the solid light guide structure used in many commercial projective dental lamp, the hollow tubular light guide structure can decrease illuminance energy lose due to the absorption by tube material. Because the required objective light shape could not be achieved by using the designed light guide structure only, so a lens component was adopted and designed in order to shrink the output light shape to the required size. Finally, through the specific arrangement of position and angle of each LED lamp module, a projective LED dental lamp with 9 LEDs lamp modules which conform with the required illuminance energy was proposed.

Inspection of LCD light-guide plate using digital image processing is proposed. Binary dot-pattern images from SEM observation are obtained by image segmentation. Pattern recognition for the images is then performed using moment invariants, Bayes classifier, and Neural network. The rotation independent classification for the recognition using only one descript shape factor are also proposed to reduce storage space. It is found the method has been applied successfully in inspection of different defects on the plate subject to any rotation angles and image scales.

Liquid crystal display (LCD) has been widely used as an important human interface with typical portable devices such as notebook-type computers, digital camera and cell phones, etc. The LCD panel does not emit light spontaneously, and thus it needs a surface backlight source. The function of light guide plate (LGP) was to guide light from a light source and radiates it homogeneously from all over its output surface. In this thesis, the research object was focused on this optical component. This thesis mainly concludes two major parts. The first part focused on the design of cold fluorescent lamp (CCFL) light source LGP. If the bottom structure of the LGP in a backlight module was made up of V-Cut micro-structures, then conventionally, the shape and spacing between any two adjacent columns of micro-structure should be designed specifically in order to obtain a more uniform illuminance distribution. It was required to apply complicated mathematics and cost a lot of time to design. In this study, a simplified bottom structure of the LGP was proposed. The considered bottom structure of the LGP was proposed to be made up of same shape high energy V-Cut micro-structures, and the spacing between any two adjacent columns of the micro-structure was also the same. The design parameters were determined by using optimization technique. Also, the LCD design time could be reduced. In order to eliminate the dark region phenomenon caused by the proposed simplified bottom structure of the LGP, a simple new type of edge structure of the LGP was proposed also. The proposed simplified LGP design concepy has many merits, such as only three design parameters needed, manufacturing easily, the design time can be reduced, and can prevent the consumption of light source energy between the gaps of CCFL and LGP. The proposed design concept was applied on the design of 7 inches, 15 inches and 20 inches of backlight module (BLM). Through the numerical simulation by utilizing commercial software Light Tools, it can be shown that more than 80% of uniformity can be easily obtained. The second part focused on traditional dot pattern bottom structures. As the same concept mentioned in the first part, the proposed dot pattern was made up of same geometrival shape of dots, and the spacing between any two adjacent columns of the dots was also the same. The design parameters were determined by using optimization technique. The proposed design concept of the dot patten distribution can be applied on the design of LGP with either LED or CCFL light source. Also, the dark phenomenon did not occur, and so the corresponding edge structure did not need either. The proposed design concept was applied on the design of 7 inches, 15 inches and 20 inches of BLM with CCFL light source and on the design of 7 inches of BLM with LED light sources. The optical simulation results showed that about 90% of uniformity can be easily obtained.

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