[The analysis of polarized display characteristic of LCLV].

The polarized TN effect of LCLV is discussed, and the twist of LC molecule with the AC voltage in LCLV is analyzed after its reorientation. While changing the applied voltage continuously at certain frequency, the twist angle of LC molecule in TB3639 LCLV and the electro-optical characteristic of the LCLV were measured. The results show that when the voltage is changed in series, the transmittance of the incidence linearly polarized light will alter continuously and nonlinearly, and the twist degree may control the nonlinear change. And the 1800 twist of the LC molecule will make the curve of electro-optical characteristic of the LCLV steeper, which allows multicenter matrix addressing LCLV to have more matrix lines and higher contrast.

[Study on electro-optical performance of frequency driven liquid crystal light valve].

The electro-optical characteristic and principle of frequency-driven liquid crystal light valve were discussed and analyzed. Under different electric field frequency and certain AC voltage, the electro-optical characteristic of frequency-driven TB3639 liquid crystal light valve was measured. The results show that it can display gray scale in visible light region, and it can not only display black and white, but also can display different gray scale. The influence of frequency-driven way to the transmission spectrum change tendency of different wavelength in visible light is approximately same, which will avoid high chromatism in application. The new frequency-driven liquid crystal light valve can improve display quality of liquid crystal display device. It will develop new application of liquid crystal display device and has practical application value.

[Study of LCD tricolor spectrum characteristic].

The electro-optical characteristic of TB3639 liquid crystal light valve under both voltage-drive and frequency-drive modes was measured using spectrophotometer, and the change in tricolor transmissivity with the two methods was analyzed. The result shows that the changes in tricolor transmissivity with these two methods are not identical, and color cast will appear, which will influence display quality. The change in tricolor transmissivity becomes more obvious with the changes in voltage in voltage-drive mode, in which the maximum difference is 11% and the minimum is 0. The change in tricolor transmissivity has better uniformity in frequency-drive mode and the difference of transmissivity is relatively small with the maximum difference of 4% and the minimum of 2.5. The color should be adjusted and compensated in order to get exact hue and color saturation, and this will help to study further for improving the performance of liquid crystal display.

[Analysis of LCD aging with polarized optical texture and transmission spectrum].

Light radiation experiment was done to a group of liquid crystal display devices, and the influence of light radiation on the display quality of liquid crystal display devices was studied. The changes in their polarized textures after light radiation were observed with a polarized optical microscope. Parallel stripe texture and black holes, which lost extinction function, appeared in liquid crystal texture. With the increase of light radiation time, more and more black holes result, and the area of black holes gets bigger and bigger. The authors tested the transmission spectrum with computer-controlled ultraviolet/visible light spectrometer, finding that the transmission rate declines with the increase of light radiation time. The results show that the appearance of stripe texture and black holes resulted from the changes in liquid crystal molecular structure after ultraviolet radiation, and the occurrence of black holes, which lost extinction function, is the main reason for the continuous decline of transmission rate.

[Influence of sun radiation on optical properties of liquid crystal display device].

Sunlight affects mainly the light stability and life of liquid crystal display device, which will lead to rapid aging of the device. By measuring the optical properties of liquid crystal display devices radiated with different time by spectrophotometer, the influences of long time sunlight radiation on the optical properties of the device were studied, and the changes of its optical properties were analyzed. The results indicate that structural and optical properties of liquid crystal slices of calculator LCD (B group) and telephone LCD (C group) are similar and the qualities are relatively good, while the aging problem of personal computer LCD (A group) liquid crystal slice is more serious than those of B and C groups, moreover, the qualities of liquid crystal slices in A group are worse. The structural and optical properties of liquid crystal display device will change accordingly after long time sunlight radiation. The surface of liquid crystal display device will become yellow and nigrescent, and the spectrum transmission properties will decline markedly, which is related to liquid crystal materials and manufacturing techniques.

[Analysis of spectral properties of car solar films].

A dual-beam ultraviolet/visible spectrometer (UV-Vis 8500) automatically controlled by computer was used to measure qualitatively and to analyze the spectral properties of car solar films of a certain brand in the market. The experimental results indicate that transparency characteristics of the ordinary series of solar films are well, but their violet insulation and heat insulation properties are moderate, and moreover, their thermal-proof property is not ideal. The heat insulation, violet-proof and transparency properties of the anti-crack series are all in normal level. The heat insulation and transparency properties of anti-crack and anti-wear series are moderate, however, their violet insulation characteristics are better than those of other series mentioned above. For the super front film, its transparency property is excellent, moreover, its violet insulation and heat insulation properties are quite well. In general, it can be concluded that the super front series are the best car solar films.

[Study on photoelectric dispersion characteristic of liquid crystal light valve].

The electro-optical properties and dispersion characteristics of a liquid crystal light valve (LCLV) were investigated. A 90 degrees twisted light valve (model TB3639) was used as a typical LCLV in the authors' experiment. At 27 degrees C and a fixed frequency of 1000 Hz, the transmitted light intensities (T) of the LCLV were measured as a function of wavelength (lamda) at different applied voltages. From the measured T-lamda curves, the dependence of contrast ratio k on the wavelength can be derived. The authors' results showd that the TB3639 LCLV has a comparatively high contrast ratio and low dispersion within the visible region. In the range of 450-750 nm, the contrast ratio, with its value higher than 0.8, does not change much with the wavelength. Particularly the contrast ratio is higher than 0.95 with a minimum dispersion in the range of 550-670 nm.

[Analysis of chromaticity and spectral properties of car solar films].

Chromaticity and spectral properties of the ordinary car solar films of a certain brand in the market were qualitatively measured and analyzed with WGS-9 chromaticity analysis system, UV-Vis 8500 double-beam ultraviolet/visible spectrometer and WGD-4A grating spectrometer. The result shows that getting low infrared/ultraviolet transmissivity and high visible light transmissivity at the same time is impossible, so only one aspect can be fulfilled when we choose solar films. Solar films with main wavelength 587.3 nm (Cambridge blue) and 522.1 nm (diamond green) should be chosen if we want to get high visible light transmissivity and low ultraviolet transmissivity. Solar films with main wavelength 497.3 nm (diamond blue) and 507 nm (emerald green) should be chosen if the authors want to get high visible light transmissivity and heat insulation function.

[Analysis of spectral properties of novel holographic transmission notch filter].

Optical filter has extremely important applications in spectroscopy, optical measurement and laser physics. Holographic filter, especially the transmission volume holographic notch filters using dichromate gelatin (DCG), is a new kind of filter with the main characteristic of a very narrow bandwidth. In this paper, measurements were carried out on the spectral properties of this transmission volume holographic notch DCG filter using an ultraviolet-visible transmittance spectrometer. The experimental results show that the relative transmittance of main spectrum of this filter is less than 2% in the visible region between 400 and 800 nm, and the relative transmittance of other spectra are more than 85%. Moreover, the filter has a narrow bandwidth with a half-bandwidth less than 12 nm, and a 1/10 width of the bandwidth less than 15 nm. These results indicate that this new kind of filter has an excellent filter characteristic to the main spectrum of Ar+ laser at the wavelength of 514.5 nm.

[Analysis of spectral properties of oil matrix raw materials in skin care products].

There are many kinds of oil matrix raw materials used in skin care products. Their spectral properties are different. The matrix raw material that has better ultra-violet absorption will enhance the sun-screening agent effect obviously. In the present article the spectral properties of six oil matrix raw materials often used in skin care products were mainly measured and analyzed by spectrophotometer. The analysis of T-lambda spectra shows that castor oil can absorb ultraviolet as well as near infrared light. It was shown that castor oil chosen as the matrix raw material will improve the effect of sun-screening agent and enhance the products. The function of sun-screening agent and skin health care product will stand out clearly.

[Study on spectral properties of natural plant ultraviolet absorbent].

Natural plant ultraviolet absorbent is a safe cosmetic-typed ultraviolet additive, with no side-effect and bright future. Natural plant ultraviolet absorbent is ground from ultraviolet absorbing plant into organic solvent under dry-vacuum condition. This new type of ultraviolet absorbent has brown colour in solid form, but when it mixes with alcohol and water, its colour changes to light yellow in liquid form. This paper focuses mainly on using ultraviolet/visible spectrometer to examine its spectral properties under ultraviolet light. The result shows that this absorbent has a relative transmittance below 0.2% in the UVC and UVB zones, while in the UVA zone around 375 nm, the value raises up only to 2.1%. This concludes that the natural plant ultraviolet absorbent has a high absorbing ability under ultraviolet light and can withstand ultraviolet light with long wavelength.

[Study on spectral properties of Chinese herbal medicines additives in cosmetic].

Chinese herbal medicines as additives in cosmetic can both keep the properties of cosmetic and have maintaining, health protection and remedial effect. Some of the Chinese herbal medicines can absorb ultraviolet and cure sunburn. This article mainly studies the spectral properties of several kinds of Chinese herbal medicine additives in cosmetic by ultraviolet and visible spectrophotometer, and analyses the ultraviolet absorption of the Chinese herbal medicine additives. It was shown that gynostemma pentaphyllum can absorb ultraviolet very well. It can be a promising natural additive in the health protection cosmetic. Codonopsis pilosula, floss chrysanthemum indicum, radix scutellariae and radix glycyrrhizae can absorb ultraviolet. They can also be the additives, while ligusticum wallichii can't absorb ultraviolet, so it can not be used as the sunburn protection additive.

[Analysis of anti-ultraviolet characteristic of liquid-crystal display].

As liquid-crystal display is developing to be used outside and becomes colorful and larger, the influence of ultraviolet on liquid-crystal display is becoming more and more apparent. And the anti-ultraviolet character of liquid-crystal display becomes more important. In this paper, the spectroscopic characteristics of ITO glass and polaroid were measured with ultraviolet of various wavelengths. By comparing the ultraviolet transmission spectrum of normal polaroid (LN-1205T) with that of anti-ultraviolet polaroid (F-1225DU), the anti-ultraviolet characteristic of a new style liquid-crystal display (LCD) was discussed. And the results show, the anti-ultraviolet polaroid (F-1225DU) is better in the absorption of ultraviolet. The anti-ultraviolet polaroid (F-1225DU) can enhance the performance of liquid-crystal display used outside.