Reading Lamps, Parameter Assessment Model Based On Visual Ergonomics

Reading lamps are very popular in Chinese markets, with various light sources and optical designs and other characteristics. Nowadays many so-called visual protective reading lamps emerged, and it was advocated that these lamps have the optimized parameters to increase visual comfort and release eye fatigue, which attracts many users, especially students. However, up to now there is few suggestion or specification about the parameters for visual comfort of reading lamp. The quality of reading lamps on the market varies in a wide range, and users tend to feel confused when purchasing them. Among the research on lighting and visual comfort, only a few of them focused on the parameters of reading lamps, and a model for the evaluation is not established. It is very important to establish a model to give a general evlaution of the visual quality of reading lamps, so as to make supplement to the existing specification of reading lamp, to testify the quality of the reading lamps on the markets, and to provide suggestions for the users when purchasing.In the thesis, ergonomic experiments were conducted to study the key parameters of reading lamps that have effects on the visual quality. They were illuminance, Correlated Color Temperature, glare and color quality. The results showed that visual performance increase with illuminance level as well as color temperature; By reducing the reflected glare, the visual contrast of target and background was improved and with the same illuminance level, people's perception of glare reduced; CRI and CQS cannot reflect people's perception of color difference exactly, and cannot evaluate people's preference of color. Based on the experiment results, a model was developed to evaluate the visual quality of reading lamp. In the model, there are three parts, and they are illuminance-CCT (including the effects of illuminance and CCT on performance and preference and the effects of illuminance uniformity), glare (including direct glare and reflected glare) and color quality. In order to testify the effectiveness of the model,6 sample lamps were picked from the existing reading lamps on market. Their physical parameters were measured and evaluation was given based on the model. Meanwhile ergonomic experiments were also conducted to rate their visual comfort. The rating of visual comfort turned out to be in accord with the evaluation from the model.