With the gradual popularization of multimedia teaching and the acceleration of education informatization process, using projection equipment auxiliary teaching in schools has become more and more common,What kind of projection equipment have a better quality, more suitable for classroom use ,National digital audio and video and multimedia products quality supervision and inspection center recently released the performance analysis report about the health&safety impact in the field of education raised by LCD (LCD) projection and flat-panel display (FPD) system .
According to introduction,relying on the national digital audio and video and multimedia products quality supervision and inspection center testing platform,simulate the state of students' classroom, geared to the needs of education field, Report taken the LCD (LCD) projection and flat-panel display system as the main research object,Through the blue light energy,flicker, working noise,brightness attenuation, contrast, brightness perspective, index of energy efficiency and other indicators,and they do relatively comprehensive analysis of the performance of the system for health and safety.
As an important part of education informationization, electronic whiteboard's interaction function is increasingly applied to the teaching process.while it's more efficent in dealing with real-time and convenient but also bring health and safety problems,especially the negative effect on the eye is unable to ignore.according to a survey done by Chinese Education Department:we have more than 400million myopia patients,Teenagers has become a "disaster zone",Pupils myopia rate over 40%,middle student 70%.
It is understood that blue light energy is used to test the strength of different display devices blue-ray radiation energy,the higher blue light energy is,the more tired human eye feels after a specified long time,the bigger damage to the human eye;Blinking is used to test the scintillation degree between different display equipment,Flashing more serious,stronger the eye fatigue is; the lower the noise value is, the less discomfort it will be; contrast test is to test the black&white color ratio of different display equipment under the conditions of various testing conditions,including the white and black ratio and contrast of checkerboard,to measure the characteristic of contrast;
Visual angle is to detect the visual angle of display devices from different distances, the size of visual angle can decide students at different position of the classroom can see the same teaching content, the bigger the perspective is,the better the students can see;
The energy efficiency index is the ratio of the power consumption, the brightness and the display size
of the display device in the display of different contents.
The test results in the report show that:in the aspect of the blue light energy index, FPD blue light energy is higher than the projector, about 3 times the projector Blue ray energy, 1.5 times and 3 times,respectively, the long-time use of FPD has about 2 times probability of damage to the eye than the use of the projection system.
The scintillation index is much higher than that of the two FPD system,it feels less tired after the samelong-time view of projection system compared to the FPD system .More prone to fatigue caused by flashing, work noise indicators, the two kinds of display system of the working noise is less than 1dB, the human ear is more difficult to distinguish, are acceptable in the ideal range.
In addition, the brightness attenuation index, brightness projection system attenuation is the smallest, the average attenuation is less than FPD; contrast index, black and white contrast, projection system is much higher than that of FPD System, checkerboard contrast, FPD system slightly outperforms the projection system, but practical application, picture contrast above 50:1 can, so levels, mutual advance and retreat; perspective,
The shadow system at different distances and different angles of the brightness is basically the same, the whole process without dead angle, FPD display system visual angle between 40 degrees to 60 degrees, energy efficiency index, the projection system is relatively a Like flat panel display system has the advantage.
（Link：http://epaper.cqn.com.cn/html/2015-09/11/content_44064.htm?div=-1）
