Report from our correspondent (reporter xu) 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, exactly the sort of projection equipment quality better, more suitable for classroom use? National digital audio and video and multimedia products quality supervision and inspection center of the recently released "LCD (LCD) projector and flat-panel display (FPD) health and safety in the field of education and system performance analysis report (hereinafter referred to as reports) showed that both health and safety and performance of the system, projection system is better than that of the flat display system.
According to introducing, relying on the national digital audio and video and multimedia products quality supervision and inspection center testing platform, simulation, students' classroom scene oriented education field, report to the LCD (LCD) projection and flat-panel display (FPD) system as the main research object, through the blue light energy, flicker, working noise attenuation, contrast, brightness, view, index of energy efficiency and other indicators, for health and safety, relatively comprehensive analysis of the performance of the system. The objective test shows that the comprehensive evaluation of the projection system is better than the flat-panel display system in the education field.
The national medium and long-term education reform and development plan outline (2010-2020), "pointed out that to accelerate the construction of education information infrastructure" and "built in 2020, the basic system covering urban and rural schools of various levels of education informatization, promote education content, teaching means and methods of modern". As an important part of education informationization, electronic whiteboard, etc have interaction function display system is increasingly applied to teaching, to solve the real-time convenient also bring health and safety problems, especially with eye health more nots allow to ignore. According to the ministry of education survey data, China has more than 400 million myopic patients, teenagers have become "disaster areas", the myopia rate among primary school students is over 40%, middle school students up to 70%.
The report, the authors of national digital audio and video and multimedia products quality inspection center engineer Hu Peng said, in the field of education teaching, the application of various display system for the influence of students' health and safety of audience moot. This objective test is based on the evaluation platform of national digital audio and video and multimedia product quality supervision and inspection center, and simulates students in the classroom.
It is understood that the blue light energy is the strength of the detection of the blue radiation energy of different display devices. The higher the blue ray energy value, the greater the possibility of prolonged viewing of the human eye injury. The scintillation is to detect the flashing degree of different display devices. The more severe the flashing, the stronger the weariness of the human eye will become, and the more fatigue it will be. The lower the working noise value, the lower the discomfort will be. Contrast is to test different display devices in a variety of different test illustrations ratio under the condition of white and black, including on-off ratio (white/black contrast) and checkerboard contrast two kinds, from various angles to measure contrast features; Perspective is to detect the brightness of the display device in different distance from different visual Angle, its size to determine whether the classroom different position of students to be able to see the same teaching content, the greater the Angle, the better for students; The energy efficiency index is the ratio of power consumption, brightness and display size of the display equipment when displaying different contents.
Report of the test results show that the blue energy indicators, FPD blue energy overall higher than that of the projector, about 3 times of the projector light energy, respectively 1.5 times and 3 times, the probability of using FPD to cause damage to the human eye is to use about twice the average of the projection system; In the aspect of scintillation index, the scintillation energy of the two FPD systems is much higher than that of the projection system, and the long term viewing of the FPD system's relative projection system is more likely to generate the fatigue caused by flicker. In terms of work noise indicators, the noise difference between the two display systems is less than 1dB, and the human ear is more difficult to distinguish, which is in the acceptable range.
In addition, in terms of brightness attenuation index, the brightness attenuation of the projection system is minimum, and the average attenuation is less than that of FPD system. Contrast indicators, black and white contrast, far higher than that of FPD projection system, contrast of checkerboard lattice, FPD system is slightly better than the projection system, but in practical application, contrast ratio in than 50:1, therefore both the same, with each other in a; Angle of view, the brightness of the projection system in different distance from different angles, no dead Angle, when watching in FPD display system can perspective in 40 ° to 60 ° between; On the energy efficiency index, the projection system has an advantage over the general flat-panel display system.
