Generally, the lumens of projectors used in classrooms are below 3000. Therefore, in order to ensure the visibility of the screen, teachers often need to pull up the shading curtain to reduce the illuminance of the ambient light in the classroom. However, this has caused a decrease in the illumination of the students’ desktops. When the students’ eyes are repeatedly switched between the desktop and the screen, it is equivalent to repeatedly switching between the dark field and the bright field.
And after the projector is used for a period of time, the lens aging, lens dust and other reasons will cause the projected image to be blurred. Students need to repeatedly adjust the focus of the lens and ciliary muscles when watching, which is more likely to cause visual fatigue.
On the other hand, the interactive smart tablet uses a built-in backlight, which is a direct light source. The surface brightness is between 300-500nit and is not greatly affected by the ambient light source. There is no need to reduce the ambient light brightness during actual use, which ensures that the student desktop has A bright reading environment.
In addition, the desktop illuminance is not much different from the front-screen illuminance, and the pupils change very little when the visual field is switched between the desktop and the screen, which is not easy to cause visual fatigue. At the same time, the service life of the interactive smart tablet can reach more than 50,000 hours. There is no need to replace bulbs and other consumables throughout the life cycle, and no dust removal is required. The screen definition and contrast can be guaranteed to be much higher than that of projection, and the color restoration is more realistic , Can effectively relieve eyesight fatigue.
Post time: May-14-2021