When writing desk lamp is in normal working position, the main optical performance requirements are three points
People in the normal posture, the eyes to the horizontal direction, should not see the shade of the inner wall and light source;
(2) Desktop illuminance requirements
The working area of lamp illumination should be 250lx-500l, the minimum illumination should be ≥ 120LX.
(3) Uniformity of illumination requirements
Should ensure that the work area illuminated by the lamp, the illuminance is relatively uniform, can not produce special bright or dark spot, only to ensure that these three points of basic optical performance requirements, can slow the eyes fatigue, can be called a desk writing table lamp.