It is known that the illumination requirement is dependent on the visual qualities of the subject being illuminated and appropriate lighting can enhance human experience and make the task at hand easier to perform. For example, bright light is better for reading, soft warm light is better for resting, etc.
In the area of desk lighting, some of the relevant literature recommends a task-area-to-background contrast ratio of 10:3 for providing eye protection and eye comfort. However, this recommended “comfortable” contrast ratio does not consider the need to improve the working efficiency of desk lamp users.
US2007/0258243A1 provides a lighting system for delivering dynamic, fully customized and automatic illumination to a subject. The provided lighting system can adjust the pattern and spectra of light generated by a light source, on the basis of detection information on a target area detected by a sensor pad. However, US2007/0258243A1 fails to point out the relation between work efficiency and comfort of a user's eyes, and therefore fails to give the solution of adjusting the illumination with a view to working efficiency and eye comfort.
There is a need to provide a luminaire, taking into consideration both the requirements of improving working efficiency and maintaining eye comfort.