Abstract: A method for controlling ON/OFF of LED in a scanner which replaces CCFL with LED as a light source is provided so as to solve the problem of excessively long warm-up time of CCFL in the prior art. Meanwhile, to achieve intermittent heat dissipation, LED is switched ON/OFF according to the frequency of the scanner receiving optical signals.

Abstract: A method of coating photoresist is provided. A wafer is first provided and a spouting site is set up in a location within the circumference of the wafer. The spouting site is disposed at a distance from the center of the wafer. Next, the wafer is spun and a solvent is simultaneously dispensed on the spouting site. After that, photoresist agent is dispensed to the center of a wafer through a spout and then the photoresist agent and the solvent are spun around to spread out. Because a ring of solvent is dispensed on the wafer before spouting photoresist agent at the center of the wafer, the photoresist agent will be diluted when the photoresist agent and the solvent are being spread out. As a result, the layer of photoresist outside the original circle of solvent is thinner than the layer of photoresist inside the circle.

Abstract: A method for controlling ON/OFF of LED in a scanner which replaces CCFL with LED as a light source is provided so as to solve the problem of excessively long warm-up time of CCFL in the prior art. Meanwhile, to achieve intermittent heat dissipation, LED is switched ON/OFF according to the frequency of the scanner receiving optical signals.