Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: A method for cleaning a wafer stage is provided. First, a wafer stage with a wafer thereon is provided. Second, a leveling scanning step is carried out to examine the evenness of the wafer. The wafer is removed from the wafer stage once an abnormal evenness is detected. Afterwards, a vacuum cleaner device is used to in-situ clean the surface of the wafer stage after the wafer is removed.

Abstract: A liquid supplying device includes: a first liquid supplying element, a second liquid supplying element inside the first liquid supplying element, a first driving element connecting to the first liquid supplying element, and a second driving element connecting to the second liquid supplying element. The first liquid supplying element contains a first liquid, and the second liquid supplying element contains a second liquid. Therein the first driving element and the second driving element selectively control the first liquid or the second liquid to spray out from the liquid supplying device. A method of using a liquid supplying device is also provided.

Abstract: A photoresist solution dispensing volume monitoring system comprises: a photoresist solution dispensing apparatus having a photoresist bottle storing photoresist solution; and a weight scale being installed at the circumferential surface of the photoresist bottle, the weight scale measuring the weight of photoresist solution within the photoresist bottle. Via this arrangement, the monitoring system can monitor the practical photoresist solution dispensing volume and the predefined photoresist solution dispensing volume. If the two volumes are not the same, an alarm message will be produced to inform users. So the users can immediately examine or repair the photoresist solution dispensing apparatus. This present invention further provides a photoresist solution dispensing volume monitoring method.