Abstract: A folding lens system includes: a polarization-dependence device, a first optical device, a first polarization controller, a second optical device and a second polarization controller. The polarization-dependence device has a first surface and a second surface opposite to the first surface. The first optical device is located at a side facing toward the first surface of the polarization-dependence device. The first polarization controller is located between the polarization-dependence device and the first optical device. The first polarization controller has the same curvature as the first surface of the polarization-dependence device. The second optical device is located at a side facing toward the second surface of the polarization-dependence device. The second polarization controller is located between the polarization-dependence device and the second optical device. The second polarization controller has the same curvature as the second surface of the polarization-dependence device.

Abstract: A mounting device for a filter has a distributor and a connecting member. The distributor has a base and a tube. The base has a top surface, an annular surface, a tube mount formed in the top surface and an outlet formed radially in base and communicating with the tube mount. The tube is mounted in the base, communicates with the tube mount and has a proximal end, a distal end, an outer surface and multiple through holes formed through the outer surface of the tube. The connecting member is mounted on the distal end of the tube and has a sealing segment mounted on the distal end of the tube. Therefore, the mounting device can precisely position a filter element and prevent the filter element from damage.

Abstract: A water remover for an air compressor system has a housing and at least one baffle mounted in the housing to define a tortuous air-flowing channel in the housing. Accordingly, the moisture in the high-pressured air will condense on the surface of the housing and the baffle when the air flows through the tortuous channel. Only little power is needed for the operation of the water remover, and the structure of the water remover is simple.

Abstract: A water remover for an air compressor system has a housing and at least one baffle mounted in the housing to define a tortuous air-flowing channel in the housing. Accordingly, the moisture in the high-pressured air will condense on the surface of the housing and the baffle when the air flows through the tortuous channel. Only little power is needed for the operation of the water remover, and the structure of the water remover is simple.

Abstract: A water level controller for a tank has control circuitry and multiple conductance terminals connected to the control circuitry and located at different heights from the other. By such an arrangement, the water level can be determined when the conductance of the water measured by corresponding conductance terminals becomes zero. The water inlet can be controlled to add to the tank by the control circuitry as the conductance measured by two of the corresponding terminals becomes practically negligible. Consequently, the water level in the tank can be accurately controlled, and the controller can be used with pure water so as to enlarge the useful scope of the controller.