Abstract: The present invention provides a sheet-fed scanner which can preview a document. The sheet-fed scanner comprises a housing having an opening for feeding a document to be scanned, a scanning module installed in the housing for scanning the document, a driving mechanism for driving the document forward and backward, first and second sensors installed at a front end and a rear end of the driving mechanism for detecting the document, and a control circuit for controlling operations of the scanner. When the document is fed into the opening and detected by the first sensor, the control circuit uses the driving mechanism to drive the document forward until the document is detected by the second sensor. And when the control circuit receives a preview instruction, the control circuit uses the driving mechanism to drive the document forward and uses the scanning module to perform a preview scan over the document until the document is no longer detected by the first sensor.

Abstract: A lens module testing apparatus includes a light source, a grating reflects the light emitting from the light source to form a object light locating at a object location, an adjustable holding device holds a lens module between the object location and a image location, adjusting the holding device to position the lens module to form a testing image of the object light at the image location. A CCD is located at the image location to receive the intensity of the testing image and then generate an electrical signal. A PC analyzes the electrical signal.

Abstract: A membrane switch including a plurality of upper dot-pads and a plurality of lower dot-pads is provided to enhance the operational sensitivity while avoiding unexpexted actuation of membrane switch is provided. The plurality of upper dot-pads are provided during the print process of the top switch-pad and distributed to surround the top switch-pad. A plurality of lower dot-pads corresponding the plurality of upper dot-pads are provided during the print process of the bottom switch-pad and distributed to surround the bottom switch-pad. Each of the plurality of upper dot-pads has a lower-edge and each of the plurality of lower dot-pads has an upper-edge. As the top membrane is free of an external force, the lower-edge of top switch-pad is spaced from the upper-edge of bottom switch-pad by a first dimension greater than a second dimension by which the lower-edge of each upper dot-pad is spaced from the upper-edge of each lower dot-pad.