Abstract: A sheet sensing module and a duplex scanning apparatus having the sheet sensing module are provided. The sheet sensing module includes a first sensing arm, a second sensing arm, and an electronic sensor. The first sensing arm is partially exposed to a sheet feeding channel of the duplex scanning apparatus. The second sensing arm is partially exposed to an inverting channel of the duplex scanning apparatus. When a document is transferred through the sheet feeding channel to trigger said first sensing arm or the document is transferred through the inverting channel to trigger the second sensing arm, the electronic sensor generates a sensing signal.

Abstract: A duplex scanning apparatus and a sheet-feeding control method thereof are provided. The duplex scanning apparatus includes a sheet feeding channel, a sheet transfer channel, an inverting channel, and a sheet sensing module. A first end of the inverting channel is connected to a junction between said sheet feeding channel and the sheet transfer channel. A second end of the inverting channel is connected to the sheet transfer channel. A distance between the sheet sensing module and the first end of the inverting channel is greater than a distance between the sheet sensing module and the second end of the inverting channel. When a document is transferred through the sheet sensing module at the second time, a next document is fed into the sheet feeding channel through a sheet entrance.

Abstract: A duplex scanning apparatus and a sheet-feeding control method thereof are provided. The duplex scanning apparatus includes a sheet feeding channel, a sheet transfer channel, an inverting channel, and a sheet sensing module. A first end of the inverting channel is connected to a junction between said sheet feeding channel and the sheet transfer channel. A second end of the inverting channel is connected to the sheet transfer channel. A distance between the sheet sensing module and the first end of the inverting channel is greater than a distance between the sheet sensing module and the second end of the inverting channel. When a document is transferred through the sheet sensing module at the second time, a next document is fed into the sheet feeding channel through a sheet entrance.

Abstract: A sheet sensing module and a duplex scanning apparatus having the sheet sensing module are provided. The sheet sensing module includes a first sensing arm, a second sensing arm, and an electronic sensor. The first sensing arm is partially exposed to a sheet feeding channel of the duplex scanning apparatus. The second sensing arm is partially exposed to an inverting channel of the duplex scanning apparatus. When a document is transferred through the sheet feeding channel to trigger said first sensing arm or the document is transferred through the inverting channel to trigger the second sensing arm, the electronic sensor generates a sensing signal.

Abstract: An automatic document feeder includes a paper guide casing, a photo interrupter, a first sensing unit, a second sensing unit and a controller. During the paper is transported through the paper guide casing, the first sensing unit and the second sensing unit are respectively triggered by two ends of the paper. Consequently, the photo interrupter is conducted for a first duration T1 or a second duration T2. According to the first duration T1 or the second duration T2, a skew angle of the paper is calculated by the controller.