Device for acquiring image of slice medium

An image acquiring device for a sheet-type medium, comprising:

• an upper passage plate, mounted cooperatively with a lower passage plate, with a gap being reserved between the upper passage plate and the lower passage plate to form a passage;
• the lower passage plate, mounted cooperatively with the upper passage plate, with the gap being reserved between the lower passage plate and the upper passage plate to form the passage;
• a driving wheel, with at least two driving wheels mounted on the lower passage plate, and the driving wheels being configured to drive the sheet-type medium entered into the passage to advance along the direction of the passage;
• a floating pinch roller, with at least two floating pinch rollers mounted on the upper passage plate, and each of the floating pinch rollers being mounted cooperatively with a respective driving wheel and being tangent to the driving wheel at a tangential point, and being configured to apply a pressure to the sheet-type medium to allow the sheet-type medium to cling to the driving wheel, and
• an image collecting device, mounted between two sets of the driving wheels and the floating pinch rollers, and configured to collect an image of the sheet-type medium in a process of the sheet-type medium passing through the passage;
• wherein all tangential points are located in the passage, and are located in a plane in parallel with an advance direction of the passage.