Paper size detection module

A paper size detection module installed on a paper supporting plate, the paper size detection module comprising:

• a position sensing assembly located under the paper supporting plate, and comprising a carrier plate, a sensing circuit board and plural elastomers, wherein the sensing circuit board is installed on a bottom side of the carrier plate, first ends of the elastomers are connected with the sensing circuit board, and second ends of the elastomers are protruded out of the carrier plate and have corresponding pressed surfaces of the elastomers;
• and
• a sliding block assembly comprising a paper positioning block and at least one roller, wherein the paper positioning block is installed on the paper supporting plate, and the roller is located under the paper positioning block and the paper supporting plate, wherein the roller is connected with the paper positioning block and rolled along the carrier plate,
• wherein while the paper positioning block is moved, the roller is correspondingly rolled along the carrier plate and the pressed surfaces of the elastomers, wherein when a position of one of the pressed surfaces of the elastomers rolled and pressed by the roller is detected, the sensing circuit board generates a paper size signal.