To provide a paper feeder capable of maintaining constant paper pressing force regardless of paper thickness, and preventing reduction in printing quality to be caused by variation of paper feeding amount, and to provide a printer.
A paper feeder 5 of a printer 1 includes a pressing device 9 that biases a paper pressing roller 8 toward a paper feeding roller 7. The pressing device 9 includes a coil spring 13 for biasing a rocking lever 11 with the paper pressing roller 8 from above, an assist coil spring 14 for biasing the rocking lever 11 from below, and a powering device 15 for powering the assist coil spring 14. The assist coil spring 14 is made of a shape memory alloy, and when it is powered, internal heat generation occurs and its free length changes. The biasing force of the assist coil spring 14 is increased or decreased by supplying power according to the thickness of recording paper, thereby offsetting the variation in biasing force of the coil spring 13 to be caused by the paper thickness, and keeping the paper pressing force constant.
Osamu Suzawa
Kazuhiko Miyasaka
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