Abstract: A magnetic cooling apparatus including a plurality of magnetic regenerators including a plurality of magnetocaloric materials to emit heat when magnetized and to absorb heat when demagnetized. The magnetic regenerators are rotatably disposed on a circumference having a predetermined radius, at least one coil is disposed on the circumference and coupled to the magnetic regenerators, and a plurality of permanent magnets is provided inside and outside the circumference to generate a magnetic field to magnetize or demagnetize the magnetic regenerators. The at least one coil interacts with the magnetic field generated by the permanent magnets to rotate the magnetic regenerators. The coil interacting with the magnetic field to magnetize or demagnetize the magnetic regenerators is coupled to the magnetic regenerators such that the magnetic regenerators reciprocate or rotate, thereby minimizing a size of the magnetic cooling apparatus, relative to the use of a motor.

Abstract: An ink-jet image forming apparatus. The ink-jet image forming apparatus includes a print head having a plurality of nozzles to eject ink, an ink tank to store the ink, an ink supply passage to supply the ink in the ink tank to the print head, an ink return passage to return the ink in the print head to the ink tank, a regulator mounted in the ink supply passage to regulate ink flow supplied to the print head, a shut-off valve mounted in the ink supply passage, between the ink tank and the regulator, to intercept ink flow supplied to the regulator, and an ink pump mounted in the ink return passage to forcedly flow the ink in the ink return passage. The ink pump is configured to be driven in forward and reverse directions so as to change an ink flow direction. Since the shut-off valve intercepts forcedly the ink flow in the ink supply passage, the ink in the ink tank is prevented from flowing abnormally to the print head and leaking from the print head.