Abstract: A rotary type expander (60) is provided with two rotary mechanism parts (70, 80). These two rotary mechanism parts (79, 80) differ from each other in displacement volume. The outflow side of the first rotary mechanism part (70) of small displacement volume is fluidly connected to the inflow side of the second rotary mechanism part (80) of large displacement volume. In addition, the process in which the volume of a first low-pressure chamber (74) in the first rotary mechanism part (70) decreases is in synch with the process in which the volume of a second high-pressure chamber (83) in the second rotary mechanism part (80) increases. Refrigerant at high pressure is first introduced into a first high-pressure chamber (73) of the first rotary mechanism part (70). Thereafter, this high-pressure refrigerant passes through a communicating passage (64) and then flows by way of the first low-pressure chamber (74) into the second high-pressure chamber (83) while expanding.

Abstract: Disclosed is a displacement type expansion machine. In the displacement type expansion machine, a communicating passage (72) for allowing fluid communication between an expansion-process intermediate position and an outflow position in an expansion chamber (62) is provided thereby to allow the fluid at the outflow side to return to the expansion chamber (62). Such arrangement prevents the pressure of the expansion chamber (62) from being lowered to an excessive extent in predetermined operating conditions, thereby avoiding the drop in power recovery efficiency.

Abstract: A refrigerant circuit (10) of a refrigeration apparatus is filled up with carbon dioxide as a refrigerant. In the refrigerant circuit (10), a first compressor (21) and a second compressor (22) are arranged in parallel. The first compressor (21) is connected to both an expander (23) and a first electric motor (31), and is driven by both of the expander (23) and the first electric motor (31). On the other hand, the second compressor (22) is connected only to a second electric motor (32), and is driven by the second electric motor (32). In addition, the refrigerant circuit (10) is provided with a bypass line (40) which bypasses the expander (23). The bypass line (40) is provided with a bypass valve (41). And, the capacity of the second compressor (22) and the valve opening of the bypass valve (41) are regulated so that the COP of the refrigeration apparatus is improved after enabling the refrigeration apparatus to operate properly in any operation conditions.

Abstract: In a gas pressure-driven type cryogenic refrigerating machine, an inner space of a cylinder 2 is divided into a lower pressure room 20, an upper pressure room 29 and expansion rooms 30, 31 by a slack piston 17 and a displacer 22 connected to the slack piston, a rotary valve 35 alternately changes between a high-pressure valve-open position for supplying high-pressure helium gas to the upper pressure room 29 and the expansion rooms 30, 31 and a low-pressure valve-open position for discharging the helium gas in the upper pressure room 29 and the expansion rooms 30, 31, and a difference in gas pressures between the upper and lower pressure rooms 29, 30 causes the slack piston 17 to be driven to reciprocate the displacer 22 thereby producing a cold condition at an extremely low temperature level.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.