Abstract: A sheet conveying device includes a conveyor, a sound collector, and circuitry. The conveyor conveys a sheet. The conveyor conveys a sheet in a sheet conveyance direction. The sound collector collects an operating sound generated by a conveyance of the sheet. The circuitry is to extract a feature amount of the operating sound collected by the sound collector, and determine, at different positions in the sheet conveyance direction based on the feature amount, whether an abnormal conveyance of the sheet occurs until the sheet is conveyed to a given position in the sheet conveyance direction.

Abstract: A sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.

Abstract: A sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.

Abstract: A solenoid device including a plunger, a solenoid configured to cause a displacement of the plunger, and a driving control unit configured to control driving of the solenoid. The driving control unit supplies current pulses to the solenoid and changes a pulse interval of the current pulses.

Abstract: A solenoid device including a plunger, a solenoid configured to cause a displacement of the plunger, and a driving control unit configured to control driving of the solenoid. The driving control unit supplies current pulses to the solenoid and changes a pulse interval of the current pulses.

Abstract: A heat insulating box, such as a refrigerator box, comprises a heat insulator and a box member that is in contact with the heat insulator. The heat insulator is formed of a urethane foam using either HCFC-123 (CHCl.sub.2 CF.sub.3) or HCFC-141b (CH.sub.3 CCl.sub.2 F) or both as a forming agent, and the box member is formed of a styrene/acrylonitrile/butadiene terpolymer, a styrene/ethylene-.alpha.-olefinic rubbery copolymer/acrylonitrile terpolymer (AES resin), a styrene/alkyl acrylate ester containing rubbery copolymer/acrylonitrile terpolymer (AAS resin), or a mixture of the AES resin and the AAS resin.

Abstract: A heat insulating box, such as a refrigerator box, comprises a heat insulator and a box member that is in contact with the heat insulator. The heat insulator is formed of a urethane foam using either HCFC-123 (CHCl.sub.2 CF.sub.3) or HCFC-141b (CH.sub.3 CCl.sub.2 F) or both as a forming agent, and the box member is formed of an acrylonitrile/ethylene-.varies.-olefinic rubbery polymer/styrene resin (A/epdm/S resin), an acrylonitrile/alkyl acrylate ester rubbery polymer/styrene resin (ASA resin), a mixture of an A/epdm/s resin and an ASA resin, or a mixture of an ASA resin with an acrylonitrile/butadiene/styrene resin.