Abstract: A dryer has a container holding goods to be dried, suction and exhaust ducts communicating with the container, a blower forcibly blowing air through the suction duct, the container and the exhaust duct and a heater for heating air flowing through the suction duct. An absolute humidity sensor is provided to measure a degree of absolute humidity in exhaust air flowing through the exhaust duct. Drying generation of the dryer is interrupted when a measured degree of absolute humidity of the exhaust air and a degree of absolute humidity in the surrounding air has a predetermined relationship.

Abstract: A twisted flexible optical fiber bundle adapted to be used in viewing devices for transportation vehicles such as automobiles, the twisted fiber bundle being prepared by twisting each of flexible optical fiber gatherings by 180.degree. prior to longitudinally laminating the thus twisted optical fiber gatherings, thereby forming a right side-left side inverted image when used in viewing devices; and viewing devices in which the twisted flexible optical fiber bundle is used as the image transmitting means.