Abstract: A light scanning system employing a rotating mirror, spherical lens, and a toric-surfaced reflecting mirror. The toric-surfaced reflecting mirror is disposed in the optical path between the spherical lens and the image plane. The spherical lens sufficiently corrects field curvature and the toric-surfaced reflecting mirror corrects scan nonlinearity. And by the spherical lens and the toric-surfaced reflecting mirror together, the field curvature and the scan nonlinearity are satisfactorily corrected. The toric-surfaced reflecting mirror is surfaced to have a circular arc with a larger radius of curvature in the scan plane and to have a circular arc with a smaller radius of curvature in the cross-scan plane.

Abstract: Many frozen foods are now sold on the market and also produced by household refrigerators, and most of these frozen foods are eaten after thawing or after cooking under heat subsequent to thawing. The importance of thawing is thus increasing more and more. This invention provides a heating apparatus of simple construction capable of effectively thawing a frozen food to meet the above demand. The heating apparatus of the present invention is based on the fact that the dielectric loss of a frozen food itself varies as the frozen food is progressively heated. In the heating apparatus, a signal wave is directed toward a frozen food, and the variation of the rate of absorption of the signal wave due to the dielectric loss of the food is measured, so as to automatically control the process of heating for thawing on the basis of the result of measurement.

Abstract: A novel high frequency heating apparatus for detecting the internal temperature of an object contained in a heating chamber and controlling the heating thereof is disclosed, in which the temperature change of the object is picked up as a change of the resistance value of a thermistor. The resistance change is converted into a change of the oscillation frequency of an oscillator and transmitted with the ultrasonic wave as a medium. The power supply for the transmitter circuit is provided in such a manner that the high frequency filled in the heating chamber for heating the object is received by an antenna and rectified by a diode. At the receiving end, this ultrasonic wave is picked up as a temperature signal of the object, and processed by a microcomputer, so that the temperature of the object is detected for heating control.