Abstract: The invention provides a rotatable polygon mixture having a body shaped in a form of polygon. At the axis of rotation of the body is provided a shaft hole, and to each side of said body is provided a mirror surface. The thickness of each center portion of the body corresponding to a portion between the center part of each side and the axis of rotation is made thinner than that of each corner portion corresponding to a portion between the corner part of each side and the axis of rotation to control the flow speed of molding resin.

Abstract: The invention provides a rotatable polygon mirror consisting of (a) cylindrical boss being disposed at the center part of polygon and having a hole therein, (b) side plate being disposed at each side of polygon, the outer surface of the side plate forming a mirror surface, (c) connecting-plate for connecting between the cylindrical boss and the side plate, and rib being radially disposed between the cylindrical boss and each corner of polygon.

Abstract: A tuner circuit for converting the frequency of an input signal with a local oscillator to a predetermined channel frequency. The tuner circuit includes an attenuation circuit responsive to the input signal for controlling the attenuated level of the input signal for reducing cross modulation and intermodulation distortions of the circuit, and for reducing distortion from the interference of the local oscillation, an amplifier circuit coupled to the attenuation circuit for amplifying the attenuated input signal, and a frequency conversion circuit coupled to the amplifier circuit for converting the frequency of the amplified input signal to a corresponding predetermined channel frequency.