Abstract: A picture frame molded in one piece from synthetic resin which includes a back plate for supporting a sheet to be framed on its face side, a plurality of frame members disposed along marginal portions of the back plate and being rotatable about respective hinge portions to constitute a front frame work when turned toward the face side of the back plate, each of the frame members having a pressor member formed at its free end and adapted to hold the sheet in association with the face side of the back plate when the frame member is turned toward the face side of the back plate, and locking elements each comprising a male member and a female member, one of which is disposed on the inner side of the frame member or of the pressor member, with the other being disposed on a marginal portion of the back plate in the position corresponding to the one of the male and female members, whereby the frame members are secured on the sheet set on the face side of the back plate.

Abstract: The channel current of an MOS transistor is controlled by varying the potential distribution in the source area. The source area is formed of a resistive material and provided with at least two electrodes on at least one of which a controlling voltage is applied. The current between the source and the drain terminals increases more rapidly than the linear change with respect to the increase in the voltage between the terminals, i.e. current-voltage characteristics are convex toward the lower direction. This device has excellent characteristics for use as a discharge impedance element in a sustain function circuit of an indirect keying or other circuit of an electronic musical instrument.