Abstract: A jig frame and a wire mesh tray are reliably and simply fixed, and the wire mesh tray is simply replaced. A heat treatment jig includes a jig frame having on an upper surface side thereof an opening and a wire mesh tray having an upper end portion that abuts on an upper end portion of the jig frame. The wire mesh tray is detachably mounted on the jig frame by a plurality of clips. The clips grip the upper end portion of the jig frame and the upper end portion of the wire mesh tray.

Abstract: The present invention provides a process cartridge having components which are easy to assemble and disassemble and are convenient to reuse. A process cartridge of the present invention comprises a first unit having a photosensitive drum; a second unit having a cleaning means for the photosensitive drum; and wherein the first unit and the second unit are rotatably hinged to each other by a coupling shaft projecting from the side wall of the first unit and a coupling hole perforating the side wall of the second unit. The second unit is fixed at a position where the hinged rotation of the second unit in a predetermined direction with respect to the first unit is stopped.

Abstract: An optical system of a video camera is moved to a plurality of positions having a minute predetermined interval, and detected video images of an object at the respective positions are memorized in a frame memory in turn, the video images are compared with each other, and the video image having the highest contrast is selected, thus the position at which the video image having the highest contrast is detected is recognized as a focused position, and the optical system is shifted to the position.

Abstract: In the method for producing a high impact polystyrene from a monomer of styrene or/and its derivative and a rubbery polymer as reactants, an improvement is provided which comprises passing said reactants through a tubular reactor having parts where the passage way of flow of said reactants is constricted, while keeping said reactants in a laminar flow as much as possible in the parts other than said parts, in a first stage polymerization to prepare a reacted mixture containing a prepolymer until the conversion of monomer to polymer becomes 10 to 60%, and subjecting the resulting reacted mixture to a second stage polymerization in the state where almost no shearing is exerted thereupon.The shearing during said first stage polymerization can be uniformly carried out.The resulting product has superior high impact properties.