Abstract: A die set capable of suppressing breakage or wrinkling of the workpiece during bending and a processing method using the die set. A die set used for bending a plate-like workpiece includes a lower die on which the workpiece is placed, and an upper die having a pressing surface formed to press the workpiece against the lower die. The lower die includes a lower movable part slidable in the same direction as a moving direction of the upper die, a reaction force generating member configured to elastically support the lower movable part from beneath, and receiving members located on both sides of the lower movable part. The pressing surface has an arc-shaped cross-section protruding toward the lower die and extends in a longitudinal direction of the workpiece. The maximum push-in position of the lower end portion of the pressing surface is deeper than a position lowered by a finished inner diameter dimension of the workpiece from an upper surface of the lower die.

Abstract: A die set for bending a metal plate workpiece includes a lower die for placing the workpiece, an upper die having a pressing surface which presses the workpiece toward the lower die by movement, a lower movable part provided in the lower die and being slidable in the same direction as the direction of the upper die movement, and a gas spring elastically supporting the lower movable part from below. The pressing surface of the upper die is moved, contacts with the upper surface of the workpiece and presses the workpiece toward the lower die. The lower movable part being elastically supported by the gas spring from below brings an opposing surface into contact with the lower surface of the workpiece and makes the upper die to be close to the lower die while applying force in the upward which is opposite direction of the upper die movement.

Abstract: A die set for bending a metal plate workpiece includes a lower die for placing the workpiece, an upper die having a pressing surface which presses the workpiece toward the lower die by movement, a lower movable part provided in the lower die and being slidable in the same direction as the direction of the upper die movement, and a gas spring elastically supporting the lower movable part from below. The pressing surface of the upper die is moved, contacts with the upper surface of the workpiece and presses the workpiece toward the lower die. The lower movable part being elastically supported by the gas spring from below brings an opposing surface into contact with the lower surface of the workpiece and makes the upper die to be close to the lower die while applying force in the upward which is opposite direction of the upper die movement.

Abstract: A black level correction circuit includes: a counter counting a black signal level of an image; a black level determination section determining a feedback gain by comparing data outputted from the counter with a previously set threshold; an average value calculation section calculating an average value from data supplied from the counter; a feedback calculation processing section selecting the feedback gain by a control signal supplied from the black level determination section and calculating the selected feedback gain and the averaged data; and a digital-analog converter correcting data to which feedback calculation processing has been performed and converting the corrected data into analog data to output an analog black signal.

Abstract: A black level correction circuit includes: a counter counting a black signal level of an image; a black level determination section determining a feedback gain by comparing data outputted from the counter with a previously set threshold; an average value calculation section calculating an average value from data supplied from the counter; a feedback calculation processing section selecting the feedback gain by a control signal supplied from the black level determination section and calculating the selected feedback gain and the averaged data; and a digital-analog converter correcting data to which feedback calculation processing has been performed and converting the corrected data into analog data to output an analog black signal.