The JP-4 photoelectricity corrects an error the system is to theproduction line in the volume material when the transmission thedisalignment carries on the control the system, has function and so onautomatic detection, automatic tracking, automatic control. Can to thepaper, the thin film not do material the and so on adhesive tape, aluminum foil scribe mark and the edge carries on the track to correctan error, guaranteed the coiling, is divided neat which cuts. Thissystem used in the light industry, the spinning and weaving, theprinting, printing, the belt just, profession and so on non-ferrousmetal. Its machinery execution partially uses the exchange synchronousmachine, the ball bearing, has the structure simply, the precisionmaintenance merit and so on is high, exempts, the expansion andcontraction partially uses in the ball bearing guide screw to set atthe type, ceased guide screw with standing and influence thedust.