A tendency for a metal rod, tube, cylinder, or roller to bend or deform between its bearings when pressure is exerted, such as when rollers and cylinders exert increased pressures on each other. Deflection, when occurring on inking rollers, can result in inconsistent ink transfer to the plate, blanket, and/or substrate across the press. Deflection also refers to a cylinder or roller's pressure-induced out-of-roundness. Deflection is also known as flex.
In a cathode-ray tube, a technique added (by means of a device called a deflection unit) that increases the angle at which the electrons beams are spread on the back of the screen. Increased angle of deflection increases the flatness of the monitor.