Display calibration cradle for portable device

A cradle 1 for recalibrating the unevenness in the output of a display due to pixel degradation is disclosed. The cradle (fig. 1) may comprise a light sensing device 2 and contacts 13 for electrical connection with a portable device 11. Alternatively (fig. 2) the cradle may comprise light reflection means to reflect light from the device display 12 onto an optical sensor 2 in the device. Calibration electronics may be mounted either in the cradle or portable device, and the cradle may have multiple sensors (fig. 4). The cradle may also be used to recharge the batteries of the device. The portable device may be a phone, hand-held computer, camera or game console.