Apple currently uses ambient light sensors to detect the amount of light in the environment and to adjust the brightness of the display based on the amount of light. With an ambient light sensor doubling as a solar cell, Apple could charge the user's device throughout the day.
An electronic device is provided with a display and a solar cell ambient light sensor that receives light through a portion of the display. The solar cell ambient light sensor may include one or more thin-film photovoltaic cells. A voltage that accumulates within the thin-film photovoltaic cell in response to ambient light is sampled and converted into ambient light data. The device includes control circuitry that modifies the intensity of display light generated by the display based on the ambient light data from the photovoltaic cell. The solar cell ambient light sensor is attached to a transparent cover layer, a color filter layer, or any other layer of the display. When the accumulated voltage is not being sampled for ambient light measurements, the voltage may be used to provide charge to a battery in the device.
While Apple patents don't always make their way into future products, it would make sense for Apple to implement such a technology into a wearable device, like an iWatch. It has been citied that Apple was facing battery issues on its rumored iWatch device, but perhaps the company found other ways to solve that challenge.
Read More via Patently Apple