The invention, which was filed with the U.S. Patent and Trademark Office in May 2011, describes a system that uses on-board sensors like a camera, infrared proximity sensor or SONAR sensor, to determine the distance between a user's face and the display. By using this information, the system can enlarge or reduce text or images being displayed on screen for maximum readability and user comfort.
There are two modes outlined in the application's description: comfort mode and zoom mode.
In comfort mode, the device scales content to reduce in size when a user's face is close to the screen and enlarges it when it is farther away. This mode aims to "maintain the visual content at a comfortable size for the user regardless of how far the display is from the user's face. Thus, this mode of operation is referred to as comfort mode."
For zoom mode, the system reverses the above process and enlarges content, or zooms in, as a user brings the device close to their face and reduces, or pans out, when it is farther away. The embodiment may be useful in certain applications like games and mapping, as it "provides a convenient way to zoom in and out of visual content."
Essential to operation is a preliminary calibration procedure that asks a user to hold the device at various distances away from their face to gather reference data, which the system will later draw upon to scale content. Such calibration can include the closest comfortable viewing distance, the farthest comfortable viewing distance and any variations between the two.
As described in one implementation, the mechanism can use a camera to determine distance from a user based on facial recognition techniques. The corresponding information is sent to a processor that uses the reference information as a key to regulate the dynamic sizing of on-screen content.
If Apple chooses to one day use the invention, a likely device could be a future iPhone or iPod touch as users constantly resize content with their fingers due to the devices' relatively small display size, and the portable form factor is an ideal candidate for the patent's described operation. The iPad and iPad mini could also make use of the tech, though the pinch to zoom heuristic is already convenient on larger format screens and is perhaps more comfortable than moving the device back and forth.