Apple wins a Patent for Biometric Sensors under the Display while providing Exposure Truncation For Image Sensors
Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to image sensors and, more particularly, to controlling the exposure or integration time for one or more image frames of an image sensor. Apple's patent covers biometric sensor for Touch and Face ID under the display as illustrated in our cover graphic.
Beyond the granted patent describing the use of biometric sensors beneath a future iPhone display, the patent covers a wider purpose. Apple notes that some iPhones support a night mode and a tripod mode in which the integration time for an image frame may be lengthened—sometimes to one second, ten seconds, or more. However, if natural or artificial light brightens the scene that is being imaged, or if the iPhone is removed from a tripod or other stable surface (e.g., if the iPhone is picked up by its user), or if the iPhone's user believes a photographic moment has been missed, it may be desirable to shorten, or truncate, an otherwise lengthy integration time. There may also be instances in which it is desirable to truncate an integration time of more modest duration.
Although it might be possible to implement exposure truncation in software, a software solution may be too slow to achieve a desired truncation. Hardware-based solutions are therefore described in the present description. In most of the described solutions, a set of pixel values are read out for an image frame after truncation. This avoids the need to flush some or all of an image sensor's data pipe, reset the data pipe, reset a software stack, and restart an image sensor.
In Apple's patent FIG. 1A below, an iPhone #100 may include various components including a bio-authentication sensor, or a facial recognition sensor. The sensors may be positioned within the interior volume below the display.
Apple's patent FIG. 3 shows an example block diagram 300 of an image sensor 302 in communication with an image sensor host 304. In some embodiments, the image sensor 302 may be an image sensor used in one of the cameras
For finer details, review Apple's granted patent 11653111.