Today the US Patent & Trademark Office published a patent application from Apple that relates to using electronic diffusers for camera-based ambient light sensing, enhanced flash features and/or message display.

In Apple's patent background they note that digital still and/or video cameras are often incorporated in a number of electronic devices, including mobile phones, tablet computers, laptop computers and desktop computers. Some electronic devices may even have multiple cameras - e.g., a tablet device may include a front-facing camera intended mainly for video chats or other communications, and a back-facing camera for higher quality photographs and/or higher definition video. In some devices, flashes may be built-in, or external flash devices may be used in conjunction with one or more digital cameras of the device. Such camera-containing devices may also include fairly sophisticated image processing software and camera control software. In many cases, at least a portion of the encasing or outer cover of the device that is located in front of the camera lens may be constructed of transparent material such as glass. As a result, during periods when an embedded camera is in an “on” or enabled state, its lens is typically exposed to most or all of the light incident on the transparent covering.

Although such levels of exposure to the external light may be ideal for various types of photographs or videos, for other functions more control of the amount of light reaching the camera lens and sensor may be useful – and this is what Apple's invention covers.

Apple's invention covers systems and methods of using electronic diffusers, comprising one or more layers of materials whose optical properties can be modified using electrical signals, for enabling ambient light sensing using digital cameras incorporated within electronic devices are described. 

In at least some embodiments, diffusers may be used for additional functions as well, such as for providing privacy screens and/or privacy indicators to users of the electronic devices, providing indicators of application state or subcomponent state, displaying various types of messages, to enhance the aesthetic appeal of the electronic device, and/or for supporting various flash photography features.

Diffusers may be used in a number of different types of camera-equipped electronic devices or components in various embodiments, including mobile phones, tablet computing devices, personal digital assistants, audio playback and/or recording devices, electronic book (e-book) reading devices, portable multifunctional devices, electronic gaming or video gaming devices, cable set-top boxes, satellite set-top boxes, smart televisions, laptop computers, desktop or deskside computers, or servers.

In the context of electronic devices that support flash illuminators for their cameras, a different diffuser may be used for a flash device in at least some embodiments than the diffuser that is used for the camera for which the flash device provides illumination.

In some embodiments, diffusers may be used in standalone cameras or standalone flash devices. In one embodiment, a diffuser may be used to improve the functionality of non-camera based ambient light sensors, e.g., by modifying or enhancing the angles over which the ambient light is collected by an ambient light sensor using a photodiode.

Diffusers Positioned Away From Light Paths of Cameras or Flashes

In at least some embodiments, diffusers may be located at areas other than camera windows or flash windows, e.g., on various areas of the front face and/or back face of an electronic device or display, away from the incoming light path of the camera and the outgoing light path of the flash.

Apple's patent FIG. 10 below illustrates several diffusers distributed on the front and back faces of a tablet computer device. Touch screen #1020 may be considered the primary user interface and primary display of the tablet computer device, while one or more diffusers attached to the tablet may be considered secondary displays.

During a given time period, the primary user interface and the diffuser-based displays may show information from different sources and/or for different purposes. In at least one embodiment, a user may be able to submit diffuser display configuration requests (e.g., via a “settings” menu available using the primary user interface), indicating the data sources for the information to be displayed via one or more diffuser segments, and/or the kind of data to be displayed.

The user may, for example, select different information sources for different diffuser segments, configure a given diffuser segment to switch between several different types of informational messages at specified rates (e.g., a diffuser segment may be configured to show an indication of the number of unread e-mail messages for five seconds, and an indication of the weather the following five seconds) and so on.

After the data sources and the durations for which the informational messages of various types have been determined, the contents of specific message or messages to be displayed during a given time interval (e.g., the numeral “5” to indicate five new e-mail messages, or a red exclamation mark symbol to indicate an indication of inclement weather in the near future) may be determined, and the appropriate signals may be sent to the diffuser segments.

It is noted that at least in some embodiments, the amount of power needed for the informational messages displayed using diffuser segments may be low enough that such messages may be displayed even while the electronic device itself is in a low power mode, e.g., while the laptop/phone/tablet/camera is in a sleep mode, hibernation mode, or a restricted-functionality mode such as an airplane mode.

In some embodiments in which diffuser-based information display is supported during low power modes or restricted functionality modes, an additional step of wiping the diffuser display may be added to the shutdown process of the electronic device, in order to fully clear the diffuser display and avoid indeterminate or scrambled diffuser display contents. 

(Click on patent figures to Enlarge)

This in-depth patent filing is broken down into 19 segments as noted below:

• Camera-as-ALS Functionality Using Diffusers
• Privacy Screen and Privacy Indicator
• General-Purpose State/Information Indicator
• Diffuser as a Design/Aesthetic Element Extending Beyond the Camera Light Path
• Diffuser as a Virtual Shutter for Enhanced Flash Synchronization
• Diffusers for Flash Windows
• Diffusers for Non-Camera Ambient Light Sensors
• Example Diffuser-Equipped Electronic Devices
• Diffuser Materials
• Diffuser Placement
• Example Change in Diffusivity With Applied Signal
• Diffusers for Information Display
• Supplemental Light Sources for Information Display Through Diffuser
• Diffusers Positioned Away From Light Paths of Cameras or Flashes
• Changing Angular Sensitivity of Ambient Light Sensors Using Diffusers
• Diffuser for Synchronization of Camera Image Sensor Exposure With Flash Illuminations
• Multiple Flash Modes Using Diffusers
• Methods Utilizing Diffusers
• Example Components of Electronic Device

For those interested in diving into the details, review Apple's patent application number US 20230117997.

Apple's sole inventor is listed as Joel S. Armstrong-Muntner who is an academic researcher for Apple Inc.. The author has an h-index of 8, co-authored 11 publication(s) receiving 293 citation(s).