Apple patent involves secondary backlight indicator for portable media devices
Posted by Dennis Sellers 
Nov 20, 2008 at 1:21pm
An Apple patent (number 20080284696) for a secondary backlight indicator for portable media devices has appeared at the US Patent & Trademark Office. The invention relates to electronic devices and more particularly to providing display indicators for electronic devices. In other words, it’s for always-on status indicators for devices such as the iPhone.
According to Apple, systems and methods are provided for displaying icons directly on a display, such as an LCD, regardless of whether the display is ON. When the display is ON, a primary backlight may be used to illuminate the display. When the display is OFF, a secondary backlight may project light through the primary backlight to display one or more icons on the display. The displayed icons may be of various shapes, colors, and sizes.
Here’s Apple’s background and summary of the invention: “Portable electronic devices such as digital electronic devices (e.g., music players and video players) are known. These devices are typically powered by one or more batteries. Batteries store a fixed amount of energy. Therefore, efficient use of the fixed energy source is desirable in order to maximize the length of time between battery replacements or recharges.
“One way to conserve energy is to turn off a display (e.g., LCD) of a portable electronic device when the user does not need or want to view media. For example, the display of a music player may be turned off after the user is done choosing music to play. However, if the display of an electronic device is turned off, it may be difficult or impossible for a user to determine the status of the device, or to identify that the electronic device itself is still on. Thus, it is desirable to provide one or more low-power consuming indicators to inform the user of the status of the device.
“Known indicators, however, are provided through a hole in the casing of an electronic device, where a low-power light may be generated to show through the hole. However, this approach requires extra assembly or packaging considerations that may be expensive and may detract from the aesthetic appeal of the device. Therefore, there is a need for electronic devices that provide indicators directly on the display.
“The display system of an electronic device can include a display (e.g., an LCD), a primary backlight system, and a secondary backlight system. Each of these components may be ON or OFF. When the display is ON, it can provide media, such as video clips or graphics. When the primary or secondary backlight systems are ON, they may generate light to illuminate the display.
“The display system may have multiple operating modes. The display system may be in a first operating mode when a user wants to view media on the display. In this mode, the display may be turned ON to display the desired media. The primary backlight system may also be turned ON to allow the user to easily see the contents of the display. Alternatively, the primary backlight system may remain OFF, and the user may rely on external lighting to view the contents of the display. The display system may enter a second, less power consuming mode when a user does not want to view media. In this mode, the display may be turned OFF. Also, because no content is available for the user to view, the primary backlight system may also be turned OFF.
“In the second operating mode, even though the display is OFF, information such as a status indicator can be provided on the display. To provide an icon on the display of the electronic device that is indicative of the status of the device, the secondary backlight system may be turned ON. The secondary backlight system may be separated from the display by the primary backlight system. Thus, the light provided by the secondary backlight system may be projected through one or more transparent or semitransparent regions of the primary backlight system to reach the display. The primary backlight system may block light from the secondary backlight system except for those one or more regions. Thus, the size and shape of the status indicator may be set by sizing and shaping the transparent or semitransparent regions of the primary backlight system. In addition to setting the size and shape of the icon, the color of the icon may also be set by adjusting the color of the light provided by the secondary backlight system.
“In accordance with another aspect of the present invention, a display system may provide multiple status indicator icons or information displays of any suitable size, shape, and color, and may selectively choose between them. In some embodiments, the icons may be displayed at different locations on the display. In these embodiments, each icon may correspond to a separate transparent or semitransparent region of the primary backlight system. Thus, during operation, the secondary backlight system may selectively guide light toward certain regions of the primary backlight such that only selected icons are shown on the display. To ensure that the light from the secondary backlight system only reaches the proper region or regions on the primary backlight system and does not leak to other regions, the display system may additionally include one or more color filter layers between the primary and secondary backlight systems. Each color filter layer may include color filters that may only transmit certain colors and may block other colors. Thus, if each icon is associated with a different color, the color filters may ensure that colored light guided from the secondary backlight system toward a particular transparent or semitransparent region of the primary backlight system does not leak through another region.
“In some embodiments, multiple status indicator icons may be displayed at substantially the same location on the display. To vary the shape or size of each indicator, the shape and size of the color filters may be varied rather than the shape and size of the transparent or semitransparent regions of the primary backlight system. For example, color filters of different shapes and with different properties may be superimposed on each other. Thus, the shape of an icon on the display may depend on the color of light provided by the secondary backlight. This technique may also be used for icons that are displayed side-by-side.
“In accordance with another aspect of the present invention, the one or more displayed icons may be dynamic. For example, a light source within the secondary backlight system may be turned ON and OFF to create a blinking effect, or the intensity of the light may be varied through, for example, pulse-width-modulation. Also, the one or more icons may be displayed in short time intervals (e.g., for half a second every five seconds) in order to conserve battery power.
“Therefore, each status indicator provided by the electronic device, whether located at different locations on a display or at substantially the same location, may be associated with light having particular properties. For example, each indicator may have a particular color, blinking speed, or light intensity. These properties may be programmed into the electronic device by the user, or may be hard-coded or hard-wired into the system. Thus, when the secondary backlight is turned ON (e.g., when switching to the second operating mode as discussed above), the properties of the light provided by the secondary backlight system may depend on the status of the device. Also, if the status of the electronic device changes while the secondary backlight is ON, the properties of the light provided by the secondary backlight system may change to reflect the new status.”
The inventor is Michael Rosenblatt. The graphic below shows a block diagram of an electronic device in accordance with an embodiment of the present invention.
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Contributor
Dennis Sellers
Dennis has been a newspaper editor/reporter (seven years) and teacher (seven years). He has over 4,000 magazine, newspaper and online articles to his credit. He has also covered the Mac and tech industries for over a decade for such online publications as MacCentral, MacMinute and now MacsimumNews.
