Patent Application
20060227122
This disclosure relates to displays and techniques for presenting information on displays.
Portable electronics devices are commonplace and widespread. Traditionally, these devices were designed to perform a single function. Cellular phones enabled wireless communication, PDAs (portable digital assistants) maintained calendars and email, MP3 players provided music storage and playback, digital cameras captured digital images, and personal video players played movies or other video content. Today, portable devices are designed to support multiple functions. Cellular phones not only facilitate wireless communication, but also allow users to take digital pictures, receive and send email, play games, and store and playback music.
These various functions have different display requirements. Certain functions can be supported with small, low power displays. MP3 players and cell phones, for example, can use limited displays to show alphanumeric characters for song title and track information, phone numbers, or time-of-day. Other functions, however, require more sophisticated displays. Higher resolution color displays are preferable for depicting digital images, reading and writing emails, or watching video.
Power consumption is another important consideration for designers of portable devices. Designers continually look for ways to conserver power. Displays are one primary consumer of power, often accounting for anywhere from 20% to 60% of the power consumption of the entire electronic device. In display panels, such as those used in portable electronic devices, power consumption is proportion to the number of pixels being driven. Today, displays are either on or off. When on, all pixels are active and consuming power, even if the display does not depict images on the entire screen. After a time-out period or in response to a user command, the display is turned off where all pixels are inactive and not consuming power.
Because of power consumption issues and different display requirements for supporting multiple functions, designers have turned to using two different displays—a small, limited feature display for simple or rudimentary functions and a large, high feature display for more enhanced functions. As one example, many of the “clamshell” or “flip-phone” models of cellular phones use two displays. A small, low power display is visible on the outside of the phone when its lid is flipped shut. This external display can show limited information (e.g., time-of-day, power reserves, cell signal strength, etc.) and requires very little power while waiting for a phone call. A larger color display is exposed on the inside when the lid is flipped open. This larger display can be used to read and write email, display pictures captured by a built-in camera, play games, or watch video clips.
Unfortunately, adding a second display increases the cost and complexity of the device.
Accordingly, there is a need to improve the way information is displayed on such multi-function devices, allowing better power conservation, while decreasing their cost and complexity.
An electronic device has a single display panel that operates in multiple modes to support different display capabilities. In one implementation, the device operates the display panel in a first mode to support a rich user experience, such as watching video, playing games, reading and writing email, and so forth. In the first mode, the entire display panel is operational, where substantially all pixels are active and available to depict image data. While this mode offers the highest quality user experience, it is also consumes the most power. The device alternatively operates the display panel in a second mode that supports limited display capabilities, such as depicting alphanumeric characters and small graphics. In the second mode, a portion of the display panel is operational while the rest of the display panel is powered off. This partial display mode may be implemented by controlling on/off select rows and columns of pixels, where a subset of the pixels is active and available to depict data and the rest of the pixels are powered off. Additionally, or alternatively, the partial display mode might involve turning on or off portions of backlighting, or circuitry that supports the display panel. As a result, power is conserved as only a portion of the display is operational in the second display mode.
The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
This disclosure is directed to implementing two or more display modes on a single display. In the described implementation, the display is a relatively large, color, high-feature display panel that is capable of depicting text, graphics, digital images, motion video, and the like. In a first or full display mode, the entire display, including all pixels and any backlighting, is on and available for depicting image data. The display panel thus functions as a full-feature “first display” that can be used to show videos, play games, render graphics, read and write email, browse the Internet, and so forth. In a second or partial display mode, only a portion of the display is used while the rest of the display is turned off and not drawing power. The smaller portion of the display is defined by activating a subset of the pixels, certain backlights (if any), and/or a part of the circuitry for the display (e.g., frame buffer, display controller). The smaller display portion thus functions as a “second display” that offers limited functionality to depict information (e.g., time-of-day, power levels, cell signal strength, control settings, song title, and so forth) while conserving power.
Implementing multiple display modes on a single display provides flexibility to designers of multi-function devices. They are able to configure modes of operating the display to support different capabilities and satisfy power requirements, without the cost and complexity of adding a second, separate display.
A single display with multiple display modes may be implemented in any number of devices. For discussion purposes, the display modes are described in the context of portable electronic devices, such as portable entertainment devices, portable digital assistants (PDAs), cellular phones, audio players, video players, notebook computers, digital cameras, laptop computers, and the like. Exemplary implementations are shown in
Portable Entertainment Device
Device 100 has a body or casing 102 and a display panel 104 mounted centrally of the casing 102. The display panel 104 is a flat panel, color display with sufficient resolution to depict digital images or motion video. The display panel may optionally be implemented with a touch screen overlaying the display to facilitate user input. The display panel may be implemented using different technologies, including LCD (liquid crystal display), OLED (organic light emitting diode), plasma, and DLP (digital light processing).
Function control buttons 106 are positioned left of the display panel 104 to support user control of the device 100. In the illustrated implementation, the control buttons 106 include four directional buttons and an entry key. Shuttle control buttons 108 are positioned right of the display panel 104 to facilitate video playback. One or more other buttons may also be provided to permit control of other functions, such as volume, brightness, contrast, and so forth. It is noted that the device 100 is just one exemplary implementation, and that other configurations and physical layouts, with more or less buttons and features, may be used.
The display panel 104 may be operated in multiple modes, with each mode offering different functionality and varying levels of power consumption. Operating the single display panel in multiple modes enables the device 100 to offer essentially the functionality as conventional devices with two displays, but without the cost, complexity, and power considerations of adding a second display. In the described implementation, there are two modes of operation. In a first mode, the entire display panel is fully operational, where substantially all pixels and any backlighting are powered on and available to present image data in a full display mode area 110. The pixels are drawing power and ready for illumination, even if not all of them are used to depict images. While this mode offers the highest quality user experience, it is also consumes the most power of any mode of operation.
The display panel 104 may alternatively be operated in a second mode in which part of the display is operational while the rest of the display is powered off. In the second mode, the display panel provides a smaller area for depicting a reduced amount of image data (e.g., alphanumeric characters, small graphics, etc.), as represented by the partial display mode area 112. This partial display mode may be implemented by activating a subset of the pixels, while powering off or inactivating the remaining pixels. In
In addition to power conservation, the multiple display modes offer versatility from a single display. For instance, suppose the user wants to play music on the portable entertainment device 100. The device operates in the full display mode while the user browses the audio library and selects a song for play.
Once the user selects a song, the device 100 transitions to the partial display mode to conserve power, while still depicting enough information to inform the user of the current status of audio playback.
Switching between full and partial display modes can be achieved in a number of ways. One approach is use of a mechanical switch that allows a user to physically choose a desired mode of operation. In
While only two modes are described in this implementation, more than two modes may be implemented. For instance, the device may be configured to operate the display panel in three modes, where the first mode involves a full screen, a second mode drives pixels in a first portion of the screen and a third mode drives another portion of the screen.
Device Architecture
A graphics driver 408 writes the image data into the frame buffer 404. The graphics driver 408 is illustrated as being implemented in software that executes on the CPU 402, but may alternatively be implemented in hardware. The CPU 402 may be a general-purpose processing unit, or a specially-tailored graphics processing unit.
The display controller 406 reads the image data from the frame buffer memory 404. If the frame buffer memory 404 stores image data for several graphic surfaces, the display controller 406 may also combine the surfaces into a single image. The display controller 406 sends the image data to driver circuits for the display panel. Generally, there are one or more row driver circuits to turn on rows of pixels in sequential order and one or more column driver circuits to place the image data received from the display controller 406 into the appropriate columns of pixels. The rows are turned on at a fast cycle rate to refresh the image data (e.g., 60 times per second).
In the implementation of
Device 100 may optionally be configured with backlighting to provide additional lighting on the display panel 104. A backlight component 414 has three LEDs 416(1), 416(2), and 416(3) that are individually controlled by CPU 402 to selectively light all or portions of the display panel 104. The LEDs may be white or multi-color indicators. The LEDs are positioned along an edge of the display panel so that each illuminates approximately one-third of the panel. It is noted that more or less lights may be employed, and other backlighting arrangements may be used, including positioning the backlighting underneath the display panel.
A battery 418 supplies power to the components and display panel of the entertainment device 100. The battery 418 is preferably a rechargeable battery, such as a lithium-based battery.
The device 100 is further configured with a panel mode control driver 420 to select a display mode for the display panel 104. The panel mode control driver 402 implements mode switching functionality to choose among the various display modes, including the full display mode and the partial display mode. It is capable of controlling power to all or portions of the display panel 104, the backlight 414, and other circuitry that supports the display panel (e.g., frame buffer memory 404, display panel controller 406). The panel mode control driver 420 is illustrated as being implemented in software that executes on the CPU 402, but may alternatively be implemented at least partially in hardware.
The panel mode control driver 420 independently controls the row drivers 410, column drivers 412, backlight LEDs 416, frame buffer memory 404, and/or panel controller 406 to support multiple display modes. When in full display mode, the panel mode control driver 420 directs the row drivers and column drivers to drive all pixels of the display panel so that the pixels are active and ready for use. Image data received from the frame buffer memory 404 via the display panel controller 406 is placed on all columns of pixels and the rows are cycled to depict full screen images. Additionally, the panel mode control driver 420 turns on all LEDs 416(l)-416(3) of the backlight component 414. Accordingly, in the full display mode, the device 100 is capable of supporting applications that use a full-featured display. A user may use the full display mode to play movies, show digital images, read and write email, navigate menus, browse the Internet, and so forth.
The panel mode control driver 420 may switch from the full display mode to a partial display mode to conserve power or support a different set of display capabilities. In the partial display mode, the panel mode control driver 420 controls the row and column drivers to drive a subset of pixels. For instance, the panel mode control driver 420 might turn on the top row driver 410(1) and the middle column driver 412(2) exclusively of the other row and column drivers to activate exclusively the pixels in the top-middle section of the display indicated by the dashed rectangle. Image data received from the frame buffer memory 404 via the display panel controller 406 is placed on the middle-third columns (e.g., columns 220-439) driven by middle column driver 412(2) and the first half of the rows (e.g., rows 0-239) are cycled by top row driver 410(1) to depict images on a fraction of the screen. Thus, one-sixth of the pixels are active, while five-sixth of the pixels are inactive and not drawing power.
Additionally, in the partial display mode, the driver 420 might turn off all LEDs or turn on just the middle LED 416(2) of the backlight component 414. Image data stored in the frame buffer memory 404 can also be reduced to supply data only to the pixels in the top-middle section of the screen.
Thus, in the partial display mode, the device supports applications that use a limited-featured or reduced-size display. Information about a song being played (e.g., album title, song title, artist name), time-of-day, or system information (e.g., battery level, phone signal strength, mode data, etc.) are all examples of image data that might be displayed in the partial display mode. Since fewer components are driving fewer pixels, the partial display mode consumes significantly less power than the full display mode. Additional power savings result from powering down unused column and row drivers, and accessing less image data in the buffer memory.
While selection of separate drivers is illustrated in
Also, while the illustrated example left one-sixth of the display panel operational in the partial display mode, there are many other possible configurations. In one alternative, the partial display mode might be configured to activate the pixels in the right-third of the display panel through controlling the right column driver 410(3) and both row drivers 410(1) and 410(2). Or, perhaps, the partial display mode might be configured to activate the middle of the display panel by selecting the lower rows of first row driver 410(1) and the upper rows of second row driver 410(2) and selecting the columns of middle column driver 412(2). With control of individual rows and columns, any number of layouts may be achieved in the partial display mode.
As noted above, the partial display mode may be implemented by selectively turning on and off the backlights, independently of controlling the row and column drivers. For example, the panel mode control driver 420 may turn on the first LED 416(1) while leaving the other two off to illuminate only the left side of the display panel 104. Leaving two-thirds of the backlighting off conserves power.
With this architecture, the panel mode control driver 420 can activate the appropriate small frame buffer(s) 502 and display panel controller(s) 504 when operating in partial display mode. For instance, to display images in the top-middle screen area referenced by the dashed rectangle, the panel mode control driver 420 activates the column driver 412(2), and the corresponding frame buffer 502(2) and display controller 504(2), to place image data on the appropriate pixels in this area. This allows the external frame buffer memory 404 and display panel controller 406 to power down, thereby conserving additional power.
While two different architectures are shown in
Other Representative Devices
The architectures for implementing multiple display modes on a single display panel can be implemented in many types of electronic devices. In addition to the portable entertainment device 100 of
Notice that the dual display mode allows the same display panel to be used for both full-featured functionality (e.g., presentation and navigation of menu in
The lid 802 pivots about the hinge between an open position to expose the display panel 806 and keypad 808 (
The panel mode control driver 420 operates the display panel 806 in the full display mode when the lid 802 is flipped open (
Dual Display Mode Operation
For discussion purposes, the process 1200 is described with reference to the portable entertainment device 100 and architecture shown in
At block 1202, the device 100 operates in the full display mode, such as that illustrated in
At block 1204, the panel mode control driver 420 detects a full-to-partial mode change event, which initiates a conversion from the full display mode to the partial display mode. Such an event may be mechanical detection of the user interaction with the device, such as pressing the switch 114 on device 100, or sliding closed the covers on the audio player 600, or closing the lid of cellular phone 800. Alternatively, the event may be triggered by an activity time-out that suggests the user is no longer interacting with the device. For a time-out condition, the device converts to the partial display mode as a way to conserve power. Another full-to-partial mode change event might be generated by software running on the device. Audio playback software, for example, may direct the device to convert to the partial display mode in response to a user selecting a particular song title or album. Still another full-to-partial mode change event might be triggered by direct user request. The user may stipulate conditions when to operate in partial display mode, or may input a direct command to change the display mode. Another triggering event may be battery level, where the device switches to partial display mode when the battery level falls below a certain threshold.
At block 1206, in response to the full-to-partial mode change event, the device 100 operates in the partial display mode, such as that illustrated in
The partial display mode allows the device to conserver power, yet still provides useful information to assist the user when interacting with the device.
At block 1208, the panel mode control driver 420 detects a partial-to-full mode change event, which triggers a conversion from the partial display mode back to the full display mode. The partial-to-full mode change event may be mechanically triggered (e.g., pressing the switch 114 on device 100, opening a flip phone, etc.) or a software generated event. In response to the change event, the device begins operating in full display mode again (block 1202).
At block 1302, the data designated for either the large display or the small display is received. At block 1304, the panel mode control driver 420 determines whether the data is intended for presentation on the large display or the small display. If intended for the large display (i.e., the “large” branch from block 1304), the panel mode control driver 420 operates the single display panel in full display mode to depict the data using a fully active display. Conversely, if the data is intended for the small display (i.e., the “small” branch from block 1304), the panel mode control driver 420 operates the single display panel in partial display mode to depict the data using a limited-feature display where part of the display panel is powered down.
Additionally, there can be a cost associated with switching between full and partial display modes. Accordingly, the device may optionally determine, before making a switch, whether the data is well suited for the opposite display mode given the intended display duration. For instance, if the device is operating in full display mode and the data is designated for a small display, the device may first determine the computation and power cost of switching to a partial display mode for the duration of depicting the data and then determine whether switching to the partial display mode is worth the cost.
Although the invention has been described in language specific to structural features and/or methodological acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms of implementing the claimed invention.
