Patent Application
20060146042
Contained herein is material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent disclosure by any person as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights to the copyright whatsoever.
The present invention relates generally to the field of power management. More specifically, the present invention relates to power management associated with displays.
As more functionality is integrated into modern computer systems, the need to reduce power consumption becomes increasingly important, especially when the computer systems are mobile systems that operate on battery power. Users of mobile systems continuously expect longer battery life. Mobile system designers try to address the need for longer battery life by implementing power management solutions that include reducing clock speeds of processor, reducing clock speeds of chipset, and disabling unused components
The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which like references indicate similar elements and in which:
For one embodiment, a method to reduce power consumption of a computer system having an organic light emitting diode (OLED) display is disclosed. The reduction of power consumption may be performed by transitioning a display area from one display size to another display size.
In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known structures, processes, and devices are shown in block diagram form or are referred to in a summary manner in order to provide an explanation without undue detail.
Computer System
Chipset 107 may be coupled to the bus 105. The chipset 107 may include a memory control hub (MCH) 110. The MCH 110 may include a memory controller 112 that is coupled to system memory 115 (e.g., random access memory (RAM), read-only memory (ROM), etc.). The system memory 115 may store data and sequences of instructions that are executed by the CPU 102 or any other processing devices included in the computer system 100. For example, in addition to the CPU 102, the computer system 100 may include a secondary CPU or controller (not shown).
The MCH 110 may include a display controller 113. A display 130 may be coupled to the display controller 113. The display 130 may be a liquid crystal display (LCD) which is commonly used in devices such as flat panel displays for laptop computers, personal digital assistants, cellular phones, and the like. LCDs frequently use a cold cathode fluorescent lamp (CCFL) or similar devices as a backlight. The CCFLs may consume large quantities of power.
Some manufacturers recently use OLED materials as a backlight source. OLED is a technology developed by the Eastman Kodak Company of Rochester, N.Y. OLEDs are thin film materials which emit light when excited by electric current. Since OLEDs emit light of different colors, they are be used to make displays. Displays made from OLED materials, therefore, do not need additional backlights, thus eliminating the need for the CCFL. OLED displays are usually lightweight and may operate efficiently at relatively low voltages, thus consuming less power from the system. For one embodiment, the display 130 may be an OLED display or a display that includes picture elements (pixels) having brightness individually controllable.
The chipset 107 may also include an input/output control hub (ICH) 140. The ICH 140 is coupled with the MCH 110 via a hub interface. The ICH 140 provides an interface to input/output (I/O) devices within the computer system 100. The ICH 140 may be coupled to a peripheral bus (e.g., Peripheral Component Interconnect (PCI) bus). Thus, the ICH 140 may include a PCI bridge 146 that provides an interface to a PCI bus 142. The PCI bridge 146 may provide a data path between the CPU 102 and peripheral devices. An audio device 150 and a disk drive 155 may be connected to the PCI bus 142. For wireless communication, an antenna (not shown) may also be coupled to the PCI bus 142. Although not shown, other devices (e.g., keyboard, mouse, etc.) may also be connected to the PCI bus 142. The computer system 100 may use a direct current (DC) power source such as, for example, a battery. Alternatively, it may use an alternating current (AC) power source by, for example, plugging into an electrical connector. The computer system 100 may consume the most power when it is in a normal power mode. The computer system 100 may consume less power when it is in a low power mode (e.g., suspend or standby mode), which may be important when a DC power source is used.
Display Area
It may be noted that the display 250 may also be an OLED display. That is, the display 250 may include pixels that emit light (self-luminous pixels) when an electric current passes through them. There may be no requirement to have a backlight, as may be required when the display 250 is a LCD. Furthermore, because the current passing through each of the pixels of the display 250 may be controlled, each pixel may emit light independently of the others. This may be advantageous because the power consumption may occur mostly by the pixels that are turned on (i.e., emit light). Those pixels that are turned off (i.e., not emit light) may not consume any power. In the example when the display 250 is an OLED display, the display controller 113 would still output or turn on all of the pixels enabling the display area 200 to occupy the entire display screen. The properties of pixels in an OLED display are known to one skilled in the art.
For another embodiment, the transformation may be performed in software using, for example, video driver and the Operating System (OS), such that the display content may be reduced with little loss of readability. For example, the OS may have a ‘simple’ mode where a lot of the graphic details on icons, tool bars etc may be eliminated to save space. The OS may have an entirely new user-interface mode that can be switched to accommodate smaller display areas as those typically used in cell phones, personal digital assistants (PDA), etc. The interface protocol between the display controller 113 and the display 350 (e.g., the Low Voltage Differential Signaling (LVDS) interface) may also be enhanced to support such modes. For example, the display controller 113 may send only data for a fraction of the screen and the display 350 may fill in the rest of the areas with black (pixels turned off). Power may be saved on the interface also by not having to send a lot of black pixels. The new interface may default all pixels to black unless data is sent for that pixel. Referring to the example in
Power Monitoring Logic
For one embodiment, a power monitoring logic (not shown) may be used to monitor a current charge level of a DC power source (e.g., battery) that is used to provide power to the computer system 100. The power monitoring logic may be coupled to the display controller 113. The power monitoring logic may be implemented in software, hardware or a combination of both software and hardware.
The power monitoring logic may generate a signal when the current charge level of the battery decreases to a certain predetermined level. There may be multiple predetermined levels. The signal may be sent to the display controller 113 and may indicate that reducing the current size of the display area may be necessary. For example, when the current charge level of the battery is at 50% of its full capacity, the display area may be reduced from its normal full size. When the battery capacity is at 15% of its full capacity, the display area may be further reduced from a current size. For one embodiment, when the computer system 100 is powered on, and the power monitoring logic detects that a battery power source is being used but the battery is at less than its full capacity, a reduced display area (e.g., display area 300) may be used to display information.
For one embodiment, the power monitoring logic may also generate a signal when the computer system 100 switches from a DC power source to an AC power source. When this signal is received by the display controller 113, the size of the display area may be restored to its normal full size. This full size may be a largest size possible with the display 350. Alternatively, this full size may be a size previously specified even though it may not be a largest size possible with the display 350.
Displayed Information
For one embodiment, the information included in a display area may be the same even though the display area may have different sizes. For example, the information included in the display area 300 may be similar to the information included in the display area 200 illustrated in
Pixels associated with the display area 360 may be turned on, and pixels associated with the area 361 may be turned off. For one embodiment, the display area 360 may be used when the computer system 100 is in the suspend or standby mode. For example, the information displayed in the display area 360 may be limited to information that is sufficient for quick reference for on the go situations including calendar appointments, email headers, reminders, to do list, etc.
Multiple Display Areas
For one embodiment, information displayed in the two display areas 370 and 390 may be controlled by two different graphics controllers. For example, the display area 370 may be associated with the display controller 113, and the display area 390 may be associated with a secondary display controller (not shown). For one embodiment, all of the multiple display areas (e.g., display areas 370 and 390) may be visible on the OLED display at the same time. Alternatively, there may only be one display area (e.g., display area 370 or display area 390) visible at a time. For one embodiment, the secondary display controller may be a low power graphics controller. The secondary display controller may be active when the computer system 100 is in the suspend/standby mode or when the charge level of the DC power source is low. The secondary display controller may allow the computer system 100 to be in a low power consumption state while still making some information in the computer system 100 available.
Display Process
Although the examples described above includes rectangle display areas, it may be possible for the display controller to set the display area to be in different forms such as, for example, circle, triangle, etc. The display controller may also set the display area in different locations. Furthermore, although the descriptions refer to the OLED displays, one skilled in the art will recognize that other displays implemented with display technologies that allow pixels to be individually controlled, including controlling the brightness of each pixel, may also be used.
The operations of the various techniques described above may be implemented as sequences of computer program instructions that are stored in a memory which may be considered to be a machine-readable storage media. The memory may be RAM, ROM, a persistent storage memory, such as mass storage device or any combination of these devices. The instructions may be loaded into memory of the computer system from a storage device or from one or more other computer systems (e.g. a server computer system) over a network connection. The instructions may be stored concurrently in several storage devices (e.g. RAM and a hard disk, such as virtual memory). Consequently, the execution of these instructions may be performed directly by a processor. In other cases, the instructions may not be performed directly or they may not be directly executable by the processor. Under these circumstances, the executions may be executed by causing the processor to execute an interpreter that interprets the instructions, or by causing the processor to execute a compiler which converts the received instructions to instructions that which can be directly executed by the processor. In other embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement embodiments of the present invention. Thus, the present invention is not limited to any specific combination of hardware circuitry and software, or to any particular source for the instructions executed by the computer system.
Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
