BACKGROUND OF THE INVENTION

[0001] The invention is related to the display of images on a display screen of a portable computing device. More specifically, the invention is related to systems and methods for switching an orientation of images appearing on a display screen of a portable computing device when an orientation of the portable computing device itself is changed.

[0002] Portable computing devices, such as smart phones, typically include a display screen. Many portable computing devices are configured such that an orientation of the images that appear on the display screen can change when an orientation of the portable computing device itself changes.

[0003] Figures 1 A and 1 B illustrate a smart phone 100 in first and second orientations, respectively. The smart phone 1 10 includes a speaker aperture 140 towards one end of the smart phone 1 1 0 which is located so that it will be adjacent a user's ear when the smart phone 1 1 0 is held adjacent to one side of a user's head during a telephone call. A control button 1 30 is located at the other end of the smart phone 1 10. A display screen 1 20 is located between the speaker aperture 140 and the control button 130.

[0004] Figures 1 A and 1 B depict an e-mail message on the display screen 120 of the smart phone 1 10. When the smart phone 1 1 0 is in a first orientation, as illustrated in Figure 1 A, the e-mail message appears on the display screen 120 in a first orientation. When the smart phone 1 10 is rotated 90° counterclockwise to a second orientation, a display unit of the smart phone 1 10 causes the image of the e-mail message to appear on the display screen 120 in a second orientation. This change in the orientation of the image appearing on the display screen 120 is made to help a user to view the image. The assumption is that the user will find it easier to view of the image if the image is always orientated the same way, regardless of the orientation of the smart phone 1 1 0 and its associated display screen.

[0005] One or more orientation sensors in the smart phone 1 10 sense when the orientation of the smart phone 1 10 changes from the first orientation illustrated in Figure 1 A to the second orientation illustrated in Figure 1 B. When the orientation sensor(s) detect the change in orientation of the smart phone, a display unit of the smart phone 1 10 causes the images appearing on the display screen 120 to change from the first orientation illustrated in Figure 1 A to the second orientation in Figure 1 B.

[0006] There is typically a small time lag between the time that the orientation of the smart phone 1 10 changes and the time that the display unit causes the orientation of the images on the display screen 120 to change. This delay can be due, at least in part, to the time required for the orientation sensor(s) to detect and register the change in orientation of the smart phone 1 1 0, and for this information to be passed along to the display unit. Also, the display unit itself may require some time to cause a corresponding change in the orientation of the images on the display screen 120.

[0007] Because there are a wide range of tilted positions at which the smart phone 1 10 could be held by a user between the orientation illustrated in Figure 1 A and the orientation illustrated in Figure 1 B, the orientation sensor(s) are typically designed to report a change from the first orientation to the second orientation only after the smart phone 1 10 has been rotated a predetermined number of degrees counterclockwise from the position illustrated in Figure 1 A. This predetermined number of degrees could be 45°, or some other amount. Likewise, when the smart phone starts in the position illustrated in Figure 1 B and begins to rotate clockwise, the orientation sensor(s) are typically configured to report a change from the second orientation back to the first orientation only after the smart phone has rotated a predetermined number of degrees clockwise. [0008] If a user is holding the smart phone 1 10 while moving, such as while walking, jogging, or perhaps riding in a vehicle, the user may end up holding the smart phone 1 10 in a tilted position that approaches the point at which the orientation sensor(s) will register a change from one orientation to the next. Continued movement can cause the user to frequently tilt the smart phone 1 10 back and forth past the point at which the orientation sensor(s) report changes between first and second orientations. When this occurs, the display unit may cause the images being displayed on the display screen 120 to rapidly switch back and forth between the first and second orientations. This makes it difficult for the user to view and/or read to the images on the display screen 120.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figures 1 A and 1 B depict a portable computing device in first and second orientations, and illustrate how images on a display screen of the portable computing device can switch from a first orientation to a second orientation when the orientation of the portable computing device itself changes;

[0010] Figure 2 is block diagram illustrating elements of a display unit of a portable computing device;

[0011] Figure 3 is a diagram of various elements of a processor that could form part of a display unit of a portable computing device;

[0012] Figure 4 is a flowchart illustrating steps of a first method for controlling how images are displayed on a display screen of a portable computing device; and

[0013] Figure 5 is a flowchart illustrating steps of a second method for controlling how images are displayed on a display screen of a portable computing device. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] The following detailed description of preferred embodiments refers to the accompanying drawings, which illustrate specific embodiments of the invention. Other embodiments having different structures and operations do not depart from the scope of the present invention.

[0015] Figure 2 illustrates elements of a display unit 200 that controls the display of images on a display screen of a portable computing device. The portable computing device could be any type of device that is intended to be handheld, and which includes a display screen. This could include portable computers, cellular telephones, smart phones, digital cameras, music players, GPS navigation units, as well as other types of similar devices. Among other things, the display unit 200 is configured to alter the orientation of images on the display screen when a user repositions the portable computing device into a new orientation.

[0016] The display unit 200 includes a display screen 202, and a display control unit 204 that is configured to control how images are displayed on the display screen 202. As mentioned above, the display control unit 204 is configured to alter the orientation of images on the display screen 202 when the orientation of the portable computing device itself is changed.

[0017] An orientation determining unit 206 is responsible for sensing and reporting the orientation of the portable computing device. The orientation determining unit 206 could include one or more accelerometers which are capable of sensing gravity. Determining the direction in which gravity is acting would help to determine what direction is "up," and what direction is "down" relative to the current orientation of the portable computing device. The orientation determination unit 206 could also include gyroscopes and/or other inertial sensors that are configured to detect movements of the portable computing device as the user repositions the portable computing device. [0018] Images appearing on a display screen of a portable computing device are typically displayed in a limited number of orientations on the display screen. The images are usually aligned with edges of a generally rectilinear display screen, and the images usually are only displayed in, at most, four orientations that are separated by 90° of rotation.

[0019] In contrast, most portable computing device could be held in almost an infinite number of different orientations. For purposes of determining how to display images on a display screen of the portable computing device, it is usually only necessary to define a limited number of predetermined "orientations" for the portable computing device. The orientation determination unit 206 determines the actual present orientation of the portable computing device, and then determines which of the predetermined orientations corresponds to the actual orientation. The orientation determination unit 206 then reports that predetermined orientation. The display control unit 204 causes images appearing on the display screen 202 to appear in an orientation that corresponds to the predetermined orientation reported by the orientation determination unit 206.

[0020] If images are only displayed on the display screen of a portable computing device in four orientations separated by 90° of rotation, it is only necessary to define four corresponding orientations for the portable computing device. For example, the portable computing device illustrated in Figure 1 A could be considered to be in an upright, vertical orientation. If the portable computing device 1 10 is rotated 1 80° clockwise, or counterclockwise, from the position illustrated in Figure 1 A, that position could be considered an inverted, vertical orientation. The position illustrated in Figure 1 B could be considered a first horizontal orientation. If the portable computing device 1 10 is rotated 180° clockwise, or counterclockwise, from the position illustrated in Figure 1 B, that position could be considered a second horizontal orientation.

[0021] Having defined four predetermined orientations for the portable computing device 1 10, the orientation determination unit 206 of the portable computing device would determine the actual orientation of the portable computing device 1 1 0 at a given moment in time, and then determine which of the four predetermined orientations corresponds to the actual orientation. In some embodiments, a predetermined orientation could be defined to correspond to a range of actual orientations. For example, the upright, vertical orientation could correspond to the actual orientation illustrated in Figure 1 A, and any other orientation where the portable computing device is rotated clockwise or counterclockwise by 45° or less away from the orientation illustrated in Figure 1 A. The first horizontal orientation could correspond to the actual orientation illustrated in Figure 1 B, and orientations where the portable computing device is rotated clockwise or counterclockwise by 45° or less away from the orientation illustrated in Figure 1 B.

[0022] Of course, the actual range of orientations that correspond to each predetermined orientation could vary. For example, the upright vertical orientation could correspond to the actual orientation illustrated in Figure 1 A, and any orientation where the portable computing device is rotated clockwise or counterclockwise by 60° or less away from the orientation illustrated in Figure 1 A. The first horizontal orientation could correspond to the actual orientation illustrated in Figure 1 B, and orientations where the portable computing device is rotated clockwise or counterclockwise by 30° or less away from the orientation illustrated in Figure 1 B. Each predetermined orientation could be defined to correspond to any particular range of actual orientations that make sense for a given portable computing device.

[0023] In other embodiments, the orientation determination unit 206 could compare the actual orientation of the portable computing device to the predetermined orientations, and determine which of the predetermined orientations is closest to the actual orientation. The orientation determination unit 206 would then report that predetermined orientation, and the display control unit 204 would cause images to appear on the display screen 202 in an orientation that corresponds to the reported predetermined orientation. [0024] In the following description, there are references to a portable computing device changing its orientation. For example, the portable computing device could change from a first orientation to a second orientation. This actually means that the orientation determination unit 206 has determined that the orientation of the portable computing device has changed such that it is now closer to a second predetermined orientation than a first predetermined orientation.

[0025] For example, if a portable computing device 1 1 0 starts in a first predetermined orientation corresponding to the upright vertical position illustrated in Figure 1 A, the portable computing device 1 10 could change its orientation by small amounts and the orientation determination unit 206 would continue to report that the portable computing device is still in the first predetermined orientation. The orientation determination unit 206 would only report that the portable computing device 1 10 has moved to a second, different predetermined orientation once the portable computing device has changed its actual orientation such that the actual orientation now falls within a range of orientations that correspond to the second predetermined orientation.

[0026] The display unit 200 also includes a switching time period determining unit 208 that is configured to determine how frequently and/or how quickly the user is causing the orientation of the portable computing device to change. The switching time period determining unit 208 could utilize various methods to determine how frequently and/or how quickly the user is causing the orientation of the portable computing device to change, some of which are discussed below. However, the switching time period determining unit 208 could also use other methods which are not described herein. Thus, the description of several methods should in no way be considered limiting of the ways in which the switching time period determining unit 208 could operate. [0027] Figure 3 illustrates elements of a computer processor 350 that can be used as part of the display unit 200 of a portable computing device, as illustrated in Figure 2. The display unit 200, and individual ones of its various elements, could include multiple processors 350, along with their operating components and programming, each carrying out a specific or dedicated portion of the functions performed by the display unit 200.

[0028] The processor 350 shown in Figure 3 may be one of any form of a general purpose computer processor used in accessing an IP-based network, such as a corporate intranet, the Internet or the like. The processor 350 comprises a central processing unit (CPU) 352, a memory 354, and support circuits 356 for the CPU 352. The processor 350 also includes provisions 358/360 for connecting the processor 350 to other elements of the display unit 200, or to other elements of a portable computing device. The provisions 358/360 are shown as separate bus structures in Figure 3, however, they may alternately be a single bus structure without degrading or otherwise changing the intended operability of the processor 350.

[0029] The memory 354 is coupled to the CPU 352. The memory 354, or computer-readable medium, may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, flash memory or any other form of digital storage, local or remote, and is preferably of non-volatile nature. The support circuits 356 are coupled to the CPU 352 for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like.

[0030] A software routine 362, when executed by the CPU 352, causes the processor 350 to perform processes of the disclosed embodiments, and is generally stored in the memory 354. The software routine 362 may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU 352. Also, the software routines could also be stored remotely from the CPU. For example, the software could be resident on servers and memory devices that are located remotely from the CPU, but which are accessible to the CPU via a data network connection.

[0031] The software routine 362, when executed by the CPU 352, transforms the general purpose computer into a specific purpose computer that performs one or more functions of a display unit 200, or an element of a display unit 200. Although the processes of the disclosed embodiments may be discussed as being implemented as a software routine, some of the method steps that are disclosed therein may be performed in hardware as well as by a processor running software. As such, the embodiments may be implemented in software as executed upon a computer system, in hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware. The software routine 362 of the disclosed embodiments is capable of being executed on any computer operating system, and is capable of being performed using any CPU architecture.

[0032] The switching time period determining unit 208 of the display unit 200 illustrated in Figure 2 utilizes input from the orientation determining unit 206 to determine how frequently the orientation of a portable computing device is changing for the purpose of determining how rapidly the display control unit 204 should cause the orientation of images on the display screen 202 to change. If the orientation of the portable computing device only changes infrequently, then the display control unit 204 will cause images on the display screen 202 to change orientation quickly after the orientation of the portable computing device changes. However, if the orientation of the portable computing device is changing relatively rapidly, perhaps changing back and forth between first and second orientations on a frequent basis, the display control unit 204 will delay changing the orientation of the images on the display screen 202 for a certain period of time after each change in orientation of the portable computing device. This is done because rapid changes in the orientation of the portable computing device may mean that the user is moving, such as walking, jogging, or perhaps riding in a vehicle. The rapid orientation changes may not be deliberate. If the orientation of the images on the display screen 202 is quickly switched back and forth between first and second orientations each time that the portable computing device itself moves between first and second orientations, the rapid changes in the orientation of the images may make it difficult for the user to view and understand the images. To make it easier for the user to view the images on the display screen 202, the display control unit 204 deliberately delays changing the orientation of the images on the display screen 202 for a certain period of time after each sensed change in the orientation of the portable computing device.

[0033] For example, if the switching time period determining unit 208 indicates that the portable computing device is rapidly transitioning back and forth between first and second orientations, and the orientation determining unit 206 notes that the portable computing device just switched from the first orientation to the second orientation, the display control unit 204 delays changing the orientation of the images on the display screen 202 from a corresponding first orientation to a corresponding second orientation. If the portable computing device then moves back into the first orientation before the delay period expires, the images always remain in the first orientation on the display screen 202, which can make it easier for the user to read and understand the images.

[0034] Figure 4 illustrates steps of a first method that would be performed by a display unit 200 as illustrated in Figure 2 to control how images are displayed on a display screen. The method 400 begins and proceeds to step S402, wherein the switching time period determining unit 208 records the time at which a first change in the orientation of a portable computing device occurs. As explained above, a change in orientation occurs not when the actual orientation of the portable computing device changes, but rather when the orientation determination unit 406 determines that the orientation of the portable computing device has changed such that the actual orientation of the portable computing device no longer corresponds to a first predetermined orientation, and instead now corresponds to a second predetermined orientation.

[0035] In step S404, the switching time period determining unit 208 records the time at which another change in the orientation of a portable computing device occurs. This could be a change back to the original orientation, or a change to yet a new orientation. In step S406, the switching time period determining unit 208 determines the duration of a switching time period that elapsed between the last two changes in the orientation of the portable computing device.

[0036] In step S408, a check is performed to determine whether the switching time period is less than a threshold time period. If the switching time period is greater than the threshold time period, indicating that the orientation of the portable computing device is changing relatively slowly, in step S410 a delay time period is set to a first value. If the switching time period is less than the threshold time period, indicating the portable computing device is changing orientation relatively rapidly, in step S412 the delay time period is sent to a second value which is greater than the first value.

[0037] The delay time period is used by the display control unit 204 in step S414 to determine how rapidly to change the orientation of images appearing on a display screen 202. When the first delay time period is used, the orientation of the images on the display screen is quickly changed each time the orientation of the portable computing device changes to match the change in the orientation of the portable computing device itself. In fact, in some embodiments, the first delay time period may be equal to zero.

[0038] On the other hand, when the second delay time period is being used, because the orientation of the portable computing device is changing relatively rapidly, the display control unit 204 deliberately waits for a certain period of time, equal to the amount of the second delay time period, after each change in the orientation of the portable computing device before changing the orientation of the images on the display screen 202. As explained above, this may help a user to view and understand the images on the display screen.

[0039] In some embodiments, the first and second delay time periods may be pre-set for a particular display unit 200 and/or portable computing device incorporating the display unit 200. In other embodiments, one or both of the first and second delay time periods may be adjustable based on user input. Similarly, the threshold used in step S408 could be preset, or it could be adjustable based on user input.

[0040] The method then proceeds to step S416, where a check is performed to determine if display activity has been terminated. This could occur because the portable computing device is being turned off. This also could occur if the user has not performed any activity for a certain period of time, and the display unit is switched into a power saving mode in which images are no longer displayed. If display activity is terminated, the method ends. If not, the method loops back to step S404, and the steps described above are repeated.

[0041] Figure 5 illustrates steps of another method for controlling the display of images on a display screen. The method 500 begins and proceeds to step S502, where the switching time period determining unit 208 of a display unit 200 determines the duration of a first switching time period. The switching time period is the duration of time period that elapses between the first time that a portable computing device changes its orientation and the next time that the portable computing device changes its orientation. The length of the first switching time period could be determined as described above in connection with method illustrated in Figure 4, or using an alternate method. For example, the switching time period determining unit 208 could start a timer the first time that the orientation of a portable computing device changes, and then stop the timer the next time that the portable computing device changes its orientation. Of course, any other method could also be used to determine the length of the first switching time period.

[0042] In step S504, the switching time period determining unit 208 of the display unit 200 determines the duration of at least one additional, subsequent switching time period. In some embodiments, step S504 could involve determining the duration of just one additional switching time period. In alternate embodiments, step S504 could involve determining the durations of multiple subsequent switching time periods.

[0043] In step S506, the values of multiple switching time periods are averaged to generate an average switching time period. In some embodiments, the average switching time period could be calculated based on a predetermined number of switching time periods that were determined in steps S502 and/or S504. For example, the average switching time period could be based on the last two determined switching time periods, or the last three determined switching time periods.

[0044] In alternate embodiments, the average switching time period could be based on any determined switching time periods that were determined within a predetermined time window. For example, the average switching time period could be calculated based on any switching time periods that were determined within the last 60 seconds. If only one switching time period was calculated within the last 60 seconds, then that switching time period would become the average switching time period. If no changes in orientation were sensed within the last 60 seconds, there would be no switching time periods to use to calculate the average switching time period, in which case the average switching time period could be set to a predetermined large number which is greater than the threshold time period discussed below.

[0045] In step S508, a check is performed to determine whether the average switching time period is less than a threshold time period. If the average switching time period is greater than the threshold time period, indicating that the orientation of the portable computing device is changing relatively slowly, in step S510 a delay time period is set to a first value. If the average switching time period is less than the threshold time period, indicating the portable computing device is changing orientation relatively rapidly, in step S512 the delay time period is sent to a second value which is greater than the first value.

[0046] In step S514, the delay time period that has been set is used to control how rapidly the orientation of images on a display screen are changed after each change in the orientation of the portable computing device itself. The method then proceeds to step S51 6, where a check is performed to determine if display activity has been terminated. If display activity is terminated, the method ends. If not, the method loops back to step S504, and the steps described above are repeated.

[0047] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0048] As used herein, the term "and/or," when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination." [0049] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.