1. Field of the Invention
The present invention relates in general to the field of information handling system touchscreen input/output devices, and more particularly to multi-zone touchscreen sensing at a portable information handling system.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Consumers and enterprises continue to adopt portable information handling systems to perform personal and business computing functions. One factor that has increased adoption of portable information handling systems is the relative ease with which an end user can interact with applications through a touchscreen display integrated in a portable information handling system. By having input devices presented at a touchscreen display users can interact with applications without a physical keyboard or mouse. For example, tablet information handling systems provide users with a convenient way to read content. The user selects the content with touches made at the touchscreen with one hand while holding the tablet information handling system with the other hand. Once desired content is presented at the touchscreen, the user browses the content with gestures made at the touchscreen with one hand while the other hand holds the tablet information handling system, such as a page-flipping gesture to have the next page of content presented at the touchscreen. If the user needs to make complex inputs to the tablet information handling system, such as writing a document or e-mail, the user can place the tablet information handling system on a table or stand and then use a wireless keyboard or other input device to interact with the tablet information handling system.
Touchscreen displays generally operate with a capacitive touch array disposed in a transparent cover placed over a liquid crystal display. The capacitive touch array detects touches with a touch controller interfaced with the array that reports the position of the touch to an operating system. The operating system responds to detected touches based upon the image presented at the liquid crystal display. For example, the operating system generates an image of a keyboard and presents the keyboard at a defined position of the display. If the touch controller reports a touch in an array position that corresponds to a keyboard key, the operating system accepts an input for the key. Applications running on a tablet information handling system coordinate use of the touchscreen through the operating system. For instance, games present images on the LCD that the user manipulates by touches at the images to perform game functions. As another example, a movie is presented at the LCD in a window with controls to manage presentation of the movie, such as buttons to play, pause or stop the movie that an end user activates with touches made at the touch screen.
Tablet information handling systems typically have a rectangular LCD that adapts to presentation of widescreen audiovisual information, such as movies. If an end user rotates the tablet information handling system, an accelerometer in the system typically detects a vertical orientation and orients the images presented at the LCD relative to the vertical orientation. End users take advantage of this functionality by rotating the tablet information handling system to present images to fill the LCD. One difficulty with the use of accelerometers to detect a vertical orientation is that tablet information handling systems placed on a flat surface can have an orientation relative to the end user that differs from a detected vertical orientation. The closer that a tablet information handling system display gets to a perpendicular orientation relative to the acceleration of gravity, the more difficult becomes the detection of a vertical orientation. A result of this difficulty is that presentation of images may flip between orientations when a user holds the tablet information handling system in a position that approaches having the display perpendicular to vertical. Arbitrary display orientation changes annoy and confuse end users.