Patent Publication Number: US-11379060-B2

Title: Wide touchpad on a portable computer

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/354,931, filed on Nov. 17, 2016 and published on Mar. 9, 2017 as U.S. Patent Publication No. 2017-0068346, which is a continuation of U.S. patent application Ser. No. 13/351,096, filed on Jan. 16, 2012 and issued on Dec. 6, 2016 as U.S. Pat. No. 9,513,673, which is a continuation of U.S. patent application Ser. No. 11/731,118, filed on Mar. 30, 2007 and issued on Jan. 17, 2012 as U.S. Pat. No. 8,098,233, which is a continuation of U.S. patent application Ser. No. 10/927,575, filed on Aug. 25, 2004, and issued on Nov. 16, 2010 as U.S. Pat. No. 7,834,855, the contents of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to portable computers, and in one embodiment, a portable computer having a wide touchpad. 
     BACKGROUND 
     Advances in technology have enabled the size of personal computers to decrease. As a result, the use of portable computers, such as notebook computers, laptop computers, and notepad computers, is rapidly increasing. The portability of notebook computers and notepad computers enables a user to keep his or her computer readily accessible such that computing resources are effectively always at hand.  FIG. 1  illustrates a typical notebook computer with two folding halves, with a display assembly in one half and a base assembly with input devices in the other half. Input devices include, among other things, a keyboard for inputting data and a touchpad for navigating a cursor control. Palm rest areas are areas positioned on the upper surface of the base assembly below the keyboard. They allow a user to rest the base or palm of his or her hands comfortably during typing activity. The vast majority of conventional touchpads that are integrated into portable computers are, in one way or another, isolated from unwanted contact with the user&#39;s hands (e.g., during a typing activity). This is usually done by centering the touchpad below the keyboard, and minimizing the size of the touchpad, for example, by not extending the touchpad to the palm rest areas to be formed on either side of the touchpad. The touchpad is also recessed beneath the plane of the palm rest, so that palms, the most common cause of unwanted activation of the touchpad, do not come in contact with the touchpad. 
     One trend in portable computers has been to make them as desktop computer replacements, which requires them to be larger, while still maintaining their portability features. The display assembly in particular, that includes a display screen, has become larger, to become comparable to the sizes of desktop computer monitors. This has caused the housing of the base assembly to increase proportionally. Large base assembly housings can easily accommodate full-size keyboards, but the size of the touchpads must still be limited because of the high risk of unwanted activation, as discussed above, as well as providing the necessary space for palm rests. 
     Moreover, in order for larger portable computers to be practical for portability purposes, they must still be relatively thin and light. One conventional method to reduce the overall thickness of portable computers is to mount the touchpad flush with the top surface of the base assembly housing (e.g., the palm rest areas). However, this increases the likelihood of accidental brushing by a user&#39;s palms, especially during typing. 
     SUMMARY 
     Embodiments of a portable computer having one or more input devices including a keyboard and an enlarged or wide touchpad are described herein. A portable computer includes a display assembly and a base assembly coupled by hinge assembly that allows display assembly to change (i.e., rotate) between an open position and a closed position. The display assembly includes a display screen which displays images, data, and a moveable cursor. The wide touchpad and keyboard disposed on the base assembly allow a user to interact with the display screen (e.g., enter data). In one embodiment, the wide touchpad may be a cursor control device having the capabilities of conventional computer mouse devices, such as the ability to point, drag, tap, and double tap objects on a graphical user interface, as well as more general purposes such as scrolling, panning, zooming, and rotating images on display screen. The wide touchpad extends into the areas on the surface of the base assembly that are normally reserved for palm rest areas (e.g., flat areas on the surface of the base assembly that support a user&#39;s palms and/or wrists while typing). 
     In one embodiment, the wide touchpad filters each contact or contact patch sensed to either accept the contact as an intentional input command (e.g., cursor control command), or reject the contact as unintentional (e.g., when operating as a palm rest). The wide touchpad can filter multiple contact patches in order to accept a particular contact patch in one area of the touchpad while rejecting a second contact patch elsewhere on the wide touchpad. In one embodiment, a sensor is disposed between the keyboard and touchpad. The sensor defines a planar sensing region extending upwards from the top surface of the base assembly. The sensor detects a user&#39;s hand that may be resting on the base assembly with a palm portion making contact with a portion of the wide touchpad and the fingers extending toward keyboard. When this detection is made, any contact made with a corresponding portion of the touchpad is rejected, having been interpreted as unintentional contact by the user. Alternatively, detection of fingers extending toward the keyboard may be evaluated as one of many factors used to decide whether and what significance to accord to contact with the touchpad. For example, other factors may include the profile of the contact with the touchpad, the level of keyboard activity at the time of contact, etc. In this way, the touchpad may effectively serve as a palm rest (e.g., the user may intentionally rest one or more palm or other part of a hand or aim on a portion of the touchpad, which is recognized as an unintentional input) in addition to a functional touchpad when an input is interpreted as being an intentional contact by the user. 
     There are numerous other embodiments which are described herein, and these embodiments generally relate to portable computers having a wide touchpad and the accepting or rejecting of contact patches on the touchpad based on, in one example, hand location. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which: 
         FIG. 1  illustrates a conventional portable computer. 
         FIG. 2  illustrates one embodiment of a portable computer having a wide touchpad. 
         FIG. 3  illustrates a top view of the portable computer of  FIG. 2  in the open position with a touchpad that extends into the palm rest areas. 
         FIG. 4  illustrates one example of a hand position during user activity with a portable computer. 
         FIG. 5  illustrates another example of a hand position during user activity with a portable computer. 
         FIG. 6  illustrates another example of a hand position during user activity with a portable computer. 
         FIG. 7  illustrates a side view of a hand in a typing position with the portable computer of  FIG. 2 . 
         FIG. 8  illustrates a cross-sectional view of  FIG. 7  taken along line A-A through the base assembly, sensor, and hand with showing one embodiment of a sensor. 
         FIG. 9  illustrates a cross-sectional view of  FIG. 7  taken along line A-A through the base assembly, sensor, and hand with showing another embodiment of a sensor. 
         FIG. 10  illustrates a logic diagram of one embodiment of a portable computer system that supports a wide touchpad and/or hand sensor. 
         FIG. 11  illustrates a flowchart of one embodiment of an operation for rejecting or accepting a contact patch. 
         FIG. 12  illustrates an alternative embodiment of a hand detecting sensor that may be disposed on a portable computer. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous specific details are set forth such as examples of specific, components, circuits, processes, etc. in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that these specific details need not be employed to practice the present invention. In other instances, well known components or methods have not been described in detail in order to avoid unnecessarily obscuring the present invention. 
     The term “coupled” as used herein means connected directly to or indirectly connected through one or more intervening components, structures or elements. The terms “above,” “below,” and “between” as used herein refer to a relative position of one component or element with respect to other components or elements. As such, one component disposed above or below another component may be directly in contact with the other component or may have one or more intervening component. Moreover, one component disposed between other components may be directly in contact with the other components or may have one or more intervening components. 
     Various embodiments of a portable computer (also referred to as notebook computer or laptop computer) having enlarged touchpads are described. The touchpad provides input and conventional cursor control capabilities such as pointing, dragging, tapping, scrolling, panning, rotating, and zooming. In one embodiment of the present invention, the touchpad serves as palm rests for a user&#39;s hands during a typing activity. In another embodiment of the present invention, the touchpad is enlarged so as to expand along a substantial width of the portable computer base assembly, extending into the palm rest areas. The palm rest areas include those areas on the front, top portion of the base assembly, and the keyboard is located behind the palm rest areas on the base assembly. Thus, in normal use by a user, the palm rest areas are closer to the user than the keyboard, which is normally adjacent to the hinge which couples the base assembly to the display assembly. The palm rest areas typically include a left palm rest area and a right palm rest area with a central portion separating these left and right palm rest areas. In prior art portable computers, this central portion typically includes a touchpad or other cursor control device. Advantages of a large touchpad for a portable computer include increased area for dynamic input ranges, two-handed control of the touchpad, and advanced input based on more than one finger on the touchpad. 
     In one embodiment, the touchpad possesses the ability to reject accidental contact when a user does not intend to activate the touchpad (e.g., the touchpad is able to distinguish when a user is contacting the touchpad for intended use or is merely resting his or her palms on a particular portion of the touchpad during a typing activity). In one particular embodiment, a sensor is disposed near the touchpad and keyboard of the portable computer to sense hand location of a user, and subsequently determine whether the touchpad contact is intentional or accidental. The touchpad responds properly by either recognizing the action on the touchpad or rejecting the action. As a result, the user is able to work efficiently, allowing for typing and cursor control operations to occur seamlessly. In one embodiment, the enlarged touchpad/palm rest may be suitable for use with portable computers having base and display assemblies (e.g., display frame, base assembly housing) made entirely or partially of metallic materials, in particular, display and base housings made of metals such as steel, aluminum, titanium, or combinations thereof. 
       FIG. 2  illustrates a perspective view of one embodiment of a portable computer  200  that includes a display assembly  210  and a base assembly  220 . Display assembly  210  is coupled to base assembly  220  with a hinge assembly  216  that allows display assembly  210  to change (i.e., rotate) between an open position (as illustrated in  FIG. 2 ) and a closed position (not shown). Display assembly includes a display screen  212  and associated video circuitry (not shown). In one embodiment, display screen  212  may be a liquid crystal display unit. In an alternative embodiment, display screen  212  may be a video monitor or any well known display device. Display screen is centered and framed on display assembly  210  by bezel  214 . In the open position, display screen  212  is exposed on display assembly  210 . Input devices that include keyboard  222 , touchpad  224 , and actuation button(s)  226  (e.g., “mouse buttons”) are disposed on a top surface  232  of base assembly  220 . Speakers  260 ,  262  may also be disposed on top surface  232  of base assembly  220 . 
     In one embodiment, touchpad  224  may be an input device having the capabilities of conventional computer mouse devices, such as the ability to point, drag, tap, and double tap objects on a graphical user interface, as well as more general purposes such as scrolling, panning, zooming, and rotating images on display screen  212 . Touchpad  224 , along with keyboard  222  and actuation button  226 , allows a user to communicate with portable computer  200  (e.g., interact with display screen  212  or enter data). In one embodiment, a touchpad is defined herein as any two dimensional surface sensor that can detect one or more objects on the touchpad surface (the touchpad input), and output information regarding the location, width, presence, and number of said objects, (the touchpad outputs), in a manner that can be interpreted by the computer system to generate cursor movement, or otherwise interpret a user&#39;s either intentional or unintentional input. In one embodiment, touchpad  224  may be a touchpad that utilizes capacitive sensing. The surface of the touchpad may include a grid of conductive metal wires covered by an insulator. When two electrically conductive objects come near each other without touching, their electric fields interact to form capacitance. Also, when another conductive material, such as a human finger, comes in contact with the touchpad surface, a capacitance forms. 
     The dimensions of touchpad  224 , particularly the width (i.e., the distance parallel the row of keys on keyboard  222 ), are larger than conventional touchpads. In the embodiment illustrated in  FIG. 2 , touchpad  224  extends into the areas on the surface  232  of base assembly  220  that are normally reserved for palm rest areas (e.g., areas  252 ,  254 , designated by circled hash marks), but still allows a user to rest his or her palms on the surface of touchpad  224 . Alternatively, in addition to possessing conventional touchpad functionalities, all or particular portions of touchpad  224  may serve as palm rests for a user&#39;s hands. It should be noted that palm rest areas  252 ,  254  as described herein are not necessarily reserved only for a user&#39;s palms during a typing activity as other body parts may be placed on palm rest areas  252 ,  254 . For example, a user&#39;s elbow or forearm may rest on any non-keyboard portion of base assembly  220  during use (e.g., leaning on the palm rest portion  254  with the left elbow or forearm while typing with the right hand). 
     As described in greater detail below, enlarged touchpad  224  is able to reject unintentional contact while accepting intentional contact related to input device functionality (e.g., cursor control commands). In one embodiment, a sensor  240  is disposed between keyboard  222  and touchpad  224 . Sensor  240  defines a planar sensing region extending upwards from top surface  232 . In one particular embodiment, sensor  240  detects a user&#39;s hand that may be resting on base assembly  220  with a palm portion making contact with a portion of touchpad  224  and the fingers extending toward keyboard  222 . When this detection is made, any contact made with a corresponding portion of the touchpad is rejected, having been interpreted as unintentional contact by the user. Alternatively, detection of fingers extending toward keyboard  222  may be evaluated as one of many factors used to decide whether and what significance to accord to contact with touchpad  224 . For example, other factors may include the profile of the contact with touchpad  224 , the level of keyboard  222  activity at the time of contact, etc. In this way, touchpad  224  may effectively serve as a palm rest (e,g., the user may intentionally rest one or more palm or other part of a hand or arm on a portion of the touchpad and the system recognizes this and interprets the input as unintentional) in addition to a functional touchpad when an input is interpreted as being an intentional contact by the user.  FIG. 3  illustrates a top view of portable computer  200  in the open position with touchpad  224  that extends into the palm rest areas on top surface  232 . In one embodiment, touchpad  224 , having particularly wide dimension, is divided into three regions, a left region  242 , a center region  244 , and a right region  246 . Sensor  240 , which in one embodiment is a sensor strip having a width substantially similar to a width of touchpad  224 , is disposed between keyboard  222  and touchpad  224 . The three regions of touchpad  224  may be activated or deactivated selectively, based on a particular touch region or “contact patch” sensed by touchpad  224  in association with the particular region of sensor  240  that detects a hand portion or fingers extending towards the keys of keyboard  222 . In an alternative embodiment, only the specific contact patch in a region (and not the entire region) may be accepted or rejected selectively. It will be recognized that other configurations of sensor  240  are possible, for example, sensor  240  may be multiple sensors, or may not be coextensive with touchpad  224 . 
       FIGS. 4-6  illustrate three of many possible scenarios (i.e., hand positions) of user activity with portable computer  200  and the recognition by the three regions of touchpad  224  that may either accept or reject contact.  FIG. 4  illustrates a typical typing position by a user in which the fingers of left hand  280  and right hand  282  extend over keyboard  222  and both palms rest on regions of touchpad  224 . In particular, left hand  280  rests entirely on left region  242 , and right hand  282  rests on right region  246 . Sensor  240  detects the extension of the fingers from left hand  280  and associates the fingers with the contact made on left region  242 . Similarly, sensor  240  associates the fingers from right hand  282  with the contact made on right region  246 . Accordingly, the contact patches on left region  242  and right region  246  are not recognized as any form of input or touchpad operation. The user&#39;s hands may rest comfortably on these regions of touchpad  224 , and in doing so, left region  242  and right region  246  serve as palm rests. In contrast, center region  244  of touchpad  224  may be active and be responsive to touchpad sensing. 
       FIG. 5  illustrates another scenario in which the fingers of left hand  280  extend over the keys of keyboard  222  while a finger from right hand  282  makes contact with touchpad  224 . In this scenario, the contact made by right hand  282  is intentional and meant to activate a touchpad action (e.g., pointing, dragging, tapping). Sensor  240  detects the extension of the fingers from left hand  280  and associates the fingers with the contact made on left region  242 . For right hand  282 , the fingers do not extend over keyboard  222  and no detection is made by sensor  240 . Accordingly, the contact patch on left region  242  is not recognized as any form of touchpad operation. However, the contact patch on right region  246  of touchpad  224  is recognized as a valid touchpad activity, and responds with the appropriate touchpad command (e.g., dragging, pointing). The user&#39;s left hand  280  may rest comfortably on left region  242  of touchpad  224  and engage in typing activity, while the fingers from right hand  282  engage in touchpad activity. In one embodiment, center region  244  of touchpad  224  may also be active and be responsive to touchpad sensing. 
       FIG. 6  illustrates a third scenario in which both left hand  280  and right hand  282  do not extend over keyboard  222 . This hand position may occur when the user engages only in touchpad activity. In this scenario, portions of left hand  280  rests on left region  242  while a finger from right hand  282  engages in touchpad activity, and no portions from either hand extend over keyboard  222 . The contact patch made by the finger of right hand  282  is intentional and meant to activate a touchpad action/input (e.g,, pointing, dragging, tapping). The contact patches made by left hand  280  is unintentional. Although no detection is made by sensor  240 , touchpad  224  recognizes various characteristics of the contact patches made by the user&#39;s hands. In this case, the multiple contact patches recognized in left region  242 , taking into consideration the size of the patches and proximity, are interpreted by touchpad  224  as unintentional. Accordingly, the activity in left region  242  is disregarded. Alternatively, all of left region  242  may be inactivated or the inputs are ignored or filtered. However, the single contact patch on right region  246  of touchpad  224  is recognized as a valid touchpad activity, and responds with the appropriate touchpad command (e.g., dragging, pointing). In one embodiment, center region  244  of touchpad  224  may also be active and be responsive to touchpad sensing. 
     In an alternative embodiment, touchpad  224  is capable of multiple or two-handed input. With reference again to  FIG. 6 , touchpad  224  may accept the contact patch from the finger of right hand  282  for cursor control operation. The contact patches from left hand  280  may also be accepted when associated with touchpad input device functionality. For example, two fingers from left hand  280  may be used to control scrolling, panning, rotation, and zooming of objects or data on the display screen (e.g., display screen  212 ). 
       FIGS. 4-6  illustrate touchpad  224  as being divided into three distinct sensing regions. However, it may be appreciated that any number of sensing regions may be divided over touchpad  224 , and not necessarily in the relative dimensions illustrated. For example, sensor  240  can detect the extension and retraction of one finger at a time to that a single finger can be moved back and forth between touchpad  224  and keyboard  222 , being active in both places, without moving the entire hand. It will also be recognized that touchpad  224  can be activated/deactivated in portions. It can also be activated/deactivated one input (i.e., contact patch) at a time, by disregarding any particular input that is determined to be related to unintended contact rather than intentional interface activity. That is, touchpad  224  is “deactivated” if it disregards a particular input, even if the next input may be not disregarded. 
       FIGS. 7-9  illustrate in greater detail, in one embodiment, the sensing of a user&#39;s fingers over the keys of keyboard  222 . In the side view of  FIG. 7 , left hand  280  is illustrated in a typing position with respect to portable computer  200  in the open position (i.e., display assembly  210  rotated open relative to base assembly  220 ). Palm  281  rests on touchpad  224 , and fingers  283  extend over sensor  240  and keyboard  222 . As described above, the palm rest for palm  281  includes touchpad  224  because of the extra-wide or elongated dimensions of touchpad  224 .  FIG. 8  illustrates a cross-sectional view of  FIG. 7  taken along line A-A through base assembly  220 , sensor  240 , and left hand  280 . In one embodiment, sensor  240  includes a first imaging sensor  275  and a second imaging sensor  276 . The imaging sensors may be infrared (IR) sensors that look “upward” (designated by the dash lines) and “see” the cross-sectional view of A-A. First and second imaging sensors  275 ,  276  examine a planar region in space extending upwards from the general line of sensor  240 . For example, the fingers  283  of left hand  280  that breaks the planar region examined by first sensor  275 . The sensing of fingers  283  may be associated with the contact patch made by palm  281  on touchpad  224  (e.g., on left region  242  as illustrated in  FIG. 4 ), and as a result, either the entire left region  242  would not be active for any type of touchpad operation or the particular contact patch made by the palm  281  would be rejected, allowing for palm  281  to rest on touchpad  224 . Because second sensor  276  does not detect any breaks along its portion of the planar region, portions of touchpad  224  associated with second sensor  276  are responsive to touchpad commands or operations (e.g., middle region  244  and right region  246 ). 
       FIG. 9  illustrates an alternative embodiment of a sensor mechanism for sensor  240 . Multiple optical emitter-detector pairs (e.g., pairs  277 ,  278 ) are disposed along the sensor strip area to detect the presence or absence of a user&#39;s hand in the sensed plane (i.e., a planar region in space extending upwards from the general line of sensor  240 ). The results produced by the emitter-detectors pairs are similar to that produced by the IR sensors (e.g., first and second sensors  275 ,  276 ) described above with respect to  FIG. 8 . The fingers  283  of left hand  280  breaks the planar region examined by the emitter-detector pairs  277 ,  278  near one side of sensor  240 . The sensing of fingers  283  may be associated with the contact patch made by palm  281  on touchpad  224  (e.g., on left region  242  as illustrated in  FIG. 4 ), and as a result, either the entire left region  242  would not be active for any type of touchpad operation or the particular contact patch made by the palm  281  would be rejected, allowing for palm  281  to rest on touchpad  224 . The emitter-detector pairs  277 ,  278  do not detect any breaks along the planar region near the other end of fingers  283 . Accordingly, portions of touchpad  224  associated with the undetected sensor regions would be responsive to touchpad commands or operations (e.g., middle region  244  and right region  246 ). 
     The infrared sensors of first sensor  275  and second sensor  276 , as well as optical emitter-detector pairs  277 ,  278  are just two of many possible sensing mechanism that may be used for detecting a hand location. In alternative embodiments, sensor  240  may be a capacitive sensor or visible light/shadow sensor. It may be appreciated that sensor  240  does not necessarily have to be utilized with an enlarged or wide touchpad, as illustrated, for detecting a hand location. The IR sensors and optical emitter-detector sensors described herein may be associated with touchpad of any dimension (e.g., a touchpad having dimensions comparable to the dimensions of center region  244 ). 
     Referring again to  FIG. 3 , inside base assembly  220 , there may be all the essential and well known electronic circuitry for the operation of portable computer  200 , such as a central processing unit (CPU), memory, hard disk drive, floppy disk drive, flash memory drive, input/output circuitry, and power supply. Such electronic circuitry for a portable computer is well known in the art; for example, a portable computer is the Macintosh PowerBook from Apple Computer, Inc. of Cupertino, California. 
     Keyboard  222  and touchpad  224  occupy almost all of top surface  232  of base assembly  220 . In one embodiment, display assembly  210  has a width  211  and length  213  that is substantially similar to a width  217  and length  219  of base assembly  220  so that when display assembly  210  is closed over base assembly  220 , the edges of the two assemblies are flush with each other. In one particular embodiment, portable computer  200  may have a display screen size of about 12 inches (about 305 millimeters (mm), the diagonal distance from one corner to the opposite corner of the display screen). Display assembly width  211  and base assembly width  217  may be about 277 mm and display assembly length  213  and base assembly length  219  may be about 219 mm. Keyboard  222  may be substantially centered along a width of base assembly  220 , having a width  227  of about 274 mm and a length  228  of about 108 mm. 
     In one embodiment, keyboard  222  may be a full-size keyboard (i.e., a keyboard layout having dimensions similar to those of conventional desktop computer keyboards) having a conventional “QWERTY” layout, which also includes a large, elongated space bar key in the bottom row of the keyboard. The specific type of the keyboard (e.g., a “QWERTY” keyboard) that is used is not critical to the present invention. 
     Touchpad  224  has an elongated width that is substantially similar to a width of keyboard  222 . Further, the width of the touchpad may be substantially similar to the width of base assembly  220 . For example, the touchpad in certain embodiments may have a width which is about 70 to about 80% of the width of the base assembly. More generally, in other embodiments, the touchpad may have a width which is about 50% to about 95% of the width of the base assembly. Further, a substantial portion (e.g., more than 50% and typically more than 60%) of the palm rest area may include one or more touchpads. The width  223  of touchpad extends along width  227  of keyboard  222  so as to provide a palm rest area during typing activity. In one embodiment, touchpad  224  has a width  223  of about 274 mm and a length  225  of about 45 mm. While touchpad  224  is shown as being one contiguous touchpad, in alternative embodiments, several separate touchpads may be disposed in the left, right, and central palm rest areas, and these several separate touchpads may occupy a substantial portion (e.g., about 60% to about 70%) of the palm rest areas. 
     In an alternative embodiment, portable computer  200  may have a display screen size of about 17 inches (about 432 mm, the diagonal distance from one corner to the opposite corner of the display screen). Display assembly width  211  and base assembly width  217  may be about 392 mm and display assembly length  213  and base assembly length  219  may be about 259 ram Keyboard  222  may be a full-sized keyboard that is substantially centered along a width of base assembly  220 . Keyboard  222  may have a width  227  of about 274 mm and a length  228  of about 108 mm. Touchpad  224  disposed on base assembly  220  for a 17-inch display screen may have an elongated width that is substantially similar to or exceeds a width of keyboard  222 . The width of a base assembly for a 17-inch display screen may be greater compared to that of a base assembly for a 12-inch display screen. Although the dimensions of keyboard  222  may not be substantially different for the two display semen sizes, greater surface area would be provided in the base assembly for the 17-inch display screen. Accordingly, the palm rest areas formed by touchpad  224  may be larger for the 17-inch display screen base assembly. In one embodiment, touchpad  224  has a width  223  between about 274 mm to about 330 mm and a length  225  between about 45 mm to about 55 mm. 
     The dimensions for keyboard  222 , and in particular, for touchpad  224  are examples only and it should be noted that a larger range of dimensions may be utilized, depending, for example, on the size of display screen  212  and the surface area available on the base assembly. In one embodiment, touchpad  224  may have a width  223  between about 100 mm to about 400 mm and a length  225  between about 45 mm to about 200 mm. 
       FIG. 10  illustrates a logic diagram of one embodiment of a portable computer system  300  (e.g., for portable computer  200 ) that supports a wide touchpad and/or hand sensor. Note that while  FIG. 10  illustrates various components of a computer system, it is not intended to represent any particular architecture or manner of interconnecting the components as such details are not germane to the present invention. In one embodiment, the corresponding hardware components for the components described may be disposed on motherboard  301  as shown. The computer system of  FIG. 10  may, for example, be an Apple Macintosh portable computer. 
     The portable computer system  300  includes a main logic board or motherboard  301  with at least one central processing unit (CPU) or processor  302 , and one or more volatile memory units  304  such as random access memory (RAM) and read only memory (ROM), coupled to motherboard  301 , as well as a graphics processor  308 . More than one processor  302  may be part of system  300  (e.g., a dual processor system, or a dual core processor system). Processor  302  may be, for example, a G4 or G5 microprocessor from Motorola, Inc., or IBM, and is coupled to cache memory  306 . 
     A memory controller  303  allows for the interface of memory unit  304  and graphics processor  308  with CPU  302 . Graphics processor  308  is also coupled to a display device (e.g., display screen  212 ), which may be a high resolution device. Memory controller  303  also defines the speed at which data can flow between CPU  302 , memory unit  304 , and graphics processor  308  through bus  305 . Bus  305  may also be referred to as front side bus (FSB), processor bus, memory bus or system bus. An input/out (I/O) controller  320  manages the interface of other components coupled to motherboard  301  such as storage device  324  (non-volatile), and local 110  322 . Types of 110 devices include mice, modems, network interfaces, printers, scanners, video cameras, and other devices that are well known in the art. 
     In one embodiment, aspects of the recognition of user&#39;s hand location by sensor  240 , and either accepting or rejecting a contact patch on touchpad  224  may be embodied, at least in part, in software. That is, the techniques may be carried out in a computer system or other data processing system in response to its processor, such as a microprocessor, executing sequences of instructions contained in a memory, such as memory  304  (which may include ROM, RAM, cache  306 , or a remote storage device). In various embodiments, hardwired circuitry may be used in combination with software instructions to implement the present invention. Thus, the techniques are not limited to any specific combination of hardware circuitry and software or to any particular source for the instructions executed by the data processing system. In addition, throughout this description, various functions and operations are described as being performed by or caused by software code to simplify description. However, those skilled in the art will recognize what is meant by such expressions is that the functions result from execution of the code by a processor, such as the CPU  302 . 
     A machine readable medium can be used to store software and data which when executed by a data processing system causes the system to perform various methods of the present invention. This executable software and data may be stored in various places including for example memory  304 , cache  306 , or storage device  324 , as illustrated in  FIG. 7 . Portions of this software and/or data may be stored in any one of these storage devices. 
     Thus, a machine readable medium includes any mechanism that provides (i.e., stores and/or transmits) information in a form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine readable medium includes recordable/non-recordable media (e.g., read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; etc.), as well as electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), etc. 
     In at least one embodiment of the present invention, a sensor is disposed on the base assembly of a portable computer to detect a hand location. If the hand location extends from a contact patch on the touchpad to the keyboard, that particular contact patch may be recognized by the computer system as an unintentional or accidental contact, and therefore not registered as a touchpad command.  FIG. 11  illustrates a flowchart of one embodiment of an operation  400  for rejecting or accepting a contact patch on a touchpad in association with a hand location. The operation may be performed for each contact patch detected on the touchpad. In one embodiment, a capacitive touchpad (e.g., touchpad  224 ) disposed on a top surface (e.g., surface  232 ) of a base assembly (e.g.,  220 ) senses a contact patch on the touchpad. Any contact sensed by the touchpad may undergo a post processor algorithm in order interpret the contact properly. In one embodiment, the post processor is defined herein to be the software or firmware that converts the information coming from the touchpad sensor into a format that can be interpreted by the portable computer (e.g., processor  302 ). The post processor has as inputs, the touchpad outputs, which may include any type of physical contact made with the touchpad. The post processor then uses the post processor algorithm” to analyze each set of inputs (location, width, number of contacts, presence of contact, and hand location) to determine whether the contact patch should be accepted or rejected. 
     The starting point  402  of operation  400  may be when the portable computer is in a power “ON” state, with the display screen visible (e.g., displaying an image or data) and the various input devices (e.g., keyboard  222 , sensor  240 , and touchpad  224 ) in active and responsive states. When a contact patch is sensed on the touchpad, a location, trajectory, and size of the contact patch are determined, block  404 . Trajectory refers to the path of the contact patch (e.g., movement of a finger on the touchpad during a dragging operation). The contact patch may be for example, the palm region of hand during a typing activity (e.g., palm  281  of  FIG. 7 ) or during a pointing activity (e.g., right hand  282  of  FIG. 5 ). Next, a hand location is made using a sensor (e.g., sensor  240 ) disposed on the base assembly of the portable computer, block  406 . In one embodiment, the sensor may include one or more IR sensors (e.g., sensors  275 ,  276 ) disposed along a sensor strip between the keyboard and the touchpad. In an alternative embodiment, the sensors may be pairs of optical emitter-detectors (e.g., pairs  277 ,  278 ) disposed along a sensor strip between the keyboard and the touchpad. 
     Once a hand location is determined, a probability of intentional contact is estimated using the measured quantities of the contact patch location, trajectory, size of the contact patch, in addition to the hand location detected by the sensor, block  406 . As discussed above, the touchpad may be divided into multiple sensing regions, for example, a left sensor region  242 , center sensor region  244 , and right sensor region  246  or there may be separate touchpads, one for each of these regions which are separated by small areas which are not touchpads. For example, the size of a contact patch made by palm  281  resting on left sensor region  242  would be larger compared to a contact patch made by a finger moving during a pointing or dragging cursor operation (e.g., finger of right hand  282  over right sensor region  246  illustrated in  FIG. 5 ). In one embodiment, a contact patch having a relatively small size and a trajectory with a certain distance along the surface of the touchpad, coupled with no detection by the sensor would be initially estimated with a high probability of intentional contact. This may correspond to, for example, a pointing or dragging cursor operation. In contrast, a contact patch of a large size, and with no or minimal trajectory, coupled with detection by the sensor, would be initially estimated with a very low probability of intentional contact. This may correspond to a palm resting on the touchpad surface. 
     The estimated probabilities are repeatedly calculated to establish a narrow or strict accept/reject criteria for the contact patch, block  410 , and the contact patch is also measured repeatedly over a period of time, block  412 . These calculations are done repeatedly to provide the system with the most recent of sampling data. In one particular embodiment, the measurements may be repeated in the range of about 120 Hz to about 3 Hz. Lastly, the contact patch is accepted or rejected based on the criteria established from the measured contact patch/sensor calculations, block,  414 . Once an accept/reject decision has been made, the operation ends, block  416 . 
     The accept/reject operation  400  may further be described with respect to the scenarios in  FIGS. 4-5 .  FIG. 4  illustrates a conventional typing position with the palms of both hands resting on touchpad  224  and fingers extending over keyboard  222 . The contact patches made on left sensor region  242  and right sensor region  246  would be rejected. The relatively large sizes of the contact patches made by the palms in connection with the detection of hand location would be interpreted as unintentional or accidental contact. In this position, touchpad  224  operates only as a palm rest.  FIG. 5  illustrates a dual mode position in which the left hand  280  is in a typing position and right hand  282  is in a touchpad position. The contact patch from left hand  280  (e.g., the palm) would be rejected because the location of left hand  280  would be detected by sensor  240 . Accordingly, either the entire left sensor region  242 , which is associated with the location of left hand  280  and the contact patch, or the particular contact patch made by left hand  280  on left sensor region  242  would be rendered inactive for touchpad commands, and operate only as a palm rest. The contact patch made by the finger of right hand  282  would be accepted as an intentional contact. The sensor would not detect any hand presence associated with right sensor region  246 . As described above, the calculations performed by operation  400  include measuring the size and trajectory of the contact patch made by right hand  282 . A comparison with the contact patch from left hand  280  may also be performed to establish the accept/reject criteria. 
       FIG. 12  illustrates an alternative embodiment of a hand detecting sensor that may be disposed on a portable computer. Portable computer  500  is illustrated in an open position with display assembly  510  rotated open with respect to base assembly  520 . Base assembly  520  includes a wide touchpad  524  disposed below keyboard  522 . An imaging sensor  545  is disposed on bezel  514  that frames display screen  512 . Imaging sensor  545  detects an area of base assembly  520  that includes keyboard  222  and touchpad  524 . When activated, imaging sensor  545  may detect a particular hand location and establish accept/reject criteria as described above (e.g., operation  400 ). In an alternative embodiment, imaging sensor  545  may also provide video-conferencing functionality when not operating as an imaging sensor. 
     In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.