Abstract:
A cover for an electronic device made of a transparent material and having a form factor that protects function buttons of the device from inadvertent actuation. The cover has an opening of a size, shape and location to afford access to an interface device for multi-way navigation with the cover in place. Protrusions in tabs at the sides of the cover snap into cutouts located midway along the side of the electronic device and may be used to hold the cover in place. The cover may be stored on the back of the device while the device is in use. The transparent nature of the cover affords viewing of a display screen with the cover in place.

Description:
This is a continuation of application Ser. No. 10/375,999 filed on Feb. 27, 2003 now U.S. Pat. No. 6,914,774 which is hereby incorporated by reference to this specification. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of portable electronic devices, such as personal digital assistants or handheld computer systems. Specifically, the present invention relates to a protective transparent cover allowing access to an interface mechanism for navigating among applications with the protective cover in place. 
     2. Related Art 
     A portable computer system, such as a personal digital assistant (PDA) or handheld computer, is an electronic device that is small enough to be held in the hand of a user. By virtue of their size, portable computer systems are lightweight and so are exceptionally portable and convenient. Portable computer systems are rapidly becoming smaller and, at the same time, increasing functionality and user friendliness. 
     These systems, and others like them, have in common some type of screen for displaying images as part of a user interface. Many different kinds of screens can be used, such as liquid crystal displays, field emission displays or other types of flat screen displays. Many have keyboards that can be displayed on a touch screen and selected with a stylus. Many have the capability of reading handwritten memos. Recently, complete keyboards have been incorporated in the form of small depressible buttons on the housing of the devices. 
     These systems also have in common some type of user interface allowing a user to input commands and information and to navigate either within an application or from one application to another. Handheld computers and many other handheld devices typically have multiple built-in, dedicated or programmable buttons or keys that can be used to implement various functions and to navigate among and within different applications. Some also have a one-touch navigation assembly that allows scrolling in four directions and making a selection from a single central location on the housing. 
     In order to protect these pocket-sized devices from being inadvertently activated while in a pocket, briefcase, purse or other transport facility, many of these devices have protective covers that cover the buttons.  FIGS. 1A and 1B  illustrate two embodiments of covers found in the prior art.  FIG. 1A  illustrates a rigid flip cover that snaps onto a PDA device at the back of the device and is lifted to provide access to the buttons and display screen. A flip cover needs a solid connection to the device, which then becomes difficult to remove when so desired. When the cover is in place, the device cannot be used. Once lifted, the cover can prove to be unwieldy when attempting to hold the PDA while using it. 
       FIG. 1B  illustrates another example of covers found on handheld computer devices in the prior art. In this example, the cover is in the form of a rigid notebook style cover that has a flexible frame on one side into which the device may be slipped. The frame fits around the perimeter of the device and below the navigation buttons and has a strip that fits above the navigation buttons but below the screen to further secure the device in the cover. This cover, as with the cover of  FIG. 1A , proves uncomfortable for holding while navigating or executing applications. The device is best used, while in the cover, when placed on a flat surface. In neither of the embodiments shown in  FIGS. 1A and 1B  does the cover lend itself to comfortably navigating with one hand, and in both embodiments the cover must be lifted or removed in order to access the navigation buttons. There are a number of types of covers available in the prior art, but they either do not allow for easy release, or they do not allow for use of the handheld device while in place. 
     Referring to Prior Art  FIG. 2A , an exemplary handheld electronic computing device  200   a  is illustrated, according to one embodiment of the prior art. Device  200   a  is configured for single-handed navigation utilizing a ring and button assembly. In the present embodiment, navigation ring  210  and button  215  are located at the lower portion of the face of device  200   a  and the ring  210  may be pressed at positions corresponding to twelve o′clock, three o′clock, six o′clock and nine o′clock to cause a highlighting feature to move up, right, down and left, respectively, among icons on display screen  220 . The highlighted icon may be selected by pressing button  215 . 
     The ring and button assembly has the advantage of performing multiple functions using one hand within a concentrated area. The present assembly is relatively large and occupies a considerable amount of space on housing  225  of  FIG. 2A . Some newer handheld devices are incorporating additional function buttons and even complete keyboards. With the ever-increasing need for smaller form factors and additional function keys, it would be desirable to have a navigation ring and button assembly that is smaller in size than the current design. 
     Prior Art  FIG. 2B  illustrates actuator devices  200   b  used in one embodiment of the prior art. Actuators  230 ,  240 ,  250 ,  260  and  270  are small, depressible steel domes placed in a matrix with circuitry below for communicating with the handheld device. The ring  210  of  FIG. 2A  would fit over outer four domes  230 ,  240 ,  250  and  260  and button  215  of  FIG. 2A  would fit above center dome  270 . In order to achieve up, down, right and left movement and a select function, 5 domes are used. The dome can be cycled (e.g., pressed and released) only a limited number of times during its lifetime. The larger the dome, the greater the number of cycles in a lifetime. Thus, to maintain reliability, it would not be desirable to reduce the size of the domes to fit a smaller space. The spacing between the domes allows the sides of the ring and button to have sufficient clearance for movement. 
     In summary, prior art mechanisms for protecting hand-held devices are problematic. A solution to the problems described above would be advantageous. The present invention, in various embodiments, provides such a solution. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus for a navigational interface with a portable electronic device. The present invention would allow for an increase in the number of function keys and/or a reduction in device size to more fully utilize the advantages afforded by the portability of handheld devices. An improved interface may facilitate the user&#39;s experience and thus provide an advantage over other devices that employ conventional user interfaces. 
     In one embodiment, the present invention is implemented as a cover for an electronic device comprising a transparent material and having a form factor that protects function buttons of the device from inadvertent actuation. The cover has an opening of a size, shape and location to afford access to an interface device for a multi-way navigation assembly located on the top face of the device, the opening allowing for navigating with the cover in place. 
     According to one embodiment, the cover has protrusions that snap into cutouts located midway along the side of the electronic device. The cover may be stored on the back of the device while the device is in use. According to one embodiment, the opening in the cover is circular. 
     In one embodiment, the multi-way navigation assembly comprises actuators coupled to circuitry within the electronic device. According to one embodiment, the actuators are steel domes. The actuators may be actuated, according to one embodiment, by the interface device, wherein the interface device comprises a ring surrounding a central button. 
     In one embodiment, the ring interfaces with actuators on a first plane and the button interfaces with actuators on a second plane, through an opening in the first plane. According to one embodiment, the first plane is offset from the second plane so that a space between the actuators in the first plane aligns on an orthogonal axis with the actuator of the second plane. In one embodiment, the button comprises an extension for depressing the actuator on the second plane through the opening in the first plane. 
     According to one embodiment, the power switch on the device is accessible with the cover in place. In one embodiment, the electronic device is a portable digital assistant. In another embodiment, the electronic device is a global positioning system. In yet another embodiment, the electronic device is a portable game. 
     These and other objects and advantages of the present invention will become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates a cover for a handheld electronic device in accordance with one embodiment of the prior art. 
         FIG. 1B  illustrates a handheld electronic device having a cover in accordance with one prior art embodiment. 
         FIG. 2A  illustrates a prior art electronic device with a ring and select button device for navigating among menu items. 
         FIG. 2B  illustrates a prior art arrangement of domed actuators for connecting a ring and button device to circuitry. 
         FIG. 3A  illustrates a perspective front side view of a cover designed to allow navigation, according to one embodiment of the present invention. 
         FIG. 3B  is an illustration of a top side view of a cover designed to allow navigation while in place, according to one embodiment of the present invention. 
         FIG. 3C  is an inside view illustrating a protrusion on a tab of a cover designed to snap into a cutout in the side of a handheld device to hold the cover in place, according to one embodiment of the present invention. 
         FIG. 4A  illustrates a portable electronic device in accordance with one embodiment of the present invention 
         FIG. 4B  illustrates a side view of a portable electronic device having a cutout for accepting protrusions in a transparent removable cover. 
         FIG. 5A  illustrates a portable electronic device having a cutout for accepting protrusions in a transparent removable cover. 
         FIG. 5B  illustrates a top view of a portable electronic device having a transparent removable cover in place according to one embodiment of the present invention. 
         FIG. 6  illustrates a top view of a portable electronic device having a transparent removable cover stored on the back in accordance with one embodiment of the present invention. 
         FIG. 7A  is a topside perspective view of a portable electronic device in accordance with one embodiment of the present invention. 
         FIG. 7B  is a cut-away side view of a portable electronic device in accordance with one embodiment of the present invention. 
         FIG. 7C  is a top view of an arrangement of actuator domes in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details or with equivalents thereof. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. 
     The present invention is described primarily in the context of a portable computer system, e.g., a handheld or personal digital assistant (PDA). However, it is understood that the present invention is not limited to implementation in portable computer systems, but can also be implemented in other portable electronic devices such as cell phones, global positioning system devices, electronic games, mobile phones and the like. Indeed, aspects of the present invention can be implemented in numerous electronic devices in which it is necessary or desirable to navigate among functions while a protective cover remains in place or to reduce the device size while maintaining or increasing functionality. 
       FIG. 3A  is an illustration of a front side view  300   a  of a cover  350  designed to allow navigation, according to one embodiment of the present invention. While in place, cover  350  protects a device from inadvertent activation. Cover  350  is substantially transparent so as to allow a display screen to be read while cover  350  is in place. Cover  350  may or may not be removable. In this embodiment, cover  350  has tabs  330  at the center portion of each side that are designed to fit over the side of a handheld electronic device. Cover  350  is held in place by protrusions  310  on the inside of tabs  330  that fit into cutouts in the sides of the device. Cover  350  is not limited to snapping in place. In one embodiment, cover  350  may slide into place. In another embodiment, cover  350  may pivot into place. Cover  350  may be constructed of any suitable rigid or semi-rigid material that is transparent so that the display screen is readable with the cover in place. 
       FIG. 3B  illustrates a perspective top side view  300   b  of a transparent removable cover  350  designed to allow navigation while in place with a multi-way navigation assembly, according to one embodiment of the present invention. Tabs  330  at each side of cover  350  fit over a handheld device and snap into cutouts at the midpoints of the sides of the device to secure the cover to the device. Cover  350  may be secured to the device, either on the front for protection of the screen and function buttons, or on the back when the device is in use. 
       FIG. 3C  is an inside view  300   c  illustrating a protrusion  310  on tab  330  of a transparent removable cover (e.g., cover  350  of  FIG. 3B ). Protrusion  310  is designed to snap into a cutout in the side of a handheld device to hold cover  300   b  in place, according to one embodiment of the present invention. 
       FIG. 4A  illustrates a top view  400   a  of a portable electronic device  410  in accordance with one embodiment of the present invention. In this embodiment, device  410  has a cutout  420  at the midline of each side that may accept protrusions (e.g., protrusion  310  of  FIG. 3A ) on side tabs of a cover (e.g., cover  350  of  FIGS. 3A and 3B ). Electronic device  410  also has a ring and button interface device  430  for navigating among and selecting applications via icons on a display screen, for example. 
     Power switch  440  is located, according to one embodiment, on the back of device  410  so that it is not prone to inadvertent activation. Opening  340  on cover  350  of  FIG. 3B  may be sized to fit around interface  430  so that applications may be selected with transparent cover  350  still in place. Cover  350  does not extend over power switch  440  so that power switch  440  is accessible with cover  350  in place. Thus device  410  may be powered on or awakened without removing cover  350  and applications may be selected by means of navigation interface  430  that is available through opening  340 . 
     It is understood that, although electronic device  410  is illustrated herein in the context of a portable computer system, e.g., a handheld or personal digital assistant (PDA), the present invention is not limited to implementation in portable computer systems, but can also be implemented in other portable electronic devices such as cell phones, global positioning system devices, electronic games, mobile phones and the like. 
       FIG. 4B  illustrates a side view  400   b  of one embodiment of a portable electronic device  410  having a cutout for accepting protrusions in a cover. It may be observed that the cutout is at the midline of the side so that cover  350  may be removed and stored on the back of the electronic device while the device is in use. 
       FIG. 5A  illustrates a top perspective view  500   a  of another embodiment of a portable electronic device  510  having a cutout  520  for accepting protrusions on a tab on a cover. Portable electronic device  510  is shown having a keyboard  750 , function buttons  512 ,  514 ,  516  and  518  for such functions as checking mail, dialing a wireless phone, checking phone messages, or connecting to the Internet, and a multi-way navigation interface device  710 . In order to accommodate a keyboard and maintain the form factor of a device such as device  410  of  FIG. 4A , interface device  710  may be reduced in size from that of interface device  430  of  FIG. 4A . 
       FIG. 5B  illustrates a top view  500   b  of a portable electronic device (e.g., device  510  of  FIG. 5A ) having a transparent removable cover  550  in place, according to one embodiment. Cover  550  is shown with opening  540  that is sized and located to fit around navigation interface device  710 , according to one embodiment, thus affording a user access to navigate among applications with cover  550  in place. In another embodiment, cover  550  may have multiple openings to allow access to other function or navigation buttons such as, for example, buttons  512 ,  514 ,  516  and  518  of  FIG. 5A . It is understood that, in various embodiments, a variety of openings of varying shapes, sizes and locations may be located within cover  550  to accommodate a device for which cover  550  is designed. 
       FIG. 6  illustrates a top view  600  of portable electronic device  410  having transparent removable cover  350  stored on the back, in accordance with one embodiment of the present invention. Cover  350  may be removed and stored on the back, held by protrusions (e.g., protrusions  310  of  FIG. 3A ) on the inside of tabs  330  into cutouts (e.g., cutouts  420  of  FIG. 4B ) on the midline of device  410 . It is understood, however, that cover  350  is not limited to being removable and snapping on and off. In other embodiments, cover  350  may slide up and down or left and right, or, according to one embodiment, cover  350  may pivot from a single pivot point or from two pivot points. 
       FIG. 7A  is a topside perspective view  700   a  of the top face of portable electronic device  510  in accordance with one embodiment of the present invention. The top face contains a display screen  720 . Display screen  720  is a touch screen that is able to register contact between the screen and the tip of a stylus. A keyboard  750  is below display screen  720  on the top face of device  510  and above navigation interface device  710 . Navigation interface device  710  comprises a button  730  at the center and a surrounding ring  740 . 
       FIG. 7B  is a cut-away side view of a multi-way navigation assembly  700   b  and navigation interface device (e.g., interface device  710  of  FIG. 7A ) within portable electronic device  510  in accordance with one embodiment of the present invention.  FIG. 7C  is a top view of an arrangement of actuator domes  715 ,  725 ,  735 ,  745  and  755  located on two planes within multi-way navigation assembly  700   b  in accordance with one embodiment of the present invention. By locating the actuator domes in two substantially parallel planes, one plane being offset from the other so that a space between the actuator domes on one plane aligns on an orthogonal axis with an actuator in the other plane, a smaller form factor may be achieved for an interface device (e.g. device  710  of  FIG. 7A ). 
       FIGS. 7B and 7C  are discussed in concert to clearly describe assembly  700   b . In one embodiment, ring  740  resides above actuator domes  715 ,  725 ,  735 , and  745  and button  730  resides above actuator dome  755 . The actuator domes are coupled to circuitry within a handheld device such as device  510  of  FIG. 7A . Actuator domes  715 ,  725 ,  735  and  745  reside in one plane while actuator dome  755  resides in a separate, substantially parallel plane. In one embodiment actuator dome  755  may reside on the plane furthest from the navigation button  730  as shown in  FIG. 7B . In another embodiment, dome  755  may reside on the plane closest to navigation button  730 . 
     In the embodiment illustrated in  FIG. 7B , ring  740  is designed to depress actuator  715 ,  725 ,  735  or  745  when pressed in a position above a specific actuator. Pressing a position that resides above and between two actuator domes may depress both domes in accordance with one embodiment of the present invention. Actuator dome  755 , according to one embodiment, resides on a plane below actuator domes  715 ,  725 ,  735  and  745 . A hole  760  in the center of actuator domes  715 ,  725 ,  735  and  745  provides access to actuator dome  755 . According to one embodiment, button  730  has an extension  765  that fits through hole  760  so that pressing button  730  depresses dome  755 , causing it to make contact with circuitry and respond accordingly. In one embodiment, button  730  is a select button that would cause an application to be opened. 
     Still referring to  FIGS. 7B and 7C , according to one embodiment, pressing  740  at the 12 o′clock position causes actuator  735  to be depressed, making contact with the circuitry. This may cause a cursor or highlighting feature on a display screen (e.g., screen  720  of  FIG. 7A ) to move upward. Likewise, when ring  740  is pressed at the three o′clock position, actuator  745  is depressed and may cause a cursor or highlighting feature to move to the right on display screen  720 . Pressing ring  740  at the one thirty o′clock position depresses both actuators  735  and  745 . Pressing both actuator domes may, according to one embodiment, cause a cursor or highlighting feature to move diagonally up and to the right. Likewise, actuator  715  would be depressed by pressing the six o′clock position on ring  740  and actuator  725  would be depressed by pressing the nine o′clock position on ring  740 . In one embodiment, combinations of two actuators are depressed by pressing a position on ring  740  that lies between them. The direction moved by the cursor or highlighting feature is a function of software and may vary depending on the program. 
     In another embodiment, additional buttons may be provided for navigating diagonally. These buttons may be separate buttons or they may be additional actuators. Additional actuators may be located in yet another substantially parallel plane that may be accessed by one of a series of concentric rings or by single buttons placed around ring  740 . There may, according to one embodiment, be several stacked parallel planes of actuators, accessed by various length extensions from a combination of concentric rings and buttons for navigation and for other appropriate functions. 
     The preferred embodiment of the present invention, a transparent cover with access to multi-way navigation assembly, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.