Easily replaceable cover window for electronic device

[0001] The present invention relates to portable electronic devices, and more particularly to a method and apparatus for assembling a cover window to a portable electronic device.

[0002] The cover window of a portable electronic device, such as a pen-based “tablet” portable computer, is subject to damage. For example, extensive use may scratch the window, or the window may be cracked or broken during the rigors of portable use. Repair of a worn or damaged cover window is often expensive, and often requires a user of the device to return it to its manufacturer, leaving the user without the use of the device for an extended period.

[0003] There is a need for a way to repair or upgrade the cover window of a portable electronic device with minimal inconvenience and cost to the user.

[0004] A cover window attachment system for an electronic device comprises a cover window on a top side of the electronic device; a frame attached to the cover window, the frame further comprising at least one boss configured to protrude into the electronic device; a fastener receiving feature on a distal end of each boss; and a fastener engaging the fastener receiving feature on each boss, the fastener contacting a bottom side of the electronic device, opposite the top side.

[0012] FIG. 1 shows a tablet portable computer 100 in accordance with an example embodiment of the invention. A tablet computer uses a pen-based user interface, and performs substantially all of the functions that are performed by a traditional portable computer that uses a keyboard. Computer 100 has a cover window 101 on its top side. Cover window 101 is preferably made of glass, but may also be made of any substantially rigid, substantially transparent material now known or later developed. A user of tablet computer 100 uses pen 102 to “write” on the cover window 101 of computer 100. Computer 100 senses the location and movement of pen 102, and provides appropriate feedback on a display behind cover window 101. The display (not visible in FIG. 1) may be a liquid crystal display, or another kind of display. For example, if computer 100 is executing a drawing program, the display may show a line that appears to be drawn by pen 102 as the user moves pen 102 over cover window 101. Computer 100 may sense the location of pen 102 using radio-frequency signals, or by other methods. Such methods are known in the art.

[0013] Cover window 101 is subject to damage. For example, during use, pen 102 repeatedly contacts cover window 101, and can cause wear. And because computer 100 is lightweight and portable, it may be subjected to other external effects. For example, computer 100 may be repeatedly slid in and out of a carrying case, scratching window 101 in the process. Or computer 100 may be dropped or have another object dropped on it, chipping or breaking window 101.

[0014] In prior tablet computers, repair or replacement of the cover window is expensive and difficult. In a computer in accordance with an example embodiment of the invention, repair or replacement of the cover window 101 is simplified, and may even be performed by the computer user.

[0015] FIG. 2 shows an exploded perspective view of the tablet computer of FIG. 1. FIG. 3A shows an exploded section view of part of computer 100, and FIG. 3B shows section view of part of computer 100 in its assembled state. Referring to all three FIGS. 2, 3A, and 3B, cover window 101 attaches to frame 201. Frame 201 may be made, for example, of die-cast magnesium, injection-molded plastic, or by other materials and methods. Frame 201 comprises bosses 202–205 which may be integrally formed with the main portion 210 of frame 201, or attached to it. Cover window 101 and frame 201 make up a cover window assembly 206. The attachment between cover window 101 and frame 201 may preferably be made using an adhesive, or an adhesive tape. Suitable adhesives and tape are known in the art.

[0016] Cover window assembly 206 is assembled into computer 100 by inserting bosses 202–205 into openings in case 207 of computer 100. Upon assembly, frame 201 partially surrounds display 208, and cover window 101 is in close proximity to display 208. A gasket 209 may be situated between frame 201 and case 207 in order to prevent dust, liquids, or other materials from entering computer 100, and especially to keep dust from finding its way between cover window 101 and display 208.

[0017] In example computer 100, each of bosses 202–205 comprises a threaded opening in its distal end. The distal end of each boss 202–205 is the end furthest from the main portion of frame 201. For example, boss 205 comprises threaded hole 301. Each of the threaded openings receives a screw from the bottom side of computer 100. For example, hole 301 receives screw 302. When computer 100 is fully assembled, the head of screw 302 resides in boss 303 comprised in the lower shell 304 of computer 100, and contacts a bottom side 305 of computer 100. The other screws reside in similar bosses.

[0018] FIG. 4 shows computer 100 with cover window assembly 206 in position to be assembled to the rest of computer 100. The attachment is simple and can be performed with simple tools. A user of computer 100 may replace the cover window assembly inexpensively, and quickly enough that the user would experience little computer downtime. For example, should cover window 101 became scratched, cracked, or broken, a user may order a replacement and do the repair without sending the computer to a repair center.

[0019] FIG. 5A shows an exploded section view of part of a computer 500 in accordance with a second example embodiment of the invention, and FIG. 5B shows section view of part of computer 500 in its assembled state. In this second example embodiment, cover window 501 and frame 502 make up cover window assembly 503. Frame 502 comprises a boss 504, which further comprises a threaded stud 505 protruding from it. During assembly, stud 505 protrudes through lower shell 507 of computer 500. Stud 505 receives a nut 506, which secures cover window assembly 503 to the rest of computer 500. After assembly, nut 506 resides in boss 508 comprised in lower shell 507 of computer 500, and contacts a bottom side 509 of computer 100.

[0020] One of skill in the art will recognize that other kinds of fasteners may be used to assemble a cover window assembly to a tablet computer or other electronic device in accordance with the invention.

[0021] An additional advantage of a cover window attachment system in accordance with the invention is that it also provides an upgrade path for computer 100. For example, a less expensive model of computer 100 may comprise a lower-performance window 101 as compared with a more expensive computer model. After owning the computer for a time, a computer user could upgrade to a high-strength glass, or a window with other desirable properties, such as anti-reflective coatings. For example, a less expensive model of computer 100 may have a window made of a plastic, such as polycarbonate, and a user may wish to upgrade to a window made of glass.

[0022] In a method in accordance with an example embodiment of the invention for assembling a cover window to an electronic device, a cover window assembly as previously described is provided. Each boss on the assembly is inserted into the electronic device from its front side. A fastener is provided to engage with a fastener receiving feature on each boss. Each fastener contacts the back side of the electronic device. When a worn or damaged cover window is to be replaced, the method further comprises removing a second, prior cover window assembly before assembling the new cover window to the electronic device.

[0023] While the example embodiments described thus far have used a portable computer as the example electronic device, other devices may be used as well. For example, the invention may be embodied in a system comprising a personal digital assistant (PDA). A PDA is a portable device, often handheld and carried with its user, that stores information for ready retrieval and use. For example, a user may store addresses and telephone numbers of people that are frequently contacted, digital books for convenient reading at any location, digital photographs, digital music that can be played when desired, or other kinds of information. A user of a PDA may enter data into or control the PDA using a stylus, “writing” or making selections by touching the stylus to a cover window on the PDA. A PDA may comprise a cover window that is subject to wear or other damage, and a PDA may benefit from a design in accordance with the invention.