Abstract:
There is provided by this invention a protective enclosure for a personal electronic device that is generally comprised of a shell that is capable of enclosing and substantially surrounding the electronic device disposed to make the shell substantially watertight, substantially rigid and substantially crush-resistant. The enclosure has a transparent flexible protective membrane that is integrally fixed on the shell so that the flexible protective membrane is positioned over the touch screen of the electronic device when the electronic device is enclosed in the shell. The flexible protective membrane having a back side that has a substantially planar smooth surface that is adjacent to the touch screen of the electronic device wherein tactile inputs on a front side of the flexible protective membrane are communicated to the touch screen through the transparent flexible protective membrane. The enclosure also has a second transparent flexible protective membrane that is integrally fixed on the shell so that the flexible protective membrane is positioned over an alphanumeric keyboard of the electronic device forming a keyboard in the flexible protective membrane such that the flexible protective membrane has total interface with the enclosed keyboard allowing the user to use the keyboard of the enclosed electronic device through the flexible protective membrane.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a Continuation in Part of U.S. Continuation application Ser. No. 11/270,732 filed Nov. 8, 2005 by Curtis R. Richardson, et al entitled “Protective Case for Touch Screen Device” which is a continuation of U.S. patent application Ser. No. 10/645,439 entitled “Protective Membrane for Touch Screen Device” by Curtis R. Richardson and Douglas A. Kempel, filed Aug. 20, 2003, which claims the benefit of and priority to U.S. Pat. No. 6,646,864 entitled “Protective Case for Touch Screen Device” by Curtis R. Richardson, issued Nov. 11, 2003, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 60/335,865 filed Nov. 19, 2001 by Curtis R. Richardson entitled “Protective Case for Touch Screen Device,” the entire contents of the applications are hereby specifically incorporated herein by reference for all they disclose and teach. 
    
    
     BACKGROUND OF THE INVENTION 
     a. Field of the Invention 
     Portable electronic devices (PEDs) such as PDAs, computers, MP3 players, music players, video players, smart phones, GPS receivers, telematics devices, cell phones, satellite phones, pagers, monitors, etc. are being very widely used, and are being deployed in industrial as well as office environments. PEDs are being used in industrial environments for data collection, such as service information on an airplane, or for data delivery such as maps for fire fighters and other emergency personnel. When PEDs are deployed in such industrial applications, the data that is collected and displayed on the PED can be extremely valuable and can be life saving. 
     The industrial environments impose harsh conditions that typical PEDs are not designed to accommodate. For example, damage can be done to the PED through rough handling and dropping. Further, industrial chemicals, grease, water, dirt, and grime may damage or destroy a functioning PED and inhibit the use of the PEDs valuable data. 
     It is common to hold the PEDs inside a protective case for transport. However PEDs are usually removed for use since most cases used for transport are not interactive. Interactive cases are also useful for non-industrial applications to provide protection for PEDs. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the disadvantages and limitations of the prior art by providing a watertight, crush-resistant, and impact resistant protective enclosure that protects devices that have an interactive flat-panel control. The present invention may therefore comprise the flexible protective membrane having a back side that has a substantially planar smooth surface that is adjacent to the touch screen of the electronic device wherein tactile inputs on a front side of the flexible protective membrane are communicated to the touch screen through the transparent flexible protective membrane. The flexible protective membrane being transparent such that the touch screen is visible through said flexible protective membrane so that said the touch screen is capable of displaying and capturing information through said flexible protective membrane. Also, a second transparent flexible protective membrane that is integrally fixed on the protective enclosure so that the flexible protective membrane is disposed over an alphanumeric keyboard of the electronic device forming a keyboard in the flexible protective membrane such that the flexible protective membrane has total interface with the enclosed keyboard allowing the user to use the keyboard of the enclosed electronic device through the flexible protective membrane. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the invention shown in the closed position. 
         FIG. 2  is a perspective view of an embodiment of the invention shown in the open position. 
         FIG. 3  is a perspective view of an embodiment of the invention shown in an exploded state. 
         FIG. 4  is a perspective view of an embodiment of the invention shown from the rear. 
         FIG. 5  is a front view of an embodiment of the invention, showing a section line. 
         FIG. 6  is a section view of an embodiment of the invention. 
         FIG. 7  is a detailed view of a section shown in  FIG. 6 . 
         FIG. 8  is a perspective view of another embodiment comprising a single piece encapsulating cover. 
         FIG. 9  is a perspective view of a third embodiment comprising a non-encapsulating snap over cover. 
         FIG. 10  is a perspective view of an embodiment that comprises a belt clip. 
         FIG. 11  is a second perspective view of an embodiment that comprises a belt clip. 
         FIG. 12  is a perspective view of another embodiment of the present invention of a protective cover for a PED or other device. 
         FIG. 13  is a perspective view of a PED case with integrated back lighted keyboard; 
         FIG. 14  is a perspective view of a PED case with integrated back lighted keyboard in the open position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of an embodiment of the invention. Embodiment  100  comprises a rigidly molded front case  102  and rear case  104 . An overmolded grommet  106  forms a receptacle for stylus  108  and also aids in sealing membrane  110 . A flexible hand strap  112  attaches to the rear case  104 . A hinge  114  joins front case  102  and rear case  104 . A ring  124  for a lanyard is shown as an integral feature of rear case  104 . 
     Embodiment  100  is designed to hold a conventional personal digital assistant (PDA) in a protective case. A PDA, such as a Palm Pilot, Handspring Visor, Compaq Ipaq, Hewlett Packard Jornada, or similar products use a touch screen for display and data entry. The touch screen display comprises either a color or black and white liquid crystal display with a touch sensitive device mounted on top of the display. The display is used for displaying graphics, text, and other elements to the user. The touch screen is used with a stylus  108  to select elements from the screen, to draw figures, and to enter text with a character recognition program in the PDA. The stylus  108  generally resembles a conventional writing implement however, the tip of the writing implement is a rounded plastic tip. In place of a stylus  108 , the user may use the tip of a finger or fingernail, or a conventional pen or pencil. When a conventional writing implement is used, damage to the touch screen element may occur, such as scratches. 
     For the purposes of this specification, the term PDA shall include any electronic device that has a touch screen interface. This may include instruments such as voltmeters, oscilloscopes, logic analyzers, and any other hand held, bench top, or rack mounted instrument that has a touch screen interface. Hand held devices, such as cell phones, satellite phones, telemetric devices, and other hand held devices are also to be classified as PDAs for the purposes of this specification. The term PDA shall also include any computer terminal display that has a touch screen interface. These may comprise kiosks, outdoor terminal interfaces, industrial computer interfaces, commercial computer interfaces, and other computer displays. Additionally, the term PDA may comprise barcode scanners, hand held GPS receivers, and other handheld electronic devices. The foregoing description of the term PDA has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and other modifications and variations may be possible in light of the teachings of this specification. 
     In addition, the PDAs typically have a handful of additional buttons as part of the user interface. These buttons are generally on the front of the device, near the touch screen element. The additional buttons may be used as shortcut buttons to instantly call up a certain program on the PDA, may comprise a method of scrolling, may be used to select items from a list, or may have any function that the designer of the PDA software may assign to the button or set of buttons. The button size, layout, and function may vary for each manufacturer and model of PDA. 
     Further, PDAs typically have at least one method of connecting to another computer. This may be through a direct electrical connection, such as through a wire cable or fiber optic, or through another medium such as infrared communication or through a radio communication. 
     Additionally, the PDAs typically have an electrical source. The electrical source may be a rechargeable or non-rechargeable battery or solar cells. The electrical source may be a remote source of electricity that is transmitted to the PDA through a wire cable or through other methods of electrical transmission. 
     Further, PDAs may have indicator lights, such as status lights for power, communication, battery status, or other functions. The lights may be located on any of the sides of the PDA and may be viewable on one or more sides. 
     Front case  102  and rear case  104  form a protective cover for the PDA. The protective cover may be designed for rugged industrial use, recreational use, commercial use, or many other uses. An industrial use may require the protective cover to be watertight, chemically resistant, protect the unit when dropped, and be crush proof. A typical application may be for fire fighters to use a PDA for a display of maps for directions to an emergency scene or for a building plan at the scene of a fire. Another example may be a maintenance mechanic in a chemical plant using a PDA to record maintenance records in the plant that processes. A recreational use may require the cover to be watertight, afford some protection against dropping and being crushed, float in water, and be dust resistant. A recreational use may be to take the PDA during kayaking, diving, or other water sport activity. Further, the case may be used when the PDA is taken camping, hiking, or other outdoor activity. A commercial use may additionally require the protective cover to be elegant, but may also require the cover to be replaceable so that scratches and other signs of wear and tear can be easily and cheaply replaced. 
     The protective cover for the PDA may take on many embodiments. The embodiment  100  comprises a front case  102  and rear case  104  that are joined by a hinge  114  and a clasp mechanism that is on the side of the cases opposite the hinge  114 . Other embodiments may have a small door into which the PDA slides, or the protective cover may not completely enclose the PDA and only cover the face where the user interface exists, leaving one or more sides of the PDA exposed. Those skilled in the art may use other designs of protective covers without deviating from the scope and intent of the present invention. 
     The protective cover may be constructed of rigid plastic, metal, flexible rubber, or any other type of material that could be adapted to afford the protection of the PDA desired for the application. For example, a metal cover may be used in an application where an elegant style is necessary but watertightness is not. A flexible rubber cover may be selected for an application in a wet environment. A rigid plastic cover may be selected for an application where dropping the PDA is a concern. Those skilled in the art may use other types of materials and constructions without deviating from the spirit of the present invention. 
     The PDA may be mounted in the protective cover using many different mounting techniques. For example, the PDA may be mounted using open or closed cell foam inserts in the protective cover. In another embodiment, the PDA may be mounted by attaching the PDA to the cover with a fastener. In another embodiment, the PDA may be mounted by snapping into the protective waterproof cover. In another embodiment, the PDA may be held in place by resting in molded features of two halves of a protective case that clamps onto the PDA. Those skilled in the art may use other types of locating and holding mechanisms without deviating from the spirit of the present invention. 
     The overmolded grommet  106  of the present embodiment is constructed by injection molding a thermoplastic polymerized rubber (TPR) over the front case  102 . The grommet  106  has molded features  116  and  118  adapted to retain the stylus  108 . Features  116  and  118  capture the stylus  108  during transportation, but allow the user to remove the stylus  108  to operate the PDA. In other embodiments of the present invention, the stylus  108  may be constrained to the PDA with a tether or lanyard, or the constraining features may be incorporated into other components that make up the protective cover. Further, the stylus  108  may not be present in the embodiment, rather that the PDA be adapted to be used with the user&#39;s fingernail or with another implement similar to the stylus  108 . 
     The membrane  110  of the present embodiment is constructed by thermoforming a sheet of thin plastic. The plastic is selected to be thin enough that the deformation of a stylus conducts the touch to the touch screen, but thick enough to have enough rigidity that the stylus does not catch and rip the membrane. Additionally, the membrane  110  should have enough thickness to endure scratches and other wear and tear without breaking and sacrificing the protective function. Polyvinylchoride material at 0.010 in to 0.015 in thickness gives acceptable results. Alternatively, membrane  110  may be constructed by injection molding or other methods. Alternative materials may be used by those skilled in the art to achieve the same results while maintaining within the spirit and intent of the present invention. 
     The membrane  110  in the present embodiment may be transparent or at least partially transparent, so that the images displayed on the PDA may be visible through the membrane  110 . The membrane  110  may be tinted or colorized in some applications. For example, a protective cover designed as a decorative cover may incorporate a colorized membrane  110 . Further, the membrane may be selectively colorized and the opaqueness may vary. For example, the protective membrane may be printed or painted in the areas not used for the touch screen. A printing process may incorporate a logo, graphics, or labeling for individual buttons for the PDA. The printing process may further incorporate features, such as text or graphics, that are used by the software on the PDA for a purpose such as simplifying data input or for designating an area on the touch screen for a specific function, such as a help function. The printing or painting processes used on the membrane  110  may be purely decorative and may be for aesthetic purposes only. The printing process may also comprise logos or graphics for the brand identity of the PDA cover. Other processes, such as colorizing the raw material for the membrane  110  or adding other components to the raw material, such as metal flakes or other additives, may be used to change the optical features of the membrane  110 . 
     The optical performance of the membrane  110  may be changed or enhanced by changing the texture of the area of the touch screen. For example, the membrane may be frosted on the outside to hide scratches or may be imprinted with a lens or other features that change the optical characteristics of the membrane  110 . The membrane  110  may have optical features that are used in conjunction with the software of the PDA. For example, all or a portion of the membrane may comprise a lens that magnifies an image to a user. When the user touches the image on the membrane  110  and the touch is transferred to the touch screen, the software in the PDA may have to compensate for the positional differences between the image and actual area that was touched by the user. In another example, if a specific portion of the membrane  110  had a specific optical characteristic, the software of the PDA may be constructed to display a specific graphic for the area for an intended effect. 
     The membrane  110  in the present embodiment has a recessed portion  120  and a raised portion  122 . The recessed portion  120  may be adapted to press flat against the touch screen area of a specific PDA. The raised portion  122  may be adapted to fit over an area of the specific PDA where several buttons are located. 
     The raised portion  122  allows the user to operate the buttons on the PDA. The raised portion  122  is adapted such that the buttons on the PDA are easily operated through the protective membrane  110 . The raised portion  122  may have special features to aid the user in pressing the buttons. For example, the raised portion  122  may comprise a dimpled area for the user&#39;s finger located directly over the button. Further, a feature to aid the user may comprise a section of membrane  110  defined by a thinner area around the section, enabling the user to more easily deflect the section of membrane over the button. The area of thinner material may comprise a large section or a thin line. Further, tactile elements, such as small ribs or bumps may be incorporated into the membrane  110  in the area of the buttons so that the user has a tactile sensation that the user&#39;s finger is over the button. The tactile element may be particularly effective if the button was a power switch, for example, that turned on the PDA. 
     The configuration of the membrane  110  may be unique to each style or model of PDA, however, the front case  102  and rear case  104  may be used over a variety of PDAs. In the present embodiment, the changeover from one PDA variety to another is accomplished by replacing the membrane  110  without having to change any other parts. The present embodiment may therefore be mass-produced with the only customizable area being the membrane  110  to allow different models of PDAs to be used with a certain front case  102  and rear case  104 . 
     The hand strap  112  in the present embodiment allows the user to hold the embodiment  100  securely in his hand while using the PDA. The hand strap  112  may be constructed of a flexible material, such as rubber or cloth webbing, and may have an adjustment, such as a buckle, hook and loop fastener, or other method of adjustment. In other embodiments, a hand strap may be a rigid plastic handle, a folding handle, or any other method of assisting the user in holding the embodiment. Further, the embodiment may be adapted to be fix-mounted to another object, like a piece of machinery, a wall, or any other object. A fix-mounted embodiment may have other accoutrements adapted for a fixed mount applications, such as receptacles for a stylus adapted to a fix-mount, specialized electrical connections, features for locking the PDA inside the case to prevent theft, or designs specifically adapted to shed water when rained upon. 
       FIG. 2  illustrates a perspective view of the embodiment  100  shown in an open position. The front case  102  and rear case  104  are shown open about the hinge  114 . Membrane  110  is shown installed into gasket  106 , and the recessed portion  120  and raised portion  122  of membrane  110  is illustrated looking from the inside of the case. The clasp mechanisms are not shown in this illustration. Hand strap  112  is shown attached to rear case  104 . 
       FIG. 3  illustrates a perspective view of the embodiment  100  shown in an exploded state. The hand strap  116  attaches to the rear cover  104 . The overmolded grommet  106  holds the stylus  108  and is attached to front cover  102 . The membrane  110  attaches to the grommet  106  and is held in place with an o-ring  302 . 
       FIG. 4  illustrates a perspective view of the embodiment  100  shown from the rear. The hand strap  116  is shown, along with rear cover  104  and front cover  102 . The stylus  108  is shown inserted into the overmolded grommet  106 . 
       FIG. 5  illustrates a top view of the embodiment  100 . The front cover  102 , membrane  110 , stylus  108 , and hinge  114  are all visible. 
       FIG. 6  illustrates a section view of the embodiment  100  taken through the section line shown in  FIG. 5 . The front cover  102 , rear cover  104 , overmolded gasket  106 , stylus  108 , membrane  110 , hand strap  112 , and o-ring  302  are all shown hatched in this view. 
       FIG. 7  illustrates a detail view of the embodiment  100  shown in  FIG. 6 . Front case  102  and rear case  104  are joined at hinge  114 . Overmolded gasket  106  traps membrane  110  and o-ring  302  locks membrane  110  in place. Overmolded gasket  106  may be formed by molding thermoplastic polymerized rubber over the front cover  102 . 
     The replacement of the membrane  110  is accomplished by removing o-ring  302 , pushing the membrane  110  from the overmolded gasket  106 , snapping a new membrane  110  into place, and replacing the o-ring  302 . The ease of replacement of the present embodiment allows a user to quickly replace a damaged membrane  110 , allows a user to upgrade their case to a newer model PDA, and may allow a user to select from various membranes  110  for the particular application. One embodiment may have a single case packaged with a small variety of several types of membranes  110 . In such an embodiment, the user may purchase the packaged set, select the membrane  110  that suits the user&#39;s particular PDA, and install the selected membrane  110  with ease. 
     The protective cover of the present invention may have direct connections through the cover for connecting through the case. Such a connection is known as pass through. The connections may be for power, communication, heat dissipation, optical transmissions, mechanical motion, or other reasons. 
     Electrical connections may require an insulated metal conductor from the PDA through the wall of the protective cover so that a flexible cable may be attached or so that the PDA in its protective case may be placed in a cradle for making the electrical connection. Inside the protective cover, the electrical connections may be made with a flexible cable that is plugged into the PDAs electrical connector before the PDA is secured in the protective cover. Alternatively, a fixed connector may be attached to the protective cover and the PDA is slid into contact with the fixed connector. Another embodiment may be for a compliant, yet fixed mounted electrical connector to be rigidly mounted inside the protective cover. A compliant, yet fixed mounted electrical connector may comprise spring loaded probes, commonly referred to as pogo pins. Another embodiment may comprise spring fingers that engage the PDAs electrical contacts. On the outside of the protective cover, the electrical contacts may be terminated into a fix-mounted connector adapted to receive a cable from a computer. The connector may be designed to receive a cable that plugs directly into the PDA or it may be adapted to receive a different connector. Further, the electrical connection to the PDA may be permanently attached to a cable that extends out of the protective cover. Another embodiment may be to have a small trap door that opens in the protective cover to allow access to the electrical connections. While the trap door exposes the PDA to the elements the cover is designed to protect against, a direct electrical connection may eliminate a potential cabling connection problem. Connections for fiber optics can be handled in similar fashions as the electrical connections. An embodiment with a power connection may comprise the use of inductive coils located in proximity to each other but on opposite sides of the protective cover. Those skilled in the art of may devise other embodiments for connecting through the protective cover without deviating from the scope and intent of the present invention. 
     Through the air communications, such as infrared and over the air radio frequency (RF) communications may pass through the protective cover. The material for the front case  102  and rear case  104  may be selected to be clear plastic, such as polycarbonate. The infrared transceiver of the PDA can communicate through a clear plastic case to another infrared transceiver outside of the case. Further, the appropriate selection of material for the protective case can thereby enable various RF transmissions, such as cellular phone communications or other wireless communication protocols. 
     An infrared transmission through the protective case of an embodiment of the invention may be accomplished by making the entire protective case out of a clear material. Alternatively, a selected area of the protective case may be clear while the remainder of the case is opaque. The selected area may be constructed of a separate piece that allows the infrared light through the protective case. Alternatively, the selected area may be constructed of a portion of the protective case that manufactured in a way so as not to be opaque, such as selectively not painting or plating the area of a plastic protective case. Further, the clear material through which the transmission occurs may be tinted in the visual spectrum but be transparent or at least partially transparent in the infrared spectrum of the device. 
     A protective case may allow RF transmissions to and from the PDA while the case is closed. Such a case may be constructed of a non-metallic material. In some embodiments, the material of the protective case may be tuned to allow certain frequencies to pass through the protective cover and tune out other frequencies, through loading the material used in the protective cover with conductive media or through varying the thickness of the case and other geometries of the case in the area of the PDA transmission and reception antenna. 
     In a different embodiment, it may be desirable to shield the PDA from outside RF interference. In this case, the protective cover may be a metallic construction or may be plastic with a metallized coating. Further, membrane  110  may have a light metallized coating applied so that membrane  110  is slightly or fully conductive. An application for such an embodiment may be the use of the PDA in an area of high RF noise that may interfere with the operation of the PDA, or conversely, the use may be in an area that is highly susceptible to external RF interference and the PDAs RF noise may be interfering with some other device. 
     The PDA may be equipped with a camera or other video capture device. A protective cover may have provisions to allow a clear image to be seen by the video capture device through the case. Such provisions may include an optically clear insert assembled into the protective case. Other embodiments may have a sliding trap door whereby the user of the PDA may slide the door open for the camera to see. Additionally, other embodiments may comprise a molded case that has an optically clear lens integrally molded. Such an embodiment may be additionally painted, plated, or overmolded, with the lens area masked so that the painting, plating, or overmolding does not interfere with the optics of the lens. 
     An optically clear area may be used for a barcode scanner portion of a PDA to scan through the case to the outside world. In such an embodiment, a barcode scanner may be protected from the elements while still maintaining full functionality in the outside world. 
     The PDA may have indicator lights that indicate various items, such as power, battery condition, communication, and other status items. The indicator lights may be in positions on the PDA that are not readily viewable through the protective membrane  110 . The indicator lights may be made visible through the protective case by using light pipes that transmit the light from the PDAs status light to the outside of the protective case. Such light pipes may be constructed of clear or tinted plastic, or other transparent or semi-transparent material. The light pipes may be formed as an integral feature to the protective case or may be separate parts that are formed separately and assembled to the protective case. 
     The PDA may have a speaker or other element that makes noise and/or the PDA may have a microphone for receiving audio signals. The speaker may be an audio quality device for reproducing sound or it may be a simple buzzer for indicating various functions of the PDA. The microphone may be an audio quality device or it may be a low performance device. Special provisions may be made for transmitting sound through a protective case. Such provisions may range from a single hole in the case to a tuned cavity that would allow sound to pass through with minimum distortion. Other embodiments may include a transmissive membrane adapted to allow sound to pass through the protective case with a minimum of distortion. Such membranes may be located near the speaker and microphone elements of the PDA. Such membranes may be watertight membranes known by the brand name Gore-Tex. 
     The PDA may generate heat during its use and provisions for dissipating the heat may be built into the protective cover. A heat-dissipating device may be integral to the protective cover or may comprise one or more separate parts. For example, a metallic protective cover may be adapted to touch the PDA in the area of heat generation and conduct the heat outwardly to the rest of the protective cover. The protective cover may thereby dissipate the heat to the external air without overheating the PDA. In another example, a separate heat sink may be applied to the PDA and allowed to protrude through a hole in the protective cover. The heat sink may thereby transfer the heat from the PDA to the ambient environment without overheating the PDA. The heat sinks may be attached to the PDA with a thermally conductive adhesive. Other embodiments may include vent holes for heat dissipation and air circulation. 
     The PDA may have a button that may not be located underneath the membrane  110 . An embodiment may include a flexible, pliable, or otherwise movable mechanism that may transmit mechanical motion from the outside of the case to a button on the PDA. Such an embodiment may have a molded dimpled surface that is pliable and allows a user to activate a button on a PDA by pressing the dimpled surface. Another embodiment may have a rigid plunger that is mounted on a spring and adapted to transmit the mechanical movement from the exterior of the case to a button on the PDA. The buttons on the PDA may be located on any side of the PDA and an embodiment of a case may have pliable areas adapted to allow the user to press buttons that are not on the front face of the PDA. 
       FIG. 8  is an illustration of embodiment  800  of the present invention wherein the PDA  802  is encapsulated by a protective cover  804 . The installation of the PDA  802  is to slide PDA  802  into the opening  808 , then fold door  806  closed and secure with flap  810 , which is hinged along line  812 . Areas  814  and  816  may comprise a hook and loop fastener system or other fastening device. Recessed area  818  is adapted to fit against touch screen  820  of PDA  802 . 
     Embodiment  800  may be comprised of a single molded plastic part that may be very low cost. As shown, embodiment  800  may not be completely weathertight, since the door  806  does not completely seal the enclosure. However, such an embodiment may afford considerable protection to the PDA  802  in the areas of dust protection, scratch protection, and being occasionally rained upon. Further, the low cost of the embodiment  800  may be changed often during the life of the PDA  802 . 
     Embodiment  800  may have custom colors, logos, or designs that allow a user to personalize their PDA with a specific cover that is suited to their mood or tastes. The colors, logos, and designs may be integrally molded into the cover  804 . Alternatively, different colors, logos, and designs may be applied in a secondary operation such as printing, painting, plating, or other application process. 
       FIG. 9  is an illustration of embodiment  900  of the present invention wherein a decorative cover  902  is snapped over a PDA  904 . The ends  906  and  908  snap over the PDA ends  910  and  912  as an attachment mechanism for cover  902  to PDA  904 . Recessed area  914  is adapted to fit against touch screen  916 . 
     Embodiment  900  may be a cover for decorative purposes only, or may be for protective purposes as well. Cover  902  may be emblazoned with logos, designs, or other visual embellishments to personalize the PDA  904 . The colors, logos, and designs may be integrally molded into the cover  904 . Alternatively, different colors, logos, and designs may be applied in a secondary operation such as printing, painting, plating, or other application process. 
     Embodiment  900  may be attached by snapping the cover  902  onto PDA  904 . Special provisions in the case of PDA  904  may be provided for a snapping feature of cover  902 , or cover  902  may be adapted to hold onto PDA  904  without the use of special features in PDA  904 . 
     The features used to secure cover  902  to PDA  904  may be any mechanism whereby the cover  902  can be secured. This includes snapping, clamping, fastening, sliding, gluing, adhering, or any other method for securing two components together. 
       FIG. 10  illustrates a perspective view of an embodiment of a receiver  1002  for holding the protective case  100 . The protective case  100  is held into receiver  1002  in such a manner that the touch screen display is facing into the receiver  1002 , to afford the touch screen display with protection. 
       FIG. 11  illustrates a perspective view of the embodiment of a receiver  1002  shown from the opposite side as  FIG. 10 . Receiver  1002  is comprised of a back  1102 , a belt clip mechanism  1104 , and four clip areas  1106 ,  1108 ,  1110 , and  1112 . The protective case  100  is placed into the receiver  1002  by inserting one end into the receiver, then rotating the protective case  100  into position such that the snapping action of clip areas  1106 ,  1108 ,  1110 , and  1112  are engaged to hold protective case  100  securely. 
     Receiver  1002  may be adapted to clip onto a person&#39;s belt or may be adapted to be mounted on a wall or other location where the PDA may be stored. The orientation of the protective case  100  is such that the touch screen element of the PDA is protected during normal transport and storage, since the touch screen interface is facing the back  1102  of the receiver  1002 . 
     Receiver  1002  may be made of compliant plastic that allows the clip areas  1106 ,  1108 ,  1110 , and  1112  to move out of the way and spring back during insertion or removal of the protective case  100 . In the present embodiment, receiver  1002  may be constructed of a single part. In alternative embodiments, receiver  1002  may be constructed of multiple parts and of multiple materials, such as a metal back with spring loaded clips. In other embodiments, special features may be included in the protective case  100  where the receiver  1002  may engage a special feature for securing the protective case  100 . 
       FIG. 12  illustrates an embodiment  1200  of the present invention of a protective cover for a PDA or other device. A rigid front cover  1202  and a rigid rear cover  1204  are held together with a series of latches  1206 ,  1208 ,  1210 , and  1212 . The protective membrane  1214  protects the touchscreen of the enclosed PDA. A folding rigid cover  1216  operates as a rigid shield to prevent the membrane  1214  from any damage. The stylus holder  1220  is formed from an overmolded flexible material in which the membrane  1214  is mounted. 
     Embodiment  1200  illustrates yet another embodiment of the present invention wherein a rigid protective cover may be used to contain and protect an electronic device, but provide full usable access to a touch screen. The protective membrane  1214  and case may be watertight in some embodiments. 
       FIGS. 13 and 14  illustrate a PDA device with an electronic alphanumeric keyboard enclosed in a protective case  1400 . The PDA is not shown but it may be any one of several devices such as Palm Pilot, Handspring Visor, Compaq Ipaq, Hewlett Packard Jomada, or similar products use a touch screen for display and alphanumeric keyboard for data entry. The protective case  1400  is comprised of a keyboard design that allows the user to use the keyboard of the electronic device directly through the keyboard of the protective case  1400 . This protective case is also designed for rugged industrial use, recreational use, commercial use, or many other uses. The protective case is watertight, chemically resistant, protects the unit when dropped, and is crush proof. Depending on the application the protective case may be constructed of rigid plastic, metal, flexible rubber, or any other type of material that could be adapted to afford the protection of the PDA desired for the application. 
     This embodiment  1400  also comprises a rigidly molded front case  1402  and rear case  1404 . A hinge  1406  joins front case  1402  and rear case  1404 . As described above the protective case has a protective membrane  1408  covering the touch screen of the PDA device that is comprised of a sheet of thin plastic. The plastic is selected to be thin enough that the deformation of a stylus conducts the touch to the touch screen, but thick enough to have enough rigidity that the stylus does not catch and rip the membrane. 
     This embodiment is also applicable to handheld electronic devices that have an interactive flat-panel control because they also benefit from being enclosed in a rugged protective enclosure such as  1400  that is crush-resistant, watertight and shock-resistant and that simultaneously allows the user to interact with a sensitive interactive flat-panel control. Handheld electronic devices that have interactive flat-panel control may include music players, MP3 players, audio player/recorders, and video players. For example, Apple Computer Ipod is a popular handheld interactive device that plays MP3 or otherwise digitally-encoded music/audio. The Apple Ipod has an interactive flat-panel control in which a portion of the front panel is a flat-panel display and portion of the front panel is an interactive flat-panel control, called a touch wheel in some versions of the Ipod and click wheel in other versions of the Ipod, that has capacitive touch/proximity sensors. One function of the interactive flat-panel control, i.e. touch wheel, emulates a rotary control knob by sensing circular motion of a user&#39;s finger using capacitive sensors. The click wheel has the same function with the additional feature of sensing proximity of a user&#39;s finger and emulating button presses by a user&#39;s finger at pre-determined areas. 
     The protective membrane  1408  may have capacitive sensors which are part of a proximity/touch detector circuit. When a grounded object, such as a person&#39;s finger, which has free air capacitance of several hundred picofarads, is brought close to the capacitive sensors, the total capacitance measured by the detector circuit increases because the capacitance of the object with free air capacitance adds to the capacitance of the sensors since the total capacitance of two capacitors in parallel is additive. Multiple sensors may also be arranged so that movement of an object with free air capacitance can be detected, for example, movement of a person&#39;s finger in a circular motion analogous to turning a mechanical control knob. Some examples of interactive flat-panel controlled PDA&#39;s include Ipod and Ipod Mini music and audio players from Apple Computer. In some PDAs, such as the Apple Ipod, capacitive sensors may be disposed below a front panel made from a dielectric such as polycarbonate which has a dielectric constant in the range of 2.2-3.8. In the embodiment of  FIG. 13 , the protective control membrane  1408  is made of thin polycarbonate that is slightly flexible or other engineered thermoplastics that provide the rugged watertight protection and at the same time permit the capacitive sensors function correctly. Likewise, a protective control membrane  1408  with a dielectric constant that is too high may retain an electric charge long enough to reduce the response rate of the sensor to motion of a user&#39;s finger from one capacitive sensor zone of the interactive flat-panel control of the electronic device to another. A protective control membrane  1408  that is conductive or has a dielectric constant that is too low may diminish the sensitivity of the capacitive sensor by combining in series the capacitance of the protective membrane and the dielectric front panel of the PDA which results in a lowering of the overall capacitance. 
     Total capacitance between an object, such as a finger touching the protective control membrane  1408 , and interactive flat-panel control of the electronic device is a function of the thickness and the dielectric constant of the protective control membrane  1408 . The capacitance between the object, such as a finger, and the capacitive sensors of the interactive flat-panel control of the electronic device is proportional to the distance between the object and the sensors. The sensitivity of the capacitive sensors to the object may be diminished or completely eliminated if the protective control membrane  1408  is too thick. In the embodiment of  FIG. 13 , the thickness of the protective control membrane is approximately 0.020 inches. The protective control membrane  1408  may be any thickness in the range of 0.003 inches to 0.060 inches that is adequate to provide a rugged watertight membrane through which capacitance can be correctly sensed by the interactive flat-panel control of the electronic device. 
     Similar to the protective membrane  1408  a protective membrane keyboard  1410  is disposed to cover the alphanumeric keyboard section of the PDA. The protective membrane keyboard  1410  is printed with the same design of the keyboard of the electronic device that is disposed to be enclosed in the protective case  1400  so as to have total interface with the enclosed keyboard. The alphanumeric keys and function keys are transparent so that back light from the keyboard of the electronic device is seen. The user can type on the protective membrane keyboard  1410  so that backlighting from the keyboard of the PDA device actually lights up the keyboard so that the user can see what was typed into the electronic device. This allows the user to use the keyboard of the electronic device directly through the keyboard of the protective case  1400 . 
     The touch screen  1408  and the keyboard  1410  are attached to the protective case  1400  by a single frame  1403 . The keyboard protective membrane  1408  and the touch screen protective membrane  1410  may be a single framed unit that attaches to the case using fasteners such as  1420 . 
     The PDA is held in place by resting in molded features of two halves of a protective case  1402  and  1404 . Depending on the type of PDA and the manufacturer the PDA is designed to meet the specifications so that the PDA mounts on the shock absorbing cushions  1412 . The case may be then closed and sealed utilizing the clamps  1414 . Once closed and sealed access to the PDA may be obtained utilizing the access ports  1416  and  1418 . Also, once the PDA is sealed in the case the protective keyboard membrane  1410  faces and matches the keyboard of the PDA device. 
     The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.