HK1070972A - Keymat - Google Patents

Description

Key pad

Technical Field

The present invention relates generally to the field of mobile station construction, and more particularly to a novel construction of user replaceable keymats for use in conjunction with mobile telephones and similar devices.

Background

Mobile phones are ubiquitous in modern society. Previously only affluents or persons engaged in specialized professions who both required and supported mobile phones had and carried mobile phones, many, and sometimes even the majority of a given population, now own mobile phones. Mobile phones are no longer used by only a small percentage of people, but by people of all ages and in all industries.

There are a number of reasons for the widespread use of mobile phones. Of course, the first and foremost reason is technology. The development of cellular systems for organized radio communication has led to the subscription of thousands of consumers in large urban areas. Improved multiplexing and modulation techniques can compete for a large number of consumers. The coverage area, i.e., the amount of geographical area within range of the network antenna for the mobile system user, is also improved. Meanwhile, the cost of the mobile phone itself and the subscription cost of the mobile communication network have been reduced, thereby making it possible for people to pay for the mobile phone. Improved technology has also led to the creation of smaller and easier to use phones. As such, technological improvements are also often made, and the increasing popularity of mobile phones has led to an increasing market demand, which in turn has further stimulated technological innovation.

In the past, mobile phones were simple in design and functional when used by only a limited group of users (commonly referred to as subscriber subscribers). As long as the device is capable of performing its given task, appearance is not an important consideration. The first generation of mobile phones were large and bulky, except that they were typically placed out of view when in use. Since radio calls are expensive, the use of mobile phones is usually kept to a minimum. Even having such a device is a social metaphor, and merely having a mobile phone is sufficient to convey the significance of its identity.

However, mobile phones have become commonplace due to an increase in the number of mobile user subscribers, as well as a decrease in the cost of airtime. It is now unusually intrusive to public life, and no longer looks at someone else's cellular radiotelephone as it was in the past when using the cellular radiotelephone. It is conceivable that with increasing widespread use, the need for aesthetically attractive phones has increased. Of course, the vastly increased sales of mobile phones allowed manufacturers to diversify their products, and the cost of previously implementing one or more than two basic designs was prohibitive. The need for novel and varied designs arises from the fact that many mobile phone owners are young people and teenagers with different tastes than professional business homes.

Meanwhile, the practicability of the wireless communication device is increased. In addition to making and receiving calls, mobile phones and similar devices now have the ability to store speech and record calls directly. Many mobile phones also include the functions of a clock, calendar and calculator. Other mobile phones may be used as electronic organizers, or for playing games, or even downloading web pages in the case of a wireless connection to an Internet Service Provider (ISP). Thus they emulate modern Personal Digital Assistants (PDAs), starting as simple managers and improving their own functionality. In fact, there is a diversification among different types of wirelessly communicable portable devices. In light of this diversity, the term "mobile station" will be used herein to refer generically to these and similar devices, whether they perform wireless communications or simply some other function.

However, one feature all of these devices must include is one or more forms of user interface. Most devices include a visual display screen, typically a Liquid Crystal Display (LCD). Those means for communication (or recording) will have a microphone and a speaker or at least one port through which a separate microphone and speaker are connected. Finally, all or almost all mobile stations include a keypad. The keypad is an external set of user accessible buttons or similar mechanism for entering information or causing the device to perform certain functions. There are a number of different keypad designs and different button designs that may be included therein. Each button may have more than one function. However, in conventional devices, there will be a set of buttons associated with alphanumeric (and several other) characters. Dedicated buttons may be used for scrolling (moving images up and down or sideways in the display screen to display content), for starting or ending a call, or other functions that vary with the state of use. The keyboard buttons usually do not have their own switches, but correspond to and operate internally located switches. Since the voltages used by mobile stations are small and it is unlikely that a user will touch any electrical components, they are typically made of an insulating material. For ease of manufacture, all or some of the buttons may be formed in an integral manner along a sheet of (typically) non-conductive material, with individual operating buttons being distinguished by raised surfaces, visible indicia, or both. The sheet buttons are commonly referred to as keymats.

The keymat is typically made of an elastic material, and thus has non-conductive, flexible, and resilient characteristics. Any given device may have one or more keymats, with each keymat typically, although not necessarily, formed with a plurality of keys. Each keymat is received in the housing portion and is not directly accessible to a user. However, the housing portion is formed with one or more openings corresponding to each button, or key, on the keymat to allow the protruding portion of the keymat to protrude toward the exterior of the device. The key mat is also supported from the inside in such a way that the user can simply actuate the desired switch by pressing or manipulating the key, so that when the key is released, it and the switch associated therewith return to its rest state. For a more detailed description of the conventional structure, refer to fig. 1 and the related description below.

However, a keymat that is closed in a conventional manner has only a little effect on the overall appearance of the device. Its functional structure is well suited for handling the mobile station, but even if it is designed in a more attractive way, it hardly affects the appearance of the device. It is certainly not easily changeable, usually only by a service technician, and only when necessary. The keymat generally cannot be used to customize the appearance of the mobile station to any significant degree.

There is a need for a mobile station keyboard having a keymat that can be easily removed and installed so that a user can easily replace the keymat for aesthetic or functional reasons, but without significantly compromising the normal operation or integrity of the mobile station. The keymat design of the present invention provides just such a solution.

Disclosure of Invention

The present invention is a keymat for a mobile station or similar device that can be easily removed and reinstalled, allowing the user of the mobile station to interchange the keymat with other keymats to meet customized appearance or function requirements. In one aspect, the present invention is a keymat that is mounted on an exterior surface of a mobile station, i.e., that has retaining means to removably retain the keymat, thereby holding the keymat in place for mobile station operation. The retaining means may include a plurality of key pins integrally formed with the keymat and extending inwardly through an opening formed in a front cover of the mobile station, an extension formed in at least one of the plurality of key pins having an extension removably engaged with an inner surface of the front cover. In another embodiment, the retaining means may comprise a plurality of key pins retained substantially inside the front cover, and the keymat comprises a plurality of recesses for receiving the key pins so arranged. In another embodiment, the keymat is securely attached to a plurality of key pins that form grooves that engage a slide plate disposed inside the front cover.

In another aspect, the invention is a mobile station having an internal switch that is actuatable by a force applied to a corresponding key on a keymat that includes a removably attached external keymat plate that is held in place during operation by a retaining device, and that further includes a plurality of key pins that correspond to the internal switch and extend through openings formed in a front cover of the mobile station. The force applied to the keymat is transmitted to the switch through the key pins.

Drawings

FIG. 1 is an isometric view of a conventional mobile station, here a mobile phone, of the prior art;

FIG. 2 is a simplified exploded view illustrating selected components of a mobile station that may be used in conjunction with a keymat constructed in accordance with the present invention;

FIGS. 3a-3c illustrate a keymat according to one embodiment of the present invention; FIG. 3a is an isometric view showing the inside of the keymat itself; FIG. 3b is an isometric view of a keymat assembled on a surface of a front cover of an exemplary mobile station; and FIG. 3c is a partial cross-sectional view illustrating cooperation between an exemplary keymat key and other mobile station components;

FIGS. 4a-4f illustrate a keymat used in accordance with another embodiment of the present invention; FIG. 4a is an isometric view of a key pin grid; FIG. 4b is an isometric view showing the key-pin grid of FIG. 4a when assembled adjacent to a light guide; FIG. 4c is an isometric view illustrating an exemplary mobile station bezel that covers the assembly of FIG. 4 b; FIG. 4d is an isometric view showing the inside of a keymat used in accordance with this embodiment of the present invention; FIG. 4e is an isometric view showing a keymat mounted on the assembly shown in FIG. 4 c; and FIG. 4f is a partial cross-sectional view illustrating cooperation between an exemplary key and other mobile station components;

FIGS. 5a-5e illustrate a keymat used in accordance with another embodiment of the present invention; FIG. 5a is an isometric view of a skateboard; FIG. 5b is an isometric view of the sled of FIG. 5a assembled on a mobile station light guide; FIG. 5c is an isometric view of a keymat according to this embodiment of the present invention; FIG. 5d is an isometric view of the keymat of FIG. 5c assembled to a front cover of a mobile station; and FIG. 5e is a partial cross-sectional view illustrating cooperation between an exemplary key and other mobile station components; and

fig. 6a-6c illustrate a keymat according to another embodiment of the present invention. FIG. 6a is an isometric view of a specialized keymat; FIG. 6b is an isometric view of the keymat of FIG. 6a assembled onto a front cover of a mobile station; and FIG. 6c is a partial cross-sectional view illustrating cooperation between the joystick and other mobile station components.

Detailed Description

A preferred embodiment of the present invention is a keymat for use in conjunction with a mobile station, such as a mobile telephone. As mentioned above, for convenience, the term "mobile station" will be used generically to refer to both mobile telephones and other portable electronic devices, such as Personal Digital Assistants (PDAs), network-enabled telephones, palm-top computers, and the like.

Fig. 1 is an isometric external view of a conventional mobile station, in this example a prior art mobile telephone 100. The mobile phone 100 is a radio communication device used in a cellular communication network. It contains a radio transmitter and receiver (not shown) for transmitting information to nearby base stations, which in turn are connected to the main network. The network itself is naturally used for internal network communications and also includes other networks such as public switched telephone networks (PSDN) and gateways accessible to the internet. The mobile station 100 is most commonly used for real-time voice communications, but may also be used for Short Message System (SMS) messaging, data transfer, web surfing, gaming, and paging services.

The internal circuitry and components of mobile station 100 (not shown in fig. 1) are housed in a housing or enclosure, which typically comprises two or more parts and is sometimes referred to herein as a cover. Referring to fig. 1, mobile station 100 has an enclosure 101 including a front cover 120 and a back cover 122, front cover 120 and back cover 122 being detachably secured together at a joint 105 when the phone is assembled. The front cover 120 and the rear cover 122 are generally not separated except for servicing, and are typically separated only by a service technician. The front cover 120 and the back cover 122 are typically made of a rigid plastic, such as polycarbonate/ABS (PC/ABS). Such materials are strong enough to protect the phone internals from reasonable shock during normal operation and to resist penetration by objects that may be encountered when placed in a user's pocket, purse, or briefcase.

A plurality of openings are formed in the enclosure 101 of the mobile station 100, most, although not necessarily all, of which are present in the bezel 120. Keypad 110 on surface 106 of front cover 120 is a user interface that includes a plurality of openings through which keys protrude, such as alphanumeric keys 112, call control keys 114, scroll key 115, and function keys 116. These keys, as their name implies, perform various tasks in the operation of the phone, with the alphanumeric keys 112 having standard telephone keypad functionality, and the function keys and scroll keys for interacting with the display 134. That is, the function of the function keys and scroll keys is variable and determined by the application state in which the mobile phone is located, which is typically translated into a word or icon displayed on the display 134 next to the appropriate key. In the illustrated device, the alphanumeric keys 112 are part of an integral keymat 125, as are call control keys 114, scroll key 115, and function keys 116. Generally, the keymat 125 is a sheet of flexible material (depicted as dashed lines) disposed primarily inside the enclosure 101 (except for the protruding keys). Typically, but not necessarily, all of the keys of keyboard 110 are formed on the same keymat. They may also be formed on two or several key pads. A keymat may also be associated with a key. The keymat 119 includes a volume control 117 (it should be noted that in practice the scroll key 115 and the volume control 117 each comprise two "keys", an insubstantial difference from the "keymat" definition).

Display 134 is typically a Liquid Crystal Display (LCD) device. The LCD itself is protected by a plastic window pane 132, which window pane 132 is mounted to cover the display and project into window 130, i.e. the window 130 is formed in an opening in the front cover 120. As shown in fig. 1, display 134 provides the user with information such as current function key functions, telephone numbers, signal strength, and other information useful for the operation being performed. The protective glazing 132 is typically a separate component from the LCD, its chassis, and other parts of the internal assembly (not shown in fig. 1). The window glass 132 is necessary because the components constituting the LCD are generally fragile and may be damaged even by a light impact.

Also formed in the surface 106 of the front cover 120 are a small opening for the power switch 118 and a plurality of small openings 142 that serve as ports for speakers (not shown) that are mounted below the small openings 142. At the opposite end of the mobile station 100, the microphone port 144 also allows entry of sound directed to the actual microphone (not shown) mounted inside. In the embodiment of fig. 1, the microphone port 144 is formed in the side of the front cover 120, but may be formed at any location proximate to the intended sound source, such as in the middle of the alphanumeric keys 112 or at the bottom end 107 of the front cover 120.

Formed in the bottom end 107 of the front cover 120 are a power port 146 for insertion of an external power adapter and a headset hole 148 for connection of an external headset and perhaps a microphone for hands-free operation. The power port 146 and the headset hole 148 are sockets for connecting (plugging in) external accessories to the internal circuitry of the mobile station. These sockets are mounted in the internal components (not shown) of the mobile station and are accessible from the outside through openings formed in the end 107 of the front cover 120. It should be noted in this regard that, as used herein, the term "port" may refer to a mere opening in the cover or an electrical connection installed in the opening, with a distinction being made between these two types of ports only when necessary.

The rear cover 122 is typically formed with a recess (not shown) for receiving the battery 124, to which the battery 124 is removably attached in operation. In another version, the battery may be received in an internal battery compartment and closed by a rear cover or inserted into an opening in the rear cover and protected or held in place by a separate battery cover. Volume control 117 is also shown on back cover 122, as are other keys, and volume control 117 is implemented by a key element formed in the cover, in this case back cover 122, that protrudes through an opening in the cover when a user actuates a switch located on the internal telephone assembly (not shown). Finally, the wireless transmission of the mobile station 100 shown in fig. 1 is performed by using the antenna 126.

Fig. 2 is a simplified exploded view illustrating selected components of a mobile station 200, mobile station 200 being similar to the mobile station of fig. 1, although not necessarily the same, mobile station 200 is configured for use in conjunction with the keymat of the present invention. Various embodiments of this novel keymat structure are shown in fig. 3a to 6 c. The selected components are the front cover 220, the light guide 250, and a Printed Wiring Board (PWB)270 (sometimes referred to as a printed circuit board). The main components comprising the back of the mobile station, the battery and the LCD are not shown in fig. 2. The parts of the illustrated components that are not necessary in explaining the structure and operation of the present invention have not been shown.

Certain features are included for reference purposes only, however. The front cover 220 is formed with a display window 230 through which the LCD is normally visible, and a set of small openings constituting a speaker portion 242. The opening 243 allows access to a power switch (not shown). The major exterior wall of the front cover 220 will be referred to as the face 206 of the mobile station 200.

Light guide 250 is a component made of a transparent or translucent (or a combination of both) material that has the function of transmitting or scattering light from internal light sources (not shown), typically Light Emitting Diodes (LEDs). This distribution of light from the discrete sources helps to provide uniform illumination of certain visible components to the user. One such component may be an LCD (not shown in FIG. 2), which is disposed in recess 254 of light guide 250 in assembled mobile station 200. The light guide 250 may also serve as an inner cover for the internal components of the mobile station. If so, the light guide 250, together with a chassis (not shown), captures and encloses the PWB270 and its mounted electrical components. Threaded fasteners that pass through the fastener openings 256 in the light guide 250 and the fastener openings 276 in the PWB fasten the components of the internal assembly together. It should be noted, however, that the light guide 250 is preferably present, but this is not required.

It should also be noted that as used herein, the term "inner" refers to a direction that is inside or toward PWB270 and "outer" refers to a direction that is outside or toward the outside when applied to mobile station 200. The "front" of mobile station 200 is the side on which the user can see the display. Surface 206 (shown in fig. 2) forms the front exterior surface of mobile station 200. Speaker portion 242 is formed near the "top" end of surface 206.

Referring to fig. 2, PWB270 typically forms the mounting surface for most of the components, conductors, and circuitry of mobile station 200 (actually two; both front and rear are used). None of these components except key dome 280 are shown for clarity. A key dome such as key dome 281, which has been enumerated as an example, is a structure provided above two (or more) switch elements (not shown). When pressed toward the PWB270, the key dome 281 deforms and contacts the switch element to complete the circuit. Generally, when the pressure on the key dome is released, the key dome 281 returns to its original undeformed state and the circuit is broken. Pressure on the key domes 281 is generated when a user presses a key (not shown) protruding through an exemplary opening 241 formed in the front cover 220. To reach key dome 281, key pressure is transmitted internally through the key (not shown), which also extends through exemplary opening 261 in light guide 250. As with exemplary key dome 281, key openings 241 and 261 are also simple examples of a plurality of key openings 240 formed in front cover 220 and a plurality of key openings 260 formed in light guide 250, respectively. The other key openings and key domes are similar or identical to their respective enumerated examples. The keys themselves, not shown in fig. 2, will be described in more detail. In the following description, like reference numerals are used when enumerating like elements. However, the same reference numerals are not generally repeated to avoid confusion as to design variations that may or need to occur. Although a comparison of the various embodiments described below will assist in understanding the invention, the similarity in the reference numerals will not be considered to conflict with any variations explicitly described in the description and drawings.

FIGS. 3a-3c illustrate a keymat 310 according to one embodiment of the present invention; FIG. 3a is an isometric view showing the inside of keymat 310 itself; FIG. 3b is an isometric view of keymat 310 mounted on surface 306 of front cover 320 of an exemplary mobile station; and FIG. 3c is a partial cross-sectional view illustrating the cooperation between an exemplary key 313 and other mobile station components. Referring first to fig. 3a, external keymat 310 includes a plurality of keys 312, each having a key pin 315, such as exemplary key 313. In the assembled configuration, key pin 315 extends inwardly toward key dome 381 (as shown in fig. 3 c) and serves to transfer forces applied by a user pressing a key to key dome 381. The web 311 holds the keys 312 in place relative to each other. The web 311 serves to hold the keys 312 in their proper relationship to each other, thereby making installation and removal easier. In addition, it helps to maintain the proper orientation of the keys so that they do not get in operation. The web 311 may be designed in a variety of shapes and colors to personalize and customize the appearance of the mobile station 300. In practice, a user subscriber may stock a different set of keymats to be removed and installed to accommodate different situations or uses. In the embodiment of fig. 3a-3c, the key including the key pin and the web are integrally made of a strong and flexible material. It should be noted, however, that the precise nature of the materials used in construction is not obvious (unless explicitly stated or stated) so long as the elements substantially perform their function as described in connection with the particular embodiment of the invention.

Referring to FIG. 3b, keymat 310 of FIG. 3a is shown (inverted) assembled in an operative configuration adjacent surface 306 of front cover 320. The key 312 is not visible in this view, and has been received in a key opening in the front cover (see FIG. 2). Although it is not necessary that each key opening receive a key element, it is preferred that those key openings not so utilized be covered by the keymat plate 311 or other elements (such as a separate cover, not shown) so that entry of foreign matter through the unused openings is prevented. Preferably, but optionally, a label or tag is shown on the outer surface 316 of the keymat 310, but preferably if present, is relevant to which particular mobile station a particular keymat 310 is intended to be. The label may be provided in various known ways including adhesive attachment of an embossed or printed template. These options are available regardless of whether keymat 310 is produced in a one-shot molding process, as shown in the embodiment of fig. 3a-3 c. Other embodiments described below may be further optionally labeled. And although keymat 310 is shown to have a flat shape and be disposed immediately adjacent to front cover 320, these features are not a requirement of the present invention. Alternative embodiments (not shown) include placing a template or other item between keymat 310 and front cover 320, perhaps for decorative or labeling purposes; placing keymat 310 partially or completely in a recess formed in front cover 320; and forms raised areas on the outer surface 316 of keymat 310, possibly for indicating the location of keys or for additional decorative purposes.

In an alternative embodiment of the invention (not shown), an article of clothing such as a sleeve of a shirt, a motorcycle jacket, or a vest may be provided with a plurality of suitably spaced openings so that the inwardly extending portions of the keys 312 may be passed through to be mounted on a mobile station disposed on the inside of the clothing. An interior may be provided to receive the mobile station or it may be held in place by only a cloth sandwiched between front cover 320 and keymat 310. In this embodiment, remote microphones and speakers are preferably used, and may themselves be incorporated into the garment itself. While the keymat retention approach described herein may be suitable for such applications, the design may be slightly altered to accommodate the higher resultant stresses involved and the greater distance between the keymat 311 and the key domes inside the mobile station.

Fig. 3c is a partial cross-sectional view illustrating the cooperation between the key 313 and other mobile station components. Here, the external keymat 310 is clearly shown disposed outside the front cover 320, in this example, near the outside of the front cover 320. Opening 341 in front cover 320 receives key 313 in such a manner that key pin 315 is operatively proximate to key dome 381 on PWB 370. (for simplicity, the actual switch leads and conductors disposed on the surface of the PWB are not shown, but would be understood by those of ordinary skill in the art to be their locations relative to the key domes). Light guide 350, which is disposed adjacent PWB370, is formed with an opening 361 for receiving key 313. It should be noted that the relative sizes of the key members and openings are exemplary and that some changes in shape may be made as desired for a particular application. In this embodiment, the key 313 forms a circumferential flange 314 for engaging an inner surface 321 of the front cover 320 adjacent the opening 341. As mentioned above, the keys 313 are preferably made of an elastic material so as to be forced inwardly or outwardly in the relationship shown in FIG. 3c by a sufficient pulling or pushing force, but should remain in place during normal operation and handling. It should be noted that the use of elastomers or hard plastics for the key element and the front cover are possible embodiments, although not presently preferred.

FIGS. 4a-4f illustrate a keymat 410 according to a preferred embodiment of the present invention; FIG. 4a is an isometric view of key-pin grid 418; FIG. 4b is an isometric view showing key-pin grid 418 of FIG. 4a when assembled adjacent light guide 450; FIG. 4c is an isometric view illustrating an exemplary mobile station bezel 420 covering the assembly of FIG. 4 b; FIG. 4d is an isometric view showing the inside of keymat 410 used in accordance with this embodiment of the present invention; FIG. 4e is an isometric view showing keymat 410 mounted on the assembly shown in FIG. 4 c; fig. 4f is a partial cross-sectional view illustrating the cooperation of the exemplary key 413 with other mobile station components. Referring first to FIG. 4a, key-pin grid 418 is shown in isolation, where it can be seen that it includes a plurality of key-pins 414 held in substantially fixed relation by a network of branches 417. Of course, the design of the key pin grid shown in fig. 4a is only one of many designs. In the illustrated embodiment, the branches 417 are unobtrusive, with minimal light blocking effect. Other designs may be preferred in other circumstances. For example, connecting each key pin to more than one branch provides greater stability and provides a redundant connection when one branch is broken. A solid sheet of clear plastic sheeting may also be used to interconnect the key pins 414.

Fig. 4b is an isometric view of key-pin grid 418 assembled adjacent light guide 450 in its operative configuration. When so installed, each key of key-pin grid 418 is received in an opening formed in light guide 450. Exemplary key pin 415 extends through opening 461, for example. Although the pins and openings of fig. 4b are exactly equal in number, this is not necessary. However, as previously mentioned, the unused openings should be covered in some way. The key-pin grid 418 may simply be located on the exterior of the light guide 450, or the light guide 450 may be formed with grooves to receive the key-pin grid 418, thereby inhibiting lateral movement thereof and simplifying the overall profile of the assembly. In an alternative embodiment (not shown), key-pin grid 418 and light guide 450 may be formed together, with the flexibility of the material or sliding attachment of pins 414 allowing operation of the keys.

Fig. 4c is an isometric view of front cover 420 mounted on the assembly of fig. 4 b. When so assembled, front cover 420 and light guide 450 capture key-pin grid 418 between them. In this embodiment, the key-pin grid 418 is preferably left in place by normal operation and is removed and replaced only when necessary. (it should be noted that although not shown in FIG. 4c, an LCD is typically present and visible at this stage of assembly.) As can be seen in FIG. 4c, key pins 414 are accessible through key openings 440.

Fig. 4d is an isometric view of the inside of keymat 410. In this embodiment, keymat 410 is formed with a plurality of key elements 412, each key element, such as exemplary key element 413, having a first section 421 and a second section 422 of split cylinder 423, which form an opening 424 for receiving an end of a single key pin, such as key pin 415 shown in fig. 4a-4 c. Preferably, each key pin is received in a corresponding key element opening when the mobile station is assembled, and in the embodiment of fig. 4a-4f, the pins 414 and key elements 412 are made of a material and relative dimensions such that although they may be forced into and out of cooperation with each other to facilitate installation and removal of the keymat 410, frictional forces generated between the key elements and pins during normal handling and operation cause them to bond together. However, in an alternative embodiment (not shown), a (split) circumferential lip (see, e.g., fig. 3) may also be used to help retain an installed keymat. It should be noted that the split cylinder design shown in fig. 4d is preferred as it allows air to easily enter the opening during removal, but other designs may be suitable.

Fig. 4e is an isometric view showing the assembled exterior of keymat 410 with respect to front cover 420. The now familiar components such as LCD window 430, speaker port 442, and power switch opening 443 are again shown for reference purposes. It should be noted that, as is preferred in some applications, the outer surface 416 of the keymat 410 is not marked. Fig. 4f is a partial cross-sectional view illustrating the cooperation between an exemplary key 419 containing a key element 413 and pin 415 and other components of an exemplary mobile station. There is shown a key pin 415 inserted into a key element opening 424 between split cylinder first section 421 and second section 422, the assembly being formed with an operable key 419 passing through an opening 441 in front cover 420 and an opening 461 in light guide 450 and being operably proximate to a key dome 481, with key dome 481 being disposed adjacent PWB 470. It should be noted that in this embodiment, although key pin 415 is connected to key pin grid 418 or is integrally formed with key pin grid 418, the only grid portion visible in FIG. 4f is branch 417. Of course, the key pins 415 may alternatively not be connected to any grid but simply be inserted into the openings 424 of the key elements 413. However, this embodiment is not presently preferred.

Although key-pin grid 418 may take any configuration, including one solid sheet, or may include more than one separable component, the configuration of its mounting between the front cover and the light guide generally means that the mobile station can be used even in the absence of keymat 410. This may, of course, be true so long as the user has sufficient access to the outer ends of the key pins when the front cover is in place. In an alternative embodiment (not shown), the outer ends of key pins 414 are formed such that they can be manipulated by a pen tip or a ball point pen tip, for example by forming a recessed dimple. In fact some users prefer to use the mobile station in this configuration, although it would be more useful to determine that the mobile station is still operational when the keymat 410 has been lost or lost. In fact, key pins 414 remain in place even when the keymat is removed to help prevent unwanted material from entering the mobile station interior during keymat replacement.

FIGS. 5a-5e illustrate a keymat 510 used in accordance with another embodiment of the present invention; FIG. 5a is an isometric view of slide plate 521; FIG. 5b is an isometric view of slide plate 521 of FIG. 5a assembled on mobile station light guide 550; FIG. 5c is an isometric view of keymat 510 according to this embodiment of the present invention; FIG. 5d is an isometric view of the keymat 510 of FIG. 5c assembled onto a mobile station front cover 520; fig. 5e is a partial cross-sectional view illustrating cooperation between an exemplary key 513 and other mobile station components. Referring first to fig. 5c, in this embodiment, keymat 510 includes a plate 511 and a plurality of keys 512. Each key, such as exemplary key 513, includes a key pin. The exemplary key pin 515 of key 513 is generally cylindrical in shape and is formed with a pair of recesses 514. The pair of recesses 514 cooperate with slide plate 521 shown in FIG. 5a to hold keymat 510 in place. Referring to FIG. 5a, slide plate 521 includes a plurality of key openings 522 that correspond with the pins of keymat 510. Naturally, there must be at least as many sled openings 522 as there are pins 512 on keymat 510 (unless the unwanted keys are removable in some manner), but there may be more sled openings 522. Exemplary key opening 523 includes a larger portion 524 shaped to receive a key pin and a smaller portion 525 that will only receive a portion of key pin 515 that is reduced in size by the pair of recesses 514. In the embodiment of fig. 5a-5f, the key opening in slide plate 521 forms a circular portion for receiving a key pin and a narrower "slotted" portion. In an alternative embodiment (not shown), the sled key opening may also have a different shape, as is advantageous in certain applications, for example to ensure that a symmetrically shaped keymat is mounted in the proper orientation so that its numbered keys are properly arranged to actuate the corresponding switches. Some openings, such as opening 526 shown in fig. 5a, have a special purpose (see fig. 6 a).

Fig. 5b is an isometric view of light guide 550, also showing slide plate 521 in its assembled state. The opening 522 of the slide plate 521 must of course correspond to the key opening (not shown in fig. 5b) of the light guide 550. Slide plate 521 need not be limited to being so assembled, and in fact slide plate 521 must be sufficiently free to move longitudinally to perform its locking function. (the sled channel 529 may have to clear some fasteners (not shown) as they pass through fastener openings 556.)

Fig. 5d is an isometric view of front cover 520 with keymat 510 installed. Although no particular assembly sequence is required, in this embodiment, keymat 510 may be mounted on front cover 520, then the mobile station internal components added and secured using slide plate 521 before being locked by attaching a rear cover (not shown). Alternatively, if a means is provided to move slide plate 521 from outside the mobile station enclosure, keymat 510 can be removed and installed without removing front cover 520. A cut-out 533 formed in the side 534 of the front cover 520 (or in both sides or in some other suitable location) may provide access to the slide plate 521, for example, when the front cover 520 is in place.

Fig. 5e is a partial cross-sectional view of key 513 when the mobile station is assembled. In this embodiment, where the key pin 515 is shown formed separately from the plate 511, it is permissible to construct it from a different, or hard, material. It may be formed separately and attached with an adhesive, or "in-molded" using, for example, a two-shot molding process. In this embodiment, grooves 517 formed in the web of keymat 510 receive key pins 515 during the molding process, or later during the manufacture or assembly of the complete mobile station. As shown in FIG. 5e, slide plate 521 has been moved into the locked position in such a manner that the inner walls of smaller opening portion 525 are received in recesses 514, thereby retaining installed keymat 510. It should be noted that the recesses 514 in this embodiment are large enough to allow some movement of the key pin relative to the slide lock so that it does not impede actuation of the key. In another embodiment (not shown), slide plate 521 is sufficiently flexible to allow actuation regardless of whether groove 514 is substantially larger than slide plate 521 in the direction of actuation. In the illustrated embodiment, it should be noted that inner surface 531 of front cover 520 is formed with an extension tab 532 for stabilizing slide plate 521 and maintaining it in the proper orientation for securely engaging recess 514 when moved into the "locked" position. In an alternative embodiment (not shown), extension tabs 532, or some of them, may pass through openings formed in slide plate 521 to prevent undesired lateral movement. A similar plate (not shown) extending from the light guide is also desirable.

Fig. 6a-6c illustrate a keymat 610 according to another embodiment of the present invention. FIG. 6a is an isometric view of a specialized keymat 610; FIG. 6b is an isometric view of the keymat 610 of FIG. 6a assembled onto a mobile station front cover 620; fig. 6c is a partial cross-sectional view illustrating the cooperation between the joystick 628 and other mobile station components. In the embodiment of fig. 6a-6c, external keymat 610 is a dedicated keymat, for example one used for playing games. As previously mentioned, the interchangeable key mat of the present invention allows the use of different keyboards for different functions, in addition to giving the user the opportunity to change the appearance of the mobile station, or simply to replace a broken keyboard. This may be particularly advantageous in the case of applications such as game play, which is generally a secondary purpose to the primary purpose of the device. Most game players rarely use the alphanumeric keys of a standard telephone, and must remember that the "6" key performs one function and the "8" key performs another. The present invention allows the keyboard to be labeled more appropriately for the game to be played.

In addition, the keyboard itself may be variously configured. Many games tend to use joystick-like devices even if not formed on the mobile station. Typically in a game playing environment, the joystick may even be a multi-position point device in any environment, and as shown in fig. 6b and 6c, there may be no "stick" per se. Such a structure may be more specifically referred to as a "game pad," but the differences are not important to this description and may not be present. (the stick may be included in keymat 610 or added at the user's discretion.)

It should be noted that the joystick 628 of the illustrated embodiment may not function as accurately as a conventional joystick as is present in conventional mobile phones, which would operate either the four switches of the canister or on. However, as previously described, the mobile station itself may be modified to accommodate non-legacy applications. For example, power switches operated by joystick 628 may have an operating mode in which they can detect the degree of movement. Of course, the keymat 610 may also be modified to accommodate such enhancements. Turning back to the illustrated embodiment, FIG. 6a shows the inside of game keymat 610. As can be seen from fig. 6a, the keymat 610 has a different key structure than for a telephone. In this embodiment there are four separate function keys 613, each having a key pin 615 with opposing grooves 614 (where only one groove 614 is visible on each pin 615 of fig. 6 a). So configured, it may be secured to the mobile station and operated in the same manner as key 512 shown in fig. 5 c.

Referring to FIG. 6a, keymat 610 further includes four pins 609, each having a pair of opposing grooves 608 similar to grooves 614 in pin 603. However, each of the four pins 609 is formed with (or connected to) a joystick 628 in each of four locations around joystick boss 607. The operation of joystick 628 will be described more fully below with reference to fig. 6 c. Fig. 6b is an isometric view of front cover 620 with keymat 610 operably mounted therein. From this view, joystick 628 is seen to be located near the bottom of keymat 610, appearing as a slightly recessed area. Visible indicia on joystick 628 in this embodiment are openings 672 formed in web 611 through which joystick key element 605 is visible. Joystick 628 is shown formed by a two-step molding process, with key element 605 disposed in a recess 604 formed in web 611. (see fig. 6c) this form of construction allows the illumination of the indicia on joystick 628, provided key element 605 possesses the appropriate light guiding properties. It should be noted that, as a matter of design choice, the keys 613 appearing near the upper end of keymat 610 may be identically constructed or simply integrally molded with plate 611 (see, for example, the embodiment of fig. 3a-3 c). Finally, it should be noted that not all openings 640 of front cover 620 are covered by keymat 610 in fig. 6b, which means that the switches associated with them are not used in this application. Although shown in this manner for purposes of illustration, it is in practice preferable to cover these unused openings in some manner.

Fig. 6c is a cross-sectional view of the front of the mobile station taken along section line X-X in fig. 6 b. A cross-sectional line X-X is drawn across the joystick 628, wherein the joystick 628 is shown because its configuration is different from those of the previous embodiments shown. In this figure, two pins 609 are visible extending inwardly from the joystick key element 605. (the third pin 609 near the center of the drawing is partially visible and has been omitted for clarity). As previously described. Joystick 628 is formed by key element 605 disposed in recess 604 in plate 611 of keymat 610. Joystick 628 may also be integrally formed with keymat 610, but is not a preferred embodiment. In the embodiment of fig. 6c, the key elements are partially visible to the user through openings 672 in plate 311, thereby forming the key indicia visible in fig. 6 b.

Similar to the embodiment of fig. 5a-5e, slide plate 621 is used to hold the game keymat in place. Slide plate 621 is not shown separately, but slide plate 621 is similar or identical to slide plate 521 shown in fig. 5a and 5 b. While slide plate 621 performs a similar function to slide plate 521, it should be noted that in this application recess 608 should be slightly enlarged in pin 609 to allow for proper operation of lever 628. This is because when either side of the joystick is depressed (or operated with the actual stick as well), the pins on that side are forced down to their respective key domes, here key dome 682 or key dome 683. When this occurs, key element 605 rocks on joystick boss 607 causing the opposite key pin 609 to rise accordingly. (Note that key dome 684 inward of joystick boss 607 is not used in this application.)

Each pin 609 extends through an opening 640 in front cover 620 and an opening 660 in light guide 650. Joystick boss 607 also extends through opening 640, but is too large to pass through light guide opening 660. Additionally, the lever bump 607 is preferably positioned adjacent to the edge 661 of the opening 660 to provide a suitable pivot location. And while pin 609 also extends through an opening in slide plate 621, lever boss 607 is received by oversized opening 626 (see also fig. 5a and 5 b).

In the embodiment of fig. 6c, there are also extension tabs 632 formed on the inner surface 631 of the front cover 620 to stabilize and hold the slide plate 621. In alternative embodiments (not shown), the extension tab 632 is preferably removed around the joystick 628, or the extension tab 632 is removed entirely. Finally, an actual joystick "stick" (not shown) may be easily added by an extension formed from key element 605 to the outside of opposing joystick boss 607 extending through an auxiliary opening formed in web 611 of keymat 610.

In a particularly preferred embodiment, key pins such as the one shown in fig. 6b also perform a light directing function, so that they serve to mark the keys behind which they are arranged. In this embodiment, for example, small openings are formed in the keymat to receive protrusions formed on the key pins, which in operation will appear as a light-emitting pattern on the keyboard.

Claims (20)

1. A key operating device having an internal switch substantially closed by at least one front cover formed with an opening through which the internal switch is operable; and a switch operating device accessible from the outside, the key operating device comprising:

a key pin for extending through a front cover opening proximate to the internal switch such that a force applied to the key pin from outside the device can cause it to operate the switch;

a keymat for removable attachment to the device outside the front cover such that pressure on a selected area of the keymat causes an operating force to be applied to a key pin disposed proximate the selected area.

2. The switch-operating means of claim 1, further comprising a light guide disposed inside the front cover, the light guide being formed with at least one opening for receiving the key pin therethrough.

3. The switch-operating means of claim 1, wherein the means comprises a plurality of key pins retained within a front cover.

4. The switch-operating means of claim 3, wherein the plurality of key pins are retained by a member interconnecting them, the element being disposed inside the front cover.

5. The switch-operating means of claim 3, wherein at least one of the plurality of key pins is retained by a key pin extension that tends to prevent the key pin from being removed through a front cover opening through which the key pin passes.

6. The switch-operating means of claim 5, wherein the key-pin retention tendency is overcome by sufficient force to allow the key-pin to be removed without removing the front cover.

7. The switch-operating means of claim 5, wherein the key pin extension is integrally formed with the key pin.

8. The switch-operating means of claim 5, wherein the key pin is formed with an opening, and the key pin extension is a separately formed component that extends from the key pin when received in the opening.

9. The switch-operating means of claim 3, wherein the keymat comprises a plurality of openings for receiving key pins.

10. The switch-operating means of claim 9, wherein the keymat is removably attached to the device by friction generated between the key pins and the keymat.

11. The switch-operating means of claim 1, wherein the front cover has an outer surface and a recess is formed in the outer surface for at least partially receiving the keymat when it is connected to the device.

12. The switch-operating means of claim 1, further comprising a locking member disposed within the front cover for selectively engaging at least one key pin extending through the opening of the front cover.

13. The switch-operating means of claim 12, wherein the locking member is a plate having at least one opening through which the at least one key pin extends.

14. The switch-operating means of claim 13, wherein at least one key pin is formed with a recess, and wherein at least one opening formed in the plate includes a larger portion for receiving the key pin during installation of a smaller portion for engaging the at least one key pin at the recess when moved laterally after the at least one key pin has extended through the larger portion.

15. The switch-operating means of claim 1, wherein the key pins and keymats cooperate to form a joystick-type key.

16. A keymat for use with a mobile station having a plurality of key openings formed in a housing for accessing internal switches, said keymat comprising:

a plurality of keys;

a web interconnecting the plurality of keys for positioning the keys outside the housing such that at least some of the keys are adjacent some of the plurality of key openings; and

a plurality of key pins extending from the key adjacent to the key opening to the internal switch.

17. The keymat of claim 16, wherein a plurality of the key pins are interconnected to one another.

18. The keymat of claim 17, wherein the interconnected key pins are captured inside the housing.

19. A mobile station, comprising:

an internal component having a plurality of internal switches for affecting operation of the mobile station;

a housing for enclosing the internal components, the housing formed with a plurality of openings for accessing the internal switch; and

a keymat disposed outside the housing, the keymat comprising:

a plurality of interconnected keys; and

a plurality of key pins, each extending through the housing opening for transmitting user-applied pressure from the key to the internal switch.

20. The mobile station of claim 19, wherein the plurality of key pins are integrally formed with a plurality of interconnected keys.