Abstract:
A two module keyboard with splash-resistant mechanism has a key module that can be separated by a user from a base module. One group of components becomes a detachable and user-serviceable key module, while the other group stays as the base module. The detachable module contains essentially the keycap portion that causes substantially more malfunctioning of present day keyboard components than the rest. The base module has a bay that receives the detachable key module, and contains the electrical circuitry membrane and PCB that has longer durability than the key portion. Drain holes at lower end of the bay will allow liquid spillage, or water/solution if used to clean the bay, to flow out of the keyboard. Depending on applications, the detachable key module can be further broken into more sub-modules. Keyboards made according to the present invention are modular in nature, and are conducive to reducing the costs for keyboard related services and exchanges, costs for curing accumulative environmental hazards and costs for fitting suitable user keys for swapping among different languages and computer applications.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This is a continuation in part of application Ser. No. 10/439,938, filed May 16, 2003, entitled A New Type of Splash-Resistant Modular Keyboard for Computers. The present application is related to a prior application filed by the same inventor. Said prior application&#39;s filing date was Jun. 26, 2002, having application Ser. No. 10/180,423. The present application is further related to a second application filed by the same inventor. Said second application&#39;s filing date was Oct. 15, 2002, having application Ser. No. 10/272,584. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     A. Field of the Invention  
         [0003]     The present invention relates generally to keyboards for computers where a top mechanical section containing the keycaps or keys is replaceable, removable and user-serviceable away from a bottom electronics section. More particularly, the present invention helps to solve the industry problems enumerated, but not limited by, below: 
        A. Voluminous amount of keyboards still under warranty are being returned for repair/exchange due to malfunctions that are user-serviceable in nature. The amount of money that will be saved by avoiding such repair/exchange is estimated at least in the millions of dollars every year across the industry.     B. Currently, a substantial amount of metal and rare metal contained in the electronics section of a keyboard turns into scrap metal causing environmental hazards some years down the road notwithstanding the electronics section has a higher durability than the mechanical key-stroke section, which has not been made user-serviceable by itself. People are waking up to the potential hazards created by castaway computers, cell phones and other consumer electronics. The instant invention may save tremendous amount of money with reduced costs to cure the potential environmental hazards.     C. Chances of breakdown on the otherwise non-removable part of the keyboard is greatly reduced according to the present invention due to the fact the liquid spillage will no longer accumulate in the holding (aka bay) area.        
 
         [0007]     B. Discussion of Related Art  
         [0008]     Modern day keyboards for computers come in an integrated package, along with the computer system units when sold. Users can plug in the keyboard cord to a port at the back of the system unit and can then start to type on the keyboard when the desktop computer is working.  
         [0009]     Latest generations of computers are more compact than ever before. The whole system (CPU, memory, I/O ports, DVD/HD/Floppy drives and other optional equipment or connection ports) can arguably be in a single package the size of a traditional keyboard, so that a user merely sees and uses the “keyboard” to work on the computer. An example can be found at www.cybernetman.com located in Irvine, Calif. In this type of new generation computer, keyboard becomes integrated and on top of the system, similar to the notebook/laptop computers today.  
         [0010]     Most keyboards carry limited product warranty, on the condition that users do not take apart, disassemble or remove parts of keyboard in any way. Any such action voids the product warranty. If the keyboard develops any malfunction, the only recourse under the warranty is to have it returned for repair or exchange. Some manufacturers have sticker(s) covering one or more screws used to fasten the keyboard parts together. Any breaking or removal of such sticker(s) will also void the warranty.  
         [0011]     In today&#39;s technology, most keyboards have fairly high quality and durability. However, in the real-life working environment, keyboards are destined to encounter some foreign objects that tend to cause problems, including, just to name a few, grease from fingers, liquid spillage, dusts and particles in the atmosphere. Without any means to clear the accumulated foreign matter away, inevitably the mechanical functionality of the keyboard is adversely affected.  
         [0012]     Typical symptoms include, keys stuck in the holding chimneys by the accumulation of dried coffee, grease or dusts. Due to the “void the warranty” restriction, the only solution is to return the keyboard for repair service or in exchange for a new one. Since the keyboard industry in general does not factor in the cost of recycling keyboard components, the cost of sending out a new keyboard to users is lower than the labor cost of diagnosing, fixing and re-assembling a returned keyboard. Hundreds of thousands of returned keyboards gravitated towards storage bins, warehouses and even garbage dumps each year, while no one bothers to figure out how to make the best use of the re-useable resources and come up with a more environmentally sound solution to the problem.  
         [0013]     Working environment of computers is also changing. New generation of automobile on-board computing are fast replacing car electronics with fully functional computer stations for safer driving or office work as well as entertainment where wireless keyboards still play the primary role as an input interface, which becomes more susceptible to vibrations and liquid spillages.  
         [0014]     In the case of notebook/laptop computers, or in the case of the new generation compact computers, when a problem occurs that relates to the keyboard, the only recourse a user has is to send back the whole system unit for repair or exchange.  
         [0015]     The present invention examines the structure of a typical keyboard for modern day computers, and proposes a new modular keyboard structure that helps to solve the industry problems.  
         [0016]     Modern day keyboards for desktop computers are usually produced by using an upper and a lower enclosures (the outer shells for the finished keyboard product) for all internal components, which typically include key component, key-actuating mechanism, top holding plate, circuitry membrane and PCB, bottom holding plates/frame, and other optional components. Reference  FIG. 1  and  FIG. 2 .  
         [0017]     Since each manufacturer may have different assembly method, or may combine one part into another (bigger) part, understandably the components in  FIGS. 1 and 2  are just typical and not exhaustively representative.  
         [0018]     From top to bottom (in the usual orientation of daily usage), these typical internal components (excluding the top/bottom enclosures) are listed and explained below: 
        1. a key component: includes the following typical sub-components 
            a. individual keys  1  with alphanumeric characters and other control keys for any specific language. The surface of each key, printed or labeled with character(s) for visual identification, is for human fingers to type on.     b. a key-holding mechanism to provide for the vertical up-down travel of each key  1  when pressed down and then popped back. The mechanism can be in the form of a chimney  2 , as in  FIG. 2 , or in the form of a scissor switch  3 , as in  FIG. 1 .     c. a frame  4  for the holding mechanism  3  to sit on. In today&#39;s manufacturing process, the frame and the holding mechanism is usually an integrated structural piece.    
            2. a top holding plate  5 : optional, serves to hold down the key actuating mechanism  6  and protect the components beneath.     3. a key-actuating mechanism  6 : provides resistance and position restoration for the up-down travel of each key  1 . There are some variations as to the type of mechanism used for keyboard, to name a few: 
            a. rubber domes  7  in one-piece sheet: most common today, which uses dome-shaped material corresponding to each key  1 .     b. coil springs: vertical placement of coil springs along the up-down travel of each key, common for earlier generation keyboards; classical way of providing resistance and position restoration for each key.     c. a flexible metal plate.     d. buttons formed by sealed air bubbles on rubber or plastic material.    
            4. a circuitry membrane and PCB  8 : the combined circuitry membrane and PCB (printed circuitry board) electronically determine which of the keys is being pressed down and send that information to the computer for further processing.     5. a bottom holding plate  9 : used to hold the aforesaid components in place.        
 
         [0031]     It is well known in the industry that these components are just typical, because a lot of variations exist due to different designs and manufacturing processes. For example, in earlier keyboard models, the coil springs for key-actuating mechanism are integrated with and became part of the key component.  
         [0032]      FIGS. 1 and 2  sum up the structural allocation of a typical keyboard for computers. As most people can experience, these typical keyboards cannot be separated into two or more modules that can be physically removed, detached, replaced, swapped or serviced.  
         [0033]     U.S. patent application publication US 2003/0223797 A1 describes the use of ‘rubber sheet’ to use as a ‘water barrier’ for the water resistance feature. The 797 application describes a modular keyboard assembly  120 , which is meant to be a subassembly of a whole keyboard assembly  100  but not encouraged to be disassembled by a user for maintenance. Distinctive feature of the above 797 application is that in the housing  103  a liquid resistant barrier  130  is secured between the keys  102  and the circuit board  140 . It lacks any solution for the user to casually detach liquid-contaminated areas from the whole keyboard assembly for cleaning.  
         [0034]     U.S. Pat. No. 5,996,284 to Youn describes a ‘keyboard mounting apparatus’ to hold the entire keyboard assembly to the notebook computer.  
         [0035]     U.S. Pat. No. 5,612,692 to Dugas describes a method of keyboard assembly in the traditional design. The entire keyboard assembly from top to bottom is assembled together to form and seal the liquid from getting into the keyboard. U.S. Pat. No. 5,150,118 to Finkle describes the assembly of the ‘custom panel having interchangeable key-pad assembly that are installed on a keyboard’. The aperture  64  is employed to ‘captivate the keys’ with the sub-panel  32 .  
         [0036]     However, the above two patents do not attempt to separate circuit board from the keys portion to eliminate any concern for a computer user to be exposed to the electronic circuit board of the keyboard when the user himself or herself needs to service the keys portion.  
         [0037]     U.S. Pat. No. 5,865,546 describes a method of liquid draining out of the key assembly to the bottom of the keyboard, the out of the notebook computer. Similarly, U.S. Pat. No. 6,641,317 describes the assembly of draining hole to the bottom of the keyboard assembly.  
         [0038]     One object of present invention seeks to greatly reduce the costs of diagnosing, fixing and reassembling a returned keyboard, or exchange for a new one, when warranty still applies.  
         [0039]     A further object of present invention is to create a keyboard manufacturing technology that is environmentally friendly and is conducive to elimination of future environmental hazards.  
         [0040]     A still further object of present invention is to reduce the liquid spillage that stays in the keyboard holding area, thus creating moisture, which tends to adversely affect other system components of the computer.  
         [0041]     A still further object of present invention is to allow easy maintenance and cleaning of the keyboard with clean water sprays or other solution at the keyboard since the keyboard holding area (aka bay) has drainage to channel out the water or solution containing dust or other particles.  
       SUMMARY OF THE INVENTION  
       [0042]     A modular computer keyboard of the present invention separates keyboard components into two groups to incorporate a splash-resistant mechanism.  
         [0043]     The present invention provides a two module keyboard with splash-resistant mechanism comprising: a key module generally shaped into a board having at least four sides and including a plurality of keycaps, a key holding mechanism and a frame, the key-module containing no electronic circuitry and being self-sustainable in and out of the keyboard; a base module containing the electronic circuitry used for decoding the signals of the keycaps depressed by a computer user to provide the decoded signal to the computer through a wired or wireless connection, wherein the base module defining a bay area across most of its upper surface shaped to fit the key module when it docks into the bay in manufacturing process and subsequent events of maintenance performed by the user; the bay of said base module being tilted from the horizontal plain to an adjustable degree and having an inner rim abutting the key module at its entire sides leaving a plurality of holes for communicating the inner space of the rim to lowermost points of the tilted bay; a water-sealing mechanism disposed around the inside lower rim of the bay, so that any liquid spillage or splash into the space between the key module and base module will not get inside the body of the keyboard or notebook/laptop computer but gravitates towards said holes and out of the computer; and a means for releasably mounting the key module onto the base module or the bay, whereby the user may seat and unseat the key module in and out of the base module casually for cleaning behind the key module to remove liquid or foreign matter normally untouchable by the user.  
         [0044]     One group of components of the keyboard becomes a detachable and user-serviceable key module, while the other group stays as the base module. The detachable module contains essentially the key portion that should endure more than ten million strokes per key with occasional liquid spills and thus malfunctioning tends to occur more as in the present day keyboards. The base module has a bay that receives the detachable key module, and contains an electrical circuitry membrane and PCB that contains no moving parts and has longer durability than the key portion. Drain holes at the lower end of the bay will allow any liquid spillage, or when using water/solution to clean the bay, to flow out of the bay. Depending on applications, the detachable key module can be further broken into more sub-modules. Keyboards manufactured following present invention are modular in nature, and are conducive to reducing the costs for keyboard services and exchanges, costs for curing future environmental hazards and costs for fitting suitable user keys for swapping among different languages and computer applications. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0045]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the preferred embodiment of the invention and together with the description, serve to explain the principles of the invention.  
         [0046]     For reason of definition, and for further explanation of present invention, the term “key module” will be used to denote the module that contains, minimally, the keys, key holding mechanism and frame for key holding mechanism.  
         [0047]     The term “base module” will denote the module that contains, minimally, the circuitry membrane and PCB and is interchangeably used with “key bay” which is defined by the base module to seat the key module. As a matter of practice, in a keyboard produced following the teachings of present invention, anything on the keyboard other than the “key-module” is the “base module”. Therefore, base module can be the system unit of a notebook/laptop computer, or, in the case of new generation computer, the system unit of a desktop computer, excluding the display monitor.  
         [0048]     Depending on specific manufacturing technique, the present invention allows the component of a key actuating mechanism to be allocated into the key module or the base module.  
         [0049]     The cavity left in the base module when key module is removed is referred to as key bay.  
         [0050]     Drain holes on the key bay are also referred to as water channeling mechanism.  
         [0051]     A brief description of the drawings is as follows:  
         [0052]      FIG. 1  shows the typical components of a prior art keyboard for notebook/laptop computers.  
         [0053]      FIG. 2  shows the typical components of a prior art keyboard for desktop computers.  
         [0054]      FIG. 3  shows the exploded view of the inventive keyboard where the key module is removed from the base module, with water channeling mechanisms (holes) and water sealing mechanism indicated. A method for mounting key module to the key bay of base module is also shown.  
         [0055]      FIG. 4  shows the key module is removed form the base module, in this case, the system unit of a notebook/laptop computer. Water sealing mechanism around the inside edge of key bay is also shown.  
         [0056]      FIG. 5  shows the key module can be broken into sub-modules; or can be in the form of a foldable type.  
         [0057]      FIG. 6  shows an implementation of the water channeling mechanism by using drain holes and tilting the system unit of a notebook/laptop computer so that liquids will gravitate towards the drain holes and flow out of the key bay.  
         [0058]      FIG. 7  shows an implementation of the water channeling mechanism using drain holes, with key module sitting in the key bay.  
         [0059]      FIG. 8  shows the application of present invention to desktop computer keyboards using key sub-modules.  
         [0060]      FIG. 9  shows a cross-section view of the components for a desktop computer keyboard applying water sealing mechanism and water channeling mechanism.  
         [0061]      FIG. 10  shows an exploded view of the components for a notebook/laptop computer key applying water-sealing mechanism.  
         [0062]      FIG. 11  shows that key module can be mounted and secured to the base module by screws in the top-down orientation.  
         [0063]      FIG. 12  shows the key module can be mounted and secured to the base module by another form of snap-in mechanism. In this drawing, upper enclosure of the traditional desktop computer keyboard is part of the key module.  
         [0064]      FIG. 13  shows the key module can be mounted and secured to the base module by employing tabs with holes extending from the sides of key module, and corresponding cavities on the sides of the base module with sliding locking pins.  
         [0065]      FIG. 14  shows the key module can be mounted and secured to the base module by horizontally sliding the key module into the base module.  
         [0066]      FIGS. 15 and 16  show two examples of implementation by the present invention with assembled key module sitting in the key bay, along with portions of base module forming water sealing environment. 
     
    
       [0067]     Similar reference numbers denote corresponding features throughout the attached drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0068]     Referring to  FIG. 3  and thereafter, the embodiments of the present invention will be described. Terms “key module” and “base module” as used herein are defined in prior section.  
         [0069]     A keyboard  10  shown in  FIG. 3  is a first embodiment of the present invention. The keyboard  10  is generally comprised of a rectangular base module  11  and a T-shaped key module  12 . The base module  11  defines a bay area across most of its upper surface shaped to fit the key module  12  when it docks into the bay  11  in manufacturing process and subsequent events of maintenance at home or office.  
         [0070]     The key module  12  contains no electronic circuitry and is self-sustainable in and out of the keyboard to maintain its integrity. Meanwhile, even if the key module  12  is removed, the base module  11  houses the supporting components for the operation of the keyboard  10  in a water resistant manner. As a matter of practice, the base module  11  will at least have an electrical circuitry/PCB component  13  as shown in  FIG. 9 . The electronic circuitry  13  is used for decoding the signals of the keystrokes by a computer user to provide the decoded signal to the computer through a wired or wireless connection.  
         [0071]     From top to bottom, the components of the keyboard  10  will include a top key-holding plate  14  for supporting multiple keycaps  15  in their free vertical movements within a limit provided by a retaining means not shown, a key-actuating mechanism  16  in a resilient sheet formed with upward domes for biasing the keycaps  15  at a raised level, the electrical circuitry membrane/PCB  13 , a bottom holding plate  17 , upper and lower enclosure halves  18  and  19 , which allow the key-actuating mechanism  16  to be connected to the keycaps  15  of the key module  12  mechanically but not permanently as shown in  FIGS. 9, 15  and  16 .  
         [0072]     The upper enclosure  18  corresponding to the hard plastic casing of a keyboard for a traditional desktop computer may be grouped into the base module  11  as in  FIG. 9  or a key module  812  as will be described with reference to  FIG. 12 .  
         [0073]     The key-actuating mechanism  16  comprises a rubber dome and/or a spring integrated into each key  15  for providing a feedback. These mechanisms both provide the right feel to the user and reposition the key  15  after it has been released.  
         [0074]     Depending on specific manufacturing or assembly needs, the key-actuating mechanism  16  may be grouped into either the base module  11  as in  FIG. 9  or the key module  12  as will be described with reference to  FIGS. 15 and 16 .  
         [0075]      FIG. 3  shows the keyboard  10  having various arrays of rubber domes  7  formed on a single elastomeric sheet in spaced groups of various inputs such as alphabets, numbers, and software functions, etc. Drain holes  20  serve as a water channeling mechanism at one end of the keyboard  10 ; the whole keyboard unit  10  is elevated on one side  21 , causing the side  22  with drain holes  20  to be lower. Water-sealing mechanism  23  around the inside rim  24  of the key bay  11  is shown. Rubber strips or sheets are preferred material for achieving the water sealing, without blocking the drain holes  20  on the lower end  22  of the key bay  11 .  
         [0076]     The key module  12  has tabs  25  at its four sides, which can be snapped in to grooves  26  on the inside rim  27  of the key bay. Each tab  25  is U-shaped in cross section and ends with an outer end  28  extending perpendicularly up to the level of a top surface  29  of the key module  12 . The tab end  28  of the base module  11  has at its outer sidewall a laterally extending protrusion  30  adapted to be received in a lateral groove  31  formed in the rim  27  of the base module  11 . When the key module  12  is introduced into the base module  11 , the four side tabs  25  are resiliently flexed away from the rim  27  of the base module  11  and immediately return to their normal positions and then snap into the grooves  26  to secure the two modules  11  and  12  to each other.  
         [0077]     In the event of maintenance, the tabs  25  may be flexed out of the grooves  26  using a simple prying edge in order to release the key module  12  from the base module  11  for cleaning or other purposes.  
         [0078]      FIG. 4  shows a notebook/laptop computer  100  having a monitor  101  hinged to a system unit  102 , which comprises a base module or bay  111  on the top surface. A key module  112  is shown removed from the bay  111  to expose a water sealing mechanism  120  applied to around the inside edge of the bay  111 .  
         [0079]     The key module  112  has two opposite side edges  113  for sliding engagement with opposing guide rails  114  formed in an inward rim  115  of the bay  111 .  
         [0080]     In  FIG. 5 , a keyboard  200  according to another embodiment of the present invention encompasses the type of key module where it can be broken into sub-modules  212 - 215 , or it is of a foldable type.  
         [0081]      FIG. 6  shows another notebook computer  300  having a system unit  302  wherein side drain channels  320  function as the water channeling mechanism. The notebook computer  300  has a base module or bay  311  in which a key module  312  is removably secured by snap tabs similar to the tabs  25  of  FIG. 3  embodiment. The notebook computer  300  is similar to the notebook computer  100  of  FIG. 4  in that the water-sealing mechanism  120  is also applied to around an inside edge of the bay  311  although it is not visible in  FIG. 6 . The system unit  302  has four corners at rear ends  321  and front ends  322 . The drain channels  320  extend at least portions of the opposite side edges of the system unit  302  to communicate the interior of the bay  311  to atmosphere of the computer  300  at openings located at the front ends  322 . With the system unit  302  tilted up a little at the rear ends  321  relative to the front ends  322  containing the drain holes, any possible liquid spillage through the key module  312  will gravitate towards the drain channels  320 ; causing the liquid to flow out of the key bay  311 .  
         [0082]     To tilt the rear ends  321  up, traditional pullout tabs  323  may be installed at the bottom of the system unit  302 . Alternatively, the base module  311  containing the system unit  302  of the computer  300  may be manufactured to be thinner on the front ends  322  of the drain channels  320  and thicker on the other ends  321 , to create the required tilt for liquid to flow downwards.  
         [0083]     In  FIG. 7 , a keyboard  400  according to another embodiment of the present invention has a rectangular base module  411 , which defines a rectangular bay over its entire upper surface. Water channeling mechanism  420  in the form of drain holes is formed about a lower end  422  of the keyboard  400  facing the front and sides thereof. The keyboard  400  has a water-sealing mechanism (not shown) similar to the mechanism  23  of  FIG. 3  embodiment except that it now has four sides different from the eight sides because a key module  425  is shaped after the base module  411  to mate at four sides.  
         [0084]      FIG. 8  shows a keyboard  500  having a single base module  511  that is subdivided into multiple bays. The sub-bays include a primary bay  511   a  for seating an alphanumeric key module  512   a , a side bay  511   b  for seating a numeric key module  512   b , and a rear bay  511   c  for releasably holding a customizable key module  512   c , etc. The key modules  512   a ,  512   b  and  512   c  has two opposite side edges  513   a - 513   a ,  513   b - 513   b  and  513   c - 513   c  for sliding engagement with opposing guide rails  514   a ,  514   b  and  514   c  formed in inward rims  515   a ,  515   b  and  515   c  of the sub-bays  511   a ,  511   b  and  511   c , respectively. Then, they can be secured to each other by employing a latch-hinge mechanism.  
         [0085]     For each sub-bays, a rectangular water sealing mechanism is installed although only two of them are shown at  523   a  for the primary bay  511   a  and at  523   b  for the side bay  511   b.    
         [0086]      FIG. 9  is a schematic drawing in an exploded cross sectional view of the first embodiment of the present invention of  FIG. 3  wherein top drawing shows the key module  12  separated from the bay  11  according to the present invention. This is the desktop computer keyboard construct.  
         [0087]      FIG. 9  bottom drawing shows the key bay  11  having beneath it two layers of water sealing mechanism used in a traditional type keyboard construct: one above the holding plate, one (extra layer) below the holding plate. The water-sealing mechanism  23  may be formed by this three-layer plate bearing against a shoulder  24   a  formed around the inside rim  24  of the upper enclosure  18  of the base module  11 . Or it may be a gasket secured firmly between the shoulder  24   a  and the key-actuating rubber dome  16 .  
         [0088]      FIG. 10  is an exploded view of a notebook/laptop computer  600  having a monitor  601  hinged to a system unit  602 , which comprises a bay opening  611  on the top surface with a key module  612  removed from the opening  611  to show the relative vertical position of a water sealing mechanism  623 .  
         [0089]     FIGS.  11  to  14  show the various methods of mounting the key module to the bay/base module.  
         [0090]     As in  FIG. 11 , the mounting may be achieved by using screws in the top-down orientation of a keyboard  700  having multiple sub-bays on a single base module  711 . Firstly, an alphanumeric key module  712   a  may be placed in a primary bay  711   a  by four corner screws  725   a  to allow a future unscrewing by the user for maintenance. Secondly, a numeric key module  512   b  may be fastened to a side bay  711   b  by four screws  725   b  until they are unscrewed for a localized maintenance in the area. To releasably hold a customizable key module  712   c  down to a rear bay  711   c , two screws  725   c  may be sufficient.  
         [0091]     Alternatively, bottom-up screws can mount the key modules  712   a - 712   c.    
         [0092]      FIG. 12  shows a keyboard  800  having a key module  812  that can be mounted and secured to a base module  811  by yet another form of snap-in mechanism comprising four tab-like hooks  825  on the key module, so that the user can remove the top key module by slightly prying away the hooks and unseat the key module away from the base module. The hooks  825  are adapted to clinch the base module  811  at four corresponding vertical slots  826  formed at its comers. In this drawing, an upper enclosure of the traditional desktop computer keyboard is modified into a part of the key module  812 .  
         [0093]      FIG. 13  shows a keyboard  900  having a key module  912  that can be mounted and secured to a base module  911  by employing tabs  925  extending from the sides of the key module  912 , and corresponding cavities  926  on the sides of the base module  911  with sliding locking pins  927  to engage or disengage the tabs  925 . The voids where the pins  912  left may be covered by pieces  928 . The allocation of tabs/cavities can be reversed, that is, the tabs  925  can be on the sides of the base module  911 , while the sliding locking pins are on the sides of the key module  912 .  
         [0094]      FIG. 14  shows a keyboard  1000  having a key module  1012  that can be mounted and secured to a base module  1011  by horizontally sliding the key module  1012  into the base module  1011 . A number of tabs  1025  and hooks  1026  are used to engage and disengaged the key module  1012 .  
         [0095]      FIG. 15  shows an example of implementation by the present invention where portions of a base module are assembled into a key seating bay  11   a  by bottom-up screws. The water-channeling mechanism (drain holes)  20   a  is positioned at the lowermost level in use relative to other areas of the bay  11   a  to allow liquids to flow out. Here, a key module  12   a  is provided with a key actuating mechanism  16   a  comprising a rubber sheet/dome with a spring attached to it on a keycap holding plate  14   a.    
         [0096]      FIG. 16  shows another example of implementation by the present invention where an all-around rubber seal  23   a  having a T-shape in cross section is used as a water-sealing mechanism for a base module  11   b . This rubber seal  23   a  will be laid around the inside rim of the bay  11   b . The rubber seal  23   a  is provided with openings (not shown) at corresponding positions to the drain holes  20   b  of the water channeling mechanism around a lower portion of the key bay  11   b . A key module  12   b  has arrays of key  15   b  and is integrated with a key actuating mechanism  16   b  comprising a rubber sheet/dome with a spring attached to it on a keycap holding plate  14   b.    
         [0097]     Therefore, while the presently preferred form of the keyboard has been shown and described, and modifications thereof discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.