Abstract:
A keyboard allowing typists to use approximate QWERTY finger movements on a more compact, collapsible, and portable keyboard. The keyboard size is made more compact by using thin capacitance-responsive surfaces as key switches for the rows above and below the home row. The bottom, space-bar row is also touch-sensitive and is placed on the side of the keyboard facing the typist. The capacitance-responsive surface for the row of keys switches above the home row has a convex profile, and the capacitance-responsive surface for the row of keys switches below the home row has a concave profile, such that the keyboard can fold compactly upon itself. The home row retains depressible key switches in order to provide standard rest positions for the fingers. Characters and commands assigned to the rows above and below the home row are engaged by sliding the fingers over the capacitance-responsive surfaces adjacent to the home row.

Description:
I claim benefit of the provisional application No. 60/372,378, filed Apr. 15, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a compact, collapsible keyboard. 
     In the prior art, various compact, folding QWERTY keyboards have been proposed for use with mobile telephones, electronic organizers, and portable computers. Collapsible keyboards that employ mechanical, depressible key switches are constrained in size reduction by the bulk of these switches. In U.S. Pat. No. 6,174,097, a standard sized QWERTY keyboard is folded on three parallel axes, collapsing four rigid subframes of the keyboard to offer folded dimensions measuring a quarter of its unfolded width. However, the thickness of the keyboard is quadrupled when folded, and its potential size reduction is limited by its exclusive use of mechanical, depressible key switches. 
     Furthermore, such keyboards, when unfolded, demand large surface areas upon which to rest. As portable computer sizes have decreased, computer users have been able to employ these devices in situations that do not offer substantial desk or tabletop space. However, the size of standard QWERTY keyboards, foldable or otherwise, precludes their use in many of these situations. In such situations, typist must resort to the use of substantially smaller keyboards that only allow typing with the thumbs, with individual fingers, or with a stylus. 
     In U.S. Pat. No. 6,262,717, the entire keyboard is comprised of capacitance-responsive surfaces. In this way, substantial size reduction is achieved; however, this purely capacitance-responsive keyboard does not allow the fingers to rest on home keys, and, therefore, does not allow the use of familiar QWERTY style finger movements. 
     U.S. Pat. No. 5,497,151 attempts to reduce keyboard size by tightly interspersing the keys traditionally operable by the fingers of a person&#39;s left hand with the keys traditionally operable by the person&#39;s right hand. This proposal affords some reduction in size but is designed for single-handed typing and does not allow standard two-handed QWERTY typing. 
     It would be advantageous to provide a more compact keyboard offering the option of using both hands in the familiar QWERTY mode of typing. The present invention in a preferred embodiment offers two-handed typing in approximate QWERTY mode, while reducing the dimensions of the keyboard both in its folded and unfolded states. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a more compact QWERTY keyboard by reducing the number of mechanical, depressible key switches, using instead, capacitance-responsive surfaces as key switches for actuating characters and commands assigned to the rows above and below the home row. The home row employs mechanical, depressible key switches in order to provide rest positions for the fingers. This new configuration will allow typists to use approximately the same finger movements as they would use on a standard, full-size QWERTY keyboard, while taking advantage of thin space-saving capacitance-responsive surfaces. 
     It is a farther object of the invention to provide audible or vibratory feedback indicating the engagement of one of the capacitance-responsive key switches in order to alert the keyboard operator each time a character or command has been engaged. 
     It is a further object of the invention to provide the keyboard operator the ability to reprogram the active areas of the capacitance-responsive surfaces designated to engage specific characters and commands in terms of their proximity to the home row of depressible key switches. By moving these active areas further away from the home row, the keyboard operator can lessen the sensitivity of the keyboard to drifting fingers that have moved without the intention of engaging a character or command. As typists become more proficient with this manner of typing, they can reprogram the keyboard, shifting the active areas closer to the home row in order to engage characters and commands with minimized finger movements. 
     It is a further object of the invention to provide the keyboard operator with the ability to sue the capacitance-responsive surfaces as relative motion cursor positioning devices when such operation is selected. 
     It is a further object of the invention to provide greater reduction in size by using a vertically oriented, thin, capacitance-responsive surface for the row that contains the space-bar and command key switches. Due to its vertical orientation, this row will not add substantially to the overall size of the keyboard. 
     It is a further object of the invention to provide optimum size reduction and portability by housing the capacitance-responsive surface for the row of key switches below the home row within a surface with a concave profile that is designed to fold compactly upon a complementary convex surface housing the home row and the capacitance-responsive surface for the row of key switches above the home row. 
     It is a further object of the invention to provide further size reduction and portability by connecting the left half of the keyboard to the tight half by way of a hinge, such that the two halves can be folded together for compact storage. 
     It is a further object of the invention to provide a modified form of construction of the keyboard in which the left and right halves of the keyboard are separately housed and are each separately attached by way of a pivot to a computerized device such that they can be folded up an rotated into a stored position within the computerized device. 
     It is a further object of the invention to provide a modified form of construction of the keyboard in which the four rows of key switches are contained within two semi-cylindrical convex surfaces which are hinged to each other and which when closed together form an approximately cylindrical shape. The uppermost row of capacitance-responsive key switches is located within the far side, relative to the typist, of the semi-cylindrical surface further from the typist, and the upper-middle, home row of depressible key switches is located within the near side, relative to the typist, of the semi-cylindrical surface further from the typist. The lower-middle row of capacitance-responsive key switches is located within the far side, relative to the typist, of the semi-cylindrical surface closer to the typist, and the bottom row of capacitance-responsive key switches is located within the near side, relative to the typist, of the semi-cylindrical surface closer to the typist. In this variation, the hollow space of the cylindrically shaped closed keyboard can house a flexible, extractable, and retractable video screen which can be unfurled from within the closed keyboard and which can be used in conjunction with the opened keyboard. 
     It is a further object of the invention to provide a more ergonomic keyboard by allowing a majority of characters and commands to be engaged by sliding the fingers over capacitance-responsive surfaces rather than requiring the typist to reach for and push down mechanical keys. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The present invention will be more fully understood by reference to the following detailed descriptions thereof when read in conjunction with the attached drawings, and wherein: 
         FIG. 1  is a perspective view of a preferred embodiment of the keyboard; and 
         FIG. 2  is a perspective view of the keyboard shown in  FIG. 1  with a preferred QWERTY style layout of alphanumeric characters and computer commands; and 
         FIG. 3  is a plan view of the underside of the keyboard shown in  FIG. 1 ; and 
         FIG. 4  is an elevation view of the keyboard shown in  FIG. 1 ; and 
         FIG. 5  is an elevation view of the keyboard shown in  FIG. 1  with its concave section folded upon its convex section; and 
         FIG. 6  is an elevation view of the keyboard shown in  FIG. 1  with its concave section folded upon its convex section and with its right half folded upon its left half; and 
         FIG. 7  is a perspective view of a modified form of construction of the keyboard in accordance with the present invention in which the lowermost row of key switches are housed within an angled surface; and 
         FIG. 8  is a perspective view of a further modified form of construction of the keyboard in accordance with the present invention in which the switches within the lowermost row of key switches are depressible; and 
         FIG. 9  is a plan view of a still further modified form of construction of the keyboard in accordance with the present invention in which the left and right halves of the keyboard are separately housed and are each separately attached by way of a pivot to a computerized device such that they can be folded up an rotated into a stored position within the computerized device; and 
         FIG. 10  is a plan view of the underside of the keyboard and computerized device shown in  FIG. 9 ; and 
         FIG. 11  is an elevation view of the keyboard and computerized device shown in  FIG. 9 ; and 
         FIG. 12  is a perspective view of a yet still further modified form of construction of the keyboard in accordance with the present invention in which the four rows of key switches are housed within two semi-cylindrical surfaces; and 
         FIG. 13  is a perspective view of the obverse side of the example of the keyboard shown in  FIG. 12 ; and 
         FIG. 14  is a perspective view of an even further modified form of construction of the keyboard in accordance with the present invention in which the four rows of key switches are housed within two semi-cylindrical surfaces, and wherein the key switches within the lowermost row of key switches are depressible; and 
         FIG. 15  is a perspective view of a still even further modified form of construction of the keyboard in accordance with the present invention in which the four rows of key switches are housed within two semi-cylindrical surfaces, and wherein the key switches within the lowermost row of key switches are depressible, and wherein a display screen is attached; and 
         FIG. 16  is an elevation view of the keyboard shown in  FIG. 15  with its screen extended; and 
         FIG. 17  is an elevation view of the keyboard shown in  FIG. 15  with its two semi-cylindrical halves open and its screen retracted; and 
         FIG. 18  is an elevation view of the keyboard shown in  FIG. 15  with its screen retracted and its two semi-cylindrical halves closed together; and 
         FIG. 19  is an elevation view of a yet still even further modified form of construction of the keyboard in accordance with the present invention in which the four rows of key switches are housed within two semi-cylindrical surfaces attached to each other to form a single unit; and 
         FIG. 20  is an elevation view of the keyboard shown in FIG.  14 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1 , there is shown a perspective view of the keyboard showing the arrangement of the rows of capacitance-responsive key switches  1 ,  2 , and  28  and the single row of mechanical, depressible key switches  3 - 16 . Number  1  is the row of capacitance-responsive surfaces that provide key switches for actuating characters and commands assigned to spaces in the uppermost row of the keyboard. Numbers  3 - 16  are the mechanical, depressible key switches for actuating characters and commands assigned to spaces in the home row of the keyboard. The home row retains mechanical, depressible key switches  3 - 16  in order to provide standard rest positions for the fingers. Number  2  is the row of capacitance-responsive surfaces that provide key switches for actuating characters and commands assigned to spaces in the row below the home row. Number  28  is the row of capacitance-responsive surfaces that provide key switches for actuating the space-bar and assorted computer commands. 
     This keyboard is particularly useful for providing a more compact and portable keyboard. Firstly, instead of using mechanical, depressible key switches for the row above the home row, this keyboard employs a less space consuming convex row of capacitance-responsive surfaces  1  that curves downward from the elevation of the home row of mechanical, depressible keys  3 - 16 . Specific characters and commands are assigned to distinct areas of this row of capacitance-responsive surfaces  1 . A character or command is engaged when an individual fingers slides out across or taps the portion of the row of capacitance-responsive surfaces  1  to which the character or command is assigned. Using existing capacitance-responsive technology, individual characters and commands will be actuated each time the typist&#39;s finger touches or slides over and back across a specific portion of the keyboard&#39;s capacitance-responsive surfaces. 
     Secondly, instead of using mechanical, depressible key switches for the row below the home row, this keyboard employs a less space consuming concave row of capacitance-responsive surfaces  2  that curves first downward then upward from the elevation of the home row of key switches  3 - 16 . Specific characters and commands are assigned to distinct areas of this row of capacitance-responsive surfaces  2 . A character or command is engaged when an individual fingers slides out across or taps the portion of the row of capacitance-responsive surfaces  2  to which the character or command is assigned. 
     These specified portions of the capacitance-responsive surfaces  1  and  2  are adjustable, such that the keyboard operator can electronically reprogram the keyboard to place these portions further away or closer to the home row. In this way, the keyboard operator can make the keyboard less sensitive or more sensitive to finger movements away from the home row. 
     Thirdly, instead of using mechanical, depressible key switches for the row containing the space-bar and command keys, this keyboard employs a row of capacitance-responsive surfaces  28  that is substantially vertical in relation to the horizontal keyboard, with its highest elevation meeting the highest elevation of the row of concave capacitance-responsive surfaces  2 . This vertical row of capacitance-responsive surfaces  28  adds only minimally to the overall dimensions of the keyboard. Specific commands are assigned to distinct areas of this row of capacitance-responsive surfaces  28 . A command is engaged when a thumb or finger taps the portion of the row of capacitance-responsive surfaces  28  to which the command is assigned. 
     An audible tone or a vibration in the keyboard signals typists to indicate that a key switch has been engaged in a capacitance-responsive surface  1 ,  2 , or  28 . 
     Fourthly, the capacitance-responsive surfaces  1  and  2  can alternately be used as relative motion cursor positioning devices when such operation is selected. 
     Fifthly, the home row doubles as a number row when the number lock switch  3  is engaged. The number row of mechanical, non-depressible key switches found on a standard QWERTY keyboard is thus eliminated. 
     With these space-saving innovations, the keyboard is substantially narrower from front to back than previously proposed compact two-handed QWERTY keyboards. 
     Sixthly, the lower section of each half of the keyboard folds by way of hinge  29  onto the corresponding upper section, with the concave row of capacitance-responsive surfaces  2  folding neatly upon the home row of key switches  3 - 16  and the convex row of capacitance-responsive surfaces  1 . In  FIG. 4 , there is shown an elevation view of the keyboard in its open, operating position. In  FIG. 5 , there is shown an elevation view of the keyboard with its lower concave half folded compactly by way of hinge  29  upon the upper convex half of the keyboard. 
     Seventhly, the left and right halves of the keyboard can be folded together by way of hinge  30 , which connects the upper left section of the keyboard to the upper right section. In  FIG. 3  there is shown a plan view of the underside of the keyboard showing the hinge  30  between the upper sections of the left and right halves of the keyboard. In  FIG. 6 , there is shown an elevation view of the keyboard with its lower half folded upon its upper half and with its left half folded by way of hinge  30  upon its right half. And although the keyboard folds four rigid subframes upon each other, the resulting thickness of the folded keyboard is substantially less than four times its unfolded thickness due to the complementary curves of the convex row of capacitance-responsive surfaces  1  and the concave row of capacitance-responsive surfaces  2 . 
     Additionally, since a majority of characters and commands are engaged by sliding the fingers over the rows of capacitance-responsive surfaces  1  and  2  rather than reaching for and pushing down mechanical keys, this keyboard will reduce repetitive stress, thus offering ergonomic benefit. In  FIG. 2 , there is shown a possible QWERTY layout of alphanumeric characters and computer commands for the keyboard. 
     In  FIG. 7  there is shown a further example of the keyboard that employs a surface that slopes at an angle to house the row of capacitance-responsive surfaces  28  for the lowermost row. This arrangement adds to the dimensions of the keyboard but allows the thumb to more easily engage the row of capacitance-responsive surfaces  28 . With the typist&#39;s thumbs taking a home position approximately an eighth of an inch away from the row of capacitance-responsive surfaces  28 , resting on the table in front of the keyboard, the typist flicks the thumb forward, tapping specific areas of the tow of capacitance-responsive surfaces  28  to engage the space-bar and other commands. By setting the row of capacitance-responsive surfaces  28  at an angle, the thumb easily bits the middle of the row of capacitance-responsive surfaces  28  rather than the upper edge of the row of capacitance-responsive surfaces  28 . 
     In  FIG. 8  there is shown a further example of the keyboard; in this example of the keyboard, numbers  17 - 27  are depressible key switches for actuating the space-bar  22  and assorted computer commands. Number  32  is a scroll wheel which when rotated engages commands for scrolling up and down computer documents. 
     In  FIG. 9  there is shown a further example of the keyboard with its left half  38  separate and distinct from its right half  37 , and with both halves attached by way of pivoting brackets  33  to a handheld computerized device. The body of the computerized device  35  is shown in  FIG. 10 , a plan view of the underside of this example of the keyboard. The pivoting brackets are each attached to the body of the computerized device  35  by a bolt  34 .  FIG. 11  shows an elevation view of this example of the keyboard. Number  40  is the frame for the screen  36  of the computerized device. Number  39  is the protective plate on the underside of the computerized device. The left half  38  and the right half  37  of the keyboard can each be stored between the frame for the screen  40  and the protective plate  39 , and each can be rotated out by way of a pivot  33  and unfolded by way of hinge  29  for use in conjunction with the computerized device. 
     In  FIG. 12  there is shown a further example of the keyboard that employs two semi-cylindrical halves that fold by way of hinge  29  to form a portable cylinder. A preferred QWERTY layout of letters and commands is shown. In this example of the keyboard, the row of capacitance-responsive surfaces  1  provides key switches for actuating characters and commands assigned to spaces in the uppermost row of the keyboard. Numbers  3 - 16  are the mechanical, depressible key switches for actuating characters and commands assigned to spaces in the upper-middle home row of the keyboard. The home row retains mechanical, depressible key switches  3 - 16  in order to provide standard rest positions for the fingers. Number  2  is the row of capacitance-responsive surfaces that provides key switches for actuating characters and commands assigned to spaces in the row below the home row. Number  28  is the row of convex capacitance-responsive surfaces that provides key switches for actuating the space-bar and assorted computer commands. 
     In  FIG. 13  there is shown the obverse side of the further example of the keyboard shown in  FIG. 12. A  preferred QWERTY layout of letters and commands is shown. 
       FIG. 14  shows a further example of the keyboard that employs two semi-cylindrical halves that fold by way of hinge  29  to form a portable cylinder. A preferred QWERTY layout of letters and commands is shown. In this example of the keyboard, numbers  17 - 27  are depressible key switches for actuating the space-bar and assorted computer commands assigned to the lowermost row of key switches. Number  32  is a scroll wheel which when rotated engages commands for scrolling up and down computer documents. 
     In  FIG. 15  there is shown a further example of the keyboard that employs two semi-cylindrical halves that fold to form a portable cylinder, and in which a retractable, flexible computer screen  31  is seen unfurled for use in conjunction with the keyboard. Number  41  is the handle for the computer screen  31 . This example of the keyboard employs a row of capacitance-responsive surfaces  28  to provide key switches for the lowermost row of key switches.  FIG. 16  shows an elevation view of this example of the keyboard.  FIG. 17  shows this example of the keyboard with the computer screen  31  retracted and rolled up for storage.  FIG. 18  shows this example of the keyboard with the two semi-cylindrical halves folded together to form a portable cylinder with the computer screen  31  stored inside. 
       FIG. 19  shows an elevation view of a further example of the keyboard that employs two semi-cylindrical halves fused together to form a single unit. In this example of the keyboard, depressible key switches are used in the upper-middle home row of key switches, and in the lowermost row of key switches. 
       FIG. 20  shows an elevation view of a further example of the keyboard that employs two semi-cylindrical halves that fold by way of hinge  29  to form a portable cylinder. In this example of the keyboard, depressible key switches are used in the upper-middle home row of key switches, and in the lowermost row of key switches.