CA2273791A1 - Keyboard cover for use in playing computer games and method of manufacturing same - Google Patents

Abstract

An elastomeric keyboard cover for use in playing computer games and a method for its manufacture. The cover bears indicia corresponding to the control commands of a computer game to enhance user enjoyment and understanding. Preferably the cover is molded to define a plurality of raised pockets each having a flat upper surface, vertical rear walls, tapered front and side walls, and an open bottom end.
Each pocket is sized and configured to receive a subgroup of the keyboard keys, such as the function keys or the cursor keys. The indicia is printed on the cover in a flat configuration prior to the step of molding the cover in a thermoforming process. The printed elastomeric sheet and the mold are heated together in a precisely aligned position during the thermoforming process.

Description

KEYBOARD COVER FOR USE IN PLAYING COMPUTER GAMES
AND METHOD OF MANUFACTURING SAME
Field of the Invention This application relates to an elastomeric keyboard cover for use in playing computer games and a method for its manufacture.
to Background of the Invention The sale of computer game software applications is a multi-billion dollar industry. Each year new games are introduced having enhanced inter-activity features and nnultimedia effects.
Most computer games allow the user to use a conventional computer keyboard as an input device. The games are designed so that specific keyboard keys or groups of keys correlate with specific game commands. A user can thus control the order and outcome of the game by 2 o selecting a sequence of keystrokes. For example, in the popular computer game FLIGHT SIMULATORS sold by Microsoft Corporation, the "G" key corresponds to a "gear" command and the "I" key corresponds to a "smoke"
command.
Computer game users often attempt to memorize the keystrokes corresponding to each game command. However, at least during an initial learning period, it is commonplace for users to refer to printed templates which list the game commands and correlate them to specific keys. Such templates typically consist of foldable pieces of cardboard provided by game manufacturers together with software products. Users lay the templates adjacent to the keyboard for quick access during game playing.
While such templates are a useful learning tool, they suffer from several serious limitations. The need for the game user to remove his or her gaze away from the computer monitor and keyboard to refer to a desktop template can interrupt th.e gaming sequence and disrupt concentration.
Computer game enthusiasts often encounter frustration when switching between different games since the key command structures also differ. This significantly increases the time and effort required to master the key commands for different games to derive the optimum level of gaming enjoyment. Many casual game users are unwilling to commit the time necessary to learn or relearn the key commands for different games using conventional desktop templates or other learning aids.
Accordingly, casual users often restrict themselves to playing only one or two well-known games and are reluct~ult to purchase new products having 2 o different key command structures.
r Various types of overlays for computer input devices and the like are known in the prior art. Dust covers for computer keyboards are of course well known. Such dust .covers typically overlap the entire 2 5 keyboard and are not molded to conform to the shape of each individual key or group of keys. Some keyboard dust covers bear decorative designs, such as a baseball, motif (U.S. Design Patent No. D372,905 issued 20 August, 1996) or a soccer motif (U.S. Design Patent No. D372,907 issued 20 August, 1996).
While conventional rectangular computer keyboards have a standard configuration, the layout of individual keys and the spacing between key subgoups can vary significantly from manufacturer to manufacturer. Accordingly, computer :keyboard covers having a separate pocket or compartment for each individual key are not versatile enough to fit a wide variety of PC keyboard designs.
to Some keyboard overlays iziclude indicia or legends correlating to the underlying buttons or keys. For example, United States Patent No.

4,421,966, Pounds, issued 20 December, 1983 relates to an elastomeric keyboard cover having changeable legends. 'The primary object of the Pounds invention is to protect the keyboard switch subassembly from contamination by water or other liquids, grease, dust and the like. The changeable legends or indicia are for identifying the individuals keys and any correlated functions or instructions. United States Patent No.

5,089,690, Okamura, issued 18 February,1992 also relates to a removable 2 0 overlay for a user-operable keyboard which includes modified key function indicators, but it is not adapted for use in playing computer games and the like.
United States Patent 1'Jo. 5,551,497, Stanley, issued 3 2 5 September,1996, relates to a decorative computer keyboard cover which may comprise flexible sheet material configured to conform to the general size and shape of a computer keyboard. However the key covering portion of the Stanley invention is designed to be removed when the keyboard is in use and there is no suggestion that the decorations could correlate with functional key commar~ds of a computer game.
United States Patent No. 4:,119,839, Beckmann et al., issued 10 October,1978, relates to a keyboard mask for a general-purpose calculator which comprises a resilient membrane which may include extension keys bearing markings. When the extension keys are depressed, they bear through the membrane upon the respective calculator keys registering therewith which can therefore be actuated by the operator in conformity 1 o with the markings. However, the membrane component of the Beckmann et al. mask is not adapted to cover the entire keyboard and there is no suggestion that the markings could correlate with functional key commands of a computer game. Accordingly, the Beckmann et al.
invention is not intended to simulate tile appearance of an aircraft control panel or the like.
United States Patent No. 4,075,465, Funk et al., issued 21 February, 1978, relates to a keyboard overlay for changing the character representations associated with the keys of a keyboard. The Funk et al.
2 0 overlay is disposed on the keyboard arid has openings to receive each key thereof. The key indicia, such as alphanumeric or functional symbols, are marked on sloped surfaces of the overlay for association with a corresponding key. The Funk et al. overlay therefore does not entirely cover the underlying keyboard and the symbol indicia are not located 2 5 directly above the associated keyboard key.
United States Patent No. 4,438,300, Morse, issued 20 March, 1984, relates to a protective cover for a telephone push button array which comprises an elastomeric sheet having a plurality of upwardly-directed pockets for receiving the corresponding array of push buttons on the telephone set. The outwardly facing parts of the pockets carry readable indicia corresponding to the indicia of the underlying push buttons.
5 However, the Morse pockets are not adapted to cover more than one button and there is no suggestion that the symbol indicia could correspond to the commands of game running on a computer separate from the telephone set.
1 o In summary, none of th.e existing prior art is specifically adapted for use in conjunction with cornputer game key input commands.
The need has therefore arisen for an elastomeric cover which is designed to overlay virtually all standard PC keyboards and which is specifically adapted to simplify and enhance the computer game playing experience.
Summary of the Invention In accordance with the :invention, a cover for overlying a keyboard useful as an input device :in the play of a computer game is 2 o provided. The cover bears indicia corresponding to the key commands of the computer game.
The cover is designed to conform to the shape and configuration of the keyboard. Most keyboards comprise a plurality of 2 5 keys arranged into separate sub-groups (such as function keys, cursor keys, number pad keys etc.). Preferably the cover comprises a plurality of upwardly-directed pockets, each of the pockets being sized to accommodate one of the sub-groups.

The cover may be formed from a unitary elastomeric sheet such as thermoformable polyurethane film having the indicia printed on an upper surface thereof. The sheet comprises a skirt portion surrounding the pockets which extends in a common plane when the cover is placed on a flat surface. The pockets are molded in the sheet and project upwardly from the skirt. Each of said pockets is characterized by an open lower end;
front, rear and side walls each extending in a plane intersecting the skirt;
and a flat, continuous upper surface extending in a plane generally parallel to the skirt. The rear wall of each po<:ket preferable extends in a vertical 1 o plane relative to the plane of the skirt whereas the front and side walls are tapered to match the contour of the keyboard keys.
Preferably the indicia cover portions of both the pockets and the skirt. Each of the pockets may bear indicia on the upper surface comprising a plurality of different graphic symbols.
A method of manufacturing a flexible keyboard cover bearing indicia and having a plurality of upwardly directed pockets is also described. The method includes the steps of (a) creating a digital image 2 o of the indicia; (b) providing a transfer material capable of holding an electric charge; (c) writing the digital image to the transfer material in an operating environment between 35 % and 65 % relative humidity and at a temperature between 15 and 27° C; (d) transferring the image from the transfer material to a sheet of elastomer; (e) providing a mold configured 2 5 to form the pockets; (f) securely maintaining the sheet of elastomer in an aligned position relative to the mold; (g) heating the sheet of elastomer and the mold in the aligned position; and (h) applying a vacuum to cause the mold to engage the sheet of elastomer in the aligned position to form the pockets.
Preferably the step of heating the sheet of elastomer and the mold occurs at a temperature withir~ the range of 275° F - 300°
F for a period between 30 and 45 seconds.
Brief Description of the Drawings l0 In drawings which illustrate embodiments of the invention, but which should not be construed as restricting the spirit or scope of the invention in any way, Figure 1 is an isometric,, exploded view of the applicant's keyboard cover in its molded configuration overlying a standard computer keyboard;
Figure 2 is an isometric view of the keyboard cover of Figure 1 with the indicia removed for purposes of clarity;
Figure 3 is a top plan view of the applicant's keyboard cover in its flat configuration prior to molding.
Figure 4 is a cross-sectional view taken along section lines 4 -2 5 4 of Figure 2 and showing a portion of the keyboard in phantom outline.
Figure 5 is a bottom plan view of the keyboard cover of Figures 1 and 2.

Detailed Description of the Preferred Embodiment This application relates to a computer keyboard cover 10 for use in playing computer games and the like. As shown in Figures 1 and 5, cover 10 comprises an upper surface 12 bearing various graphic and/or textual indicia 14 and a lower surface 13 which is ordinarily blank. As described further below, indicia 14 preferably correspond to and identify the key commands of a parkicular computer game. The content and layout of indicia 14 will therefore vary from game to game. Cover 10 may also l0 bear non-operable indicia 15 on surface 12, such as supplementary game information and advertising.
Cover 10 is preferably formed from a sheet of flexible elastomeric material, such as thermoformable polyurethane film. As is described in further detail below, ind:icia 14 and 15 is initially printed on upper surface 12 when cover 10 is in a flat configuration (Figure 3). After the printing step, cover 10 is molded to conform to the shape and configuration of a conventional computer keyboard 16 having a plurality of keys 18 (Figure 1).
r In its molded configuration cover 10 comprises a plurality of spaced-apart, upwardly-directed pockets 20 and a flat skirt 21 surrounding pockets 20. Each of the pockets 20 is sized and shaped for accommodating a subgroup of keyboard keys 18. In particular, pocket 22 is shaped to 2 5 receive keyboard function keys 24; pocket 26 is shaped to receive keyboard typographical keys 28; pocket 30 is shaped to receive keyboard control keys 32; pocket 34, is shaped to receive keyboard cursor keys 36; and pocket 38 is shaped to receive keyboard number pad keys 40.

When cover 10 is in the molded configuration shown in Figures 1 and 2, each pocket 20 is defined by a rear wall 42, a front wall 44 and a pair of opposed side walls 46. l;ach pocket 20 further comprises a flat upper section 48 for overlying a plurality of keys 18 and an open bottom end 50 (Figure 5). Preferably upper sections 48 extend in a common plane about 8 mm above skirt 21. When cover 10 is placed on keyboard 16, keys 18 are received in a corresponding pocket 20 through an end 50 and bear against the undersurface 49 of an upper section 48. In the illustrated embodiment, each of the pockets 20 is a pentagon having a rectangular upper section 48, except for cursor pocket 34 which is inverted T-shaped.
During the molding process described further below, pockets 20 are shaped to conform to the contour of keyboard keys 18 to ensure a reasonably snug fit when cover 10 i:~ placed on keyboard 16. As best shown in Figure 4, rear walls 42 of pockets 20 may extend in a vertical plane relative to skirt 21 whereas fronit walls 44 taper forwardly and side walls 46 taper toward a respective side edge of cover 10. Preferably, walls 44, 46 taper at an angle of approximately 70°.
The size and relative spacing of pockets 20 has been carefully chosen to ensure that cover 10 will fit most rectangular computer keyboards, irrespective of the manufacturer. The preferred dimensions of cover 10 and the upper sections 48 of pockets 20 are summarized in Table 2 5 1 below. As will be apparent to a person skilled in the art, the size and shape of pockets 20 may vary to conform to the keyboard 16 in question.

Name Iief. ' Dim.ensions (mm) No.

Cover 10 268 X 483 5 Function Key Pocket 22 . 25'X 346 Typographical Key Pocket 26 90 X 278 Control Key Pocket 30 34 X 57 Cursor Key Pocket 34 33 (14) X 57 Number Pad Pocket 38 75 X 90 to The overall dimensions of cover 10 are preferably larger than the surface area of a conventional computer keyboard 16. As shown in Figures 1 - 3, cover skirt 21 includes a rear panel 50 and a front panel 52 which are not intended to overly keys 18 in use. Rather, panels 50 and 52 optionally provide space for non-operable indicia 15 (i.e. indicia not corresponding to specific key commands, such general legends, user reference notes, trademarks or advertising). In the illustrated embodiment, panel 50 is approximately 60 mm in width and panel 52 is 2 o approximately 80 mm in width. In use, front panel 52 may be draped over the front edge of keyboard 16 or fiucked under keyboard 16 as shown in Figure 1. In one possible alternative embodiment of the invention, front panel 52 may be perforated to provide user's with the option of easily removing panel 52 to reduce the overall size of cover 10.
As shown in Figure 3, upper surface 12 of cover 10 is initially printed with indicia 14,15 in a flat configuration prior to thermoforming.

b Each portion of surface 12 which will be configured to form a pocket 20 is surrounded by narrow borders 4:?a, 44a and 46a. During the thermoforming process, borders 42a, 44a and 46a are formed into pocket rear walls 42, front walls 44 and side walls 46 respectively. In one embodiment of the invention, indicia 14, 15 may be initially printed in a skewed format on cover surface 12 so that such indicia will have a realistic, undistorted appearance after the thermoforming step.
The applicant has also developed a method of manufacturing to covers 10 which involves customi<:ed printing and thermoforming techniques. According to the applicant's method it is possible to reliably produce covers 10 bearing indicia which is information dense and color intensive. Prior art systems for producing images on a thin polyurethane substrate are not adapted for highly complex graphical images and result in an unacceptable degree of image distortion and inconsistent definition.
The applicant has determined that the preferred thickness of the polyurethane sheets used to produce covers 10 is approximately 9 mil.
Covers 10 which are significantly less than 9 mil in thickness tend to sag 2 o and may result in image distortion during the printing process. Covers 10 which are significantly more than 9 mil in thickness tend to be overly rigid and do not provide users with the optimum tactile feel. If a cover 10 is overly rigid, when a user presses a particular key command printed on the upper section 48 of a pocket 20 (Figlzre 4), this may result in multiple keyboard keys 18 being depressed (i.e. the selected key and several immediately adjacent keys).

Suitable elastomeric sheets are available from J.P.S.
Elastomerics of Holyoke, Massachusetts. Preferably the elastomeric sheets are pre-printed white to provide high contrast during the colour printing steps.
Reliable techniques are not currently available for printing complex color images directly on to the surface of smooth elastomeric polyurethane sheets in an automated zzianner. Accordingly, the applicant's printing techniques involves reproducing the desired images on a transfer to material and then transferring the images from the transfer material to sheets of polyurethane to produce cowers 10.
The first step in the printing process is to capture the graphics to be printed on cover 10, namely indicia 14 and 15, in digital form.
Preferably a host computer or external rasterizer is used to convert graphic data to raster data. The raster data is then transmitted to a microprocessor-controlled graphics printer/plotter having a parallel interface input. 'The print/plotter utilizes electrostatic technology to produce high resolution color (four color composite) or monochrome 2 o images from the rasterized data. Suitable print/plotters are available from Xerox Corporation (for example, models 54E and 9154, Series 1).
According to the applicant's method the digital image is written to a transfer material coated ~Nith a conductive layer. A suitable transfer material is available from Xerox Corporation under the trade-mark WearCoat. The transfer material is passed between the backplate electrode and writing head of the printer/plotter which contains an array of writing nibs. This results in the creation of a pattern of electrical charges on the transfer material. For each scan line of the output, only writing rubs corresponding to the rasterized data charge the transfer material.
The transfer material then passes over the rotary toner fountains of the printer/plotter. The toner comprises a suspension of positively charged toner particles in iso:par. The toner contacts the transfer medium and an image is developed in the negatively charged areas of the transfer medium. Toner in the uncharged areas of the output leaves a thin 1 o film. The surface of the fountain roller moves in the opposite direction of the transfer medium in the printer/ploiaer and mechanically removes this film from the medium. Removing the undeveloped toner from the transfer medium leaves the permanent output image. According to this method the output resolution is 200 dots per inch. However, depending upon the printer/plotter being used and the extent to which the rasterized data is optimized, it may be possible ito emulate 600 dots per inch visual results.
The applicant has determined that printer/ plotter should be operated under controlled environmental conditions for best results. In particular, humidity and temperature affect the ability of the transfer material to hold a charge and maintain its preferred dimensions. A
temperature increase results in a lower humidity range. Low humidity makes it difficult for the transfer material to hold a charge, resulting in 2 5 drop out and decreased resolution. High humidity causes the transfer material to overcharge, resulting in thicker lines, flare, overtone and smear. The printing process should be carried out at a temperature between 15.5 °C and 26.7 °C and at a relative humidity within the range of 30.5 - 60%. For optimum results, the printing process should be carried out at a temperature between 18 °C and 24 °C and at a relative humidity within the range of 40.5 - 50.75 % .
Once the digital image has been written repeatedly to a roll of transfer material as described above, the image is then transferred to sheets of polyurethane using a heat and pressure transfer device, such as a heat laminator. The laminator presses the sheets of transfer material and polyurethane together between heated, pressure-sensitive rollers. The to polyurethane sheets have different expansion and contraction rates depending upon the thickness of the sheets, temperature, pressure and speed of throughput. It is important that the laminator be calibrated to ensure that the transferred image bearing indicia 14, 15 is sufficiently fixated on the polyurethane substrate, but is not distorted in size or appearance.
The printing and transferring steps described above result in a printed cover 10 having a flat configuration as illustrated in Figure 3.
The final step in the manufacturing process is to thermoform cover 10 into 2 0 the desired shape without distorting indicia 14, 15 to an appreciable extent. This requires that the thermoforming parameters also be carefully calibrated.
The thermoforming process employs a mold which has been 2 s configured to produce cover pockets 21) having the size, shape and pattern shown in Figure 2. Each cover 10 is clamped in a flat and tensioned configuration directly above the mold to prevent sagging. It is critical that the mold and cover 10 be aligned precisely. Even a slight degree of misregistration between the printed graphics and the location of pockets may render cover 10 unsuitable for its intended purpose.
The mold and cover 10 are heated in their aligned 5 configuration, such as by placing both the mold and cover in an oven operating within the range of 200° F - 400° F for a period between 16 and 60 seconds. Preferably the mold and cover are heated at a temperature within the range of 275° F - 300° F for a period between 30 and 45 seconds.
This differs from conventional thermoforming techniques where an to elastomeric sheet is heated and is then ixansferred to an unheated mold for thermoforming.
In the applicant's method, a vacuum is applied during the heating process to thermoform cover 10 to the shape of the mold.
15 Preferably the vacuum is applied at a suction pressure of between 24 - 28 mm Hg begiruling approximately 15 seconds after commencement of the heating process and lasting for a duration of approximately 15 - 20 seconds. The mold and cover are then removed from the oven and allowed to cool for approximately 1 - 2 minutes before removing the 2 o thermoformed cover 10. In order to reduce the required cooling time, the mold may be subjected to supplementary coolants, such as by circulating a liquid through the mold.
It is critical to strike the eight balance in the thermoforming 2 5 process between heating covers 10 to a sufficient extent to ensure that the shape of pockets 20 is well-defined while avoiding significant heat-related distortion of graphic indicia 14, 15, particularly in corner portions of pockets 20 which are subjected to the highest degree of heat and pressure.

Excessive heating may also cause expansion or contraction of the overall dimensions of cover 10, or of portions thereof, resulting in an improper fit on keyboard 16 or misregistration of indicia relative to keys 18.
After the thermoforming process, covers 10 are cut to their final size and packaged for shipping.
In use, cover 10 is molded to rest reasonably snugly on keyboard 16. Pockets 20 are arranged to fit virtually all regular to rectangular PC keyboards 16. As showm in Figure 1, cover 10 overlies the entire surface area of keyboard 16. Tile front panel 52 of skirt 21 may be draped over the front edge of keyboard.16, or tucked underneath keyboard 16.
Once in place, cover 10 facilitates the use of keyboard 16 as an input device during the play of a connputer game or the like. Cover 10 may be used as a training aid to help users recall the functions associated with particularly keyboard keys 18. Cover 10 also enhances the gaming experience by simulating the appearance of a cockpit control or some other 2 o similar control environment. As shown best in Figure 4, a user may actuate a particular key command by depressing the corresponding indicia 14 on cover 10 extending above the selected key 18.
As will be apparent to those skilled in the art in the light of 2 5 the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims (19)

1. A cover for overlying a keyboard useful as an input device in the play of a computer game, wherein said cover bears indicia corresponding to the key commands of said computer game.

2. The cover of claim 1, wherein said keyboard comprises a plurality of keys arranged into separate sub-groups and wherein said cover comprises a plurality of upwardly-directed pockets, each of said pockets being sized to accommodate one of said sub-groups.

3. The cover of claim 2, wherein the surface area of said cover is larger than the surface area of said keyboard.

4. The cover of claim 2, wherein said cover further comprises a flat skirt surrounding said pockets.

5. The cover of claim 3, wherein said skirt comprises a front panel adapted to overhang the front edge of said keyboard.

6. The cover of claim 2, wherein said cover comprises a unitary elastomeric sheet having a skirt which may be disposed in a flat orientation and wherein said pockets are molded in said sheet and project from said skirt.

7. The cover as defined in claim 6, wherein each of said pockets comprises:

(a) an open lower end;
(b) front, rear and side malls each extending in a plane intersecting said skirt; and (c) a flat, continuous upper surface extending in a plane generally parallel to said skirt.

8. The cover as defined in claim 7, wherein at least some of said pockets are pentagon-shaped.

9. The cover as defined in claim 7, wherein each of said rear walls extends in a vertical plane relative to said skirt.

10. The cover as defined in claim 9, having front, rear and side edges, and wherein said front walls are tapered toward said front edge and wherein said side walls are each tapered toward one of said side edges.

11. The cover as defined in claim 6, wherein said indicia cover portions of said pockets and said skirt.

12. The cover as defined in claim 7, wherein each of said pockets bears indicia on said upper surface comprising a plurality of different graphic symbols.

13. The cover ad defined in claim 6, wherein said sheet has a thickness of approximately 9 mil.

14. A cover for overlying a keyboard, the keyboard being useful as an input device for interacting with a computer program, wherein said cover bears indicia corresponding to the key commands of said computer program.

15. A method of manufacturing a flexible keyboard cover bearing indicia and having a plurality of upwardly directed pockets, said method comprising:
(a) creating a digital image of said indicia;
(b) providing a transfer material capable of holding an electric charge;
(c) writing said digital image to said transfer material in an operating environment between 35 % and 65 %
relative humidity and at a temperature between 15 and 27° C;
(d) transferring said image from said transfer material to a sheet of elastomer;
(e) providing a mold configured to form said pockets;
(f) securely maintaining said sheet of elastomer in an aligned position relative to said mold;

(g) heating said sheet of elastomer and mold in said aligned position; and (h) applying a vacuum to cause said mold to engage said sheet of elastomer in said aligned position to form said pockets.

16. The method as defined in claim 15, wherein said step of heating said sheet of elastomer and said mold occurs at a temperature within the range of 275° F - 300° F for a period between 30 and 45 seconds.

17. The method as defined in claim 15, further comprising the step of cooling said mold following application of said vacuum to said mold.

18. The method as defined in claim 15, wherein said digital image is written to said transfer material in an operating environment between 18 °C and 24 °C and at a relative humidity within the range of 40.5 - 50.75 %.

19. A keyboard cover manufactured in accordance with the method defined in claim 15.