The Motorola iBoard™ project required a general overview of the Stowaway Keyboard and a review of key-switch technology.

Think Outside utilized a Modular Platform Strategy in their product design (Figure A). The base technology consists of the folding mechanism and deployment method that includes a ollapsible key design. The modular section is used to outfit the keyboard for different connector designs (PalmV series, PalmIII series, Handspring Visor, HP Jornada PocketPC, and so on). The animated image shows several different modules, including one for the HP Jornada that incorporates a charging accessory.

                                          Figure A

The Stowaway keyboard consists of three keypad sections connected via flex circuit with two double hinges which allow folding into a compact self contained carry case.

Each individual full size key consists of a full size plastic keycap supported by a scissors mechanism (Figure B) and a rubber dome (figure C). The scissors mechanism prevents key wobble of the keytop and the rubber dome provides the spring force and tactile feel necessary for user feedback. The rubber dome contains a carbon pill on the underside that shorts runners on the interconnecting mylar flex (figure D).

                  Figure B                               Fig C                         Fig D

The two outer key sections slide outward to provide clearance prior to folding the device into its stowed position. Connectivity is maintained through a flex that sits in a shallow groove and rolls on itself to allow movement (Figure D & E).

                                          Figure D

                                                      Figure E

The single sided mylar flex circuit consists of four sections, three for the keyboard sections and one for the handheld computer connector. The four flex tails are heatseal connected (figure E) to a small circuit board which contains 1 custom ASIC and a handfull of discrete parts. The IC is powered off the handheld computer supply. The board is located adjacent to the connector for the external device and serves as a common connection point for each flex, with a single flex that routes to the connector.

                                            Figure E

Upon a review of the Stowaway, a summary of relevant keypad and keyswitch patents was created and reviewed. While not a comprehensive list, it provides a good sense of the state of the art in keyswitch technology. Each patent can be downloaded via the pdf icons.

PDF	Patent #	Title	Issued	Assignee
	3,800,104	Low Profile Keyboard Switch Assembly with Snap Action Cantilever Contact	03/26/74	Becton, Dickinson Electronics Company, Ritherford, NJ
	3,909,564	Keyboard assembly with foldable printed circuit matrix switch array, and key actuator locking slide plate	09/30/75	AMP Incorporated, Harrisburg, PA
	4,032,729	Low profile keyboard switch having panel hinged actuators and cantilevered beam snap acting contacts	06/28/77	Rockwell International Corporation, El Segundo, CA
	4,099,037	Key board switch assembly having canti-levered leaf spring contact assembly on common conductive frame	07/04/78	National Semiconductor Corporation, Santa Clara, CA
	4,118,611	Buckling spring torsional snap actuator	10/03/78	International Business Machines Corporation, Armonk, NY
	4,316,066	Key switch with snap-action contact and resilient actuator	02/16/82	International Telephone and Telegraph Corporation, New York, NY
	4,480,937	Breakaway leafspring actuated keyswitch apparatus	11/06/84	none
	4,950,874	Expansion joint for keyboard dome sheets	08/21/90	Key Tronic Corporation, Spokane, WA
	5,163,765	Collapsible keyboard	11/17/92	Apple Computer, Inc., Cupertino, CA
	5,268,545	Low profile tactile keyswitch	12/07/93	Lexmark International, Inc., Greenwich, CT
	5,278,374	Assembly with an asymmetrical resilient spring	01/11/94	Brother Kogyo Kabushiki Kaisha, Nagoya, Japan
	5,329,084	Keyswitch assembly	07/12/94	Brother Kogyo Kabushiki Kaisha (Nagoya, JP)
	5,422,447	Keyboard with full-travel, self-leveling keyswitches and return mechanism keyswitch	06/06/95	Key Tronic Corporation, Spokane, WA
	5,424,516	Low profile pushbutton switch	06/13/95	none
	5,457,453	Folding keyboard	10/10/95	none
	5,512,719	Key switch having elastic portions for facilitating attachment of scissors-type support linkage to keytop and holder, and removal of keytop from linkage	04/30/96	Brother Kogyo Kabushiki Kaisha (Nagoya, JP)
	5,519,569	Compact notebook computer having a foldable and collapsible keyboard structure	05/21/96	Compaq Computer Corporation (Houston, TX)
	5,532,904	Collapsible keyboard structure for a notebook computer, responsive to opening and closing of the computer's lid	07/02/96	Compaq Computer Corporation (Houston, TX)
	5,562,203	Keyswitch	10/08/96	Brother Kogyo Kabushiki Kaisha (Nagoya, JP)
	5,574,481	Detachable folding keyboard device	11/12/96	Silitek Corporation, Taipei, Taiwan
	5,590,020	Collapsible notebook computer keyboard structure with resiliently deflectable key cap skirts	12/31/96	COMPAQ COMPUTER CORP (US)
	5,602,715	Collapsible keyboard structure for a notebook computer, responsive to opening and closing of the computer's lid via relatively shiftable key support member and shift member	02/11/97	Compaq Computer Corporation (Houston, TX)
	5,621,610	Collapsible computer keyboard structure with associated collapsible pointing stick	04/15/97	Compaq Computer Corporation, Houston, TX
	5,635,928	Data processing device with a keyboard having pop-up keys	06/03/97	Brother Kogyo Kabushiki Kaisha, Nagoya, Japan
	5,703,578	Folding keyboard	12/30/97	International Business Machines Corporation (Armonk, NY)
	5,747,758	Keyboard arrangement	05/05/98	Preh-Werke GmbH & Co. KG (Bad Neustadt, DE)
	5,767,464	Electronic device low profile keyboard switch assembly with deployed and stored actuating mechanism	06/16/98	Texas Instruments Incorporated (Dallas, TX)
	5,772,008	Keyboard switch actuator assembly including keycap and scissors type linkage	06/30/98	Behavior Tech Computer Corporation (Taipei, TW)
	5,793,605	Collapsible portable computer keyboard with resilient preload key stabilization	08/11/98	Compaq Computer Corporation (Houston, TX)
	5,828,015	Low profile keyboard keyswitch using a double scissor movement	10/27/98	Texas Instruments Incorporated (Dallas, TX)
	5,833,378	Collapsible typing keyboard tray	11/10/98
	5,874,696	Key switch, keyboard and portable information processing unit with keyboard	02/23/99	Fujitsu Takamisawa Component Limited, Tokyo, Japan
	5,874,697	Thin keyboard switch assembly with hinged actuator mechanism	02/23/99	International Business Machines Corporation, Armonk, NY
	5,934,454	Thin keyboard having multiple hinge members per keyswitch	08/10/99	International Business Machines Corporation, Armonk, NY
	5,941,648	Personal digital assistant having a foldable keyboard component	08/24/99	Olivetti Office U.S.A., Inc. (Bridgewater, NJ)
	6,005,209	Thin keyboard having torsion bar keyswitch hinge members	12/21/99	International Business Machines Corporation, Armonk, NY
	6,056,456	Keyboard device	05/02/00	none
	6,068,417	Electrical key connection for expandable keyboard	05/30/00	none
	6,080,948	Pushbutton structure of computer keyboard	06/27/00	Hon Hai Precision Ind. Co., Ltd (Taipei Hsien, TW)
	6,088,220	Pocket computer with full-size keyboard	07/11/00	none
	6,091,036	Keyswitch for computer keyboards	07/18/00	Silitek Corporation (Taipei, TW)