How it works
Brief overview
Figure 1 shows an overview of the prototype Combimouse.

Figure 1. Overview of system
The left hand unit is a stationary keyboard part.
The right hand unit is a mobile combination keyboard and mouse that
can be gripped and moved around on a support surface as is done with a
conventional mouse.
Normally the right hand unit is in keyboard mode. To change to mouse
mode, the user clenches his/her hand and grips the right hand unit touching
the area labelled Contact switch 1. A proximity circuit detects the finger
contact, and the unit changes to mouse mode. During mouse mode the cursor
is enabled so that movement of the right hand unit on the table/mousemat,
causes the cursor to move. In addition, during mouse mode and depending
on how the unit is gripped, the keys indicated become the mouse click
buttons and the Scrolling keys.
Touching contact switch 2 enables the 2nd Fn keys. So if the user would
like to press the Pg up, Pg Dn, Home, Endl keys, the palmrest is gripped,
with the small finger touching contact switch 2 and the three middle fingers
resting on the Home, Pg dn and End keys ready to press the required key.
(Contact switches 1 and 2 are actually implemented as the same switch,
however in terms of functionality it is easier to think of them as two
separate switches.)
As a mouse, the right hand unit has a similar mass and centre of gravity
to the Microsoft Intellimouse. It has a similar grip to a conventional
mouse.

Figure 2. Overview of prototype system
To accommodate left handed users; the left hand unit could also be designed
as a mobile unit.
Detailed description of Right hand unit

Figure 3. Right hand unit
Characteristics
CHARACTERISTIC |
COMMENTS |
Mass |
120 grams. Similar to Microsoft Intellimouse(with
rolling ball) which is 115grams. The new Logitech Cordless MouseMan
optical has a mass of 145 grams while the new Microsoft Wireless Intellimouse
Explorer mouse has a mass of 152 grams. Production units will be lighter
due to optimum design and state of the art components/materials (eg.
Magnesium and light notebook keyboards). |
Centre of resistance to horizontal motion
relative to user's hand |
Similar to the Microsoft Intellimouse.
(Determined by pushing the side of the unit with a pointed object
and determining which position does not cause the unit to rotate).
|
Ease of movement |
The prototype requires 25% less force
to move than the Microsoft Intellimouse. |
Wrist rest. Used to rest the wrist during
breaks between typing |
Same length as Microsoft Natural keyboard.
Same slope as Microsoft Natural keyboards. Same effective resting
area as Microsoft Natural keyboard. |
Factors Contributing to High Mobility
The following factors have contributed to the high mobility of the right
hand unit:
- Low friction sliders.
- As opposed to mouse rolling ball technology, optical movement detection
technology is used, which doesn't contribute significantly to the mass
of the unit. The rubber rolling ball in a conventional mouse has a mass
of 30g.
- Light notebook keyboard technology used.
- Careful mass implementation. Conventional mice designs do not have
a low-mass requirement and are inefficient in this respect.
- Locating the user's hand well forward over the keyboard section during
mouse modes, ensuring a favourable centre of gravity with respect to
the user's hand.
Mouse modes
There are two ways of gripping the right hand unit during mouse mode.
The first is referred to as normal mouse mode (see Figure 4), as this
is the way that most people grip a mouse.

Figure 4: Normal Mode
In this mode only two fingers are on the mouse buttons (keys). The thumb
grips the left side of the mouse. The small and ring fingers grip the
right side of the mouse.
The second method of gripping the mouse is with three fingers are on
the mouse buttons (keys). This is shown in Figure 5.

Figure 5: Three-finger Mode
Figure 6 shows the hand in the home position while typing.

Figure 6: Keyboard Mode
Numeric keypad
An integrated numeric keypad is implemented similarly to notebook computers.
Due to the ability to move easily between keyboard and mouse modes, numeric
entry in spreadsheets is very easy. This is shown in the demonstration
video.
Adjustable palm grip
In order to accomodate different size hands it is possible to exchange
the palm grip. In addition the palm grip can be slided to various positions
to suit the user's hand size.
Communications from RHU to the LHU
For the prototype combination keyboard and mouse communications from
the RHU to the LHU is via infra red.
The final design might use a RF link. This may increase the cost of
the product and a commercial decision is required. The new Bluetooth technology
may be the best solution.
|