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COMPUTER INPUT DEVICE
1 Background to the invention
1.1 Field of the invention
People frequently need to enter alphanumeric data, punctuation or instructions into an electronic machine Generally, a computer user enters this using a keyboard or a pointing device such as a mouse, a mobile telephone user enters text using the phone's numerical keypad and a user of a personal digital assistant (PDA) enters data using either a small keyboard or a pointing device on a touch screen This invention offers an alternative to keyboards, pointing devices and touch screens.
1.2 Problems addressed by the invention
Keyboards will enable fast data entry if the operator can touch-type, that is to type while looking at the screen Many users have not learnt this skill and rely on the slower technique known as "hunt and peck" which requires looking for each key and then looking back at the screen. Keyboard usage is also associated with illnesses such as repetitive strain injuries
Entering data via a mobile phone's keypad is slow as each key has to be pressed a number of times to present the required letter or number. Although a mobile phone keypad is smaller than a computer keyboard, it is large compared with the overall size of the phone and limits the size of screen that can be included. Small keypads are also more difficult to use for people with large fingers.
Keyboards on PDAs and small portable computers are difficult and slow to use because of their small size.
Most entry methods require the use of two hands to achieve reasonable speeds of data entry
1.3 Prior art used to address these problems
There are various devices available to mitigate the problems caused by keyboards and keypads Keyboards can be curved and angled to improve the angle at which the hands approach the keyboards, including natural keyboards and vertical-split keyboards where the palms of each hand face each other
Dvorak keyboards are based on designs created by August Dvorak, who determined the most common letter combinations and then replaced the QWERTY pattern with a keyboard layout that reduces fatigue and speeds up typing. Expanded keyboards have large keys for the use of disabled
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people. Chording keyboards have ten or fewer keys, and the character is specified by the combination of keys that have been depressed. Projection keyboards use a laser to project the image of a keyboard onto a desk or other flat surface and cameras monitor the movement of the fingers over the keyboard image and determine which "key" was pressed.
Predictive typing is used to speed up the entry of text on a mobile telephone.
There are also mechanisms to replace keyboards, frequently designed for disabled people One such device has ten pockets into which the fingers and thumbs are inserted horizontally Each pocket can move approximately one centimetre in any of four directions (right, left, away and towards) and each such movement or combination of movements specifies a character to be entered.
Another device uses two "domes", one for each hand. Each dome can move in one of eight directions, and the combination of these two sets of eight specifies the required character.
Eye-gaze technology determines where the eye is looking and uses eyelid movements to "click". "Sip and puff' uses the breath to control cursor movement and to click. These two are often used with onscreen keyboards, where the eye-gaze or breath moves a cursor over the character is to be selected.
Voice recognition software provides an alternative to the mechanical entry of data.
1 4 Prior art relating to touch pad and display screen technology
Touch pads are well-known technology, which work by various principles. Most often they work by placing a grid of wires beneath a non-conducting surface. The presence of a finger on the surface affects the capacitance of the grid at that point and so operating software can determine the centroid of the finger contact and allocate a value to that position
The software required to operate the touch pads and to display the characters on the screen are readily available or easily produced within the existing art, and will not be described herein.
2 The invention
2.1 Features of the invention
This invention uses the four fingers of one hand each to present one of a plurality of characters on the screen of the computer, PDA or mobile phone and to select one of this choice of four to be entered into the computer or phone. The thumb is used to multiply the number of available characters. Each of the four fingers selects its character to be presented on screen by its small movements along one of
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four touch pads Thus at any time there are four characters on offer on the screen, and one is selected by momentarily removing the finger from the pad, and then replacing it. The thumb has its own touch pad and its position on that pad determines which sets of characters the fingers present.
2.2 Introduction to the drawings
An example of the invention will now be described by referring to the accompanying drawings.
Figure 1 shows a top-view of the invention for right-handed use
Figure 2 shows a computer screen with the four selected characters displayed.
Figure 3 shows a top view of the invention for either-handed use.
Figure 4 shows the front and left side view of the invention applied to a mobile telephone.
Figure 5 shows the front and right side view of the invention applied to a mobile telephone.
Figure 6 illustrates the main actions that the software is required to undertake when the invention is used for inserting characters or giving instructions.
Figure 7 illustrates the main actions that the software is required to undertake when the invention is used to move a cursor.
2.3 One embodiment of the invention
An embodiment of the invention designed for right-handed use with a computer will now be described. There is a box 1 approximately 20 cm in length, approximately 15 cm wide and approximately one cm deep It is placed so that the long sides extend away from the user. There is a gel-filled wrist support 2 attached on the top face close to the edge nearest to the user. Four touch pads 3 are inset into the top face. These are 1.5 cm wide and eight cm long, and lie almost parallel to each other and to the long side of the box, with a 0 5 cm space between them. The pads are slightly further apart from each other at the distant end than at the user end, as fingers tend to separate as they extend from the flexed position The outer touch pad 4 is closer to the user than the other three, as the little finger is shorter than the other fingers. These pads are offset towards the right of the box so that the thumb pad 5 can be placed to their left. This thumb pad is two cm by four cm, and is placed almost perpendicular to the other pads, angled so that it matches the arc described by the thumb moving right and left.
In use, the user rests his wrist on the wrist support and relaxes his fingers. He then lowers his fingers so that they fall naturally onto their respective touch pads. Software on the computer notes the position of each finger on its touch pad and sets this as the midpoint of its range. Similarly the thumb is lowered onto its touch pad and its midpoint is also set.
Each finger touch pad is able to present eight different characters on the computer screen. By moving each finger up to one cm forwards or backwards from its initial position one of eight characters is
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selected, depending on the position of the finger. At any time, therefore, four characters are selected from the 32 available, one by each finger, and these can be changed by a small movement of the fingers. Although the required movement to display all eight characters is chosen to be only two cm, the touch pads are longer than this to accommodate fingers of different lengths and differences in the comfortable degree of flexion of the fingers. The touch pads are coated with a low-friction material to prevent damage to the fingers from repeated sliding across them.
The four selected characters are displayed on the computer or phone screen as shown in Figure 2 In this embodiment they are presented in a horizontal row 6 below the cursor, and therefore below where one of them will be inserted. When the row of characters includes the character required for insertion the user lifts the finger corresponding to that character momentarily from the touch pad. This selects the displayed character and it is inserted into the document.
Each finger can display one of eight characters These may be letters, numbers, punctuation, symbols or may represent functions normally found on a keyboard, such as "Page up" or "Delete" An optional computer program can rank the characters by their frequency of usage and to distribute these around the mid-points of the fingers for each different user.
The thumb in its midpoint determines that the fingers display lower case characters, in a position 0.5 cm closer to the fingers it determines that the fingers will display upper case and in the position one half cm to the left of the midpoint the fingers will display numbers or be used to instruct other functions which would be accessed by the function, control, Windows and alt keys on a standard keyboard. Optionally two small ridges on the thumb touch pad give a tactile indication when the thumb crosses from one set of characters to another. With four fingers each offering eight characters and three thumb positions a total of 96 characters or instructions are available
If the thumb is removed from its touch pad the finger touch pads cease to offer characters, and instead offer a means to move the cursor as an alternative to a mouse or other pointing device. Movement of the index finger on its touch pad moves the cursor left and right, and movement of the forefinger on its touch pad moves the cursor up and down the screen. A tap on its touch pad by the ring finger is equivalent to a left mouse-click and a tap on its touch pad by the little finger is equivalent to a right mouse-click
The software that controls the invention offers the option to adjust the following factors:
• the length of finger travel required to encompass all available characters or instructions
• the number of characters or instructions available from each finger
• the number of fingers used, to allow for users with missing or unusable fingers, and the option of using one finger to replace a missing or inoperative thumb
• the number of thumb positions used
• the character selected by each combination of finger, finger position and thumb
• the font, size and position of the character display
• when the fingers are being used to move the cursor, the relative distances moved by the fingers and the cursor, and to what extent these vary according to the speed of the finger movement
• the sensitivity of the tap used to emulate a mouse-click.
2 4 Other embodiments of the invention
A further embodiment of the invention is designed for use by the right or the left hand, shown in Figure 3. There are two thumb touch pads, one on either side of the finger pads, and the outer two pads are elongated so that both are suitable for the little finger or for the index finger
Another embodiment of the invention uses either two either-handed units or a left-handed and a right-handed unit. The software will enable the display to show either all eight characters or the most recently selected ones
The embodiment of the invention described above is for a stand-alone unit, but the invention can be incorporated into a portable computer, the base of a computer screen, a mobile phone or a PDA.
In most embodiments of the invention the software required to control the touch pads and the screen display is run by the processor of the computer itself. If it is wished to operate the invention on computers or other devices without installing appropriate software on them a processor to run the necessary software can be incorporated into the unit
In another embodiment of the invention the finger tips and the thumb sit in small cups and the characters are changed by pressure on the front or back of the cup instead of movement, and character selection is by pressing downwards on the cup. The horizontal and vertical pressures are measured by pressure-sensitive semiconductors or by their effect on piezo-electric devices
A further embodiment of the invention is in a mobile telephone. Figure 4 shows a phone designed to be held in the right hand with the finger pads located on the left side of the phone. The movement available for selecting the character is limited to approximately one cm from the back to the front face of the phone, but this is sufficient to discriminate between the necessary number of characters. The touch pad for the thumb is on the right side of the phone towards the top, shown in Figure 5, and the direction of movement is again between the front and back faces. The phone is held in the right hand gripped at any one time between the ball of the thumb and three of the fingers, a fourth finger being loosely in contact to select the required character. An optional sixth touch pad 7 is provided on the right hand side of the phone to make contact with the ball of the thumb. Only when the software
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senses all six points of contact does the invention become active, and this prevents inadvertent operation of the phone. Such an embodiment could be designed for holding in the left hand.
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