GB2161755A - Computer peripheral device - Google Patents

Abstract

A computer peripheral device comprising a hand-sized mobile enclosure known as a "mouse", and having a plurality of finger- or hand-operated keys which may be actuated together with the motion of the enclosure to translate positional information into coordinates as input to a computer system, is characterised by the additional facility for inputting symbols such as alpha-numerics by suitably coded actuation of the same keys. For example, in the position mode for sending data in a digitising stream, the "mouse" has ball 4 in contact with surface 2; if tilted onto heel 3, string mode is entered so that keys 6 send signals to the symbol stream. An additional keypad may be accommodated in the other hand. Applications include computer-aided design and drafting, video graphics, word processing and television subtitling. <IMAGE>

Description

SPECIFICATION Computer peripheral device This invention relates to a computer peripheral device which can communicate both positional and symbolic information to a computer system. Typical applications for such a device are where graphical information is being manipulated but requires a significant amount of alpha-numeric annotation and qualification, for example in the following fields: -Computer Aided Design (CAD), -Computer Aided Drafting, -Word Processing, -Video graphics, -Television subtitling.

There are many types of transducers available for translating positional information into coordinates for input into a computer system. Such instruments, called 'digitisers', have naturally found wide use in Map making and Drafting applications. With the increasing penetration of CAD in industry developments have taken place in the man-machine interface in order to facilitate the task of such computer users. This has been reflected in the emergence of an International Standard which formally describes the way graphical interaction workstations should be implemented. The terminology of the standard, 'The Graphical Kernel System (GKS)' ISO/DIS 7942, will be used hereafter.

A popular interaction technique with CAD type computer programs is through the use of a 'puck' or 'mouse', both of which feature a hand sized, mobile enclosure, which can move freely over an ordinary or special flat surface adjacent to the user's computer display or terminal. In contrast to the traditional way of using a digitiser, it is the relative movements of the puck or mouse which are important, rather than its absolute position. The puck is an adaptation of the accurate digitising 'tablet' technology where the puck enclosure moves over a special surface from which signals are received to derive positional information.The mouse is a more recent development in which the mobile enclosure contains the transducers that derive the positional information, usually relative to its last position.Either may contain extra keys that the user may press to 'locate' a position or 'pick' items on the screen once movement has finished. Both the mouse and puck are functionally the same and hereafter the generic term 'mouse' will be used. A mouse is a physical instance of a device which can readily fulfil the functions of the GKS Input Devices 'locator', 'pick', 'choice', 'valuator' and 'stroke'.

To use a mouse, the user grasps it with a hand, positioning the fingers over any button or keys that may be needed for locating or picking. On the user's screen 'echoing', typically using a cross-hair cursor, provides visual feedback, the 'echo' moving in a manner which follows the directions and extent of travel of the mouse. Once the echo is positioned correctly, a key on the mouse is pressed to communicate a location or effect one of the other GKS input functions. Thus the essential and attractive feature of the mouse is that during operation the user does not need to move the eyes away from information presented on the screen.

Many forms of graphical interaction also involve the communication of alpha-numeric as well as positional information. Hereafter the more general term 'symbol' will be used to refer to alpha-numeric and other symbolic information. To communicate such information to the computer a 'string' device, such as a conventional QWERTY keyboard, must be used in conjunction with the mouse. This involves repositioning the hand between mouse and keyboard which is very difficult to do quickly without visual assistance. Alternatively, to avoid repositioning the hand, 'menus' may be presented on the screen from which the user selects, using the mouse to effect menu choices.However, if the symbolic information is from a large or indeterminate vocabulary then menu selection is not an efficient input technique for experienced users.

It is an object of the present invention to provide an improved form of computer peripheral device and which-enables communication of both positional and symbolic information to a computer system without the user needing to move the eyes away from the computer display with which the user is interacting.

According to the present invention there is provided a computer peripheral device comprising one or two hand-sized mobile enclosures each having a plurality of finger-or hand-operable keys or switches, hereafter called simply 'keys', arranged to perform the dual functions of (a) a GKS string device, such as a OWERTY computer keyboard, and (b) a GKS non-string input device, such as a mouse, said keys being arranged on each enclosure for single-handed operation and enabling communication of both positional and symbolic information to a computer system without the user needing to move the eyes away from the computer display with which the user is interacting.

The device according to the present invention combines the facilities of GKS string and non-string input devices and thus enables one-or two-handed operation of a computer system, called hereafter the 'host', which demands both positional information and alpha-numeric, symbolic and function qualifying information such as would in the absence of the present invention by typically supplied by a QWERTY computer keyboard and a mouse.

Preferably said keys are suitably positioned on each enclosure for comfortable operation by the fingers of each hand. Additionally some keys or switches may be operable by the manner in which the enclo sure(s) are held, as will be presently explained. The part of the device comprising the set of keys is called hereafter the 'device keypad'. Singly key presses, or combinations of key presses, on the device keypad cause symbol codes to be generated or the state or mode of the device to change.The action of pressing either a single key or a combination of keys, followed by the releasing of at least one thereof, is called hereafter a 'stroke'.

The device works in two modes, reflecting the requirement to perform the dual functions of (a) a GKS string device and (b) a GKS non-string device.These are termed the "string mode" and 'position mode' respectively.

It will be understood that the interface to the host comprises at least two logical data streams: a) The 'symbol stream', which bears the codes corresponding to the key stroke combinations when the device is in string mode or in position mode; and b) The 'digitising stream', which bears the positional information from the device when in the position mode of operation.

Though logically separate, the streams may be multiplexed onto a single physi#cal data path to the host. A particular instance of this is when the positional information is transmitted as 'cursor control' codes such as would generated by a conventional computer keyboard with cursor control keys.

The device further comprises the following parts: a) The device keypad subsystem, which interprets the key presses on the device keypad in terms of symbol codes or mode changes.

b) The digitiser subsystem, which translates the motion of one (or both) of the enclosures into a suitable digitisation information stream for the host, typically as coordinate. pairs or cursor control codes.

c) The interface to the host and other subsystems such as ancillary controlling electronic circuitry and a power supply.

The hand sized enclosure(s) may be large enough to contain all the subsystems mentioned to fulfil all the functions of the device. However, it may be more practical or convenient to divide the subsystems between further enclosures.

Communication with the host using one hand is possible using the device described in this invention.

In this instance the device keypad is wholly contained within a single, mobile enclosure from which the symbolic and positional information is derived. This enclosure is termed the 'mouse keypad' and is normally operated using the dominant hand, such as the right hand for a right-handed person. If specifically single-handed operation of the device is- not required, advantage of the other hand may be- made to increase the effectiveness of the device. A second enclosure containing an 'auxiliary keypad' will be used in this instance. The mouse keypad and auxiliary keypad, if used, together comprise the device keypad.

Though it is not necessary for the auxiliary keypad to be involved in the generation of the positional information for the host, instances of the device may choose to use the position of both enclosure to derive data for the digitising stream. A second digitising stream may be generated from the position of the auxiliary keypad if desired.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings and tables in which: Fig. I shows a first mouse keypad key arrangement; Fig. 2 shows an alternative mouse keypad key arrangement; Table 1 enumerates the keypad combination sets; Fig; 3 shows a keypad state diagram; Table 2 lists recommended use of the key sets; Fig. 4 illustrates an implementation of a mouse keypad Fig. 5 shows an implementation of the device for use with two hands; Table 3 lists recommended use of the keys for a two-hand device An essential feature of the mouse keypad element of the device is that it is to be operated by one hand. Since the fingers are the most agile part of the hand, these are used in the most efficient manner possible compatible with the vocabulary of symbols in use.The particular symbol set of interest in this document is that used in English text and in computer languages and interaction as enumerated in the ISO 646 7-bit code standard.Some applications may not involve the communication of the aforementioned type of texts and utilise restricted subsets of the ISO 646 symbols or non-standard symbols. The design of the keypad and its use in these situations should be in accordance with the guidelines below in order to optimise its effectiveness.

In general, the device keypad comprises a set of m keys operated by the fingers of the hand(s). The m keys may be distributed over the mouse keypad and auxiliary keypad or reside solely on the mouse keypad, as in the single-handed instance of the device. A symbol is communicated by pressing and then releasing a combination of these m keys in a stroke. A 'keycode' must be devised for each in the set of n symbols in use in which one or more strokes will be necessary to communicate a chosen symbol. The average time to make the necessary finger positioning and the strokes for the rth symbol in the set is t(r).

The keypad is to be used to communicate symbol sequences in which the statistical distribution of symbol usage will typically be unequal. This may be expressed by letting the rth symbol have a probability of occurrence in the sequences of p(r).The effectiveness of the keycodes chosen for a particular application can be judged by evaluating the average time to communicate a symbol T, given by the formula below.

Since the average speed of communication of symbols is inversely proportional to T, the keycodes should be chosen to minimise T.

In general, using the fingers of both hands, a stroke involves pressing up to ten keys, through in certain circumstances more keys can be involved (see below). The following formula gives the number of distinct strokes possible C on a keypad of m keys, each operable by one off fingers:

The strokes may be used to directly communicate the symbol required and/or change the state of the device.A particular use of the latter is to enable access to other symbol sets ('shift' sets). However, the penalty payed for this facility is that t increases for the range of symbols whose keycodes use this method. The requirement for shift sets can be reduced if more keys are used in the keypad, as becomes the case if an auxiliary keypad is used where f > 5.

In the instance of the device which uses only the mouse keypad, more combinations become available if m > 5. The extra keys would be grouped to facilitate positioning from one set to the other utilising spatial sensing relative to at least one fixed finger, or the palm of the hand, to take into account the mobility of the mouse keypad. The strokes available from-each additional set reduced by the number that apply to the shared keys alone, excepting the combination where no keys are pressed. Thus, with a keypad with the minimum of one shared key and alternate sets each comprising 4 keys, each alternate set offers a further 30 strokes. Using 2 shared keys and alternate sets of 3 keys, each set enables a further 28 strokes.

The use of more keys in the manner described above enables more unique strokes to be available if use is made of combinations between the key sets. These combinations comprise strokes which straddle key sets where at least one of the keys pressed belongs to one of the other sets of keys.

Other types of stroke include the use of the same finger to press two keys from differing sets simultaneously. Depending on the type of key layout this operation may require a different type of finger motion, such as-flattening the finger to make the tip cover both keys. Another technique is to exploit the order in which the keys are depressed whilst forming a stroke, though this may be difficult to utilise.

Other degrees of freedom, beyond that available from finger strokes, may be exploited to enhance the number of keycodes available. This is discussed below with particular reference to the manner in which the change between the string and position modes is effected.

A recommended mouse keypad comprises six keys as illustrated in the plan view in Figure 1. This layout and an alternative layout illustrated in Figure 2 are both intended for use as computer keyboard replacements for the communication of English and computer language type texts using one hand. The arrangement in Figure 1 is suitable for a right-handed person, the mirror image of the arrangement would be used for a left-handed operator. The keys marked F1 to F4 are positioned for easy use by the four fingers and those marked T1 and T2 are for operation with the thumb. The key T1 is normally positioned beneath the thumb and key T2 can be reached by slightly bending the thumb.Both T1 and T2 can be pressed simultaneously by laying the thumb flat over the two keys.

An alternative key arrangement is shown in Figure 2 whereby, instead of the shared finger keys F1 to F4, the thumb key T1 and little finger key F5 are shared. The remaining fingers are normally positioned on keys F1, F2 and F3 and may be crooked slightly further to position them on the alternate set F5, F6 and F7. The keys are positioned such that, for instance, F1 and F5 may be pressed simultaneously by the index finger alone.

Both the keypad layouts illustrated would be suitable for use as auxiliary keypads in their mirror image form. However it is likely that no more than the five keys, T1 and F1-F4, will be required for an auxiliary keypad.

The keys of the keypad are depressed in combination in order to identify the desired symbol or state/ mode change, which is then communicated to the host, if applicable. Table 1 categorises the various key combination sets that are used for the two mouse keypad styles. These sets are used in such a manner that the mouse keypad can generate at least as many symbols as the traditional, ten finger, computerstyle keyboard. Such keyboards are designed to generate codes which have symbolic interpretations according to the US ASCII or ISO 646 standards, whose cardinality is 128. The state diagram is shown in Figure 3 shows how this may be done. When the device is reset it always starts in the same state, state GO in the Figure.From thereon the user's key presses will cause it to change its internal state and/or send symbol codes to the host. The solid transition lines in the Figure denote a state change together with the emission of a symbol code, the particular symbol code being determined by the prior state. Dotted transition lines denote a change of state without the emission of a symbol code.

The symbols which are easiest to generate result from key combinations in from sets A and- B from states GO to 10. Thus, assuming that ordinary English text is to be generated using the keypad, set A should be used for alpha characters and the most popular other symbols, such as 'space', 'newline', 'fullstop' and 'comma'. Set B should be used for numeric characters, other popular punctuation and 'backspace'. The states OX and 1X are designed to mimic the effect of a keyboard alpha shift lock and as such the only difference between them is that the key combination set A produces lowercase symbols from state GO and uppercase from state 10.A single letter shift is available, either from lowercase to uppercase or vice-versa, from states 01 to 11 respectively.For ease of use there should be symmetry between the states# OX and 1X. An exception is introduced in that combination R will always 'reset' the keypad state If the user forgets the current state, easy recovery is possible without needing to look at any keypad status indications that may be available. Table 2 summarises the recommended mapping between the key combination pressed, the keypad state and the symbol code generated for use in the creation of English and types of text used in computer interaction.

The symbol code is generated and/or a state transition effected when the user positively releases at least one of the keys in the combination that has been selected. The code is added to the symbol stream and its interpretation by the host may be different depending on whether the device is in string mode or position mode.

The digitising part of the device may use any suitable techniques for position sensing. Because the mouse keypad is being used in a closed feedback loop whereby the user provides the corrections, the technique employed need not be repeatedly accurate. A digitising tablet may be used, though these usually feature a very high absolute precision which is not required in this application. The tablet, being of limited size, also limits the area over which the mouse keypad may be moved. Another method is to use a patterned surface over which the mouse can move, sensing and counting elements of the pattern as it moves using an optical technique. This suffers from the same limitation of the digitising tablet in that the active area of operation of the mouse keypad is limited by the extent of the surface.The recommended digitising method is an inverted 'tracker ball' mounted in the base of the mouse keypad. The ball rotates when it is in contact with the surface and the mouse keypad is moved.The movement is resolved in cartesian coordinates by orthogonally mounted shafts which are friction driven by the ball. Rotary encoders driven by the movement of each shaft produce the positional information required.

The remainder of the device is concerned with the generation of the two data streams for the host. The user must be able to control the mode of the device so that the keypad symbols are added to the correct data stream. In the instance of the device which has an auxiliary keypad, this may be simply arranged through use of one- of its keys. Alternatively, it may be a mechanical or touch sensitive switch positioned under the palm of the hand used for the mouse keypad or a switch operated by rocking the# mouse keypad. These type of switches may work (a) as conventional two state, (b) by momentary action in which activation changes the current mode, (c) the combination of either of the previous two and time or (d) the combination of any of the previous methods and the device state.

The rocking switch method of communicating the mode is particularly suited for the ball type digitiser.

If the digitising ball is suspended in a sprung mounting then the switch may be positioned over the ball mounting to sense when it comes into contact with the working surface. Thus, in order to signify operation in position mode, the user tilts the mouse keypad to engage the ball with the surface. As long as the ball remains in contact with the surface-the device remains in position mode, otherwise it returns to string mode.

Figure 4 illustrates a mouse keypad that uses the recommended key arrangement in Figure 1 together with the ball type digitiser. From the base of the mouse keypad two ballbearing type 'wheels' protrude (1). The 'heel' of the mouse keypad has a high friction surface (3) to brake the motion of the enclosure against the working surface on which it is being used (2). Also emerging from the base is the friction ball of the digitiser (4). On the top of the contoured surface of the enclosure (5) are mounted the finger and thumb keys (6). To operate the mouse keypad in the string mode the user causes the enclosure to rest ba#ck on- its heel, as shown in the Figure. To operate in the position mode, the enclosure is tilted forward to cause the digitiser ball to engage with the working surface.The enclosure is then free to move with both the ball wheels and the digitising ball able to rotate. The enclosure may contain as much of the ancillary electronic circuitry as is practical. It is likely that the physical data path to the host will comprise some cable (7) and power will need to be supplied via this or another cable.

It may be operationally more convenient to have position mode active when the mouse keypad is rocked back. In this instance the position of the digitising ball would be changed so that it protruded between the heel (3) and the ballbearing wheels (1). The motion braking friction surface would be positioned on the 'toe' of the device beneath the cable entry (7).

To facilitate connection to an existing computer system two physical data paths would be used, one for each data stream. The symbol stream would be transmitted in a form compatible with computer style keyboards, typically as an asynchronous, serial format using standard voltage levels (such as RS232 or TTL).The digitising stream would be similarly transmitted serially, but with the coordinate information formed into blocks. Each block would typically contain (a) the X-coordinate, (b) the Y-coordinate and (c) a block separator.

Figure 5 illustrates a device keypad layout that may be used for two-handed operation of the device.

For right-handed persons the mouse keypad would be held in the right hand and the auxiliary keypad in the left. For left-handed persons the mirror image arrangement may be preferred in order to exploit the ability of the dominant hand. Table 3 explains how the keycodes available in the two-handed version may be used in order to fulfil the desired functions of the device. This device has two keypad states in a manner corresponding to the position of the "alpha-lock" key a conventional computer keyboard. The mouse keypad is of the same design as illustrated in Figures 1 and 4 and mode control is effected via the ball switch as already described.

An example of how the device may be used in a typical application is given as follows. An operation that a user may wish to perform while interacting with a computer based drawing aid might be: -draw a box, using the 'rubber' box command, -fill the box with a colour selected from a menu, -place the title 'MOUSE' in the box using the default font.

The drawing aid program would display the current picture and menus on a colour display and the user would interact with the program using only a one-or two-handed instance of the device described. The operations required would be performed as follows: In position mode, the following: -move the cursor to the top, left hand point where the box is to start; -type the command code for 'rubber box' on the device keypad, e.g. R; -move the right hand, bottom point of the rubber box now being displayed until the box is of the desired -shape; -type the 'end operation' command code, e.g.

(or briefly leave position mode); -move the cursor to the colour menu and position it over the desired fill colour; -select the colour by typing the 'save colour 1' command code, e.g. 1; -move the cursor into the area inside the box; -type the command 'boundary fill with colour 1', e.g. F1; -move the cursor to the starting position for the title; In string mode, the following: -type the title 'MOUSE' on the mouse keypad.

The device is now ready for use in another graphical or textual operation.

TABLES Set Keys used in stroke: Id. Figure 1 Figure 2 A T1,F1,F2,F3,F4 T1,F1,F2,F3,F4 in any combination in any combination (31 strokes) (31 strokes) B At least one of T1,F5,F6,F7,F4 Fi,F2,F3,F4 with in any combination T2 always with either T1,F4 depressed depressed, excl.

(15 strokes) F5 alone (27 strokes) S T2 F5 R T1 and T2 F1 and F5 Table 1 States Key Set Symbol 01- > 00 A Uppercase aiphabetics, most frequent 10- > 10 punctuation, space, newline.

OO- > OO Lowercase alphabet ics, most frequent 11- > 10 punctuation, space, newline.

00- > 00 B Numbers, backspace, punctuation and 10- > 10 non-alphanumerics.

02- > 00 A,B Less frequent punctuation and 03- > 03 non-alphanumerics, special functions.

12- > 10 The particular symbol set used depends on 13- > 13 the shift set id given in 01- > 02, 11- > 12.

Table 2 Alpha Key# Set Symbol Lock used or State (Fig. 1,5) State chang (- > ) Off A Lowercase alphabetics, most frequent punctuation, space, newline.

On A Uppercase alphabetics, most frequent punctuation, space, newline.

Off A + F1' Uppercase alph#abetics, most frequent (+ T1') punctuation, space, newline.

On A + F1' Lowercase alphabetics, most frequent punctuation, space, newline.

On/ B Numbers, backspace, punctuation and Off non-alphanumerics.

On/ B + F1' Less used punctuation and Off non-alphanumerics.

On/ A + F2' Less frequent punctuation and Off or non-alphanumerics, control codes.

-B + F2' On/ A + F3' Special functions Off or B + F3' On/ T1' - > Alpha lock ON Off# and F1' Oni T1' - > Alpha lock OFF Off only Note: for "+ XX" read "with key XX depressed" Table 3 FIGURES follow

Claims (5)

1. A computer peripheral device comprises a mobile, hand-sized enclosure having a number of finger operable keys and a sensing mechanism for determining the extent and direction of motion of the enclosure over a surface, actuation of one or more of the keys in a chord combination being arranged to generate selection data selected from a code set, and the motion of the enclosure generates position data which augments the selection data, both these data being transmitted to a host computer in a manner which is discernable to the host computer as emanating from separate sources.

2. A computer peripheral device as claimed in claim 1, wherein a second enclosure with keys operable by the fingers of the other hand is connected to contribute to the chord combinations for the purpose of generating the selection data.

3. A computer peripheral device as claimed in claim 1 or 2, in which the addition of the position data to the output stream to the host computer is controlled by one of the finger operable keys of the mobile enclosure.

4. A computer peripheral device as claimed in claim 1, wherein a second enclosure with keys operable by the fingers of the other hand is connected to contribute to the position data by way of motion of the second enclosure.

5. A computer peripheral device substantially as hereinbefore described by way of example with reference to the accompanying drawings.