Cursor control device for 2-D and 3-D applications

A device for remote positioning and control of graphic representations of objects (e.g. cursors) projected on a computer screen or in a "virtual space", and for control of physical objects e.g. in robotics; comprising a finger-or hand-grippable member (2) resiliently mounted on a plate support (3) functioning as control elements, and means for determining the spatial orientation of the control elements relative to reference planes, utilizing laser beams and addressable sensor arrays (7); and further means for translating said position information to electronic signals indicative thereof, said signals being provided to an object control means.

The present invention relates to an input device intended for remote
 positioning and control of graphic representations of two- or
 three-dimensional objects (e.g. cursors) projected on a computer screen or
 in a `virtual space` created by visualising devices, and for control of
 physical objects e.g. in robotics.
 The most important reason why computer use is steadily increasing is
 probably related to the development of software which is generally
 applicable, in addition to a simplified interaction between user and
 hardware enabling the layman without special computer training to operate
 the system without any particular difficulties. In addition to the
 traditional data input and program activation via the keyboard, the user
 can now enter information and execute commands by selecting among menus
 and graphic symbols appearing on the computer screen.
 On present-day computers, this selection and execution is generally
 accomplished by use of several different input devices, of which the most
 popular are the mouse, the track-ball, the touch pad and the "pin-mouse".
 The electromechanical "grandfather" mouse was developed at Stanford
 Research Institute and is disclosed in U.S. Pat. No. 3,541,541. This mouse
 employs a pair of wheels that turn potentiometer shafts to encode X and Y
 motion into analog signals. Further development led to the employment of a
 ball or sphere instead of two wheels for more uniform tracking. In a
 typical "mouse" system, a hand-held transducer provides positional
 movement signals to the display system. Traditionally, the movement of
 wheels within the cursor control device are coupled to potentiometers to
 provide signals indicative of an X-Y position on the display screen (U.S.
 Pat. Nos. 3,304,434; 3,541,541; 3,269,190; 3,835,464; 3,892,963 and
 3,987,685). Other mouse systems utilise rotating balls on wheels which are
 in turn coupled to rotate apertures interrupting beams of light, thereby
 providing positional signals to the display system (U.S. Pat. Nos.
 3,892,963; 3,541,521; and 4,464,652). A trackball is similar to the mouse,
 but has the advantage that it can be incorporated in portable computers.
 Contrary to the mouse, however, this device remains stationary while the
 user rotates the ball with the thumb, fingers or palm of the hand.
 Examples of trackballs are shown in U.S. Pat. Nos. 5,122,654 and
 5,008,528.
 While these mice and trackballs have proved to be quite useful in
 performing display functions, they have not been outstandingly reliable,
 particularly over long periods of use. For example, the mechanical moving
 parts of the mouse, such as the balls and wheels, become dirty and slip on
 the work surface or pad, rather than provide continuous rolling action, or
 the commutators become dirty and skip. One goal in construction of new
 mouse varieties, therefore, has been to reduce the number of moving parts
 thereby eliminating the above mentioned mechanical disadvantages and
 providing a mouse with high reliability over long periods of time. One
 direction toward the goal of no moving parts is optical detection of mouse
 tracking functions. The concept of optical tracking, i.e., optical
 detection of an image, such as a track, lines, bars or grating, is not
 new. Examples of such tracking utilising one or more optical detectors are
 disclosed in U.S. Pat Nos. 3,496,364; 3,524,067; 4,114,034 and 4,180,704.
 However, none of these optical tracking devices disclose techniques
 suitable to perform the functions required in a cursor or object control
 device, i.e., they do not provide multi-directional tracking indicative of
 direction and amount of movement. U.S. Pat. No. 4,409,479 discloses a
 device which utilises optical sensing techniques to detect mouse motion.
 The output is indicative of the amount and direction of movement of the
 device relative to an orthogonal coordinate system. The device relies on a
 planar grid pattern comprising orthogonally positioned grid lines of
 uniform spacing. An alternative mode of optical tracking is described in
 U.S. Pat. No. 5,288,993 where a cursor pointing device includes a randomly
 speckled ball illuminated with diffuse lighting. An image of the
 illuminated area is focused by an optical element onto a photosensitive
 array. Logic associated with the photosensitive array determines movement
 of the ball across the array, and translates that movement into
 conventional cursor control signals supplied to a host system.
 Another direction toward the goal of few moving parts is magneto-electric
 detection of tracking functions. The European patent application EP
 0,539,599 describes a device that superficially looks like a trackball,
 and it is operated in the same manner. The device incorporates a
 dome-shaped slider with a strong magnet attached to the bottom surface.
 The housing is provided with a plurality of magneto-electric conversion
 elements. If the slider is slid, the magnetic flux density cutting across
 the magneto-electric conversion elements changes along with the output
 voltage. This change is used to control the position of the pointer. The
 described pointing device has furthermore means for changing from a
 position control to a speed control when the slider is moved beyond its
 confined sliding area. When shifting from positional control to speed
 control, the latest and the preceding positional information are used to
 find the vector between the two positions, and this vector is used for
 controlling cursor speed and direction. It is therefore not possible to
 change direction while using the speed control function.
 The trackballs and the dome-shaped slider are operated using the thumb,
 which is not by itself trained for precise movement. Other systems employ
 index finger control or incorporate finger-grippable control elements, and
 are thus providing better precision. U.S. Pat. No. 4,736,191 describes a
 device that incorporates a finger pad actuator mounted to a base so as to
 be movable in several directions. The position of the finger pad is
 sensed, e.g. by variable resistance potentiometers, and used to control
 the movement of a cursor or other image on a computer screen. U.S. Pat.
 No. 4,680,577 describes a multipurpose cursor control keyswitch that moves
 laterally to provide cursor control and that moves vertically for
 character entry. Sensors, e.g. strain gauges or pressure sensors, are
 coupled to the key cap for sensing the lateral movement. An almost
 identical keyswitch is described in PCT/US89/05662, comprising a key cap
 that is displaceable within the horizontal plane with one finger.
 Displacement of the key cap results in similar directional movement of the
 cursor; vertical force applied to the key cap activates an electric switch
 which corresponds to the "click" of a mouse button. Several different
 transducers are suggested as means for detecting the displacement of the
 key cap in the horizontal plane (strain gauge, optical detector,
 capacitor, inductor, and contacts).
 A specific limitation of many of the devices of the prior art is that the
 degree of precision control available is crude compared to the power and
 precision of the data processing devices themselves and detection of fine
 movements of the input devices is a particular limitation. Another reason
 for the lack of precision is that the devices are difficult to control
 because they do not conform to the user's ordinary motor skills and
 capabilities of the human musculature. The device described in U.S. Pat.
 No. 4,719,455 provides somewhat greater precision and conform more closely
 to the operator's motor skills, being operated by hand and finger
 movements, including both fine movement control and gross movement
 control. The assembly includes a graspable outer cover and an inner puck
 with a movable finger cup and a movement detector utilising a raster
 pattern created by a laser beam. Other prior art devices incorporate a
 single finger-grippable unit as a central control member. PCT/JP89/01148
 utilises a pen-like member to input characters and symbols. The member is
 moved on a surface, passing a plurality of pre-set detection positions.
 Several paths of action are defined beforehand and correspond to
 characters, symbols and processing commands. The device is not intended
 for cursor control. A similar device intended for input of characters is
 described in PCT/CA90/00022, comprising a plurality of switches adapted to
 be activated by a disk movable with the tip of a pen. The device described
 in U.S. Pat. No. 4,935,728 employs two modes of moving a cursor in
 correspondence with movement of a finger-grippable element, wherein one of
 the modes produces a cursor movement proportional to the movement of the
 finger-grippable element and the second mode produces cursor movement
 which is dependent upon the distance from an edge of the display area. The
 second mode can be called by a movement greater than a predetermined rate
 or at a position within an outer ring area of the pointer area of
 movement. The device utilises an opto-electronic system for movement
 detection, where light beams traverse gratings in transparent walls of the
 detector member and generate pulses concurrent with the movement in two
 dimensions. A similar photoelectric cursor controller is described in EP
 0,556,936, where a pair of plates slidably mounted for movement in two
 orthogonal directions contain gratings that create light pulses indicative
 of the extent of movement in the two directions. The plates are coupled to
 a finger-grippable control element.
 The present author has developed a cursor control device as described in
 PCT/NO94/00113, where the central control element is a finger-grippable
 member attached to a single plate support, to which there are connected
 two separate signal generating means. The first, constituting an
 electromechanical, roller-based system or an opto-electronic system based
 upon the use of reflecting grids, is connected to the plate support and
 will sense the plate movement in any direction in the X-Y plane. A plate
 movement will instigate a congruent movement of the screen cursor. The
 second means is connected to the grippable member, and will sense an
 applied, pivotal or lateral force, utilising pressure sensors or
 opto-electronic sensing devices. It is argued that this invention has many
 of the advantages looked for in an ideal cursor control device.
 The previously described devices are mainly intended to detect and convey
 motion within two dimensions. However, with the increased use of computers
 in representation and manipulation of information in three-dimensional
 space, attempts have been made to design devices that allow for control of
 objects in three dimensions. This is particularly true in the case of
 robotics, modelling, simulation, and animation of objects that are
 represented in either two or three-dimensional space. U.S. Pat. No.
 3,898,445 relates to a means for determining the position of a target in
 three dimensions by measuring the time it takes for a number of light
 beams to sweep between reference points and the target. U.S. Pat. Nos.
 4,766,423 and 4,812,829 disclose display and control devices and methods
 for controlling a cursor in a three-dimensional space by moving the cursor
 by use of joystick and throttle type devices to alter the direction and
 velocity of a cursor. U.S. Pat. No. 4,835,528 illustrates a cursor control
 system which utilises movement of a mouse device upon a two-dimensional
 surface that contains logically defined regions within which movement of
 the mouse is interpreted by the system to mean movement in
 three-dimensional space. An input device disclosed in U.S. Pat. No.
 4,787,051 utilises a mouse equipped with inertial acceleration sensors to
 permit an operator to input three-dimensional spatial position. U.S. Pat.
 No. 5,181,181 describes a mouse which senses six degrees of motion arising
 from movement within three dimensions. The device includes accelerometers
 for sensing linear translation along three axes and angular rate sensors
 for sensing angular rotation. The UK patent application GB 2,247,938
 describes a control device comprising a puck which slides on the surface
 of a platter, where the position of the puck is being detected
 capacitatively. The puck may also input pull push and rotatory information
 in addition to translational information, and it can thus be used for
 three-dimensional control.
 The aforementioned input devices have a number of limitations, deficiencies
 and drawbacks. The most important are the following:
 The movement of the mouse across a surface is guided by muscles that are
 not trained for very precise manoeuvring. Accordingly, the accompanying
 movement of the screen cursor is not particularly precise. While the
 mouse's precision is sufficient for most practical purposes, it is not
 very well suited for graphics and free-hand drawing. The mouse as a
 separate entity has furthermore limited applicability in conjunction with
 portable computers (laptops, notebooks, sub-notebooks and palmtops).
 Further, time is lost in ensuring precise positioning of the cursor over
 icons or symbols, in giving commands and in switching between keyboard
 input and mouse input. The ball and the rollers are easily coated with
 dirt, leading to an uncontrolled and erratic movement of the cursor after
 a short time in use. The movement of the hand guiding the mouse may
 furthermore cause injuries, particularly as a result of frequent use.
 Similar stress effects are seen with the touch pad (pointing pad).
 The track-ball and similar thumb-operated devices provide inaccurate
 movement of the cursor. It is, however, less subject to dirt and wear than
 the classical mouse, and is well suited for incorporation in portable
 computers.
 Finger- or hand-operated devices based on the joystick principle (e.g. the
 "track-point" and other keytop input devices) allow for rapid and
 unlimited movement of cursors. Although the operation may be simple and
 intuitive, such devices are not suitable for precision tasks.
 Detection systems used in prior art devices are not very precise, and do
 not conform with the precision demanded by modern computer displays, for
 control in virtual space and for use in robotics. Even previously
 described laser-based detectors do not fully utilise the potential for
 precision inherent in this technology.
 Prior art devices intended for multi-dimensional control lack the power of
 intuitive manipulation, and do not, by far, provide the precision needed
 for satisfactory object control e.g. in a three-dimensional, virtual
 space.
 Ideally, the input device should
 be sufficiently exact to be used for multi-dimensional operations and for
 graphical computer work,
 allow for rapid and continuous movement of an object or cursor across a
 computer screen or in a virtual space, and for rapid and precise
 positioning and repositioning of the object,
 be well suited for precise and rapid interaction with computers and
 programs via a graphical interface (menus, icons, etc.),
 be suitable for incorporation both in stationary and portable computers, in
 a way that the same technique can be applied for all types of hardware,
 allow for complete integration in a keyboard or computer chassis,
 allow for unlimited cursor movement,
 allow for rapid execution of commands
 require minimum changes of grip during operation,
 provide logical cursor response, i.e. object or cursor responds as
 intuitively expected in two or three dimensions,
 have good ergonomic properties,
 have few movable parts,
 be suitable for modular construction; i.e. should allow to be put together
 to satisfy different demands, and
 be simple, durable, hard wearing and inexpensive.
 The aforementioned device developed by the present author and described in
 PCT/NO94/00113 satisfies many of the above requirements, particularly
 because its main control member, the finger grip is handled according to a
 writing or drawing motion, and thereby utilises the high-precision motor
 skills of the hand, thumb and index finger in combination. However, the
 described embodiments of said invention do not fully exploit all potential
 control modes inherent in this device configuration. This is mainly due to
 the fact that the sensor systems employed do not allow a more extensive
 exploitation of control possibilities. This potential can only be realised
 if a totally different approach is taken to movement and position
 determination.
 Most control devices utilise the movement of a control member to generate a
 signal indicative of direction and speed of movement. So is also the case
 with the detection system associated with the plate support member
 described in PCT/NO94/00113, which will generate two pulse-trains
 accompanying the plate's movement in the X- and the Y-direction. The
 number of pulses generated in each direction, and the speed by which the
 pulses are generated will reflect the control member's speed and direction
 of movement. Such pulse-trains can easily applied for cursor control.
 Other movement detecting systems described in prior art are generally less
 accurate.
 These signal generating systems are not very well suited for use with more
 than two control modes; as a construction intended to accommodate several
 control modes will become very complicated, inaccurate and expensive.
 The new device classes developed by the inventor and presented herein, are
 based on a similar configuration of control elements as is described in
 PCT/NO94/00113. However, the new invention described herein makes use of
 two very important modifications: It utilises an entirely different system
 for position definition and control signal generation, and it exploits
 fully all possible control modes inherent in the handle and plate
 configuration, making it ideal for e.g. object control in three
 dimensions.
 Instead of having detector systems create a pulse-train or a variable
 analog signal based upon movement, position change or force, the present
 invention utilises a system for address-reading for exactly and
 unambiguously defining the position of the device's control members. In
 order to achieve this, the device utilises one or several reference
 planes, relative to which the control members' positions are defined. A
 prerequisite for this exact position definition, is that the reference
 planes are equipped with arrays of electronically addressable elements, or
 that each of these elements carries position information that can be read
 by a proper device. This is obtained in several ways, as described below
 for the various embodiments of the invention.
 The technologically simplest, and thus preferred class of embodiments
 utilises an array of light detecting units (photodiode arrays,
 charge-coupled devices, active pixel sensors, etc.) laid out on the
 surface of a reference plane, where each unit's position is identifiable,
 e.g. when hit by an incident laser beam. In another class of embodiments
 the surface of the reference planes are sub-divided into pixels carrying
 imprinted, engraved or magneto-polarised address information in digitised
 form. This address is read by means of a laser beam or another form of
 directed, condensed light or electromagnetic radiation. For simplicity,
 the term laser beam or light beam is used hereinafter to encompass all
 said forms of radiation.
 Pixel addresses on the surface of reference planes are employed both for
 congruent movement control and to define vectors used as basis for
 continuous, directed object or cursor movements.
 Whenever a control member change position relative to a reference plane,
 this movement is accompanied by a change of position of a laser beam
 striking said reference plane. Consequently, new light-sensitive units on
 the plane surface are being hit by the beam, or new pixel addresses are
 read from the reflected beam. Since each light-sensitive unit and each
 pixel has a unique address, this change of spatial orientation of the
 control members can be exactly defined, and the change of addresses can
 subsequently be used to induce a position change or a continuous, directed
 movement of objects that are subject to control, being it a screen cursor
 or a physical object. This is achieved by having a microprocessor
 transform change of addresses or vectors into pulse trains that define
 translocations in the objects' space, or by having a device driver
 interpret and transform address information directly. Techniques for
 handling address information associated with the device's control modes
 and making it usable for object control will be familiar to persons
 skilled in the art.
 The employment of specific address information for defining the spatial
 orientation of control members has several advantages over other systems.
 A certain position change need only be defined by the start and final
 addresses if the intermediary postitions are insignificant. However, if
 the track itself is important, the fine structure of the movement path can
 be determined by adjusting the frequency of address determination. The
 more frequent the address sampling, the higher the sensitivity and
 precision of the device operation. The sensitivity and precision of object
 control can thus be adjusted according to needs by adjusting the address
 sampling frequency. For this reason, it is also possible to increase the
 precision of object control by slowing down the speed of operation of the
 control members, this in contrast to systems where signal generation is
 associated with device movement.
 The described address-reading system can be used both for instigating a
 congruent movement of an object in response to a device movement (mouse
 operation), and to induce a continuous, vectorial movement (joystick
 operation). The latter is achieved by having control members' position
 addresses describe vectors, where the `normal` or relaxed position defines
 the start, and any off-set from this normal position defines the end of
 the vector. Thus, the direction and magnitude of the vector are defined by
 two sets of addresses.
 The device may also incorporate provisions for interpreting position
 changes of a control member differently, depending upon the degree of
 off-set from its normal position. A position change near the outer limit
 of its mobility range may e.g. instigate a more extensive movement of the
 object than changes near the control members' normal position.
 The described principle, where the point of impact of a laser beam upon one
 or more reference planes is used to define the spatial orientation of
 control members, can be implemented technologically in basically four
 different ways:
 First class: Employing reference planes equipped with light-detecting units
 (sensor array), each unit having a specific address. A device part
 responsible for directing laser beams towards each reference plane
 (encompassing laser, mirrors, lenses, focusing coils, etc.; hereinafter
 referred to as the beam director) is linked to the control member. A
 change of spatial orientation of the control member will alter the
 orientation of the beam director and its associated beam(s), and
 consequently the beam's point of impact on the reference plane. One
 reference plane is sufficient for defining the position of a multitude of
 control members, provided that the different beams can be identified as
 being associated with certain specific control members. This can be
 achieved either by relative position determination or by employing a
 system of sequential light emission from the different beam directors.
 Second class: Employing reference planes equipped with light-detecting
 units. The paths of the laser beams are fixed relative to the device,
 while the reference planes are linked to, or otherwise arranged such that
 a movement of the control members will change the position of the
 reference planes relative to the incident laser beams. A change of spatial
 orientation of a control member will consequently alter the beam's point
 of impact. This technical solution requires the use of several reference
 planes, depending upon the number of control modes employed.
 Third class: Employing reference planes with address-carrying pixels. Beam
 directors are linked to the control members. A change of spatial
 orientation of a certain control member will alter the orientation of the
 beam director and its associated beam(s), and consequently the beam's
 point of reflection from the reference plane. One reference plane is
 sufficient for position definition of a multitude of control members and
 their associated laser beams, provided that the different beam reflections
 can be identified as being associated with certain control members. The
 device also incorporates utilities for analysing beam reflections, e.g.
 single sensors associated with scanning devices, or sensor arrays.
 Fourth class: Employing reference planes with address-carrying pixels. The
 paths of the laser beams are fixed relative to the device, while the
 reference planes are linked to, or otherwise arranged such that a movement
 of the control members will change the position of the reference planes
 relative to the incident laser beams. This technical solution requires the
 use of several reference planes, depending upon the number of control
 modes employed. The device also incorporates utilities for analysing beam
 reflections, e.g. single sensors associated with scanning devices, or
 sensor arrays.
 The plate-and-grip configuration employed as control elements by the
 present invention has the potential of incorporating five control modes.
 These five modes are the following:
 1. Movement of the plate support in all directions in an X-Y plane (mouse
 operation);
 2. Pivotal movement of the handle relative to the plate support (joy-stick
 operation);
 3. Lateral movement of the handle relative to the plate support;
 4. Vertical movement of the handle relative to the plate support;
 5. Rotational movement of handle relative to the plate support.
 The mouse and the joy-stick are only utilising one of the described control
 modes for motion and position control, while PCT/NO94/00113 utilises two
 (1 and 2). However, the present invention can potentially utilise all five
 control modes simultaneously, and does therefore provide the capability of
 extensive control of objects in three dimensions: Mode 1 and 4 (and
 optionally 2 or 3) can be used for positioning of the object centre, 2 and
 5 for rotation, and 3 for scrolling or transposition of the reference
 frame. A more detailed description of the device's parts and operation is
 given below.
 According to the present invention there is provided an object control
 device comprising a finger- or hand-grippable member which is mounted on
 top of a plate support, the grip and plate together constituting the
 central control elements of the device. The grippable member has
 cylindrical shape with a diameter of b 3-50 mm and a height of 5-150 mm,
 preferably sculptured and coated with a suitable material for maximum
 handling comfort.
 The plate support is restricted in its movements to within a delimited area
 of a plane equivalent to a circle of diameter 5-100 mm; the area itself
 can have an arbitrary form, but the form is preferably circular. The plate
 support is defined to be in its `normal` position when the grippable
 member is located at centre of the delimited area. The grippable member is
 resiliently mounted to the plate support, permitting a simultaneous
 movement of the two control elements relative to stationary parts of the
 device, and at the same time allowing the grippable member to be moved
 relative to the plate support. Flexible collars, springs, pneumatic
 devices, etc. will automatically bring the grippable member back to a
 normal, preferred position relative to the plate support when not
 subjected to a directed force. It may also incorporate provisions that
 make the user sense when the grippable member attains its normal position,
 and utilities for preventing the grippable member induce object movement
 until the degree of off-set from said normal position has passed a
 threshold value.
 The five control modes described above are utilised as follows:
 1. Movement of the plate support relative to a stationary part of device is
 used for exact positioning and motion control of an object in the X-Y
 plane. The movement patterns of the support plate and the object are
 generally congruent;
 2. Bending of the grippable member in any direction relative to the plate
 support is used to elicit a continuous movement and to control the speed
 and direction of movement of an object in the X-Y plane; or alternatively,
 to induce and control the rotation of an object around an axis in the X-Y
 plane. The bending direction and inclination angle of the member relative
 to a normal position will determine the direction and speed of object
 movement or direction and speed of rotation;
 3. Lateral movement of the grippable member in any direction relative to
 the plate support is used to elicit a continuous movement and to control
 the speed and direction of movement of an object in the X-Y plane; or
 alternatively, being used for scrolling purposes whereby the frame of
 reference is transposed. The direction and the degree of off-set from a
 normal position will determine the direction and speed of object movement
 or direction and speed of scrolling;
 4. Lifting depressing the grippable member relative to the plate support is
 used to control the movement of an object along the Z-axis in a
 three-dimensional co-ordinate system, whereby the direction and degree of
 off-set from a normal position control the speed of movement in either
 direction along the Z-axis. Lifting depressing the grippable member may
 also be employed for switching purposes using three or four switch
 positions;
 5. Rotation of the grippable member clockwise or anti-clockwise relative to
 the plate support is used to rotate an object around the Z-axis. The
 device is constructed to allow one out of two possible modes of operation:
 1) In the first mode a normal position is defined, and clock-wise or
 counterclock-wise rotation is limited to within a certain sector; the
 direction and degree of off-set from the normal position defines the
 direction and speed of rotation; or 2) in the second mode the handle is
 enabled to rotate without limitations, and a rotation of the handle is
 accompanied by a congruent rotation of the object.
 The described control modes can be put together in any combination
 according to specific needs. The control modes can be utilised
 simultaneously and independently, although the lateral movement of the
 grippable member relative to the plate support is preferably executed
 while being pushed towards the outer edge of its mobility area.

more detailed description of the various parts of the device and different
 embodiments are given in the following:
 FIGS. 1 and 2 and illustrate the main components of the control device 1 in
 accordance with a preferred embodiment of the invention, consisting of a
 finger-grip 2 and a circular plate support 3 incorporated in a computer or
 device chassis 4. The diameter of the visible part of the support plate 3,
 which is approximately equal to the mobility range of the finger-grip,
 should be between 0.5 cm and 10 cm and is typically between 1 cm and 4 cm.
 Other embodiments of the invention may utilise other technical solutions
 where the plate support is partly or totally obscured, and where the
 relationship between the mobility range and the visible part of the plate
 is different from the one described.
 The control device is located in a recess in a keyboard (FIG. 3) or a
 computer top (FIG. 4) which has sloping walls giving room to grip the
 handle 2 and move it in all directions. A guide plate 36 (FIG. 2) together
 with the recess 4, creates a slot for permitting a guided, horizontal
 movement of the plate support 3.
 The finger-grip is resiliently mounted to the plate support using a
 particular attachment system enabling the grip to be moved in all
 directions relative to the plate, which, together with a flexible collar 5
 (FIG. 5)ensures that the finger-grip returns to a normal position after an
 off-set in any direction. Other attachment systems may be used to obtain
 the same effect.
 When in use, the finger grip is held between the thumb and the index
 finger, or the tip of the finger may rest on top of the grip. An
 horizontal movement of the hand and finger(s) will cause a corresponding
 movement of the plate support.
 As shown in FIG. 2, laser beams are generated and emitted from two
 beam-directing members (beam directors), 81 and 82, being aimed at the
 reference plane 7. (It should be noted that by using optical fibres, the
 laser itself may be localised elsewhere within the computer chassis). The
 reference plane contains on its surface an array of light-detecting units,
 providing an output signal that enables an analyser to determine the exact
 position of impact of the laser beams.
 The beam director 81 is attached to the plate support, and the path
 described by the beam's impact spot on the reference plane will thus be
 congruent with the movement path of the plate support itself.
 The beam director 82 is connected to the finger grip 2, and can thus be
 given a pivotal and a lateral movement relative to the plate support.
 Since the director 82 is connected to the cap of the finger-grip via a
 slideable piston, it can also be rotated and moved vertically by
 manipulating said cap.
 In the present embodiment two laser beams are used to describe the spatial
 orientation of the finger-grip. These beams may stem from one source,
 utilising a beam splitter (see FIGS. 7 and 8), or alternatively by
 employing two separate laser sources.
 The plate support incorporates a movement direction guide that will prevent
 the plate from being rotated. In this particular embodiment, the guide
 comprises two slots 35 located in the plate support, and two similar slots
 in the plate guide 36; the two pairs of slots being positioned at right
 angles to each other, and with two guide members 34 resting in both slots.
 Other guide principles may also be employed, and will be familiar to
 persons skilled in the art.
 FIG. 5 gives a more detailed description of the finger grip 2 and beam
 directors 81, 82 and 83. The finger grip consists of an outer cap 16,
 covered with a rubber-like material 23 for maximum handling comfort. The
 inner part of the finger grip consists of a piston 18 which is attached to
 the cap, and which can be moved vertically within a cylinder 17. The
 cylinder is equipped with a lip or protrusion 24 that limits the vertical
 movement of the piston. The cap can be pushed and pulled vertically, and
 will return to a "normal" position by means of two flexible rings 85 made
 of a durable, resilient material that will retain its original shape after
 deformation, or alternatively by springs or pneumatic devices. The beam
 director 82 is connected to the piston 18 via a smaller-diameter piston
 87. The piston 87 can be slid up and down and rotated in a bore in the
 centre of the ball-hinge 25, and can thus convey to the light-directing
 part vertical and rotational movements of the grip's cap. The ball-hinge
 further allows the finger-grip to be moved pivotally relative to the plate
 support, and at the same time providing a firm attachment of the
 finger-grip to the plate via a set of clamps 37. The finger-grip is
 further provided with a flexible collar 5 made of a durable, resilient
 material that will allow a certain degree of bending, but will re-locate
 the grip to a normal position after relaxation of the applied force. A
 bending of the finger-grip will thus cause beam(s) emitted from the beam
 director 82 to change direction. Beam director 81 is used for position
 determination of the plate support. This embodiment employs a third beam
 director 83 which is used for detecting lateral movement of the finger
 grip relative to the plate support. The beam director is directly attached
 to the clamps 37, and will not move relative to director 81 unless the
 grip and clamps change position relative to the plate support. This
 position change is allowed due to the presence of a flexible ring 29
 positioned between the plate and the clamps, making the clamps and finger
 grip return to a normal position after the lateral force is relaxed. This
 lateral movement can be instigated by e.g. arresting the plate with one
 finger, and pushing the flexible collar 5 sideways with another finger.
 Preferrably, this movement is accomplished when the plate and grip is
 positioned at the edge of their mobility range where a ring-formed stopper
 84 prevents further outward movement, at which time the collar and finger
 grip can be pushed further outwards in a particular direction.
 By using a resilient ring-formed stopper (84), the plate support may be
 forcibly displaced beyond its natural mobility range in any horizontal
 direction. Provided that addresses outside the normal, non-restricted
 range represent vectors instead of positions, this option is equivalent to
 the use of a lateral movement of the finger grip relative to the plate
 support as control mode.
 FIGS. 6 and 7 illustrate two beam directors, incorporating different
 combinations of lasers, focusing coils and reflectors that are employed in
 order to obtain the desired convergence, divergence, directioning and
 splitting of beams according to present needs. (The depicted lasers 90,
 focusing coils 88, reflectors 89 and beam splitters 94 are not
 neccessarily drawn according to actual proportions, but are merely acting
 as symbols to indicate their use in certain device members). Lenses,
 focusing coils, mirrors and other beam-modifying members may also
 substitute each other, without this being specifically indicated in the
 actual description. Such modifications and specific requirements will be
 familiar to persons skilled in the art.
 The beam director illustrated in FIG. 6 incorporates a laser 90 and a
 focusing coil 88 used for narrowing and directing the laser beam via the
 reflecting mirror 89 towards the reference plane. In FIG. 7, the coil is
 directing the beam towards a beam splitter 94 with a semi-penetrable,
 half-silvered surface. This arrangement will create two, diverging beams
 as shown in FIG. 8.
 The result of using two different beam directors as described above is
 shown in FIG. 9. The beam directors 81 and 83 will aim single beams of
 light at right angles relative to the sensor array 104, while director 82
 will produce two beams, one diverging from, and the other following the
 central axis A towards the reference plane 7. The resulting pattern of
 light spots occurring when the beams from the three directors hit the
 sensor array 104 with its individual light-detecting units 99 is shown in
 FIG. 10. Spot 95 stems from the plate-connected director, spot 98 from the
 grip clamps-connected director, and spots 96 and 97 stem from the grip
 piston-connected director.
 The distance between the impact spots where the two beams from director 82
 strike the reference plane will be dependent upon the beam director's
 distance from the plane. This effect is utilised for determining the
 vertical position of the finger grip relative to the reference plane, as
 illustrated in FIGS. 11 and 12. Here, the distance d1 between the impact
 spots 96 and 97 is increased to d2 after the grip is retracted, causing
 the piston 87 to move the beam director away from the sensor array 104.
 The use of different control modes are illustrated in FIGS. 13, 14 and 15,
 where FIGS. 13A-C show the effect of lifting and bending the finger-grip 2
 in a direction of P. The effect on the beams is shown in FIG. 13B, where
 the distance between B and C is slightly increased compared to a situation
 when being lifted vertically, due to the bending. This effect is taken
 care of by trigonometric computations, and is part of the position
 calculation performed by the control device's associated
 analyser/processor or by the device driver.
 FIGS. 14A-C illustrate the effect of rotating the finger grip an angle
 .alpha. counterclock-wise (approx. thirty degrees), while the grip
 otherwise attains a normal position.
 FIGS. 15A-C illustrate a composite-manipulation of the finger grip,
 utilising three different control modes. The grip is bent towards P,
 rotated an angle .alpha. counterclock-wise, and pushed laterally in the
 direction of T.
 FIGS. 16A and 16B illustrate that the size of the light-detecting units 99
 relative to the size of the beam impact spot 95 will affect the precision
 of the position determination, provided that the illumination of the
 individual units gives 1 (one) or 0 (zero) as result when compared to a
 treshold value.
 FIG. 17 summarises how address information associated with different
 control modes are used to control cursor or object movement. In general,
 the P-address is used to determine the object's position in an X-Y plane;
 i.e. a shift of address signifying a position change of the plate support
 will cause a similar position change of the object. Plate movement and
 object movement will normally be congruent.
 The C-address describes the inclination angle and the bending direction of
 the finger grip. The inclination angle defines the magnitude of a vector
 VC, which in size is equal to the length of line OC but points in an
 opposite direction from O. The line OC also defines the bending direction
 .beta. of the finger grip, being equal to .angle.POC-180.degree.. The
 magnitude of VC and .beta. are key parameters used for controlling the
 speed and direction of movement of an object, either around an axis or
 laterally in an X-Y plane. It should be noted that if G is moved from its
 normal position, C will move in an identical manner and the C-address will
 have to be corrected accordingly in all computations.
 The B-address describes, together with C the rotation and elevation of the
 finger-grip. The rotation is determined by the angle .alpha., equal to the
 angle between the lines PO and CB. The finger-grip's off-set from the
 "mid" (normal) position is described by R, being equal to the distance BC.
 By using trigonometric computations, a normal R value corresponding to the
 grip's mid position can be determined for every inclination angle and grip
 rotation, and any deviation from this normal value signifies and
 quantifies an off-set in -Z or +Z direction. The .alpha. parameter will
 normally be used for controlling the speed and direction of rotation of an
 object around a Z-axis, but can optionally be used to define the
 rotational position of same object, and to control rotation in a congruent
 manner. The R parameter is used to control speed and direction of movement
 along the Z-axis.
 The G-address signifies a lateral movement of the grip and its associated
 clamps relative to the plate support. The magnitude and direction of the
 vector VG is defined by the "normal" address (which is determined relative
 to P) and the off-set address. The VG parameter is used to control a
 continuous movement in an X-Y plane, or may be used for scrolling
 purposes. The direction and speed is determined by VG's direction and
 size.
 Neighbouring addresses will normally be equidistant in every part of the
 reference plane(s) and evoke a uniform response irrespective of control
 member position. However, the use of position addresses gives the extra
 benefit of assigning e.g. addresses near the border of the control
 members' mobility range different values and functions. For example may
 bordering addresses be used to define vectors (as basis for continuous,
 directed movement), while addresses within these borders have values and
 functions that will elicit a congruent movement of objects in response to
 control member movement. By modifying the address usage in this manner, it
 is possible to further extend the control potential of the device.
 As support for the above computations, the device incorporates utilities or
 utilises software for determining geometric parameters that describe
 shapes or patterns formed by laser beams when hitting the reference
 planes, such as area, position of geometric centre, axis lengths, radii,
 focal points, distance from a plane's origin, rotation angle, angle and
 direction of impact etc., based upon output from the individual
 light-detectors.
 The same general principles also apply for other embodiments, although
 several reference planes may be needed, and each control mode may employ a
 different number of laser beams for position identification.
 FIGS. 18A-C illustrate the effect of utilising the different control modes
 on the pattern of light spots created by beams from the three directors
 81, 82 and 83. FIG. 18A shows a "normal" situation, where the plate 3 is
 located in an arbitrary position in the X-Y plane as defined by its
 associated beam impact spot P. The position of the other impact spots C, B
 and G are described, both by their absolute addresses and their positions
 relative to the reference address P. In this illustration, their relative
 positions are described by P/C(X), P/G(X) and R. The impact spot C
 coincides with the point O where the grip/director's central axis A cross
 the reference plane when the finger-grip is located in its "normal"
 position.
 In FIG. 18B, the grippable member is lifted, increasing the diameter R
 between B and C, and at the same time the member is bent towards 4.30
 (clock position), directing the beam in the opposite direction towards
 10.30. Based upon the detected beam impact addresses P, B, C and G, the
 parameters P/C(X), P/C(Y) and R can be easily calculated by the analyser,
 and also derived information such as the vector OC describing the grip's
 inclination angle and exact bending direction, and also the grip's
 vertical off-set (Z axis position) which can be computed on the basis of
 R, OC and trigonometric relationships.
 The distance and position of G relative to P has not changed, and thus no
 lateral movement of grip relative to plate support has occurred.
 FIG. 18C illustrates a more complex situation, where the utilisation of
 four of the five control modes is resulting in composite position changes
 of the light spots. Besides the plate support attaining an arbitrary
 position in the X-Y plane as defined by P, the finger grip is rotated
 thirty degrees clock-wise and bent towards 10.30 (clock position) as
 defined by the position of B and C. At the same time the grip is moved
 laterally in a 4.30 direction relative to the plate support, as indicated
 by the position of G. All parameters can be computed on the basis of
 detected spot addresses, unambiguously defining the spatial orientation of
 the control members.
 Instead of using a two-component beam for determining the spatial
 orientation of the finger grip, other beam shapes and patterns can be
 used. Some of these are shown in FIGS. 19A-H, where FIG. 19A illustrates
 that the beam (or bundle of beams) should be divergent (or alternatively,
 convergent) in a direction away from the beam director. This can be
 obtained by proper combinations of lenses, beam splitters, screens and
 apertures (93 and 100) as indicated. Except for the circular pattern
 indicated in FIG. 19B (which is not suitable for measuring rotation angle
 when the grip is in a normal position), all patterns can be utilised for
 position determination for all previously described control modes.
 FIGS. 20 to 24 illustrate a second class of embodiments of the invention,
 where reference planes are connected to the control members and beam paths
 are fixed. A change of orientation of a control members is thus associated
 with a change of position of the reference planes, and consequently the
 beam's impact spot. This group of devices requires the use of several
 reference planes, and the construction is more complicated than for the
 class of embodiments described above. The main differences are associated
 with the beam-conducting system and utilities used for the positioning of
 reference planes. The operation of the five control modes are identical to
 operations described above. The use of an array of addressable,
 light-sensitive units on the surface of the reference planes is also
 identical to the sensor array described earlier. This class of embodiments
 can also make use of optical fibres for conducting beams from a laser
 source towards the reference planes, which may in many circumstances be
 preferred. However, in order to illustrate that the invention allows for
 other beam-guiding means, reflecting mirrors and lenses are utilised as
 beam guides in the following descriptions.
 FIG. 20 is a cross-section of the device, showing the finger grip 2, a
 laser 11, a beam splitter 12, a beam guide 13, a signal analyser/processor
 15, and one reference plane 7. The guides confining the plate movement to
 one plane and at the same time preventing the plate from being rotated are
 shown (3, 4, 34, 35 and 36). Reference plane 7 is attached to the device
 housing 6, and will determine the lateral position of the control members
 relative to the housing.
 FIG. 21 is a detailed cross-sectional view of the beam guide, also showing
 the coupling between the ball-hinge 25 and the reference plane 9
 incorporating a spring-loaded plunger positioned in a recess on top of the
 plane 9. A detailed view of this reference plane is given in FIG. 24. FIG.
 21 further illustrates that the beam guide encompasses beam-reflecting
 mirrors (43, 44, 45 and 46), directing the laser beams towards the various
 reference planes. The figure also indicates that the optical fibre 38
 responsible for conducting the laser beam to the grip's reference plane is
 held in position while at the same time being allowed to move vertically
 in a bore in the fastening clamps.
 A horizontal cross-section of the beam guide 13 is shown in FIG. 22, where
 11 represents the laser source, 12 the beam splitter, 50 the guide
 housing, 43-46 the mirrors, 8 and 9 are indications of the positions of
 the circular reference planes, and 15 the analyser/processor.
 FIG. 23 shows details of the beam splitter incorporating totally reflecting
 and half-silvered mirrors, generating four separate, parallel beams.
 FIG. 25 illustrates part of a representative of a third class of
 embodiments of the invention. This embodiment utilises reference planes
 with address-carrying pixels, demanding utilities for analysing reflected
 beams. Technologically, this embodiment is similar to the one described in
 FIGS. 20-24, with the exception that this device incorporates a reflecting
 mirror 42 and a light sensor or sensor array 14 capable of analysing light
 pulses or patterns of reflecting/non-reflecting areas in the pixel
 addresses. Beam paths, both of beams directed towards, and of beams
 reflected from the reference planes are illustrated in FIG. 26.
 Since light pulses are simpler to handle analytically than patterns, the
 device preferably incorporates a scanning utility, e.g. a provision that
 makes the laser beam scan defined areas of the reference planes, in
 combination with a timing device. Sequential scanning of reference planes
 will further limit the use of analysers to one single light sensor. Other
 similar or equivalent solutions will be familiar to persons skilled in the
 art.
 FIG. 27 gives an example of an address-carrying pixel 66, where X- and Y-
 co-ordinates are presented in binary form, separated by a non-reflecting
 area 70. The pixel has also a blank, reflecting border 69, separating it
 from its neighbouring pixels. The address is made up of a sequence of
 reflecting 67 and non-reflecting sub-units. The pattern, here considerably
 idealised, is prepared by laser-engravement, magneto-polarisation or
 deposition of a non-reflective material upon an otherwise reflecting
 surface. FIG. 28 illustrates an array of pixels 66. Reflecting sub-section
 may have the value of 1 (one), and a non-reflecting sub-section the value
 of 0 (zero); or alternatively other values depending upon the width,
 spacing and combinations of sub-sections.
 FIG. 29 illustrates the use of a "one-dimensional" address pattern,
 identifying X- and Y-co-ordinates by particular groups of reflecting and
 non-reflecting stripes positioned to the left of the digitised address. A
 one-dimensional laser scan 72 can be employed for reading this address.
 FIGS. 30 and 31 illustrate the use of two different switch options, where
 in FIG. 31 the switching function is coupled to a depression or retraction
 of the grip's cap, enabled through a coupling of the grip's piston to a
 micro-swithch 21; while in FIG. 32 the swithching function is performed by
 depressing a separate button 74, which can be done in any vertical
 position.
 FIG. 32 illustrates how the described invention can be used as basis for a
 hand-grippable device.
 FIGS. 33A-G illustrate the different modes of operation of the device. FIG.
 31A shows the device in its normal position. A computer monitor 77
 displays a hexagonal pyramid 78 positioned in a three-dimensional
 co-ordinate system 79. With the pyramid selected, a lateral (XY) movement
 of the finger-grip in X-direction will move the pyramid to the right, as
 shown in FIG. 31B. FIG. 31C illustrates the effect of a rotation (R),
 turning the pyramid around the Z-axis. Lifting the finger grip in positive
 Z-direction as shown in FIG. 31D will move the pyramid upwards. A pivotal
 movement (P) in a one o'clock direction will instigate a similar tilting
 of the pyramid, as shown in FIG. 31E, while a subsequent tilting movement
 in a three o'clock direction will cause a similar tilting of the pyramid.
 Finally, a lateral movement (L) of the finger grip relative to the plate
 support will instigate a scrolling movement, transposing the co-ordinate
 system (together with other, non-selected objects) to the left on the
 screen.