Abstract:
An auxiliary isometric computer pointing device for attachment to a P/S-2 mouse port connector along the right-hand side of the IBM ThinkPad laptop computer includes a TrackPoint IV pointing assembly, a mating electrical connector, a manually operated momentary switch, all enclosed in a compact, self-aligning enclosure. When provided with a suitable mouse driver, the laptop computer equipped with the auxiliary pointing device permits 3-D manipulation and alternative scrolling operations, independent of normal cursor positioning. The auxiliary pointing device derives operating power via the P/S-2 connector and provides a standard mouse output signal.

Description:
RELATED APPLICATIONS 
     This Application is related to a co-pending U.S. patent application Ser. No. 09/052,805 entitled “Low Noise Circuit Board for TrackPoint® Pointing Device,” filed on the same date as the present Application, also to co-pending U.S. Patent Application entitled “Force Transducer With Screen Printed Strain Gauges,” Ser. No. 08/181,648, filed Jan. 14, 1994, and to co-pending U.S. Patent Application entitled “Floating Triangle Analog-to-Digital Conversion System and Method,” Ser. No. 08/773,420, filed Dec. 27, 1996, all assigned to the International Business Machines Corporation. The disclosure of each related Application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention generally relates to information processing systems, and more specifically, to computer pointing devices used with graphical user interfaces. The invention has a particular applicability to the ThinkPad® line of laptop computers provided by IBM®, and the IBM TrackPoint® IV computer pointing device. (IBM, ThinkPad and TrackPoint are registered trademarks of the International Business Machines Corporation.) 
     BACKGROUND OF THE INVENTION 
     The IBM ThinkPad line of laptop computers includes an isometric pointing device embedded at a convenient location within the keyboard. This primary pointing device and related user operable momentary switches are used for manipulation of the computer&#39;s graphical user interface. 
     Each ThinkPad computer also includes a P/S-2 mouse port connector located near the rear along a right-hand side of the laptop enclosure. This connector permits a secondary pointing device to be attached for two-handed manipulation or for use by those who require a different type of manipulation device. The P/S-2 connector provides operating power and is compatible with a standard mouse output signal. 
     It would be desirable to connect a second TrackPoint IV pointing device to this connector without having to make the connection via a cable. What is needed is a compact, self-contained pointing device that can attach directly to the P/S-2 connector at the side of the ThinkPad computer. The secondary pointing device should derive operating power from the connector, and should provide a standard mouse output signal. The secondary device should be compatible with the ThinkPad computer primary device so that two-handed 3-D manipulation and simple document scrolling are easily and naturally accomplished. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a compact, self contained pointing device which can be connected to the P/S-2 mouse port at the right-hand side of each ThinkPad laptop computer. 
     This object is met by a computer pointing device including a user manipulation member; 
     sensors mechanically coupled to said member and providing sensor signals corresponding to user manipulation of the member, 
     a transform circuit connected to receive the sensor signals for transforming the signals to at least one pointing device output signal; 
     a device electrical connector adapted for mating with a compatible receptacle for receiving operating power and for transmitting the at least one pointing device output signal; and 
     a frame for supporting the user manipulation member, the sensors, the transform circuit and the device electrical connector in a fixed relation with respect to the compatible receptacle. 
     In a specific embodiment of the invention, this object is met by a computer pointing device including a mini-DIN, 6-pin male connector for making a compatible connection with the female receptacle of the P/S-2 mouse port; 
     a TrackPoint IV pointing device connected to the male connector for receiving operating power and supplying a standard mouse output signal; 
     at least one manually operated momentary switch connected to the TrackPoint IV pointing device for providing select, activate, drag-and-drop signals via the standard mouse output signal; and 
     an enclosure for supporting the male connector, the TrackPoint IV pointing device, and the at least one manually operated momentary switch in a fixed relation with respect to the female receptacle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the objects, features and advantages of the present invention, reference should be had to the following description of the preferred embodiment, taken in conjunction with the accompanying drawing, in which like parts are given like reference numerals and wherein: 
     FIG. 1 is a perspective view illustrating a laptop computer attached to a pointing device according to one aspect of the present invention. 
     FIG. 2 is a front view of the computer pointing device of FIG.  1 . 
     FIG. 3 is a left side view of the computer pointing device of FIG. 1 
     FIG. 4 is a top view of the computer pointing device of FIG.  1 . 
     FIG. 5 is a cutaway front view of the computer pointing device of FIG:  1   
     FIG. 6 is a side view of a TrackPoint IV computer pointing device as shown in FIG.  5 . 
     FIG. 7 is a block diagram illustrating another aspect of the present invention. 
     FIG. 8 is a schematic diagram illustrating details of another embodiment of a computer pointing device according to the present invention. 
     FIG. 9 is a top view, of another embodiment of a computer pointing device according to the present invention. 
     FIG. 10 is a front view of the computer pointing device shown in FIG.  9 . 
     FIG. 11 is a partial front view of a computer pointing device illustrating cooperation between the device and a laptop computer for maintaining a precise alignment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1 there is shown a perspective diagram of a pointing device, designated generally by the numeral  10 , attached along a right side  12  of a laptop computer  14  in accordance with one aspect of the present invention. The IBM ThinkPad line of laptop computers includes a mini-DIN, 6-pin female receptacle located near the rear along the right side  12 , in the approximate location of the pointing device  10  as illustrated in FIG.  1 . The receptacle (not shown) is compatible with a standard IBM P/S-2 mouse port for attachment of a computer pointing device. The receptacle provides operating power for the standard mouse pointing device and accepts an industry-standardized digitally formatted mouse-type input signal from the device. The present invention represents a variety of embodiments of computer pointing devices  10  for attachment to the receptacle along the right side  12  of the typical ThinkPad laptop computer  14 . 
     The standard ThinkPad laptop computer includes a TrackPoint pointing device embedded within the typing keyboard (not shown). When equipped with a standard mouse software driver, the laptop computer  14  sums the pointing commands of the embedded and the P/S-2 input for commanding cursor position. But when provided with specialized software drivers, the ThinkPad permits several alternative modes of operation using the separate pointing devices. Such alternative modes include: one of the pointing devices being used for cursor positioning and the other pointing device being used for scrolling; and the two pointing devices being used for 3-dimensional navigation in a virtual 3-dimensional space. 
     FIGS. 2-5 illustrate a preferred embodiment of the computer pointing device according to one aspect of the present invention. FIG. 2 is a front view of the pointing device  10  shown adjacent to the right side  12  of the ThinkPad laptop computer  14 . The laptop computer is represented by the broken line  14 . The pointing device  10  includes a mini-DIN, 6-pin male connector  16  which is compatible with the female receptacle (not shown). The pointing device  10  also includes a user manipulation member  18  extending above a top side, a manually-operated momentary switch  20 , located at a front side, and an enclosure  22  for supporting these components. 
     FIG. 3 is a left side view of the pointing device  10 , illustrating the male connector  16 , the manipulation member  18 , the momentary switch  20 , and the enclosure  22 . 
     FIG. 4 is a top view of the pointing device  10 , illustrating the connector  16 , the manipulation member  18 , the momentary switch  20 , and the enclosure  22 . 
     FIG. 5 is a cutaway front view of the computer pointing device  10  in which the enclosure is shown by the broken line  22 . The manipulation member  18  is shown as part of a TrackPoint IV assembly  24 . The connector  16  and the momentary switch  20  are connected to the TrackPoint IV assembly  24  via electrical wires, designated generally by the numeral  25 . 
     FIG. 6 is a side view of a TrackPoint IV assembly  24 , which includes the manipulation member  18 , strain gauge sensors  26 , a printed circuit card  27 , and electronic components including integrated circuits, designated generally by the numeral  28 . The assembly  24  is described in the related U.S. Patent Application entitled “Force Transducer With Screen Printed Strain Gauge.” But, in general, the circuit board  27  supports and interconnects the other components  28 , including the strain gauge sensors  26 . The manipulating member  18  is mechanically attached to the sensors  26 , forming an isometric pointing device in which pressure on the member  18  in three orthogonal axes produce corresponding electrical changes in sensor output signals. These sensor output signal changes are processed by the components  28  to provide the standardized mouse output signal. Operating power is obtained from the connector  16  (FIGS.  2 - 5 ). The momentary switch  20  (FIG. 5) provides an input to the assembly  24  and forms a portion of the standardized mouse output signal. 
     In typical operation, user pressure applied to the manipulation member  18  from side-to-side and forward-backward are used for cursor positioning. In one specific embodiment of the invention, pressure in a downward direction against the tip of the manipulation member is converted by the assembly  24  into a momentary switch signal and made a part of the standardized mouse output signal. In this specific embodiment, momentarily pressing in a downward direction and then releasing the tip of the manipulation member  18  is recognized by a mouse driver as operation of one standardized mouse switch. 
     FIG. 7 is a block diagram which illustrates another embodiment of a computer pointing device according to the present invention. The computer pointing device is designated generally by the numeral  30  and includes a user manipulation member  32 , sensors  34 , a transform circuit  38  providing an output signal  40  to a device electrical connector  42  for mating with a compatible receptacle (not shown). Operating power  44  for the sensors  34  and for the transform circuit  38  is derived from the compatible receptacle via the device electrical connector  42 . 
     The sensors  34  are mechanically coupled to the user manipulation member  32  for providing sensor signals  36  which correspond to user manipulation of the member. The transform circuit is connected to receive the sensor signals  36  and to transform the signals into at least one pointing device output signal  40 . In a specific embodiment, the user manipulation member  32  defines a control stick which is grasped by the user and manipulated in three orthogonal axes for producing changes in the at least one output signal described above with respect to FIG.  6 . 
     In another specific embodiment, the control stick and sensors define an isometric pointing device (see, for example the TrackPoint IV assembly  24  of FIG.  6 ). In an isometric pointing device changes in the sensor output signals  36  are proportional to pressure applied to the user manipulation member  32 ; the member itself moves only an imperceptible amount in response to an applied pressure. 
     In a specific embodiment the computer pointing device  30  includes a frame ( 22  of FIG. 5) for supporting the user manipulation member  32 , the transform circuit  38 , and the device electrical connector  42  in a fixed relation with respect to the compatible receptacle (see, e.g., FIG.  11 ). 
     FIG. 8 is a schematic diagram which illustrates a computer pointing device according to another aspect of the present invention. The computer pointing device is designated generally by the numeral  50  and includes a control stick  52 , sensors defining a strain gauge assembly defining a bridge network  54  coupled to the control stick  52 , strain gauge output signals  56 , ramp circuits and comparators  58 , orthogonal strain signals  60 , ramp control signals  62 , a micro-controller  64 , a pair of manually operated momentary switches  66 ,  68 , and an output signal  70 . 
     FIG. 8 illustrates a preferred embodiment of the electrical circuit of the computer pointing devices defined by the invention. Though not shown in FIG. 8, operating power for the pointing device is derived from the female receptacle via the male connector ( 42  of FIG.  7 ). The ramp circuits and comparators  58  and the micro-controller  64  correspond to the transform circuit  38  of FIG.  7 . 
     The specific operation of the circuits  58  and  64  in converting the strain gauge output signals  56  to a standard mouse output signal  70  is described in related U.S. Patent Applications entitled “Force Transducer With Screen Printed Strain Gauge,” and “Floating Triangle Analog-to-Digital Conversion System and Method.” In general, the low level analog strain gauge output signals  58  are converted to three orthogonal digital signals. The duration of each of the digital signals is proportional to a pressure applied by a user to the control stick  52  along one of three defined orthogonal axes. Generally, the two axes correspond to the horizontal and vertical axes of a computer display, and a third axis is typically reserved for use as an additional momentary switch, as described above. The micro-controller  64  uses the ramp control signals  62  to control the conversion process. In general, the control stick  52 , the strain gauges  54 , the ramp circuits and comparators  58 , and the micro-controller  64  define the TrackPoint IV assembly  24  of FIG.  6 . 
     The computer pointing device illustrated by FIG. 8 includes two momentary switches  66  and  68 . The switches a connected to the micro-controller  64  for controlling predetermined bits of the digitally formatted standard mouse output signal  70 . In a specific embodiment, only a single momentary switch is present. In another specific embodiment, a single momentary switch is present, and the Z-axis of control stick manipulation is encoded to provide a second momentary switch, as described above. Other combinations of separate momentary switches  66 ,  68  and use of the Z-axis manipulation will be apparent to a person of ordinary skill. 
     FIG. 9 is a top view of another embodiment of a computer pointing device according to the present invention. The computer pointing device is designated generally by the numeral  80 , and includes a user manipulation member  82 , first and second manually operated momentary switches  84 ,  86 , a mini-DIN, 6-pin male connector  88 , and an enclosure  90 . In a specific embodiment, the computer pointing device  80  includes a TrackPoint IV assembly ( 24  of FIG.  6 ), a manipulation member of which extends through an opening  83  in the enclosure  90  as the user manipulation member  82 . The two momentary switches  84 ,  86  correspond to the two momentary switches  66 ,  68  of the schematic diagram shown in FIG.  8 . In a typical operation, the user manipulates the member  82  with a finger tip for positioning a computer cursor, and uses the two momentary switches  84 ,  86  as left and right mouse buttons. 
     FIG. 10 is a front view of the computer pointing device  80  of FIG. 9, showing its relative alignment with a laptop computer  92  to which it is connected. 
     Finally, FIG. 11 is a partial front view of a specific embodiment of a computer pointing device, designated by the numeral  100 . FIG. 11 also illustrates apportion of a laptop computer  102 , a mini-DIN, 6-pin male connector  104 , a mating female receptacle  106 , and a vertical stabilizing member  108 . 
     The mini-DIN, 6-pin connector series includes a mechanical detent between the male connector  104  and the female receptacle  106 . The detent is illustrated by the opposing vertical arrowheads  110 ,  112 . The effect of the mechanical detent is to create a moderate force which resists a disconnecting of the mated male and female elements  104 ,  106 , once these elements have been mated. In a specific embodiment of the computer pointing device  100 , the vertical stabilizing member  108  is not present (FIG&#39;S  2  and  10 ). In this embodiment (FIG&#39;S.  2  and  10 ) the right-hand side  114  of the laptop computer  102  cooperates with the left-hand side  116  of the computer pointing device  100  and the mated connector elements  104 ,  106  to maintain the computer pointing device  100  in a fixed relation with respect to the female receptacle  106 . The cooperation between the sides  114 ,  116  is illustrated by horizontal opposed arrowheads  118 . 
     In another specific embodiment, the computer pointing device  100  includes the vertical stabilizing member  108  located on a top surface  120  of the pointing device  100 . The member  108  is located along a left-hand edge of the top surface  120  and is fixedly attached thereto. A portion of the member  108  extends above and in sliding contact with a portion of a top surface  122  of the laptop computer  102 . The member  108  cooperates with the top surface  122  to assist in further stabilizing the pointing device  100  in a precise alignment with respect to the female receptacle  106  and the laptop computer  102 . The cooperation between the member  108  and the top surface  122  of the laptop computer  102  is illustrated by opposed vertical arrowheads  124 . 
     While the invention has been described in relation to the embodiments shown in the accompanying Drawing figures, other embodiments, alternatives and modifications will be apparent to those skilled in the art. It is intended that the Specification be exemplary only, and that the true scope and spirit of the invention be indicated by the following Claims.