Rotational X-axis pointing device

A pointing device provides a rotating member for rotatably adjusting a location of a cursor, a volume level, display settings, or other variables. The pointing device includes a control arm which a user can manipulate to make a button selection. The pointing device combines the button selection and rotational adjustment into a single apparatus. The device is sized to be comfortably used by one hand, and can be mounted within a mouse, a keyboard, or a monitor. The pointing device can be used alone, or can be used to augment a mouse, a trackball, or a touchpad.

FIELD OF THE INVENTION 
The present invention relates generally to computers. More particularly, it 
pertains to pointing devices for use with computers. 
BACKGROUND OF THE INVENTION 
A number of computer screen cursor or pointing control devices have been 
developed in recent years which allow the user of a device to selectively 
position the cursor in use at any X,Y coordinate pair on a computer screen 
or plotting device or any such graphical display. 
The central feature of previously available trackball-type mechanisms is 
the use of an individual sphere which is supported on bearings permitting 
rotation of the sphere in any direction about a central point. Motion 
detection devices are biased against the sphere which permit detection of 
sphere movement. The detected sphere movement is converted into X-axis and 
Y-axis components which are then utilized to reposition a cursor. 
It has also been typical of this art to invert the trackball mechanism 
permitting the sphere to be suspended from the bottom of a housing. The 
sphere or trackball is then rotated by movement of the housing about a 
suitable surface capable of providing frictional contact with the 
trackball. Movement of the housing then generates movement of the 
trackball which is then converted into X-axis and Y-axis components 
utilized to reposition the cursor on the computer screen. This form of 
trackball control device is typically referred to as a mouse. 
The trackball-type device and the mouse-type device present a number of 
problems to computer users. The mouse-type control device presents the 
drawback of requiring a surface of adequate size to permit movement of the 
mouse about an area sufficient to direct the cursor into all areas of the 
computer screen. If the space available is of insufficient size it is 
necessary to lift the mouse from the surface and reposition it in order to 
continue to move the mouse in the selected direction to achieve complete 
movement of the cursor or pointer across the entirety of the computer 
screen or plotter device. The unavailability of such sufficient surface 
area during travel has prompted increased use of the trackball-type device 
with computers. 
Another type of conventional screen display control apparatus only controls 
adjustment by the direction in which an adjustment lever is tilted. When 
different kinds of functions are to be controlled, an adjustment member 
other than the adjustment lever must be operated. The adjustment lever 
must be spaced apart from the other adjustment member to a certain extent 
due to the restriction resulting from an operating space and design. As a 
result, operators must move their hands and fingers in a complicated 
manner to continuously control a plurality of kinds of functions. 
Another approach to pointing devices is the IntelliMouse, made by 
Microsoft, Inc. The IntelliMouse is an inverted trackball arrangement as 
discussed above. In addition a clicking wheel is providing for scrolling 
up and down. However, the clicking wheel of the IntelliMouse is limited to 
a scrolling mechanism. 
Technology and its resulting software development is becoming more and more 
sophisticated. Computer storage continues to increase, thereby permitting 
larger, more powerful software programs. The number of parameters has 
risen, and the method of selection has become more complex. Consequently, 
the range and capability of selection devices must simultaneously become 
more sophisticated. 
Accordingly, what is needed is a single device capable of selection 
adjustment. What is further needed is a device which can accommodate more 
complex software programs. 
SUMMARY OF THE INVENTION 
A rotational pointing device is provided comprising a support arm pivotally 
mounted for pivoting about a fulcrum point. The device has actuating 
assemblies proximate to the end of the support arm. In one embodiment, the 
actuating assemblies comprise a set of micro switches. A rotating member, 
having a slip resistant surface on its outer perimeter edge, is mounted on 
one end of a control arm. The control arm extends from the fulcrum point 
to the axis of the rotating member. A position sensor is mounted near the 
rotating member, and monitors the amount of rotation of the rotating 
member. The position sensor includes an LED coupled with a photo diode. 
The LED and photo diode are oppositely disposed with the rotating member 
in between. The rotating member has holes which alternate blocking and 
passing light during movement of the rotating member. Computer users can 
move or adjust a cursor or a value of a parameter by rotating the rotating 
member. The user can also make a selection by tilting the control arm such 
that actuating members contact the micro switches. 
The pointing device also has resilient members disposed near the support 
arm for returning the pointing device to a neutral position after 
actuation. In one embodiment, the resilient members are helical springs 
disposed beneath the support arm. 
The pointing device can be used exclusively for a pointing and selection 
device. In another embodiment, the device can be used in conjunction with 
other conventional pointing devices, such as a mouse or a trackball. The 
pointing device can be mounted within a mouse, a keyboard, a portable 
computer, a monitor, or other devices.

DESCRIPTION OF THE EMBODIMENTS 
In the following detailed description, reference is made to the 
accompanying drawings which form a part hereof, and in which is shown by 
way of illustration specific embodiments in which the invention may be 
practiced. These embodiments are described in sufficient detail to enable 
those skilled in the art to practice the invention, and it is to be 
understood that other embodiments may be utilized and that structural 
changes may be made without departing from the spirit and scope of the 
present invention. Therefore, the following detailed description is not to 
be taken in a limiting sense, and the scope of the present invention is 
defined by the appended claims. 
The present invention provides a rotational pointing device having integral 
selection capabilities. The pointing device can be used in conjunction 
with known mouse or trackball devices. Alternatively, the pointing device 
can be used exclusively on a monitor, a keyboard, or a portable computer. 
One embodiment of the pointing device is shown in FIG. 1. Generally, the 
pointing device 10 is comprised of a support arm 20, actuating assemblies 
30, a control arm 40, a rotating member 50, and a position sensor 60. More 
particularly, the support arm 20, in one embodiment, has a generally 
triangular shape, with a first end 24 and a second end 26. However, other 
shapes are within the scope of the invention. For instance, the support 
arm could be fabricated in an elongate structure. 
A generally center point of the support arm 20 is rotatably mounted at a 
fulcrum point 22 such that the support arm 20 rotates over the fulcrum 
point 22. Disposed on the first and second ends 24, 26 of the support arm 
20 are actuating assemblies 30. The actuating assemblies 30 sense the 
pivotal movement of the support arm 20 and permit a user to select a 
predetermined option shown on a computer screen or similar device. The 
actuating assemblies 30 have resilient members 32 disposed thereunder for 
returning the support arm 20 to a neutral position relative to a base 
surface. In one embodiment, the resilient members 32 are helical springs, 
although other devices providing a return mechanism to the support arm 20 
could be used. Alternatively, one resilient member could be disposed at 
the fulcrum point 22 for returning the support arm to the neutral 
position. 
In another embodiment, the actuating assemblies 30 disposed on the first 
and second ends 24, 26 of the support arm 20 are actuating members 36. 
Proximate to the actuating members 36 are micro switches 34. One example 
of micro switches 34 for use with the invention is manufactured by 
Digikey, Part No. SW505-ND, although equivalent types of switches could 
also be used. When the support arm 20 is pivoted a desired amount about 
the fulcrum point 22, the actuating members 36 mechanically activate the 
micro switches 34. The helical springs 32, the micro switches and 
respective actuating members 34, 36 are positioned and sized such that the 
helical springs 32 do not interfere with the contact of the switches and 
actuating members 34, 36. 
The control arm 40 extends away from the fulcrum point 22 of the support 
arm 20. At a distal end 44 of the control arm 40, the rotating member 50 
is rotatably mounted at its axis 54. In one embodiment, the control arm 40 
has a pronged portion 42 and the rotating member 50 is mounted therein. 
The pronged portion 42 extends to a length sufficient to permit full 
movement of the rotating member 50 about its axis 54. 
The rotating member 50 is generally formed in a thin disc shape, although 
other shapes are contemplated by the scope of the invention. In another 
embodiment, the rotating member 50 is a wheel component having a rubber 
material disposed on an outer perimeter edge surface of the wheel 
component 52. Alternatively, the rotating member is provided with other 
types of slip resistant surfaces, such as a knurled or grooved surface. 
The rotating member 50 has a position sensor 60 mounted proximate to the 
rotating member 50, such that the amount of revolution can thereby be 
monitored. The position sensor detects the rotation of the rotating member 
and converts the measurement to an electrical signal. The signal is then 
communicated to a computer. 
The position sensor 60, in one embodiment, is comprised in part of a 
light-detecting element, such as a photo diode 64. The position sensor 60 
is also comprised of a light-emitting element, such as an LED 66. As shown 
in FIG. 2, the rotating member 50 has a plurality of apertures 62 therein. 
The apertures 62 are spaced substantially equally apart around the axis 54 
of the rotating member 50. The LED 66 is positioned in line with the 
rotating member 50 on a first side, proximate to the apertures 62. The 
photo diode 64 is mounted on a second side of the rotating member 50 near 
the apertures 62, and is also positioned towards the rotating member 50. 
The LED emits a light towards the rotating member 50, and when separated 
by an aperture, the photo diode 64 receives the light emitted by the LED. 
Although a photo diode and LED have been described as one embodiment of 
the position sensor 60, other detection mechanisms are known in the art 
and are contemplated by the scope of the invention. The position sensor 60 
need only be responsive to the plurality of apertures 62, or other types 
of indicia in order to track movement of the rotating member 50. For 
instance, rotating member 50 could be coupled with a magnetic coil sensor, 
which detects rotation of the rotating member 50. 
The rotational pointing device 10 is mounted in a housing 80. As 
illustrated in FIG. 3, the housing 80 has a cut out 78 for receiving the 
rotating member 50. The rotating member 50 extends through the housing 80, 
as shown in FIG. 2, sufficient to permit manipulation by hand. The length 
of the cut out 78 is sized such that the rotating member 50 can be 
revolved about its axis unobstructed by the housing 80. The width of the 
cut out 78 is sized such that the control arm 40 can be tilted over the 
fulcrum point 22, and the respective micro switches can make contact 
without interference from the housing 80. 
The rotational pointing device 10 can also be mounted in other devices or 
other types of housings. As shown in FIG. 4, the pointing device 10 is 
mounted in a keyboard 84. In one embodiment, the device can by utilized in 
conjunction with a touchpad 86 for providing additional control. In 
another embodiment as shown in FIG. 5, the pointing device is mounted in a 
monitor 82. In yet another embodiment, illustrated in FIG. 6, the pointing 
device 10 is mounted in a portable computer 88 for use in conjunction with 
a trackball 90. 
During operation, a user places a hand over the pointing device when 
modification or selection is desired. Irrespective of the type of 
mounting, the user rotates the rotating member for adjusting a level or 
scrolling through documents and the like. As the rotating member 50 
rotates, light from the LED 66 is alternatively blocked and transmitted 
through the rotating member 50 and received by the photo diode 64 
depending on whether one of the plurality of apertures 62 separates the 
LED 66 and the photo diode 64. 
When a user desires to make a selection, the user tilts the control arm 40 
using the portion of the rotating member 50 extending from the particular 
housing 80. The support arm 20 is then tilted in the direction selected by 
the user, and one of the actuating members 36 actuates one of the micro 
switches 34. When the rotating member 50 is released, the corresponding 
resilient member, or helical spring 32, returns the control arm 
automatically to a neutral position. 
If a user wishes to click-and-drag, a term known by those skilled in the 
art, the user tilts the control arm 40 using the rotating member 50 as 
described above. While holding the rotating member 50 in a tilted 
position, the user rotates the rotating member 50 to select the desired 
amount. The user then releases the rotating member 50, which then returns 
to a neutral position. 
The present invention advantageously provides a pointing device which 
operates from a fixed location, and avoids the need to move the control 
device location to bring about movement to the cursor. The device controls 
cursor movement or level control and button actuation in a single user 
control. Furthermore, the device can augment or replace conventional 
navigational aids. Integrated into a mouse-type housing, a keyboard, a 
portable computer, or a monitor, the device is comfortable for 
single-handed use by a user. 
The device would provide additional navigation methods for users and can be 
used with various on-screen displays. For instance, the pointing device 
could be used for browsing the internet or scrolling within web sites. In 
word processing software, the wheel rotation could be used to scroll up or 
down a document. The pointing device could also be used as a volume mixer 
where the wheel rotation adjusts the volume level of master or secondary 
volumes after selection by the control arm. For menus, the pointing device 
could be used to navigate a system of cascading control menus for any 
application. 
A user could change the behavior of the pointing device within a graphical 
or other type of interface, or disable the device. Since the apparatus can 
be used in combination with other devices, such as a trackball, a mouse, 
or a touch pad, the apparatus can also accommodate the increased 
sophistication of selections provided in present and future software 
programs. 
It is to be understood that the above description is intended to be 
illustrative, and not restrictive. Many other embodiments will be apparent 
to those of skill in the art upon reviewing the above description. The 
scope of the invention should, therefore, be determined with reference to 
the appended claims, along with the full scope of equivalents to which 
such claims are entitled.