Portable computer with trackball mounted in display section

A pointing device according to the present invention includes a trackball embedded in the case of a computer display. The trackball is placed adjacent to the display and the select buttons for the trackball are located on the backside of the display case behind the trackball. The user guides the trackball with his thumb and pushes the select buttons on the backside of the case with his index and middle fingers, allowing the user to operate the pointing device with only one hand. Alternatively, the trackball is embedded in the corner of the keyboard of a desktop system, with the select buttons on the opposite side of the keyboard behind the trackball. With the keyboard standing on legs, the user's fingers can reach the two select buttons opposite the trackball to operating the pointing device.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention generally relates to pointing devices used with computer 
systems, and more particularly, to a trackball for use with portable 
computers and capable of being embedded in portions of the computer. 
2. Description of the Related Art 
The tremendous growth of the computer industry in recent years has been 
accompanied by advances in both computer hardware and software. Computers 
have become more convenient to use and so affordable that many individuals 
now own personal computers. As computer systems have developed to become 
more accessible to personal users, software has also evolved into complex 
programs that are simple for a relatively untrained user to operate. To 
maximize user comfort and familiarity, much of the current software is 
graphics oriented, using icons and pointers to allow the user to choose a 
desired application. 
Pointing devices provide a simple interface between users and graphics 
oriented applications, allowing the user to indicate what he wants by 
merely pointing to it on the display. A user can initiate a program by 
simply moving the cursor to the desired option and pressing a select 
button. As the program runs, it provides the user with more options 
represented on the display of the computer, and the user directs the 
execution of the program using the pointing device. 
For desktop computers, a mouse is the most common pointing device, as it is 
reliable and easy to use. A mouse is a device moved about a flat surface 
while the cursor on the display follows the movement of the mouse. In many 
mice a ball located on the bottom of the unit is in contact with the 
desktop or a mouse pad and rolls when the mouse is moved. This rolling is 
converted into X and Y values and provided to the computer. In addition, 
mice have one, two or three buttons for indicating user selection. The 
buttons are typically located on the top side of the mouse. 
Other pointing devices include trackballs, which are essentially mice with 
the ball and buttons facing upward; digitizing pads; force sensitive keys; 
and touch screens. Most of these items are generally not integral parts of 
the computer, but are made by other manufacturers to be used in 
conjunction with the computer system. As a result, most pointing devices 
comprise separate units apart from the computer system. 
Consequently, a mouse or other common pointing device is not particularly 
well suited to a portable computer. Powerful systems are now available in 
portable units no larger than a thick notebook and can operate in almost 
any environment. But for portable systems, such as laptop and notebook 
computers, any extra equipment that has to be carried with the computer 
decreases the system's portability. Ideally, the user would only have to 
transport the computer itself. A conventional mouse, however, is a 
relatively large device, employs a long cord, requires a surface on which 
to roll, and is not an integrated part of the computer. Other pointing 
devices share these and other problems. 
The shortcomings of pointing devices in a portable system have usually been 
addressed by using trackball devices. The device's size has been reduced 
and the cable shortened to improve the device's compatibility with a 
portable system. To use the device, it is usually attached to the side of 
the computer case next to the keyboard, and plugged into a connector at 
the back of the computer during operation. The size of these devices has 
been reduced. Although these improvements are helpful, they only reduce 
the problems associated with a mouse or trackball without eliminating 
them. A smaller mouse with a shorter cord still needs a relatively wide, 
flat area to operate, and a trackball clamped to the side of the computer 
remains a hindrance that must be carried with the computer and generally 
disconnected for travel. 
Several computer systems used embedded pointing devices. Computer keyboards 
are available which use a miniature trackball mounted in one corner, with 
the trackball and the buttons facing upwardly. Another keyboard embedded 
pointing device is a small touch pad located at one end of the keyboard. 
In its Powerbook series of laptop computers, Apple Corporation has mounted 
a trackball and two arc-shaped buttons below the space bar on the 
keyboard. An alternative design used in some portable computers is the 
Isopoint (TM) unit. The Isopoint design is basically a cylinder which 
rotates axially and slides longitudinally, the cylinder mounted below the 
space bar. Buttons flank the cylinder or the entire cylinder can be 
depressed. In yet another variation, one manufacturer is providing a 
"wobble key." One special key on the keyboard is designed so that it not 
only can be depressed, but also can be moved or pivoted in four 
directions, thus providing X and Y movement. The Apple and Isopoint 
designs have the problem of requiring increased space below the keyboard, 
an area already highly cramped in notebook computers. The wobble key 
requires a very complicated key and is not necessarily highly sensitive or 
intuitive. Conventional integrated designs also occupy relatively large 
amounts of space because of the ball and buttons being accessible from 
only one side. 
Thus the known pointing devices are either too large and cumbersome for use 
if not integrated, require undesirably large amounts of space in 
integrated designs or are simply not considered sufficiently accurate and 
usable. 
SUMMARY OF THE INVENTION 
A pointing device according to the present invention permits the user to 
operate an intuitively simple pointing device comfortably, with the device 
being integrated with the computer and yet not enlarging the size of the 
computer. In the preferred embodiment, a trackball is embedded in the 
housing of the display. The trackball is placed adjacent to the display 
and facing the user, preferably near the lower right hand corner, and the 
select buttons for the pointing device are located on the backside of the 
display housing behind the trackball. To use the pointing device, the user 
guides the trackball with his thumb and pushes the select buttons on the 
backside of the housing with his index and middle fingers. In addition, 
because the user's hand is in a natural position as if it were lightly 
gripping the side of the display case, a pointing device according to the 
present invention offers improved accuracy and simplicity to the user. 
Because the user's hand can rest on the side of the base section, the 
placement of the pointing device in the display part of the case further 
reduces the discomfort and fatigue suffered by the user. In addition, with 
the trackball closer to the display and oriented in the same plane as the 
cursor, movement of the trackball correlates more intuitively to the 
movement of the cursor. Locating the trackball in the display section of 
the computer further eliminates the need to make room for the pointing 
device in the already crowded base section of a laptop or notebook 
computer. Unlike a separate mouse or trackball, the embedded pointing 
device also eliminates the extra piece of hardware to be carried with the 
computer and requires no space for manipulation. 
In an alternative embodiment, a trackball is embedded in the keyboard 
section of a desktop system. Preferably, the trackball is embedded in the 
top side and upper right hand corner of the keyboard, with the select 
buttons on the opposite or bottom side of the keyboard behind the 
trackball. With the keyboard standing on its legs, the user's fingers can 
reach the two select buttons opposite the trackball to operate the 
pointing device. Like the portable computer embodiment, this design 
improves user comfort and maximizes the useability of the pointing device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIGS. 1 and 2, a portable computer system C, like a 
notebook or laptop computer incorporating the present invention is shown. 
The portable computer C includes all of the capabilities and features of a 
desktop unit. Portable computers, however, are relatively light and 
compact, and can operate using rechargeable batteries. The portable 
computer C generally comprises two sections which are hinged together on 
one side. A base section 10 includes a keyboard 12 and most of the 
computer system components and the power supply circuitry, including the 
rechargeable batteries. Floppy and fixed disk drives and peripheral ports 
are also located in the base section 10. The top section 14, on the other 
hand, includes a generally parallelepiped-shaped housing 18 which contains 
a display 16 visible through an opening in the housing 18 and display 
control circuitry. Because the display 16 is generally a liquid crystal 
display (LCD), backlighting is required to provide a contrasting 
background for the darker images on the display 16. Thus, the top section 
14 also includes backlighting circuitry to generate light behind the 
display 16. The display 16 and the other components are encased in a rigid 
plastic housing 18 joined to the base section 10 of the computer C. The 
computer C opens so that the display 16 stands generally upright while the 
base section 10 rests flat on a surface. 
The top section 14 further includes a trackball 20 embedded in the housing 
18 of the top section 14. Moving the trackball 20 causes the cursor to 
move about the display in the same direction as the trackball's motion and 
at a proportional speed. A shallow recess 22 is formed in the front of the 
housing 18 near the display 16, and the trackball 20 is placed in the 
deepest part of the recess 22. The recess 22 is deep enough to prevent the 
trackball 20 from protruding beyond the plane of the display 16, allowing 
the computer C to fold together without hindrance from the trackball 20. 
Optimally, the trackball 20 is the width of an ordinary hand from the 
bottom of the display housing 18 and the length of an ordinary thumb from 
the side. At this location, the trackball 20 is positioned where the 
ordinary user's thumb would naturally be with his hand resting on the base 
section 10 and wrapped around the top section 14. The trackball 20, 
described in further detail below, rolls relatively freely within a socket 
36 (FIG. 7) behind the recess 22, and is held in the socket by a retaining 
ring 40. 
Referring now to FIGS. 3 and 4, the portable computer C further includes 
two select buttons 24, 26 for designating particular points on the display 
and providing various other information to the system, generally 
duplicating the buttons found on two button mice. The exact function of 
the select buttons 24, 26 depends upon the program being executed. The 
select buttons 24, 26 are placed on the backside of the display housing 
18, opposite the display 16, and one select button 26 is located directly 
behind the trackball 20. Thus, the trackball 20 is positioned so that the 
user's thumb can rest on the trackball 20, while his hand wraps around the 
outside of the display housing 18 and his index and middle fingers rest on 
the two select buttons 24, 26, respectively. To prevent damage to the 
buttons 24, 26 during transport and for aesthetic purposes, the buttons 
24, 26 are mounted so that their outside surfaces are flush with or 
recessed below the outside of the top section 14. 
It should also be noted that the trackball 20 and the select buttons 24, 26 
can be located anywhere along the outside of the display housing 18. The 
top section 14 generally includes, however, display backlighting circuitry 
27 which generates significant electromagnetic noise which can adversely 
affect the operation of an unshielded pointing device. Consequently, the 
pointing device and its connecting wires must be electromagnetically 
shielded to prevent interference. 
Referring to FIG. 6, a top view similar to FIG. 4 is provided. The 
trackball 20 is shown to be not centered between the display 16 and the 
edge of the top section 14 but is located closer to the edge of the top 
section 14. 
Referring now to FIG. 7, a trackball pointing device D of the preferred 
embodiment is shown having two select buttons 30, 32 mounted opposite a 
trackball 20. The trackball 20 can be rolled in any direction and the 
cursor moves correspondingly on the display. In the preferred embodiment, 
the pointing device D employs an optical trackball, as opposed to a 
mechanical trackball. The pointing device includes the trackball 20 
mounted within a socket 36 formed in a receiving plate 38, and is held in 
place by a retaining ring 40 which is held over the top of the trackball 
20 and attached to the socket to prevent the trackball 20 from falling out 
of the socket 36. Preferably, the trackball 20 is eleven millimeters in 
diameter, suitable for movement by the user's thumb. Inside the socket 36, 
the receiving plate 38 includes four rollers (not shown) on which the 
trackball 20 rests. When the trackball 20 is moved, the rollers rotate. 
The ends of two of the rollers are parts of separate optical systems to 
determine how fast and how far the trackball 20 rolls on each roller. From 
this information, the vertical and horizontal direction and speed of the 
cursor's intended movement can be determined and provided to the graphics 
software. 
The receiving plate 38 for the trackball 20 is attached to a circuit board 
42. The circuit board 42 includes all of the circuitry required to detect 
movement of the rollers caused by the trackball 20 and provide the data to 
the pointing device input of the computer C. On the opposite side of the 
circuit board 42, the select buttons 30, 32 are positioned within switches 
44, 46 attached to the underside of the circuit board 42. Each switch 44, 
46 is connected to the circuitry mounted on the circuit board 42 to allow 
the user to designate specific cursor locations on the display and 
interact with the system. The select button 30 is received by a mating 
location in select button 26, while select button 32 is received by a 
mating location in select button 24. Thus depressing select button 26 
activates switch 44 and depressing select button 24 activates switch 46. 
The preferred embodiment can easily be adapted to suit a left-handed user. 
As shown in FIG. 8, the portable computer C can simply be designed with 
the trackball 20 in the lower left corner, with the select buttons 24, 26 
located directly behind it. In an alternative embodiment, the pointing 
device is a removable module that can be placed, at the user's choice, on 
either the left side or the right side of the display housing. To change 
the system, a left-handed user removes a panel from the left side of the 
display case, disengages the pointing device from its position on the 
right side of the display housing, and exchanges the positions of the two 
pieces. The system is designed to respond to the trackball 20 in either 
location. 
Placing the trackball 20 near the display 16 offers several advantages. For 
graphics oriented software, easy and natural use of the pointing device is 
an important feature of the computer C. On the other hand, although a 
mouse is simple and easy to use, it is a nuisance and impractical for 
portable computers. Embedding the trackball 20 in the top section 14 
provides a practical substitute for a mouse without a separate piece of 
hardware or the need for extra space. In addition, the trackball 20 is 
oriented in the same plane as the plane in which the cursor moves, so that 
movement of the trackball 20 in a particular direction in relation to the 
top section 14 moves the cursor in exactly the same direction. 
Consequently, movement of the trackball 20 correlates more intuitively to 
the movement of the cursor. The location of the select buttons 24, 26 
behind the trackball 20 allow the user to operate the pointing device with 
one hand and minimum effort, reducing discomfort and fatigue. 
In an alternative embodiment, the embedded trackball may be adapted to a 
desktop system. Referring now to FIGS. 9 and 10, a trackball 50 is 
embedded in the upper right-hand corner of a computer's keyboard 52. 
Similar to the first embodiment, select buttons 54, 56 are placed on the 
underside of the keyboard 52 directly behind the trackball 50. The user 
operates the select buttons 54, 56 by reaching under the keyboard 52 with 
his index and middle fingers and placing his thumb on the trackball 50. 
The select buttons 54, 56 are more accessible using a conventional pair of 
legs 58 on the underside of the keyboard 52 for propping the keyboard 52 
towards the user. As in the preferred embodiment, the trackball 50 can be 
placed on either the left side or the right side of the keyboard 52, 
depending upon the user's preference. 
For desktop systems, embedding the trackball 50 in the keyboard 52 offers 
many of the same advantages as in the portable version. With the trackball 
50 on the keyboard section, all of the user input interface devices are 
located near the keyboard 52. A separate mouse unit, which requires space 
and adds to the clutter of equipment, is no longer necessary for graphics 
oriented applications. 
The above disclosure and description of the invention are illustrative and 
explanatory thereof, and various changes in size, shape, materials, 
components, PG,13 circuit elements, wiring connections and contacts, as 
well as in the details of the illustrated circuitry and construction, may 
be made without departing from the spirit of the invention.