Method and apparatus for performing power conservation in a pointing device located on a wireless data entry device

A remote control input device for use with a computer system is disclosed. The remote control input device typically includes means for wirelessly connecting the remote control input device to the computer system, a trackball, coupled to the connecting means for manipulating a pointing icon displayed on the video monitor, and a power source that powers the remote control input device. The remote control input device further includes a power management means for managing the power of the power source by monitoring the status and activity of the trackball used on the remote control input device. The remote control input device typically includes a first set of keys that provide input to the computer system and a second set of keys that are assigned to the trackball that control the pointing icon manipulated by the trackball. Additionally, the remote control input device may be a keyboard type arrangement with a trackball attached and first and second wrist wings can be located adjacent on either side of the keys typically below the key set in order to provide adequate support of the wrists during operation.

BACKGROUND 
1. Field of the Invention 
The present invention relates generally to power conservation methods and 
devices and, more particularly, to a wireless data entry device operating 
under battery power, thus requiring improved power conservation 
techniques. More specifically still, the present invention relates to a 
pointing device having a multi-level power conservation method and 
apparatus that is responsive to activity caused by the pointing device or 
by any other input key associated with the pointing device used in a 
personal computing environment. 
2. Description of the Related Art 
Personal computers ("PC's") have become a standard fixture in many of 
today's households. PC's also have the advantages of performing many tasks 
or functions that have been typically performed by other household 
appliances. For example, a PC typically includes a monitor and with a 
television tuner within the PC, the monitor can serve as a television. 
Furthermore, PC's typically include CD ROM players, which double as 
compact disk audio players. Since PC's marry several of the same functions 
and features typically found in other common electronic appliances, such 
as televisions and audio equipment, a convergence of the PC with the 
television set or the audio equipment moves the PC out of the home study 
and into the living room. Just as televisions and audio equipment now 
include remote control devices, typically wireless remote control devices, 
for operating the appliance, PC's now use wireless keyboards and remotes 
with pointing devices for operation and user input. 
With these keyboards and pointing devices, consumers will come to expect 
the same ease of use and carefree operation as the electronic remotes 
typically associated with their current video and audio equipment. 
Unfortunately, pointing devices within personal computers that are battery 
operated typically have a higher power consumption relative to the 
standard remote control used in today's television systems. This is 
because of their proactive nature to monitor constantly for use input in a 
variety of ways. Solutions to this problem have occurred in the past, but 
are lacking in that they generate other problems that also must be 
overcome. 
It is well-known that power conservation is significant when working with 
wireless devices since they rely on batteries for power source. If the 
pointing device, typically a trackball, remains active at all times, the 
battery life typically expends within a few days. Most consumers would 
find this unacceptable, as they do not wish to replace batteries every 
couple of days. Most consumers would be willing to use a device that was 
able to prolong the battery life for several months and, preferably, at 
least a year. 
One type of method of providing power conservation is to use a mechanical 
switch to turn the pointing device on and off. One disadvantage of using a 
switch to activate the pointing device is that it is inconvenient for the 
operator to remember to turn the device on or turn the device off, 
especially when finished with the computer. Further, switching the remote 
on and off is something that is not required with a standard remote 
controller or keyboard. Thus, it is counterintuitive for a user to 
actively turn on a switch on a pointing device used with either a 
television or a computer system. 
SUMMARY OF THE INVENTION 
According to the present invention, a remote control input device is 
disclosed for use with a computer system. The remote control input device 
typically includes means for wirelessly connecting the remote control 
input device to the computer system, a trackball, coupled to the 
connecting means for manipulating a pointing icon displayed on the video 
monitor, and a power source that powers the remote control input device. 
The remote control input device further includes a power management means 
for managing the power of the power source by monitoring the status and 
activity of the trackball used on the remote control input device. The 
remote control input device typically includes a first set of keys that 
provide input to the computer system and a second set of keys that are 
assigned to the trackball that control the pointing icon manipulated by 
the trackball. Additionally, the remote control input device may be a 
keyboard type arrangement with a trackball attached and first and second 
wrist wings can be located adjacent on either side of the keys typically 
below the key set in order to provide adequate support of the wrists 
during operation. 
The power management means further includes an active monitoring means that 
checks the trackball activity continually. The power management means 
further includes several sleep levels. The device selects the sleep level 
based on the amount of time the device has been idle. Typically, these 
preselected levels are three levels that are whether the trackball been 
left idle for more than twenty seconds, whether the trackball has been 
idle for more than ten minutes, or whether the trackball has been idle for 
more than thirty minutes. Based on the particular level of idleness, the 
system powers down the micro device for either activation every half 
second, every one second, or every two seconds, thereby preserving battery 
life in the remote control device. 
This remote control input device may be used in not only a computer system, 
but also in a video monitoring system that includes a video monitor and a 
display output controller. 
The power management device operates according to the method of determining 
whether the trackball pointing device is active, idle or asleep, then 
selecting a level based on the period of idleness of the trackball 
pointing device, and then reducing the power used by the remote controller 
by curtailing monitoring of the trackball pointing device according to the 
sleep level. The method automatically determines the activity of the 
trackball pointing device by sensing user input or by determining that a 
button has been pressed. If there is no activity of the trackball, or the 
button associated with the pointing device for a specified period of time, 
the system enters the Level 1 sleep mode, which means the trackball is 
checked once every half second for activity.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to FIG. 1, a diagram of a computer system 10 incorporating 
the present invention is shown. The computer system 10 is based on a 
computer 12 and includes a set of user interface devices to allow the user 
to provide data to and receive information from the computer system 10. In 
particular, the computer system 10 includes a display 14, which is the 
primary output interface component from the computer 12 to the user. 
For user-to-computer interfacing, a keyboard 16 is coupled via an infrared 
(IR) transceiver unit 18 to the computer 12 to allow the user to enter 
data and direct the execution of the software. When keys on the keyboard 
16 are struck, the keyboard 16 generates a set of signals that indicate 
which keys have been depressed. If a key has been depressed, the keyboard 
16 of the computer 12 compatible with the IBM PC generates a unique "make" 
code corresponding to the depressed key, and conversely, when the key is 
released, the keyboard 16 sends a specific "break" code. Therefore, to 
enter a character or execute a function, the user operates the keyboard 16 
to generate unique make and break signals that are received by the 
computer 12, which then enters the data or initiates the function 
according to the signal combination received. 
As the user enters data into the computer 12, the data is shown on display 
14. A wireless mouse 18 is then used to designate data for manipulation. 
It is the wireless mouse, along with its operation in various modes, such 
as, for example, standby, wait, and active, that allow the user to 
manipulate data with just the pointing device regardless of proximity to 
the computer, provided the signal can be received by computer 12. Further, 
keyboard 16 couples to the computer 12 via a wireless communication 
device, such as a transceiver that sends infrared (IR) signals between 
keyboard 16 and computer 12. Such IR transceivers are well-known in the 
art and would be well within the skill of the ordinary artisan with 
respect to implementing such a device. 
The keyboard 16 is shown in greater detail in FIG. 2, whereas the pointing 
device 20 is shown in greater detail in FIG. 3. 
In FIG. 2, the keyboard 16 is shown in greater detail. The keyboard 16 
further includes a keyboard layout that includes a full complement of keys 
22 according to the AT-standard keyboard. The keyboard 16 is kidney-shaped 
to allow a user to rest the wireless keyboard on the user's lap in such a 
manner so that wings 24 of the keyboard 16 allow a user to place his or 
her wrists in a comfortable manner during operation. To the left and right 
of the main keyboard 32 are integrated mouse keys 26 and trackball 28, 
respectively. Additionally, user activation buttons 30 are provided at the 
tips of the wings slightly above both the mouse buttons 26 and trackball 
28. An IR transceiver window 42 is placed at the front of the keyboard 16 
to send and receive IR signals to and from computer 12. The keyboard 16 in 
FIG. 3 is merely one implementation of the wireless data input device 
contemplated for use with the computer 12. An alternative wireless 
communication device is remote control 20 further depicted in FIG. 3. The 
actual operation and implementation of the timing sequences is further 
depicted in the flow chart of FIG. 4. 
The remote control 20 is further depicted in FIG. 3. The playing device or 
remote control 20 has a keypad layout substantially similar to typical 
remote controllers used in the multi-media arts. Namely, remote control 20 
is substantially similar in design to the standard television remote 
control or video cassette recorder remote controller typically found in 
the industry today. Various modifications, however, have been adapted to 
remote controller 20 to allow it to operate a computer system, namely, 
computer 12 of FIG. 1. A numerical key pad is provided on the remote 
controller. Functions that are typically associated with a computer are 
also added. These include a four-directional keypad 42, a trackball device 
44, and mouse keypads 46 and 48. Additionally, on the reverse side of a 
remote controller 20 is a second mouse button 46 which corresponds to the 
left mouse button 46 typically found on a pointing device. This bottom 
mouse button 46 provides for a trigger action that is useful in game 
playing or other type of controlling where a user's hand will fit snugly 
around the remote controller 20, such as the index finger may comfortably 
rest on the button for activation. 
The remote control 20 is capable of automatically recovering from all 
possible error conditions typically encountered in operation. When such an 
error occurs, the remote shall not stop responding to the user input. 
Further, no hard reset is required, such as removing and replacing the 
batteries, to provide recovery for the remote during an error condition. 
Instead, all possible user inputs will be acted upon when those inputs are 
valid or ignored when those inputs are invalid, thus avoiding any error 
conditions that could cause the device to stop responding. Additionally, 
when the trackball 44 is active, the remote control 20 shall send IR mouse 
data packets at a minimum rate of 40 packets per second. 
Further, the remote control 20 is programmed such that the pressing of any 
of the mouse buttons 46, 48 immediately wakes up the trackball monitoring 
system should the trackball be in a power conservation mode. When the 
trackball 44 is in a power conservation or sleep mode, and a mouse button 
46, 48 is pressed, the input passes to the system. Pressing any of the 
remote keys 50 does not necessarily activate the trackball 44. If a 
keyboard key is pressed, the trackball 44 returns to the beginning of 
level one sleep mode, as will be outlined below in the flow chart of FIG. 
1. 
There is intended to be a multi-level sleep mode to be used with the 
trackball 44. These time periods may be left to the designer to implement. 
An example of a desired sleep mode may be implemented according to the 
following: 
Level 1--After 20 seconds of idle time (no movement), the trackball enters 
the sleep mode and wakes up every half second to check for ball movement. 
Level 2--After ten minutes of idle time, the trackball wakes up every 
second to check for ball movement. 
Level 3--After 30 minutes of idle time, the trackball wakes up every two 
seconds and checks for ball movement. 
This sleep mode is directed by the level of idleness encountered by the 
remote control 20 or wireless keyboard 16 during operation. For example, 
during a Level 1 sleep mode, the remote controller 20 or keyboard 16 would 
have been idle for at least 20 seconds. The Level 2 sleep mode would occur 
should the system be idle for more than ten minutes, and the Level 3 sleep 
mode would occur should the device be idle for more than 30 minutes. Of 
course, additional idle periods may be established or constricted based 
upon the preferences of the designer. 
FIG. 4 depicts a flow diagram of the power conservation method used by 
either the wireless keyboard 16 having a trackball 28 or the remote 
control 20 having a trackball 44. The power down modes are to conserve the 
energy of the batteries, thereby prolonging operating time in either 
wireless device. Rather than having an on/off switch, the device goes into 
a sleep mode that can be awakened upon a system reset 52, a key pressed 
54, or a mouse button pressed 56. If any of these conditions are detected, 
the microcontroller of the device is awakened from its sleep mode in block 
58. In addition, the microcontroller wakes up after 0.5 s of sleep 92 for 
processing. 
Once the microcontroller is awakened, the device scans all of the keys to 
see if one has been pressed in block 60. If a key has been pressed, the 
key IR packet is transmitted in block 62 to the computer 12. The trackball 
is then returned to Level 1 sleep mode in block 63. 
Next the device checks to see if a mouse button has been pressed in block 
64. If a mouse button has been pressed, the system transmits a mouse 
button IR packet in block 66 to the computer 12. The trackball is then 
activated for 20 seconds in block 68, and processing continues in block 72 
to check for trackball movement. 
If a mouse button has not been pressed in block 64, the system then checks 
to see if the trackball is active in block 70. If the trackball is not in 
an active state, the system checks to see if it is time to check for ball 
movement in block 74. 
When active, the trackball is checked for movement continuously, in Level 1 
sleep mode the check is every 0.5 s, in Level 2 sleep mode the check is 
every 1.0 s, and in Level 3 sleep mode the check is every 2.0 s. If it is 
not time to check for trackball movement in block 74, the microcontroller 
enters the sleep mode in block 90. If it is time to check for ball 
movement, the trackball movement detection circuitry is powered up in 
block 76, and processing continues with the check for ball movement in 
block 72. 
If the trackball is active in block 70, or the trackball was activated 
because of a mouse button press in block 68, or the trackball was 
activated in block 76 because the timer to check for ball movement 
expired, the old trackball position is compared against the current 
position to check for movement in block 72. 
If movement is detected, the trackball movement IR packet is transmitted in 
block 78 to the computer 12, the trackball active timer is reset to 20 
seconds in block 80, and processing continues with a scan of the keys in 
block 60. If trackball movement was not detected in block 72, processing 
continues with a check to see if the sleep mode needs to be updated in 
block 84. If the sleep mode does not need to be updated, processing 
continues with a scan of the keys in block 60. If no trackball movement 
has been detected for 20 seconds, the sleep mode is set to Level 1, if no 
movement for 10 minutes, the sleep mode is set to Level 2, and for no 
movement for 30 minutes, the sleep mode is set to Level 3. 
If a sleep mode update is needed, the level of sleep is updated in block 
86, the trackball is powered down in block 88, and the microcontroller is 
powered down in block 90. The microcontroller sleeps for 0.5 s in block 
92, and wakes up to continue processing in block 58. 
In block 72, if no trackball movement has been detected, then the system 
proceeds to block 82 to determine whether the trackball is active and, if 
so, proceeds to block 60 to repeat the monitoring of which type of system 
activity has been implemented. If there is no trackball activity, then the 
system proceeds to block 84 where the system then determines whether the 
sleep mode needs to be updated. If the sleep mode needs to be updated, 
then the system proceeds to block 86 where the sleep mode is updated 
according from one level to the next. 
For purposes of illustration, this sleep mode level may be indicated where 
an idle time occurs after 20 seconds of activity at the Level 1 sleep 
mode. At Level 2, the system will go idle after ten minutes of inactivity, 
and at the third level, the system will go idle after 30 minutes of no 
activity. If a button is pushed or pressed, the system automatically goes 
to Level 1 for activity, thus signifying that the device is being used by 
a user. Once the sleep mode level has been updated, the system proceeds to 
block 88. 
In block 88, and if the sleep mode level does not need to be updated from 
block 84, the system then powers down the trackball before proceeding to 
block 90 where the system then powers down the microprocessor within the 
device. Likewise, in block 74, if it is not time to check for any ball 
movement, then the system will power down in block 90. Once the 
microprocessor has been powered down, the system proceeds to block 92 
where the system functions in a sleep mode where every half second the 
system determines whether any activity is occurring by powering up the 
microprocessor and repeating the steps 60-92 as previously described. 
The present implementation of providing sleep modes for trackball power 
conservation for remotes and keyboards is significant in that it overcomes 
the disadvantages that exist in prior art methods. Specifically, there is 
no on/off switch necessary to be activated that typically a user would 
forget to switch between computer use time. Further, and more importantly, 
by merely activating the device via use, the user is able to begin 
operation immediately. Further, in adding multiple levels of sleep mode, 
the system is able to further reduce power consumption during long periods 
of sleep. There are several ways in which motion detection can be achieved 
within either the keyboard trackball or the remote control trackball. One 
method would be to use a small switch on the back or a simple gyroscope 
could also be used to return the trackball to the Level 1 sleep mode. 
This achieves the goal of obtaining power conservation, thus preserving 
battery life by providing various levels of sleep mode operation that 
greatly reduce power consumption. Furthermore, this sleep mode operation 
is transparent to the user, as previously stated. 
The above disclosure and description are illustrative and explanatory 
thereof, and various changes in size, shape, materials, components, 
circuit elements, wiring connections and contact, as well as timing 
parameters, as well as the details of the illustrated components and 
construction, may be made without departing from the spirit of the 
invention.