U.S. patent application number 14/048924 was filed with the patent office on 2014-07-10 for touch pad for handheld device.
This patent application is currently assigned to Apple Inc.. The applicant listed for this patent is Apple Inc.. Invention is credited to Guy BAR-NAHUM, Steven BOLLINGER, Greg MARRIOTT.
Application Number | 20140191990 14/048924 |
Document ID | / |
Family ID | 34592119 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140191990 |
Kind Code |
A1 |
MARRIOTT; Greg ; et
al. |
July 10, 2014 |
TOUCH PAD FOR HANDHELD DEVICE
Abstract
A touch pad system is disclosed. The system includes mapping the
touch pad into native sensor coordinates. The system also includes
producing native values of the native sensor coordinates when
events occur on the touch pad. The system further includes
filtering the native values of the native sensor coordinates based
on the type of events that occur on the touch pad. The system
additionally includes generating a control signal based on the
native values of the native sensor coordinates when a desired event
occurs on the touch pad.
Inventors: |
MARRIOTT; Greg; (Palo Alto,
CA) ; BAR-NAHUM; Guy; (San Francisco, CA) ;
BOLLINGER; Steven; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Assignee: |
Apple Inc.
Cupertino
CA
|
Family ID: |
34592119 |
Appl. No.: |
14/048924 |
Filed: |
October 8, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11882422 |
Aug 1, 2007 |
8552990 |
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14048924 |
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10722948 |
Nov 25, 2003 |
7495659 |
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11882422 |
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Current U.S.
Class: |
345/173 |
Current CPC
Class: |
G06F 3/04886 20130101;
G06F 3/041 20130101; G06F 3/0416 20130101; G06F 3/03547
20130101 |
Class at
Publication: |
345/173 |
International
Class: |
G06F 3/041 20060101
G06F003/041 |
Claims
1-36. (canceled)
37. A method comprising: sending information identifying an initial
object location on a touch pad to a host device when a signal state
is changed from a first state to a second state, determining a
difference between a current object location and a prior object
location, and generating a message for the host device when the
difference is greater than a threshold value, wherein the message
comprises the current object location.
38. The method of claim 37, wherein the message is sent to the host
device when the signal state is in the second state.
39. The method of claim 38, comprising filtering messages sent to
the host device if the signal state is in the first state.
40. The method of claim 39, comprising filtering messages sent to
the host device when the signal state is changed from the second
state to the first state.
41. The method of claim 37, wherein the difference between the
current object location and the prior object location corresponds
to an amount of movement of the object relative to the touch
pad.
42. The method of claim 41, comprising determining whether the
amount of movement is associated with an undesired event or a
desired event, filtering the undesired event, and sending the
desired event to the host device when the signal state is in the
second state.
43. The method of claim 37, comprising converting the current
location into a logical device unit when the difference in object
location is greater than the threshold value, wherein the logical
device unit corresponds to a button function.
44. The method of claim 43, wherein the message comprises the
button function.
45. The method of claim 44, wherein the message is sent to the host
device only when the signal state is in the second state.
46. A touch pad assembly, comprising: a touch pad comprising one or
more sensors configured to detect a current object location and a
prior object location, a controller configured to filter an output
of the current object location when a difference between the
current object location and a prior object location is equal to or
less than a threshold value, and a user modifiable signal state
that can be set to filter the output of the current object location
even when the difference in object location is greater than the
threshold value.
47. A method comprising: receiving a current object location on a
touch pad having a surface and one or more sensors configured to
map the surface into native sensor coordinates, generating a
message comprising a changed object location when a difference
between the current object location and a prior object location
exceeds a threshold value that corresponds to a number of sensor
levels in the touch pad, and filtering the message from a host
device when a user modifiable signal state is in an inactive
state.
48. The method of claim 47, wherein the current object location is
sent to the host device when the signal state is changed from an
inactive state to an active state, even when the difference in
object location does not exceed the threshold value.
49. The method of claim 48, wherein the message is sent to the host
device if the signal state is in an active state.
50. The method of claim 49, comprising filtering messages received
by the host device when the signal state is changed from the active
state to the inactive state.
51. The method of claim 47, wherein the threshold value corresponds
to a number of sensors in the touchpad.
52. The method of claim 47, comprising converting the changed
object location into a logical device unit when a difference
between the current object location and the past object location
exceeds a threshold value that corresponds to a number of sensor
levels in the touch pad.
53. The method of claim 52, wherein the logical device unit
corresponds to a button function.
54. The method of claim 53, wherein the message comprises the
button function.
55. The method of claim 54, comprising filtering messages received
by the host device if the signal state is in an inactive state.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is related to application Ser. No.
10/188,182, entitled, "Touch Pad for Handheld Device", filed Jul.
1, 2002, and which is incorporated herein by reference.
[0002] This application is related to U.S. patent application Ser.
No. 10/256,716, entitled "Method and System for List Scrolling,"
filed on Sep. 26, 2002, and which is incorporated herein by
reference.
[0003] This application is also related to U.S. Design Patent
Application No. 29/153,169, entitled "MEDIA PLAYER," filed on Oct.
22, 2001, and which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates generally to a media player
having a touch pad. More particularly, the present invention
relates to improved touch pads.
[0006] 2. Description of the Related Art
[0007] There exist today many styles of input devices for
performing operations in a consumer electronic device. The
operations generally correspond to moving a cursor and making
selections on a display screen. By way of example, the input
devices may include buttons, switches, keyboards, mice, trackballs,
touch pads, joy sticks, touch screens and the like. Each of these
devices has advantages and disadvantages that are taken into
account when designing the consumer electronic device. In handheld
computing devices, the input devices are generally selected from
buttons and switches. Buttons and switches are generally mechanical
in nature and provide limited control with regards to the movement
of a cursor (or other selector) and making selections. For example,
they are generally dedicated to moving the cursor in a specific
direction (e.g., arrow keys) or to making specific selections
(e.g., enter, delete, number, etc.). In the case of hand-held
personal digital assistants (PDA), the input devices tend to
utilize touch-sensitive display screens. When using a touch screen,
a user makes a selection on the display screen by pointing directly
to objects on the screen using a stylus or finger.
[0008] In portable computing devices such as laptop computers, the
input devices are commonly touch pads. With a touch pad, the
movement of an input pointer (i.e., cursor) corresponds to the
relative movements of the user's finger (or stylus) as the finger
is moved along a surface of the touch pad. Touch pads can also make
a selection on the display screen when one or more taps are
detected on the surface of the touch pad. In some cases, any
portion of the touch pad may be tapped, and in other cases a
dedicated portion of the touch pad may be tapped. In stationary
devices such as desktop computers, the input devices are generally
selected from mice and trackballs. With a mouse, the movement of
the input pointer corresponds to the relative movements of the
mouse as the user moves the mouse along a surface. With a
trackball, the movement of the input pointer corresponds to the
relative movements of a ball as the user rotates the ball within a
housing. Both mice and trackballs generally include one or more
buttons for making selections on the display screen.
[0009] In addition to allowing input pointer movements and
selections with respect to a GUI presented on a display screen, the
input devices may also allow a user to scroll across the display
screen in the horizontal or vertical directions. For example, mice
may include a scroll wheel that allows a user to simply roll the
scroll wheel forward or backward to perform a scroll action. In
addition, touch pads may provide dedicated active areas that
implement scrolling when the user passes his or her finger linearly
across the active area in the x and y directions. Both devices may
also implement scrolling via horizontal and vertical scroll bars as
part of the GUI. Using this technique, scrolling is implemented by
positioning the input pointer over the desired scroll bar,
selecting the desired scroll bar, and moving the scroll bar by
moving the mouse or finger in the y direction (forwards and
backwards) for vertical scrolling or in the x direction (left and
right) for horizontal scrolling.
[0010] With regards to touch pads, mice and track balls, a
Cartesian coordinate system is used to monitor the position of the
finger, mouse and ball, respectively, as they are moved. The
Cartesian coordinate system is generally defined as a two
dimensional coordinate system (x, y) in which the coordinates of a
point (e.g., position of finger, mouse or ball) are its distances
from two intersecting, often perpendicular straight lines, the
distance from each being measured along a straight line parallel to
each other. For example, the x, y positions of the mouse, ball and
finger may be monitored. The x, y positions are then used to
correspondingly locate and move the input pointer on the display
screen.
[0011] To elaborate further, touch pads generally include one or
more sensors for detecting the proximity of the finger thereto. The
sensors are generally dispersed about the touch pad with each
sensor representing an x, y position. In most cases, the sensors
are arranged in a grid of columns and rows. Distinct x and y
position signals, which control the x, y movement of a pointer
device on the display screen, are thus generated when a finger is
moved across the grid of sensors within the touch pad. For brevity
sake, the remaining discussion will be held to the discussion of
capacitive sensing technologies. It should be noted, however, that
the other technologies have similar features.
[0012] Capacitive sensing touch pads generally contain several
layers of material. For example, the touch pad may include a
protective shield, one or more electrode layers and a circuit
board. The protective shield typically covers the electrode
layer(s), and the electrode layer(s) is generally disposed on a
front side of the circuit board. As is generally well known, the
protective shield is the part of the touch pad that is touched by
the user to implement cursor movements on a display screen. The
electrode layer(s), on the other hand, is used to interpret the x,
y position of the user's finger when the user's finger is resting
or moving on the protective shield. The electrode layer (s)
typically consists of a plurality of electrodes that are positioned
in columns and rows so as to form a grid array. The columns and
rows are generally based on the Cartesian coordinate system and
thus the rows and columns correspond to the x and y directions.
[0013] The touch pad may also include sensing electronics for
detecting signals associated with the electrodes. For example, the
sensing electronics may be adapted to detect the change in
capacitance at each of the electrodes as the finger passes over the
grid. The sensing electronics are generally located on the backside
of the circuit board. By way of example, the sensing electronics
may include an application specific integrated circuit (ASIC) that
is configured to measure the amount of capacitance in each of the
electrodes and to compute the position of finger movement based on
the capacitance in each of the electrodes. The ASIC may also be
configured to report this information to the computing device.
[0014] Referring to FIG. 1, a touch pad 2 will be described in
greater detail. The touch pad 2 is generally a small rectangular
area that includes a protective shield 4 and a plurality of
electrodes 6 disposed underneath the protective shield layer 4. For
ease of discussion, a portion of the protective shield layer 4 has
been removed to show the electrodes 6. Each of the electrodes 6
represents a different x, y position. In one configuration, as a
finger 8 approaches the electrode grid 6, a tiny capacitance forms
between the finger 8 and the electrodes 6 proximate the finger 8.
The circuit board/sensing electronics measures capacitance and
produces an x, y input signal 10 corresponding to the active
electrodes 6. The x, y input signal 10 is sent to a host device 12
having a display screen 14. The x, y input signal 10 is used to
control the movement of a cursor 16 on the display screen 14. As
shown, the input pointer moves in a similar x, y direction as the
detected x, y finger motion.
SUMMARY OF THE INVENTION
[0015] The invention relates, in one embodiment, to a touch pad
assembly. The touch pad assembly includes a touch pad having one or
more sensors that map the touch pad plane into native sensor
coordinates. The touch pad assembly also includes a controller that
divides the surface of the touch pad into logical device units that
represent areas of the touch pad that can be actuated by a user,
receives the native values of the native sensor coordinates from
the sensors, adjusts the native values of the native sensor
coordinates into a new value associated with the logical device
units and reports the new value of the logical device units to a
host device.
[0016] The invention relates, in another embodiment, to a method
for a touch pad. The method includes mapping the touch pad into
native sensor coordinates. The method also includes producing
native values of the native sensor coordinates when events occur on
the touch pad. The method further includes filtering the native
values of the native sensor coordinates based on the type of events
that occur on the touch pad. The method additionally includes
generating a control signal based on the native values of the
native sensor coordinates when a desired event occurs on the touch
pad.
[0017] The invention relates, in another embodiment, to a signal
processing method. The method includes receiving a current user
location. The method also includes determining the difference in
user location by comparing the current user location to a last user
location. The method further includes only outputting the current
user location when the difference in user location is larger than a
threshold value. The method additionally includes converting the
outputted current user location into a logical device unit.
Moreover, the method includes generating a message for a host
device. The message including the more logical user location. The
more logical user location being used by the host device to move a
control object in a specified manner.
[0018] The invention relates, in another embodiment, to a message
from a touch pad assembly to a host device in a computer system
that facilitates bi-directional communications between the touch
pad assembly and the host device. The message includes an event
field identifying whether the message is a touch pad event or a
button event. The message also includes an event identifier field
identifying at least one event parameter, each event parameter
having an event value, the event value for a touch pad event
parameter indicating an absolute position, the event value for a
button event parameter indicating button status.
[0019] The invention relates, in another embodiment, to a touch pad
assembly capable of transforming a user action into motion onto a
display screen, the touch pad system including a touch pad having a
plurality of independent and spatially distinct button zones each
of which represents a different movement direction on the display
screen so as to enable joystick implementations, multiple
dimensional menu selection or photo image panning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention is illustrated by way of example, and
not by way of limitation, in the figures of the accompanying
drawings and in which like reference numerals refer to similar
elements and in which:
[0021] FIG. 1 is a simplified diagram of a touch pad and
display.
[0022] FIG. 2 is a diagram of a computing system, in accordance
with one embodiment of the present invention.
[0023] FIG. 3 is a flow diagram of signal processing, in accordance
with one embodiment of the invention.
[0024] FIG. 4 is a flow diagram of touch pad processing, in
accordance with one embodiment of the invention.
[0025] FIG. 5 is a flow diagram of a touch pad processing, in
accordance with one embodiment of the invention.
[0026] FIG. 6 is a diagram of a communication protocol, in
accordance with one embodiment of the present invention.
[0027] FIG. 7 is a diagram of a message format, in accordance with
one embodiment of the present invention.
[0028] FIG. 8 is a perspective view of a media player, in
accordance with one embodiment of the invention.
[0029] FIG. 9 is a front view of a media player, in accordance with
one embodiment of the present invention.
[0030] FIG. 10 is a front view of a media player, in accordance
with one embodiment of the present invention.
[0031] FIGS. 11A-11D are top views of a media player in use, in
accordance with one embodiment of the present invention.
[0032] FIG. 12 is a partially broken away perspective view of an
annular capacitive touch pad, in accordance with one embodiment of
the present invention.
[0033] FIG. 13 is a top view of a sensor arrangement of a touch
pad, in accordance with another embodiment of the present
invention.
[0034] FIG. 14 is a top view of a sensor arrangement of a touch
pad, in accordance with another embodiment of the present
invention.
[0035] FIG. 15 is a top view of a sensor arrangement of a touch
pad, in accordance with another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The present invention will now be described in detail with
reference to a few preferred embodiments thereof as illustrated in
the accompanying drawings. In the following description, numerous
specific details are set forth in order to provide a thorough
understanding of the present invention. It will be apparent,
however, to one skilled in the art, that the present invention may
be practiced without some or all of these specific details. In
other instances, well known process steps have not been described
in detail in order not to unnecessarily obscure the present
invention.
[0037] FIG. 2 is a diagram of a computing system 20, in accordance
with one embodiment of the present invention. The computing system
20 includes at least a user interface 22 and a host device 24. The
user interface 22 is configured to provide control information for
performing actions in the host device 24. By way of example, the
actions may include making selections, opening a file or document,
executing instructions, starting a program, viewing a menu, and/or
the like. The actions may also include moving an object such as a
pointer or cursor on a display screen of the host device 24.
Although not shown in FIG. 2, the user interface 22 may be
integrated with the host device 24 (within the same housing) or it
may be a separate component (different housing).
[0038] The user interface 22 includes one or more touch buttons 34,
a touch pad 36 and a controller 38. The touch buttons 34 generate
button data when a user places their finger over the touch button
34. The touch pad, on the other hand, generates position data when
a user places their finger (or object) over the touch pad 36. The
controller 38 is configured to acquire the button data from the
touch buttons 34 and the position data from the touch pad 36. The
controller is also configured to output control data associated
with the button data and/or position data to the host device 24. In
one embodiment, the controller 38 only outputs control data
associated with the touch buttons when the button status has
changed. In another embodiment, the controller 38 only outputs
control data associated with the touch pad when the position data
has changed. The control data, which may include the raw data
(button, position) or some form of thereof, may be used to
implement a control function in the host device 24. By way of
example, the control data may be used to move an object on the
display 30 of the host device 24 or to make a selection or issue a
command in the host device 24.
[0039] The touch buttons 34 and touch pad 36 generally include one
or more sensors capable of producing the button and position data.
The sensors of the touch buttons 34 and touch pad 36 may be
distinct elements or they may be grouped together as part of a
sensor arrangement, i.e., divided into sensors for the touch
buttons 34 and sensors for the touch pad 36. The sensors of the
touch buttons 34 are configured to produce signals associated with
button status (activated, not activated). For example, the button
status may indicate button activation when an object is positioned
over the touch button and button deactivation at other times (or
vice versa). The sensors of the touch pad 36 are configured produce
signals associated with the absolute position of an object on or
near the touch pad 36. In most cases, the sensors of the touch pad
36 map the touch pad plane into native or physical sensor
coordinates 40. The native sensor coordinates 40 may be based on
Cartesian coordinates or Polar coordinates (as shown). When
Cartesian, the native sensor coordinates 40 typically correspond to
x and y coordinates. When Polar (as shown), the native sensor
coordinates typically correspond to radial and angular coordinates
(r, .theta.). By way of example, the sensors may be based on
resistive sensing, surface acoustic wave sensing, pressure sensing
(e.g., strain gauge), optical sensing, capacitive sensing and the
like.
[0040] In one embodiment, the user interface 22 includes a sensor
arrangement based on capacitive sensing. The user interface 22 is
therefore arranged to detect changes in capacitance as a finger
moves, taps, or rests on the touch buttons 34 and touch pad 36. The
capacitive touch assembly is formed from various layers including
at least a set of labels, a set of electrodes (sensors) and a
printed circuit board (PCB). The electrodes are positioned on the
PCB, and the labels are position over the electrodes. The labels
serve to protect the electrodes and provide a surface for receiving
a finger thereon. The label layer also provides an insulating
surface between the finger and the electrodes. As should be
appreciated, the controller 38 can determine button status at each
of the touch buttons 34 and position of the finger on the touch pad
36 by detecting changes in capacitance. In most cases, the
controller 38 is positioned on the opposite side of the PCB. By way
of example, the controller 38 may correspond to an application
specific integrated circuit (ASIC), and it may operate under the
control of Firmware stored on the ASIC.
[0041] Referring to the controller 38, the controller 38 is
configured to monitor the sensors of the touch buttons 34 and touch
pad 36 and decide what information to report to the host device 24.
The decision may include filtering and/or conversion processes. The
filtering process may be implemented to reduce a busy data stream
so that the host device 24 is not overloaded with redundant or
non-essential data. By way of example, a busy data stream may be
created when multiple signals are produced at native sensor
coordinates 40 that are in close proximity to one another. As
should be appreciated, processing a busy data stream tends to
require a lot of power, and therefore it can have a disastrous
effect on portable devices such as media players that use a battery
with a limited power supply. Generally speaking, the filtering
process throws out redundant signals so that they do not reach the
host device 24. In one implementation, the controller 38 is
configured to only output a control signal when a significant
change in sensor signals is detected. A significant change
corresponds to those changes that are significant, as for example,
when the user decides to move his/her finger to a new position
rather than when the user's finger is simply resting on a spot and
moving ever so slightly because of finger balance (toggling back
and forth). The filter process may be implemented through Firmware
as part of the application specific integrated circuit.
[0042] The conversion process, on the other hand, is implemented to
adjust the raw data into other form factors before sending or
reporting them to the host device 24. That is, the controller 38
may convert the raw data into other types of data. The other types
of data may have similar or different units as the raw data. In the
case of the touch pad 36, the controller 38 may convert the
position data into other types of position data. For example, the
controller 38 may convert absolute position data to relative
position data. As should be appreciated, absolute position refers
to the position of the finger on the touch pad measured absolutely
with respect to a coordinate system while relative position refers
to a change in position of the finger relative to the finger's
previous position. The controller 38 may also convert multiple
absolute coordinates into a single absolute coordinate, Polar
coordinates into Cartesian coordinates, and/or Cartesian
coordinates into Polar coordinates. The controller 38 may also
convert the position data into button data. For example, the
controller may generate button control signals when an object is
tapped on a predetermined portion of the touch pad or other control
signals when an object is moved in a predetermined manner over the
touch pad (e.g., gesturing).
[0043] The conversion may also include placing the control signal
in a format that the host device 24 can understand. By way of
example, the controller 38 may follow a predetermined communication
protocol. As is generally well known, communication protocols are a
set of rules and procedures for exchanging data between two devices
such as the user interface 22 and the host device 24. Communication
protocols typically transmit information in data blocks or packets
that contain the data to be transmitted, the data required to guide
the packet to its destination, and the data that corrects errors
that occur along the way. The controller may support a variety of
communication protocols for communicating with the host device,
including but not limited to, PS/2, Serial, ADB and the like. In
one particular implementation, a Serial protocol is used.
[0044] The conversion process may include grouping at least a
portion of the native coordinates 40 together to form one or more
virtual actuation zones 42. For example, the controller 38 may
separate the surface of the touch pad 36 into virtual actuation
zones 42A-D and convert the native values of the native sensor
coordinates 40 into a new value associated with the virtual
actuation zones 42A-D. The new value may have similar or different
units as the native value. The new value is typically stored at the
controller 38 and subsequently passed to the host device 24.
Generally speaking, the controller 38 outputs a control signal
associated with a particular virtual actuation zone 42 when most of
the signals are from native sensor coordinates 40 located within
the particular virtual actuation zone 42.
[0045] The virtual actuation zones 42 generally represent a more
logical range of values than the native sensor coordinates 40
themselves, i.e., the virtual actuation zones 42 represent areas of
touch pad 36 that can be better actuated by a user (magnitudes
larger). The ratio of native sensor coordinates 40 to virtual
actuation zones 42 may be between about 1024:1 to about 1:1, and
more particularly about 8:1. For example, the touch pad may include
128 virtual actuation areas based on 1024 native sensor
coordinates.
[0046] The virtual actuation zones 42 may be widely varied. For
example, they may represent absolute positions on the touch pad 36
that are magnitudes larger than the native sensor coordinates 40.
For example, the touch pad 36 can be broken up into larger slices
than would otherwise be attainable using the native sensor
coordinates 40. In one implementation, the virtual actuation zones
42 are distributed on the touch pad 36 within a range of 0 to 95
angular positions. The angular position is zero at the 12 o clock
position and progresses clockwise to 95 as it comes around to 12
o'clock again.
[0047] The virtual actuation zones 42 may also represent areas of
the touch pad that can be actuated by a user to implement specific
control functions such as button or movement functions. With
regards to button functions, the virtual actuation zones 42 may
correspond to button zones that act like touch buttons. With
regards to movement functions, each of the virtual actuation zones
42 may correspond to different movement directions such that they
act like arrow keys. For example, virtual actuation zone 42A may
represent an upward movement, virtual actuation zone 42B may
represent a downward movement, virtual actuation zone 42C may
represent a left movement, and virtual actuation zone 42D may
represent right movement. As should be appreciated, this type of
touch pad configuration may enable game stick implementations, two
dimensional menu selection, photo image panning and the like.
[0048] Although not shown, the controller 38 may also include a
storage element. The storage element may store a touch pad program
for controlling different aspects of the user interface 22. For
example, the touch pad program may contain virtual actuation zone
profiles that describe how the virtual actuation zones are
distributed around the touch pad relative to the native sensor
coordinates and what type of value to output based on the native
values of the native sensor coordinates selected and the virtual
actuation zone corresponding to the selected native sensor
coordinates.
[0049] In one particular touch pad operation, the controller 38
receives the position data from the touch pad 36. The controller 38
then passes the data through a filtering process. The filtering
process generally includes determining if the data is based on
noise events or actual events. Noise events are associated with non
significant events such as when a user's finger is simply resting
on a spot and moving ever so slightly because of finger balance.
Actual events are associated with significant events such as when a
user decides to move his/her finger to a new position on the touch
pad. The noise events are filtered out and the actual events are
passed through the controller 38.
[0050] With actual events, the controller 38 determines if the
position data should be adjusted. If not, the position data is
reported to the host device 24. If so, the position data is
converted into other form factors including but not limited to
other position data or button data. For example, the native values
of the sensor coordinates are converted into a new value associated
with a selected virtual actuation zone. After the conversion, the
controller 38 reports the converted data to the host device 24. By
way of example, the controller 38 may pass the new value to a main
system processor that executes the main application program running
on the host device 24.
[0051] Referring to the host device 24, the host device 24
generally includes a control circuit 26. The control circuit 26 is
configured to execute instructions and carry out operations
associated with the host device 24. For example, the control
circuit 26 may control the reception and manipulation of input and
output data between the components of the computing system 20. The
host device 24 may also include a hold switch 28 for activating or
deactivating communications between the host device 24 and the user
interface 22. The host device may additionally include a display 30
configured to produce visual information such as text and graphics
on a display screen 32 via display commands from the control
circuit 26. By way of example, the visual information may be in the
form of a graphical user interface (GUI). Although not shown, the
host device may additionally include one or more speakers or jacks
that connect to headphones/speakers.
[0052] The control circuit may be widely varied. The control
circuit may include one or more processors 27 that together with an
operating system operate to execute computer code and produce and
use data. The processor 27 can be a single-chip processor or can be
implemented with multiple components. The computer code and data
may reside within data storage that is operatively coupled to the
processor. Data storage generally provides a place to hold data
that is being used by the computer system 20. By way of example,
the data storage may include Read-Only Memory (ROM), Random-Access
Memory (RAM), hard disk drive and/or the like. Although not shown,
the control circuit may also include an input/output controller
that is operatively coupled to the processor. The input/output
controller generally operates by exchanging data between the host
device 24 and the I/O devices that desire to communicate with the
host device 24 (e.g., touch pad assembly 22). The control circuit
also typically includes a display controller that is operatively
coupled to the processor. The display controller is configured to
process display commands to produce text and graphics on the
display screen 32 of the host device 24. The input/output
controller and display controller may be integrated with the
processor or they may be separate components.
[0053] It should be noted that the control circuit 26 may be
configured to perform some of the same functions as the controller
38. For example, the control circuit 26 may perform conversion
processes on the data received from the controller 38. The
conversion may be performed on raw data or on already converted
data.
[0054] FIG. 3 is a flow diagram of signal processing 50, in
accordance with one embodiment of the invention. By way of example,
the signal processing 50 may be performed by the computing system
shown in FIG. 2. Signal processing 50 generally begins at block 52
where a user input is produced at the user interface 22. The user
input is typically based on signals generated by the sensor
arrangement of the touch buttons and touchpad. The user input may
include raw data. The user input may also include filtered or
converted data.
[0055] Following block 52, the processing proceeds to block 54
where the user input is reported to the control circuit of the host
device. The user input may contain both button and position data or
it may only contain button data or position data. The user input is
typically reported when a change is made and more particularly when
a desired change is made at the user interface (filtered). For
example, button data may be reported when the button status has
changed and position data may be reported when the position of a
finger has changed.
[0056] Following block 54, the processing proceeds to block 56
where an action is performed in the host device based on the user
input. The actions are typically controlled by the control circuit
of the host device. The actions may include making selections,
opening a file or document, executing instructions, starting a
program, viewing a menu, and/or the like. The actions may also
include moving an object such as a pointer or cursor on a display
screen of the host device 24.
[0057] FIG. 4 is a flow diagram of touch pad processing 60, in
accordance with one embodiment of the invention. Touch pad
processing 60 generally begins at block 62 where at least one
control object is displayed on a graphical user interface. The
control object may be a cursor, slider bar, image or the like. By
way of example, the GUI may be displayed on the display 30 of the
host device 24. The GUI is typically under the control of the
processor of the host device 24.
[0058] Following block 62, the processing proceeds to block 64
where an angular or radial referenced input is received. By way of
example, the angular or radial referenced input may be produced by
the user interface 22 and received by the processor of the host
device 24. The angular or radial referenced input may be raw data
formed by the sensor arrangement or converted data formed at the
controller. Furthermore, the raw or converted data may be filtered
so as to reduce a busy data stream.
[0059] Following block 64, touch pad processing proceeds to block
66 where the control object is modified based on the angular or
radial referenced input. For example, the direction that a control
object such as a football player in a football game is moving may
be changed from a first direction to a second direction or a
highlight bar may be moved through multiple images in a photo
library. The modification is typically implemented by the processor
of the host device.
[0060] FIG. 5 is a flow diagram of a touch pad processing 70, in
accordance with one embodiment of the invention. By way of example,
touch pad processing may be performed by the controller shown in
FIG. 2. Furthermore, it may be associated with blocks 52/54 and 62
shown in FIGS. 3 and 4. Touch pad processing 70 generally begins at
block 72 where a current user location is received. The current
user location corresponds to the current location of the user's
finger on the touch pad. For example, the controller may detect the
changes in sensor levels at each of the native sensor coordinates
and thereafter determine the current location of the user's finger
on the touch pad based on the change in sensor levels at each of
the native sensor coordinates.
[0061] Following block 72, the process flow proceeds to block 74
where a determination is made as to whether the current user
location is within a threshold from the last user location, i.e.,
the user location that precedes the current user location. In some
cases, the current user location is compared to the last user
location to determine the difference in user location, i.e., how
much movement occurred between the current and last readings. If
the current user location is within the threshold then an undesired
change has been made and the process flow proceeds back to block
72. If the current location is outside the threshold then a desired
change has been made and the process flow proceeds to block 76. By
way of example:
Undesired change:
|currentUserLocation-lastUserLocation|<Threshold
Desired change:
|currentUserLocation-lastUserLocation|.gtoreq.Threshold
[0062] In one embodiment, the threshold may be defined as the
number of sensor levels that need to change in order to report a
change in the user finger location to the main system processor of
the host device. In one particular implementation, the threshold is
equal to about 3. The threshold may be determined by the following
equation:
Threshold(T)=C*(native sensor coordinate resolution/logical device
unit resolution),
[0063] where the native sensor coordinate resolution defines the
maximum number of different positions that the sensors are able to
detect for a specific plane coordinate system, the logical device
unit resolution defines the number of values that are communicated
to the main system processor of the host device for the said
specific plane coordinate system, and coefficient C defines the
width border area between the clusters of native sensor coordinates
that define one logical device unit.
[0064] The coefficient C is generally determined by the sensitivity
needed to initiate a user event to the main system processor of the
host device. It customizes the threshold value to the physical
limitations of the sensor technology and the expected noise of the
user finger events. Larger values tend to filter more events and
reduce sensitivity. The system designer may pick the exact value of
C by testing several values to strike optimal balance between
sensitivity and stability of the user finger location. The
coefficient C is typically a value between 0 and 0.5, and more
particularly about 0.25. As should be appreciated, the threshold
(T) is about 2 when the native sensor coordinate resolution is
about 1024, the logical device unit resolution is about 128 and the
coefficient is about 0.25.
[0065] In block 76, a new value associated with a particular
logical device unit is generated based on the changed native sensor
coordinates associated with the particular logical device unit. In
most cases, the raw number of slices in the form of native sensor
coordinates are grouped into a more logical number of slices in the
form of logical device units (e.g., virtual actuation zones).
[0066] Following block 76, the process flow proceeds to block 78
where the last user location is updated. That is, the last current
location is changed to the current user location. The current user
location now acts as the last user location for subsequent
processing.
[0067] Following block 78, the process flow proceeds to block 80
where a message is sent. In most cases, the message is sent when
the difference between the current and last user location is larger
than the threshold value. The message generally includes the new
value associated with the selected logical device unit. By way of
example, the touch pad may send a message to the main system
processor of the host device. When received by the main system
processor, the message may be used to make an adjustment in the
host device, i.e., cause a control object to move in a specified
manner.
[0068] FIG. 6 is a diagram of a communication protocol 82, in
accordance with one embodiment of the present invention. By way of
example, the communication protocol may be used by the user
interface and host device of FIG. 2. In this particular embodiment,
the user interface 22 has one dedicated input ACTIVE line that is
controlled by the control circuit 26. The state of the ACTIVE line
signal may be set at LOW or HIGH. The hold switch 28 may be used to
change the state of the ACTIVE line signal (for example when the
hold switch is in a first position or second position). As shown in
FIG. 6, when the ACTIVE signal is set to HIGH, the user interface
22 sends a synch message to the control circuit 26 that describes
the Button and Touch pad status (e.g., button state and touch pad
position). In one embodiment, new synch messages are only sent when
the Button state and/or the Touch Pad status changes. For example,
when the touch pad position has changed within a desired limit.
When the ACTIVE signal is set to LOW, the user interface 22 does
not send a synch message to the control circuit 26. When the ACTIVE
signal is toggled from LOW to HIGH, the user interface 22 sends a
Button state and touch pad position message. This may be used on
startup to initialize the state. When the ACTIVE signal is toggled
from HIGH to LOW, the user interface 22 does not send a synch
message to the control circuit 26. In one embodiment, the user
interface 22 is configured to send a two data byte message if both
the Buttons and touch pad positions changes since the last message
was sent, and a one data byte message if only one button state or
touch pad position changes.
[0069] FIG. 7 is a diagram of a message format 86, in accordance
with one embodiment of the present invention. By way of example,
the message format 86 may correspond to the synch message described
in FIG. 6. The message format 86 may form a two data byte message
or a one data byte message. Each data byte is configured as an 8
bit message. The upper Most Significant Bit (MSB) of the message is
the event type (1 bit) and the lower Least Significant Bits (LSB)
are the event value (7 bits).
[0070] The event value is event type specific. In FIG. 7, the event
type bits are marked as E0, and the event value is marked as D0-D6.
As indicated in the diagram, the event type may be a touch pad
position change E1 or a button state change E0 when the button is
being touched or E1 when the button is not being touched. The event
values may correspond to different button events such as seeking
forwards (D4), seeking backwards (D3), playing and pausing (D2),
providing a menu (D1) and making selections (D0). The event values
may also correspond to touch pad events such as touchpad position
(D5). For example, in a touch pad that defines the logical
coordinates in polar coordinates from 0-127, the event value may
correspond to an absolute touch pad position in the range of 0-127
angular positions where zero is 12 o clock, 32 is 3 o clock, 64 is
6 o clock and 96 is 9 o clock, etc. going clockwise. The event
values may also correspond to a reserve (D6). The reserve is an
unused bit that may be used to extend the API.
[0071] FIG. 8 is a perspective diagram of a media player 100, in
accordance with one embodiment of the present invention. By way of
example, the media player 100 may generally correspond to the host
device shown in FIG. 2. The term "media player" generally refers to
computing devices that are dedicated to processing media such as
audio, video or other images, as for example, music players, game
players, video players, video recorders, cameras, and the like. In
some cases, the media players contain single functionality (e.g., a
media player dedicated to playing music) and in other cases the
media players contain multiple functionality (e.g., a media player
that plays music, displays video, stores pictures and the like). In
either case, these devices are generally portable so as to allow a
user to listen to music, play games or video, record video or take
pictures wherever the user travels.
[0072] In one embodiment, the media player 100 is a handheld device
that is sized for placement into a pocket of the user. By being
pocket sized, the user does not have to directly carry the device
and therefore the device can be taken almost anywhere the user
travels (e.g., the user is not limited by carrying a large, bulky
and often heavy device, as in a laptop or notebook computer). For
example, in the case of a music player, a user may use the device
while working out at the gym. In case of a camera, a user may use
the device while mountain climbing. In the case of a game player,
the user can use the device while traveling in a car. Furthermore,
the device may be operated by the users hands, no reference surface
such as a desktop is needed (this is shown in greater detail in
FIG. 6). In the illustrated embodiment, the media player 100 is a
pocket sized hand held MP3 music player that allows a user to store
a large collection of music (e.g., in some cases up to 4,000
CD-quality songs). By way of example, the MP3 music player may
correspond to the iPod MP3 player manufactured by Apple Computer of
Cupertino, Calif. Although used primarily for storing and playing
music, the MP3 music player shown herein may also include
additional functionality such as storing a calendar and phone
lists, storing and playing games, storing photos and the like. In
fact, in some cases, it may act as a highly transportable storage
device.
[0073] As shown in FIG. 8, the media player 100 includes a housing
102 that encloses internally various electrical components
(including integrated circuit chips and other circuitry) to provide
computing operations for the media player 100. In addition, the
housing may also define the shape or form of the media player. That
is, the contour of the housing 102 may embody the outward physical
appearance of the media player 100. The integrated circuit chips
and other circuitry contained within the housing may include a
microprocessor (e.g., CPU), memory (e.g., ROM, RAM), a power supply
(e.g., battery), a circuit board, a hard drive, other memory (e.g.,
flash) and/or various input/output (I/O) support circuitry. The
electrical components may also include components for inputting or
outputting music or sound such as a microphone, amplifier and a
digital signal processor (DSP). The electrical components may also
include components for capturing images such as image sensors
(e.g., charge coupled device (CCD) or complimentary oxide
semiconductor (CMOS)) or optics (e.g., lenses, splitters,
filters).
[0074] In the illustrated embodiment, the media player 100 includes
a hard drive thereby giving the media player 100 massive storage
capacity. For example, a 20 GB hard drive can store up to 4000
songs or about 266 hours of music. In contrast, flash-based media
players on average store up to 128 MB, or about two hours, of
music. The hard drive capacity may be widely varied (e.g., 5, 10,
20 MB, etc.). In addition to the hard drive, the media player 100
shown herein also includes a battery such as a rechargeable lithium
polymer battery. These type of batteries are capable of offering
about 10 hours of continuous playtime to the media player 100.
[0075] The media player 100 also includes a display screen 104 and
related circuitry. The display screen 104 is used to display a
graphical user interface as well as other information to the user
(e.g., text, objects, graphics). By way of example, the display
screen 104 may be a liquid crystal display (LCD). In one particular
embodiment, the display screen 104 corresponds to a
160-by-128-pixel high-resolution display, with a white LED
backlight to give clear visibility in daylight as well as low-light
conditions. As shown, the display screen 104 is visible to a user
of the media player 100 through an opening 105 in the housing
102.
[0076] The media player 100 also includes a touch pad 110. The
touch pad is an intuitive interface that provides easy one-handed
operation, i.e., lets a user interact with the media player 100
with one or more fingers. The touch pad 110 is configured to
provide one or more control functions for controlling various
applications associated with the media player 100. For example, the
touch initiated control function may be used to move an object on
the display screen 104 or to make selections or issue commands
associated with operating the media player 100. In order to
implement the touch initiated control function, the touch pad 110
may be arranged to receive input from a finger moving across the
surface of the touch pad 110, from a finger holding a particular
position on the touch pad and/or by a finger tapping on a
particular position of the touch pad.
[0077] The touch pad 110 generally consists of a touchable outer
surface 111 for receiving a finger for manipulation on the touch
pad 110. Beneath the touchable outer surface 111 is a sensor
arrangement 112. The sensor arrangement 112 includes one or more
sensors that are configured to activate as the finger sits on, taps
on or passes over them. The sensor arrangement 112 may be based on
a Cartesian coordinate system, a Polar coordinate system or some
other coordinate system. In the simplest case, an electrical signal
is produced each time the finger is positioned over a sensing
coordinate of the sensor arrangement 112. The number of signals in
a given time frame may indicate location, direction, speed and
acceleration of the finger on the touch pad, i.e., the more
signals, the more the user moved his or her finger. In most cases,
the signals are monitored by a control assembly that converts the
number, combination and frequency of the signals into location,
direction, speed and acceleration information and reports this
information to the main system processor of the media player. This
information may then be used by the media player 100 to perform the
desired control function on the display screen 104.
[0078] In one embodiment, the surface of the touch pad 110 is
divided into several independent and spatially distinct actuation
zones 113A-D disposed around the periphery of the touch pad 110.
The actuation zones generally represent a more logical range of
user inputs than the sensors themselves. Generally speaking, the
touch pad 110 outputs a control signal associated with a particular
actuation zone 113 when most of the signals are from sensing
coordinates located within the particular actuation zone 113. That
is, when an object approaches a zone 113, a position signal is
generated at one or more sensing coordinates. The position signals
generated by the one or more sensing coordinates may be used to
inform the media player 100 that the object is at a specific zone
113 on the touch pad 110.
[0079] The actuation zones may be button zones or positional zones.
When button zones, a button control signal is generated when an
object is placed over the button zone. The button control signal
may be used to make selections, open a file, execute instructions,
start a program, view a menu in the media player. When positional
zones, a position control signal is generated when an object is
placed over the positional zone. The position signals may be used
to control the movement of an object on a display screen of the
media player. The distribution of actuation zones may be controlled
by touch pad translation software or firmware that converts
physical or native coordinates into virtual representation in the
form of actuation zones. The touch pad translation software may be
run by the control assembly of the touch pad or the main system
processor of the media player. In most cases, the control assembly
converts the acquired signals into signals that represent the zones
before sending the acquired signals to the main system processor of
the media player.
[0080] The position control signals may be associated with a
Cartesian coordinate system (x and y) or a Polar coordinate system
(r, .theta.). Furthermore, the position signals may be provided in
an absolute or relative mode. In absolute mode, the absolute
coordinates of where it is being touched on the touch pad are used.
For example x, y in the case of the Cartesian coordinate system or
(r, .theta.) in the case of the Polar coordinate system. In
relative mode, the change in position of the finger relative to the
finger's previous position is used. The touch pad may be configured
to operate in a Cartesian-absolute mode, a Cartesian-relative mode,
a Polar-absolute mode or a Polar-relative mode. The mode may be
controlled by the touch pad itself or by other components of the
media player system.
[0081] In either case, a user may select which mode that they would
like to operate in the media player system or the applications
running on the media player system may automatically set the mode
of the media player system. For example, a game application may
inform the media player system to operate in an absolute mode so
that the touch pad can be operated as a joystick or a list
application may inform the media player system to operate in a
relative mode so that the touch pad can be operated as a scroll
bar.
[0082] In one embodiment, each of the zones 113 represents a
different polar angle that specifies the angular position of the
zone 113 in the plane of the touch pad 110. By way of example, the
zones 113 may be positioned at 90 degree increments all the way
around the touch pad 110 or something smaller as for example 2
degree increments all the way around the touch pad 110. In one
embodiment, the touch pad 110 may convert 1024 physical positions
in the form of sensor coordinates, to a more logical range of 0 to
127 in the form of positional zones. As should be appreciated, the
touch pad internal accuracy (1024 positions) is much larger than
the accuracy (128 positions) needed for making movements on the
display screen.
[0083] The position of the touch pad 110 relative to the housing
102 may be widely varied. For example, the touch pad 110 may be
placed at any external surface (e.g., top, side, front, or back) of
the housing 102 that is accessible to a user during manipulation of
the media player 100. In most cases, the touch sensitive surface
111 of the touch pad 110 is completely exposed to the user. In the
illustrated embodiment, the touch pad 110 is located in a lower,
front area of the housing 102. Furthermore, the touch pad 110 may
be recessed below, level with, or extend above the surface of the
housing 102. In the illustrated embodiment, the touch sensitive
surface 111 of the touch pad 110 is substantially flush with the
external surface of the housing 102.
[0084] The shape of the touch pad 110 may also be widely varied.
For example, the touch pad 110 may be circular, rectangular,
triangular, and the like. In general, the outer perimeter of the
shaped touch pad defines the working boundary of the touch pad. In
the illustrated embodiment, the touch pad 110 is circular. This
particular shape works well with Polar coordinates. More
particularly, the touch pad is annular, i.e., shaped like or
forming a ring. When annular, the inner and outer perimeter of the
shaped touch pad defines the working boundary of the touch pad.
[0085] In addition to above, the media player 100 may also include
one or more buttons 114. The buttons 114 are configured to provide
one or more dedicated control functions for making selections or
issuing commands associated with operating the media player 100. By
way of example, in the case of an MP3 music player, the button
functions may be associated with opening a menu, playing a song,
fast forwarding a song, seeking through a menu and the like. The
buttons 114 may be mechanical clicking buttons and/or they may be
touch buttons. In the illustrated embodiment, the buttons are touch
buttons that receive input from a finger positioned over the touch
button. Like the touch pad 110, the touch buttons 114 generally
consist of a touchable outer surface for receiving a finger and a
sensor arrangement disposed below the touchable outer surface. By
way of example, the touch buttons and touch pad may generally
correspond to the touch buttons and touch pad shown in FIG. 2.
[0086] The position of the touch buttons 114 relative to the touch
pad 110 may be widely varied. For example, they may be adjacent one
another or spaced apart. In the illustrated embodiment, the buttons
114 are placed above the touch pad 110 in a linear manner as well
as in the center of the annular touch pad 110. By way of example,
the plurality of buttons 114 may consist of a menu button,
play/stop button, forward seek button, a reverse seek button, and
the like.
[0087] Moreover, the media player 100 may also include a hold
switch 115. The hold switch 115 is configured to activate or
deactivate the touch pad and/or buttons. This is generally done to
prevent unwanted commands by the touch pad and/or buttons, as for
example, when the media player is stored inside a user's pocket.
When deactivated, signals from the buttons and/or touch pad are not
sent or are disregarded by the media player. When activated,
signals from the buttons and/or touch pad are sent and therefore
received and processed by the media player.
[0088] Moreover, the media player 100 may also include one or more
headphone jacks 116 and one or more data ports 118. The headphone
jack 116 is capable of receiving a headphone connector associated
with headphones configured for listening to sound being outputted
by the media device 100. The data port 118, on the other hand, is
capable of receiving a data connector/cable assembly configured for
transmitting and receiving data to and from a host device such as a
general purpose computer (e.g., desktop computer, portable
computer). By way of example, the data port 118 may be used to
upload or down load audio, video and other images to and from the
media device 100. For example, the data port may be used to
download songs and play lists, audio books, ebooks, photos, and the
like into the storage mechanism of the media player.
[0089] The data port 118 may be widely varied. For example, the
data port may be a PS/2 port, a serial port, a parallel port, a USB
port, a Firewire port and/or the like. In some cases, the data port
118 may be a radio frequency (RF) link or optical infrared (IR)
link to eliminate the need for a cable. Although not shown in FIG.
2, the media player 100 may also include a power port that receives
a power connector/cable assembly configured for delivering powering
to the media player 100. In some cases, the data port 118 may serve
as both a data and power port. In the illustrated embodiment, the
data port 118 is a Firewire port having both data and power
capabilities.
[0090] Although only one data port is described, it should be noted
that this is not a limitation and that multiple data ports may be
incorporated into the media player. In a similar vein, the data
port may include multiple data functionality, i.e., integrating the
functionality of multiple data ports into a single data port.
Furthermore, it should be noted that the position of the hold
switch, headphone jack and data port on the housing may be widely
varied. That is, they are not limited to the positions shown in
FIG. 2. They may be positioned almost anywhere on the housing
(e.g., front, back, sides, top, bottom). For example, the data port
may be positioned on the bottom surface of the housing rather than
the top surface as shown.
[0091] Referring to FIG. 9, the touch pad 110 will be described in
greater detail. In this particular embodiment, the touch pad is
operating in an absolute mode. That is, the touch pad reports the
absolute coordinates of where it is being touched. As shown, the
touch pad 110 includes one or more zones 124. The zones 124
represent regions of the touch pad 110 that may be actuated by a
user to implement one or more actions or movements on the display
screen 104.
[0092] The distribution of the zones 124 may be widely varied. For
example, the zones 124 may be positioned almost anywhere on the
touch pad 110. The position of the zones 124 may depend on the
coordinate system of the touch pad 110. For example, when using
polar coordinates, the zones 124 may have one or more radial and/or
angular positions. In the illustrated embodiment, the zones 124 are
positioned in multiple angular positions of the Polar coordinate
system. Further, the zones 124 may be formed from almost any shape
whether simple (e.g., squares, circles, ovals, triangles,
rectangles, polygons, and the like) or complex (e.g., random
shapes). The shape of multiple button zones 124 may have identical
shapes or they may have different shapes. In addition, the size of
the zones 124 may vary according to the specific needs of each
device. In some cases, the size of the zones 124 corresponds to a
size that allows them to be easily manipulated by a user (e.g., the
size of a finger tip or larger). In other cases, the size of the
zones 124 are small so as to improve resolution of the touch pad
110. Moreover, any number of zones 124 may be used. In the
illustrated embodiment, four zones 124A-D are shown. It should be
noted, however, that this is not a limitation and that the number
varies according to the specific needs of each touch pad. For
example, FIG. 5 shows the media player 100 with 16 button zones
124A-P.
[0093] The number of zones 124 generally depends on the number of
sensor coordinates located within the touch pad 110 and the desired
resolution of the touch pad 110. The sensors are configured to
sense user actions on the zones 124 and to send signals
corresponding to the user action to the electronic system. By way
of example, the sensors may be capacitance sensors that sense
capacitance when a finger is in close proximity. The arrangement of
the sensors typically varies according to the specific needs of
each device. In one particular embodiment, the touch pad 110
includes 1024 sensor coordinates that work together to form 128
zones.
[0094] Referring to FIGS. 9 and 10, the zones 124 when actuated are
used to produce on screen movements 126. The control signal for the
on screen movements may be initiated by the touch pad electronics
or by the main system processor of the media player. By tapping or
touching the zone, an object can be moved on the display. For
example, each zone 124 may be configured to represent a particular
movement on the display screen 104. In the illustrated embodiments,
each of the zones 124 represents a particular direction of
movement. The directions may be widely varied, however, in the
illustrated embodiment, the directions generally correspond to
angular directions (e.g., similar to the arrow keys on the
keyboard).
[0095] Referring to FIG. 9, for example, the touch pad 110 is
divided into several independent and spatially distinct zones
124A-D, each of which corresponds to a particular movement
direction 126A-D (as shown by arrows), respectively. When zone 124A
is actuated, on screen movements 126A (to the right) are
implemented. When zone 124B is actuated, on screen movements 126B
(upwards) are implemented. When zone 124C is actuated, on screen
movements 126C (to the left) are implemented. When zone 124D is
actuated, on screen movements 126D (down wards) are implemented. As
should be appreciated, these embodiments are well suited for
joystick implementations, two dimensional menu selection, photo
image panning and the like.
[0096] FIGS. 11A-11D show the media player 100 of FIG. 8 being used
by a user 130, in accordance with one embodiment of the invention.
In this embodiment, the media player 100 is being addressed for one
handed operation in which the media player 100 is held in the
user's hand 136 while the buttons and touch pad 110 are manipulated
by the thumb 138 of the same hand 136. By way of example, the palm
140 and rightmost fingers 141 (or leftmost fingers if left handed)
of the hand 136 are used to grip the sides of the media player 100
while the thumb 138 is used to actuate the touch pad 110. As shown,
the entire top surface of the touch pad 110 is accessible to the
user's thumb 138. Referring to FIG. 11A, on screen movements 126A
to the right are implemented when the thumb 138 is placed (or
tapped) on button zone 124A. Referring to FIG. 11B, on screen
movements 126B upwards are implemented when the thumb 138 is placed
on button zone 124B. Referring to FIG. 11C, on screen movements
126C to the left are implemented when the thumb 138 is placed on
button zone 124C. Referring to FIG. 11D, on screen movements 126D
downwards are implemented when the thumb 138 is placed on button
zone 124D.
[0097] It should be noted that the configuration shown in FIGS.
11A-D is not a limitation and that the media player may be held a
variety of ways. For example, in an alternate embodiment, the media
device may comfortably held by one hand while being comfortably
addressed by the other hand. This configuration generally allows
the user to easily actuate the touch pad with one or more fingers.
For example, the thumb and rightmost fingers (or leftmost fingers
if left handed) of the first hand are used to grip the sides of the
media player while a finger of the opposite hand is used to actuate
the touch pad. The entire top surface of the touch pad is
accessible to the user's finger.
[0098] FIG. 12 is a partially broken away perspective view of an
annular capacitive touch pad 150, in accordance with one embodiment
of the present invention. The annular capacitive touch pad 150 is
arranged to detect changes in capacitance as the user moves, taps,
rests an object such as a finger on the touch pad 150. The annular
capacitive touch pad 150 is formed from various layers including at
least a label layer 152, an electrode layer 154 and a circuit board
156. The label layer 152 is disposed over the electrode layer 154
and the electrode layer 154 is disposed over the circuit board 156.
At least the label 152 and electrode layer 154 are annular such
that they are defined by concentric circles, i.e., they have an
inner perimeter and an outer perimeter. The circuit board 156 is
generally a circular piece having an outer perimeter that coincides
with the outer perimeter of the label 152 and electrode layer 154.
It should be noted, however, that in some cases the circuit board
156 may be annular or the label 152 and electrode layer 154 may be
circular.
[0099] The label layer 152 serves to protect the underlayers and to
provide a surface for allowing a finger to slide thereon. The
surface is generally smooth so that the finger does not stick to it
when moved. The label layer 152 also provides an insulating layer
between the finger and the electrode layer 154. The electrode layer
1'54 includes a plurality of spatially distinct electrodes 158 that
have positions based on the polar coordinate system. For instance,
the electrodes 158 are positioned angularly and/or radically on the
circuit board 156 such that each of the electrodes 158 defines a
distinct angular and/or radial position thereon. Any suitable
number of electrodes 158 may be used. In most cases, it would be
desirable to increase the number of electrodes 158 so as to provide
higher resolution, i.e., more information can be used for things
such as acceleration. In the illustrated embodiment, the electrode
layer 154 is broken up into a plurality of angularly sliced
electrodes 158. The angularly sliced electrodes 158 may be grouped
together to form one or more distinct button zones 159. In one
implementation, the electrode layer 154 includes about 1024
angularly sliced electrodes that work together to form 128
angularly sliced button zones 159.
[0100] When configured together, the touch pad 150 provides a touch
sensitive surface that works according to the principals of
capacitance. As should be appreciated, whenever two electrically
conductive members come close to one another without actually
touching, their electric fields interact to form capacitance. In
this configuration, the first electrically conductive member is one
or more of the electrodes 158 and the second electrically
conductive member is the finger of the user. Accordingly, as the
finger approaches the touch pad 150, a tiny capacitance forms
between the finger and the electrodes 158 in close proximity to the
finger. The capacitance in each of the electrodes 158 is measured
by control circuitry 160 located on the backside of the circuit
board 156. By detecting changes in capacitance at each of the
electrodes 158, the control circuitry 160 can determine the angular
and/or radial location, direction, speed and acceleration of the
finger as it is moved across the touch pad 150. The control
circuitry 160 can also report this information in a form that can
be used by a computing device such as a media player. By way of
example, the control circuitry may include an ASIC (application
specific integrated circuit).
[0101] Referring to FIG. 13, a radial touch pad 178 (rather than an
angular touch pad as shown in FIG. 12) will be discussed in
accordance with one embodiment. The touch pad 178 may be divided
into several independent and spatially distinct button zones 180
that are positioned radically from the center 182 of the touch pad
178 to the perimeter 184 of the touch pad 178. Any number of radial
zones may be used. In one embodiment, each of the radial zones 180
represents a radial position in the plane of the touch pad 178. By
way of example, the zones 180 may be spaced at 5 mm increments.
Like above, each of the button zones 180 has one or more electrodes
186 disposed therein for detecting the presence of an object such
as a finger. In the illustrated embodiment, a plurality of radial
electrodes 186 are combined to form each of the button zones
180.
[0102] Referring to FIG. 14, a combination angular/radial touch pad
188 will be discussed in accordance with one embodiment. The touch
pad 188 may be divided into several independent and spatially
distinct button zones 190 that are positioned both angularly and
radically about the periphery of the touch pad 188 and from the
center of the touch pad 188 to the perimeter of the touch pad 138.
Any number of combination zones may be used. In one embodiment,
each of the combination button zones 190 represents both an angular
and radial position in the plane of the touch pad 188. By way of
example, the zones may be positioned at both 2 degrees and 5 mm
increments. Like above, each of the combination zones 190 has one
or more electrodes 192 disposed therein for detecting the presence
of an object such as a finger. In the illustrated embodiment, a
plurality of angular/radial electrodes 192 are combined to form
each of the button zones 190.
[0103] Furthermore, in order to provide higher resolution, a more
complex arrangement of angular/radial electrodes may be used. For
example, as shown in FIG. 15, the touch pad 200 may include angular
and radial electrodes 202 that are broken up such that consecutive
zones do not coincide exactly. In this embodiment, the touch pad
200 has an annular shape and the electrodes 202 follow a spiral
path around the touch pad 200 from the center to the outer
perimeter of the touch pad 200. The electrodes 202 may be grouped
together to form one or more distinct button zones 204.
[0104] It should be noted that although the touch pads herein are
all shown as circular that they may take on other forms such as
other curvilinear shapes (e.g., oval, annular and the like),
rectilinear shapes (e.g., hexagon, pentagon, octagon, rectangle,
square, and the like) or a combination of curvilinear and
rectilinear (e.g., dome).
[0105] The various aspects of the inventions described above can be
used alone or in various combinations. The invention is preferably
implemented by a combination of hardware and software, but can also
be implemented in hardware or software. The invention can also be
embodied as computer readable code on a computer readable medium.
The computer readable medium is any data storage device that can
store data which can thereafter be read by a computer system.
Examples of the computer readable medium include read-only memory,
random-access memory, CD-ROMs, DVDs, magnetic tape, optical data
storage devices, and carrier waves. The computer readable medium
can also be distributed over a network coupled computer systems so
that the computer readable code is stored and executed in a
distributed fashion.
[0106] As mentioned above, the touch pad assembly may communicate
with the host device via a serial interface. An example of a serial
interface will now be described. The serial interface consists of
at least four signals including a clock, ATN, DATA-IN, and
DATA_OUT. The clock and DATA_OUT are driven by the touch pad
assembly. The ATN and DATA IN are driven by the host device. In
most cases, packet transfers are initiated by the touch pad
assembly, clocked by the touch pad assembly and done at a time
convenient to the touch pad assembly. The host device relies on the
touch pad assembly to initiate transfers. The touch pad assembly
transfers a packet when it detects a change in button status or
touch pad position or if it detects an ATN signal from the host. If
the host wishes to send data to the touch pad assembly it asserts
the ATN signal and keeps it asserted until after the packet it
wants to send has been transferred. The touch pad assembly monitors
the ATN signal and initiates a transfer if it sees it asserted.
[0107] There are typically several defined packets types that the
touch pad assembly can transmit. In this example, there are at
least two kinds of packets: unsolicited packets and packets sent as
a response to an ATN signal. The touch pad assembly sends
unsolicited packets unless specifically asked by the host to send
another type. In the case of unsolicited packets, the unsolicited
packets are sent periodically whenever it detects a change in
button status or touch pad position. In the case of solicited
packets, the touch pad assembly typically only sends one for each
request by the host and then reverts back to unsolicited packets.
Unsolicited packets generally have a delay between them while
response packets may be sent at any time in response to the ATN
signal.
[0108] While this invention has been described in terms of several
preferred embodiments, there are alterations, permutations, and
equivalents, which fall within the scope of this invention. For
example, although the invention has been described in terms of an
MP3 music player, it should be appreciated that certain features of
the invention may also be applied to other types of media players
such as video recorders, cameras, and the like. Furthermore, the
MP3 music player described herein is not limited to the MP3 music
format. Other audio formats such as MP3 VBR (variable bit rate),
AIFF and WAV formats may be used. Moreover, certain aspects of the
invention are not limited to handheld devices. For example, the
touch pad may also be used in other computing devices such as a
portable computer, personal digital assistants (PDA), cellular
phones, and the like. The touch pad may also be used a stand alone
input device that connects to a desktop or portable computer.
[0109] It should also be noted that there are many alternative ways
of implementing the methods and apparatuses of the present
invention. For example, although the touch pad has been described
in terms of being actuated by a finger, it should be noted that
other objects may be used to actuate it in some cases. For example,
a stylus or other object may be used in some configurations of the
touch pad. It is therefore intended that the following appended
claims be interpreted as including all such alterations,
permutations, and equivalents as fall within the true spirit and
scope of the present invention.
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