U.S. patent application number 15/477409 was filed with the patent office on 2017-10-05 for movable track pad with smudge-resistant input surface.
The applicant listed for this patent is Apple Inc.. Invention is credited to Bartley K. Andre, Matthew P. Casebolt, Brett William Degner, Patrick Kessler, Christiaan A. Ligtenberg, Thomas W. Wilson, JR..
Application Number | 20170285781 15/477409 |
Document ID | / |
Family ID | 42056883 |
Filed Date | 2017-10-05 |
United States Patent
Application |
20170285781 |
Kind Code |
A1 |
Degner; Brett William ; et
al. |
October 5, 2017 |
Movable Track Pad with Smudge-Resistant Input Surface
Abstract
An input device is disclosed. The input device includes a
movable touch-sensitive track pad capable of detecting an object in
close proximity thereto so as to generate a tracking control
signal. The input device also includes a movement indicator capable
of detecting the movements of the ovable track pad so as to
generate one or more other control signals (e.g, button signals).
The control signals can be used to perform actions in an electronic
device operatively coupled to the input device.
Inventors: |
Degner; Brett William;
(Menlo Park, CA) ; Kessler; Patrick; (San
Francisco, CA) ; Ligtenberg; Christiaan A.; (San
Carlos, CA) ; Wilson, JR.; Thomas W.; (Saratoga,
CA) ; Andre; Bartley K.; (Menlo Park, CA) ;
Casebolt; Matthew P.; (Fremont, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
42056883 |
Appl. No.: |
15/477409 |
Filed: |
April 3, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14660800 |
Mar 17, 2015 |
9612674 |
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15477409 |
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13864193 |
Apr 16, 2013 |
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14660800 |
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12241967 |
Sep 30, 2008 |
8441450 |
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13864193 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 2203/04105
20130101; G06F 3/041 20130101; H01H 25/041 20130101; G06F 3/0443
20190501; G06F 3/0445 20190501; G06F 3/03547 20130101; G06F 1/169
20130101; G06F 3/042 20130101; G06F 3/044 20130101 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G06F 1/16 20060101 G06F001/16; G06F 3/042 20060101
G06F003/042; H01H 25/04 20060101 H01H025/04; G06F 3/0354 20060101
G06F003/0354; G06F 3/044 20060101 G06F003/044 |
Claims
1. (canceled)
2. An input device comprising: a touch-sensitive track pad
comprising: an input surface; an electrode layer positioned below
the input surface and configured to detect a location of a user
touch on the input surface; and a substrate supporting the
electrode layer; and a frame comprising a flexure configured to
flex in response to pressure on the input surface of the
touch-sensitive track pad; and a pressure sensor coupled to the
frame and configured to provide a continuous measurement of an
amount of depression of the input surface in response to the
pressure.
3. The input device of claim 2, wherein the pressure sensor
comprises a strain gauge.
4. The input device of claim 2, wherein the electrode layer is
configured to detect a location of multiple user touches on the
input surface.
5. The input device of claim 2, wherein the flexure comprises a
resilient material.
6. The input device of claim 5, wherein the resilient material
comprises spring steel.
7. The input device of claim 2, wherein the electrode layer detects
the location of the user touch based on capacitive sensing.
8. The input device of claim 2, further comprising an acoustic
module configured to provide audio feedback in response to the
detected pressure.
9. The input device of claim 2, further comprising a haptic module
configured to produce haptic vibration in response to the detected
pressure.
10. A touch-sensitive track pad comprising: an input surface; a
circuit board coupled beneath the input surface and comprising
touch sensors configured to detect a user touch and a location of
the user touch on the input surface; a frame supporting the circuit
board; a flexure hinge coupled to the frame and configured to
resist depression of the input surface; a movement indicator
disposed beneath the circuit board and configured to detect an
amount of movement of the input surface in response to the user
touch.
11. The touch-sensitive track pad of claim 10, wherein the movement
indicator comprises a strain gauge configured to provide an analog
measurement of the amount of movement of the input surface in
response to the user touch.
12. The touch-sensitive track pad of claim 10, further comprising a
stiffener material coupled to the circuit board opposite the input
surface.
13. The touch-sensitive track pad of claim 10, wherein the flexure
hinge comprises spring steel.
14. The touch-sensitive track pad of claim 10, wherein the touch
sensors detect the user touch based on capacitive sensing.
15. An electronic device comprising: a housing comprising an
aperture; and an input device positioned at least partially within
the aperture and comprising: an input surface; a touch sensor layer
coupled below the input surface and configured to detect a user
touch and a location of the user touch on the input surface; a
substrate supporting the input surface; a frame positioned at least
partially below the substrate and comprising a flexure hinge
supporting the substrate; and a pressure sensor coupled to the
frame and configured to provide a continuous measurement of an
amount of depression of the input surface in response to the user
touch.
16. The electronic device of claim 15, wherein the substrate is a
printed circuit board on which the touch sensor layer is
disposed.
17. The electronic device of claim 15, wherein the pressure sensor
comprises a strain gauge.
18. The electronic device of claim 15, wherein the flexure hinge
comprises spring steel.
19. The electronic device of claim 15, wherein the touch sensor
layer detects the user touch based on capacitive sensing.
20. The electronic device of claim 15, further comprising an
acoustic module configured to provide audio feedback in response to
the detected user touch.
21. The electronic device of claim 15, further comprising a haptic
module configured to produce haptic vibration in response to the
detected user touch.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. patent application is a continuation of U.S.
application Ser. No. 14/660,800, filed Mar. 17, 2015, and entitled
"MOVABLE TRACK PAD WITH SMUDGE-RESISTANT INPUT SURFACE," now U.S.
Pat. No. 9,612,674, which is a continuation of U.S. application
Ser. No. 13/864,193, filed Apr. 16, 2013, and entitled "MOVABLE
TRACK PAD WITH SMUDGE-RESISTANT INPUT SURFACE," now abandoned,
which is a continuation of U.S. application Ser. No. 12/241,967,
filed Sep. 30, 2008, and entitled "MOVABLE TRACK PAD WITH ADDED
FUNCTIONALITY," now U.S. Pat. No. 8,441,450, all of which are
incorporated by reference in their entirety for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates generally to track pads. More
particularly, the present invention relates to track pads capable
of relative movement in order to increase the functionality of the
track pad.
2. Background Art
[0003] 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.
[0004] In portable computing devices such as laptop computers, the
input devices are commonly track pads (also known as touch pads).
With a track 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 track pad.
Track pads can also make a selection on the display screen when one
or more taps are detected on the surface of the track pad. In some
cases, any portion of the track pad may be tapped, and in other
cases a dedicated portion of the track 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.
[0005] In addition to allowing input pointer movements and
selections with respect to a graphical user interface, or 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, track 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.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention relates generally to a track pad
capable of detecting an object in close proximity thereto. More
particularly, the present invention relates to a track pad capable
of moving in order to increase the functionality of the track pad.
For example, the track pad may be depressible so as to provide
additional button functionality.
[0007] The invention relates in one embodiment to an input device
having a track pad and a track surface. A flexure hinge is
operatively connected at one end of the track pad and is configured
to allow displacement of the track pad from a neutral position to
an activate position when a force is applied to substantially any
portion of the track surface, while at the same time urging the
track pad towards the neutral position from the activate position.
The track pad generates a first control signal when the track pad
is at the activate position and the track pad generates a second
control signal when an object is moved relative to the track
surface.
[0008] The invention relates in another embodiment to a computing
system having a computing device capable of receiving, processing
and outputting data and an input device configured to send data to
the computing device in order to perform an action in the computing
device. The input device has a depressible touch-sensitive track
pad coupled to the computing device by a flexure hinge and is
configured to generate tracking signals, and a movement indicator
configured to generate a button signal when the track pad is
depressed.
[0009] The invention relates in another embodiment to an input
device having a capacitive touch sensitive track pad with an etched
glass track surface. A flexure hinge is operatively connected at
one end of the track pad and is configured to allow displacement of
the track pad from a neutral position to an activate position when
a force is applied to substantially any portion of the track
surface, while at the same time urging the track pad towards the
neutral position from the activate position. The track pad
generates a button signal when the track pad is in the activate
position and the track pad generates a tracking signal when an
object is moved relative to the track surface.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0010] 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:
[0011] FIG. 1 is a simplified diagram of a touch pad and
display.
[0012] FIG. 2 is a perspective view of an input device, in
accordance with one embodiment of the present invention.
[0013] FIGS. 3A, 3B, 3C, and 3D are simplified side views of an
input device having a button touch pad, in accordance with one
embodiment of the present invention.
[0014] FIG. 4 is simplified block diagram of an input device
connected to a computing device, in accordance with one embodiment
of the present invention.
[0015] FIG. 5 is a side view, in cross section, of an input device,
in accordance with one embodiment of the present invention.
[0016] FIG. 6 is a another side view, in cross section, of the
input device of FIG. 5.
[0017] FIG. 7 is a perspective view of an input device being used
as a track pad in a laptop computer, in accordance with one
embodiment of the present invention.
[0018] FIG. 8 is an exploded view of the input device of FIG.
7.
[0019] FIG. 9 is a side view, in cross section, of a stiffener.
[0020] FIG. 10 is a bottom view of a portion of the input device of
FIG. 7.
[0021] FIG. 11 is a side view, in cross section of a portion of the
input device of FIG. 7.
[0022] FIG. 12 is a side view, in cross section of a portion of the
input device of FIG. 7.
[0023] FIG. 13 is a side view, in cross section of a portion of the
input device of FIG. 7.
[0024] FIG. 14 is a side view, in cross section of a portion of the
input device of FIG. 7.
[0025] FIG. 15 is a perspective diagram of a media player, in
accordance with one embodiment of the present invention.
[0026] FIG. 16 is a perspective diagram of a mobile phone, in
accordance with one embodiment of the present invention.
[0027] FIG. 17 is a perspective diagram of a desktop computer with
a peripheral input device connected thereto, in accordance with one
embodiment of the present invention
[0028] FIG. 18 is a perspective diagram of a remote control
utilizing an input device, in accordance with one embodiment of the
present invention.
[0029] FIG. 19 is a simplified block diagram of a remote control,
in accordance with one embodiment of the present invention.
[0030] FIGS. 20A, 20B, 20C, 20D, 20E, and 20F are top views of
track pads having delineated zones, in accordance with one
embodiment of the present invention.
[0031] FIG. 21 is a top view of a track pad having a full pixel
display, in accordance with one embodiment of the present
invention.
[0032] FIG. 22 is a side view, in cross section of electronic ink,
in accordance with one embodiment of the present invention.
[0033] FIG. 23 is a side view of a piece of glass, in accordance
with one embodiment of the present invention.
[0034] FIG. 24A is a side view of a piece of etched glass, in
accordance with one embodiment of the present invention.
[0035] FIG. 24b is a top magnified view of the piece of glass shown
in FIG. 24b .
[0036] FIG. 25 is a side view of a piece of etched glass, in
accordance with one embodiment of the present invention.
[0037] FIG. 26 is a top view of the surface of the piece of glass
shown in FIG. 25.
[0038] FIG. 27 is a graph of the peak-to-peak ratio of the glass
surface shown in FIGS. 25 and 26.
[0039] FIG. 28 is a side view, in cross section of a portion of an
input device, in accordance with one embodiment of the present
invention.
[0040] FIG. 29 is a side view, in cross section of a portion of an
input device, in accordance with one embodiment of the present
invention.
[0041] FIG. 30 is a side view, in cross section of a portion of an
input device, in accordance with one embodiment of the present
invention.
[0042] FIG. 31 is a side view, in cross section of a portion of an
input device, in accordance with one embodiment of the present
invention.
[0043] FIG. 32 is a side view of an input device, in accordance
with one embodiment of the present invention.
[0044] FIG. 33 is a bottom view of the input device of FIG. 32.
[0045] FIG. 34A is a side view, in cross section, of an input
device, in accordance with one embodiment of the present
invention.
[0046] FIG. 34B is a side view, in cross section, of an input
device, in accordance with one embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0047] The present invention will now be described in detail with
reference to a few 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.
[0048] With regards to track 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.
[0049] Track pads generally include one or more sensors for
detecting the proximity of the finger thereto. By way of example,
the sensors may be based on resistive sensing, surface acoustic
wave sensing, pressure sensing, optical sensing, capacitive sensing
and the like. The sensors are generally dispersed about the track
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 track 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.
[0050] Capacitive sensing surfaces generally contain several layers
of material. For example, the capacitive sensing surface may
include a protective/cosmetic shield (usually a dielectric
material), 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. The electrode layer and circuit board may be, for
example, a printed circuit board (PCB). The protective shield is
the part of the capacitive sensing surface 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.
[0051] The capacitive sensing surface 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.
[0052] Referring to FIG. 1, a touch-sensitive track pad 10 will be
described in greater detail. The track pad is generally a small
(often rectangular) area that includes a protective/cosmetic shield
12 and a plurality of electrodes 14 disposed underneath the
protective shield 12. Electrodes 14 may be located on a circuit
board, for example a printed circuit board (PCB). For ease of
discussion, a portion of the protective shield 12 has been removed
to show the electrodes 14. Each of the electrodes 14 represents a
different x, y position. In one configuration, as a finger 16 (or
alternately a stylus, not shown) approaches the electrode grid 14,
a tiny capacitance forms between the finger 16 and the electrodes
14 proximate the finger 16. The circuit board/sensing electronics
(not shown) measures capacitance and produces an x, y input signal
18 corresponding to the active electrodes 14 which is sent to a
host device 20 (e.g., a computing device) having a display screen
22. The x, y input signal 18 is used to control the movement of a
cursor 24 on a display screen 22. As shown, the input pointer moves
in a similar x, y direction as the detected x, y finger motion.
FIG. 2 is a simplified perspective view of an input device 30, in
accordance with one embodiment of the present invention. The input
device 30 is generally configured to send information or data to an
electronic device (not shown) in order to perform an action on a
display screen (e.g., via a graphical user interface (GUI)). For
example, moving an input pointer, making a selection, providing
instructions, etc. The input device may interact with the
electronic device through a wired (e.g., cable/connector) or
wireless connection (e.g., IR, bluetooth, etc.).
[0053] The input device 30 may be a stand alone unit or it may be
integrated into the electronic device. When in a stand alone unit,
the input device typically has its own enclosure. When integrated
with an electronic device, the input device typically uses the
enclosure of the electronic device. In either case, the input
device may be structurally coupled to the enclosure as for example
through screws, snaps, retainers, adhesives and the like. In some
cases, the input device may be removably coupled to the electronic
device as for example through a docking station. The electronic
device to which the input device is coupled may correspond to any
consumer related electronic product. By way of example, the
electronic device may correspond to a computer such as a desktop
computer, laptop computer or PDA, a media player such as a music
player, a communication device such as a cellular phone, another
input device such as a keyboard, and the like.
[0054] As shown in FIG. 2, the input device 30 includes a frame 32
(or support structure) and a track pad 34. The frame 32 provides a
structure for supporting the components of the input device. The
frame 32 in the form of a housing may also enclose or contain the
components of the input device. The components, which include the
track pad 34, may correspond to electrical, optical and/or
mechanical components for operating the input device 30.
[0055] Track pad 34 provides an intuitive interface configured to
provide one or more control functions for controlling various
applications associated with the electronic device to which it is
attached.
[0056] By way of example, the touch initiated control function may
be used to move an object or perform an action on the display
screen or to make selections or issue commands associated with
operating the electronic device. In order to implement the touch
initiated control function, the track pad 34 may be arranged to
receive input from a finger (or object) moving across the surface
of the track pad 34 (e.g., linearly, radially, angular, etc.), from
a finger holding a particular position on the track pad 34 and/or
by a finger tapping on a particular position of the track pad 34.
As should be appreciated, the touch pad 34 provides easy one-handed
operation, i.e., lets a user interact with the electronic device
with one or more fingers.
[0057] The track pad 34 may be widely varied. For example, the
touch pad 34 may be a conventional track pad based on the Cartesian
coordinate system, or the track pad 34 may be a touch pad based on
a polar coordinate system. An example of a touch pad based on polar
coordinates may be found in U.S. Pat No. 7,046,230 to Zadesky et
al., entitled "TOUCH PAD FOR HANDHELD DEVICE", filed Jul. 1, 2002,
which is herein incorporated in its entirety by reference
thereto.
[0058] The track pad 34 may be used in a relative or absolute mode.
In absolute mode, the track pad 34 reports the absolute coordinates
of where it is being touched. 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 track pad 34 reports
the direction and/or distance of change. For example, left/right,
up/down, and the like. In most cases, the signals produced by the
track pad 34 direct motion on the display screen in a direction
similar to the direction of the finger as it is moved across the
surface of the track pad 34.
[0059] The shape of the track pad 34 may be widely varied. For
example, the track pad 34 may be circular, oval, square,
rectangular, triangular, and the like. In general, the outer
perimeter of the track pad 34 defines the working boundary of the
track pad 34. In the illustrated embodiment, the track pad is
rectangular. Rectangular track pads are common on laptop
computers.
[0060] The track pad 34, which generally takes the form of a rigid
planar platform, includes a touchable outer track surface 36 for
receiving a finger (or object) for manipulation of the track pad.
Although not shown in FIG. 2, beneath the touchable outer track
surface 36 is a sensor arrangement that is sensitive to such things
as the pressure and/or motion of a finger thereon. The sensor
arrangement typically includes a plurality of sensors that are
configured to activate as the finger sits on, taps on or passes
over them. In the simplest case, an electrical signal is produced
each time the finger is positioned over a sensor. The number of
signals in a given time frame may indicate location, direction,
speed, and acceleration of the finger on the track pad 34, i.e.,
the more signals, the more the user moved his finger. In most
cases, the signals are monitored by an electronic interface that
converts the number, combination and frequency of the signals into
location, direction, speed and acceleration information. This
information may then be used by the electronic device to perform
the desired control function on the display screen. The sensor
arrangement may be widely varied. By way of example, the sensors
may be based on resistive sensing, surface acoustic wave sensing,
pressure sensing (e.g., strain gauge), infrared sensing, optical
sensing, dispersive signal technology, acoustic pulse recognition,
capacitive sensing and the like.
[0061] In the illustrated embodiment, the track pad 34 is based on
capacitive sensing. A capacitively-based track pad is arranged to
detect changes in capacitance as the user moves an object such as a
finger around the track pad. In most cases, the capacitive track
pad includes a protective shield, one or more electrode layers, a
circuit board and associated electronics including an application
specific integrated circuit (ASIC). The protective shield is placed
over the electrodes; the electrodes are mounted on the top surface
of the circuit board; and the ASIC is mounted on the bottom surface
of the circuit board. The protective shield 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 protective shield also provides an
insulating layer between the finger and the electrode layers. The
electrode layer includes a plurality of spatially distinct
electrodes. Any suitable number of electrodes may be used. In most
cases, it would be desirable to increase the number of electrodes
so as to provide higher resolution, i.e., more information can be
used for things such as acceleration.
[0062] Capacitive sensing 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
the configuration discussed above, the first electrically
conductive member is one or more of the electrodes and the second
electrically conductive member is, for example, the finger of the
user. Accordingly, as the finger approaches the touch pad, a tiny
capacitance forms between the finger and the electrodes in close
proximity to the finger. The capacitance in each of the electrodes
is measured by an ASIC located on the bottom (or backside) of the
circuit board. By detecting changes in capacitance at each of the
electrodes, the ASIC can determine the location, direction, speed
and acceleration of the finger as it is moved across the touch pad.
The ASIC can also report this information in a form that can be
used by the electronic device.
[0063] In accordance with one embodiment, track pad 34 is movable
relative to frame 32 so as to initiate another set of signals
(other than just tracking signals). By way of example, track pad 34
in the form of the rigid planar platform may rotate, pivot, slide,
translate, flex and/or the like relative to frame 32. Track pad 34
may be coupled to frame 32 and/or it may be movably restrained by
frame 32. By way of example, track pad 34 may be coupled to frame
32 through screws, axels, pin joints, slider joints, ball and
socket joints, flexure joints, magnets, cushions and/or the like.
Track pad 34 may also float within a space of the frame (e.g.,
gimbal). It should be noted that the input device 30 may
additionally include a combination of joints such as a
pivot/translating joint, pivot/flexure joint, pivot/ball and socket
joint, translating/flexure joint, and the like to increase the
range of motion (e.g., increase the degree of freedom). When moved,
touch pad 34 is configured to actuate a circuit that generates one
or more signals. The circuit generally includes one or more
movement indicators such as switches, sensors, encoders, and the
like. An example of a gimbaled track pad may be found in patent
application Ser. No. 10/643,256, entitled, "MOVABLE TOUCH PAD WITH
ADDED FUNCTIONALITY," filed Aug. 18, 2003, which is herein
incorporated in its entirety by reference thereto.
[0064] In the illustrated embodiment, track pad 34 takes the form
of a depressible button that performs a "picking" action. That is,
a portion of the entire track pad 34 acts like a single or multiple
button such that one or more additional button functions may be
implemented by pressing on track pad 34 rather than tapping on the
track pad or using a separate button/separate zone. As shown in
FIGS. 3A and 3 B, according to one embodiment of the invention,
track pad 34 is capable of moving between an upright (or neutral)
position (FIG. 3A) and a depressed (or activate) position (FIG. 3B)
when a force from a finger 38, palm, hand, or other object is
applied to the track pad 34. The force should not be so small as to
allow for accidental activation of the button signal, but not so
large as to cause user discomfort by requiring undue pressure.
Track pad 34 is typically biased in the upright position as for
example through a flexure hinge, a spring member, or magnets. Track
pad 34 moves to the activate position when the bias is overcome by
an object pressing on track pad 34. As shown in FIG. 3C, the track
pad 34 may be pivoted at one end such that the activate position is
slightly inclined with respect to the neutral position. When the
finger (or other object) is removed from track pad 34, the biasing
member urges it back towards the neutral position. A shim, shock
absorber, upstop or other structure (not shown) may prevent track
pad 34 from overshooting the neutral position as it returns. For
example, a portion of frame =may extend outwardly above a portion
of track pad 34 so as to stop track pad 34 at the neutral position.
In this way, the track surface can be kept flush with frame 32 if
desired. For example, in laptop computers or handheld media
devices, it may be desirable to have the track pad flush with the
housing of the computer or device.
[0065] As shown in FIG. 3A, in the upright/neutral position, track
pad 34 generates tracking signals when an object such as a user's
finger is moved over the top surface of the touch pad in the x, y
plane. Although FIG. 3A depicts the neutral position as being
upright, the neutral position may be situated at any orientation.
As shown in FIG. 3B, in the depressed position (z direction), track
pad 34 generates one or more button signals. The button signals may
be used for various functionalities including but not limited to
making selections or issuing commands associated with operating an
electronic device. By way of example, in the case of a 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. In the case of a laptop computer, the button functions
can be associated with opening a menu, selecting text, selecting an
icon, and the like. As shown in FIG. 3D, input device 30 may be
arranged to provide both the tracking signals and the button signal
at the same time, i.e., simultaneously depressing the touch pad 34
in the z direction while moving tangentially along the track
surface (i.e., in the x, y directions). In other cases, input
device 30 may be arranged to only provide a button signal when
touch pad 34 is depressed and a tracking signal when the touch pad
34 is upright.
[0066] To elaborate, track pad 34 is configured to actuate one or
more movement indicators, which are capable of generating the
button signal when track pad 34 is moved to the activate position.
The movement indicators are typically located within frame 32 and
may be coupled to track pad 34 and/or frame 32. The movement
indicators may be any combination of switches and sensors. Switches
are generally configured to provide pulsed or binary data such as
activate (on) or deactivate (off). By way of example, an underside
portion of track pad 34 may be configured to contact or engage (and
thus activate) a switch when the user presses on track pad 34. The
sensors, on the other hand, are generally configured to provide
continuous or analog data. By way of example, the sensor may be
configured to measure the position or the amount of tilt of touch
pad 34 relative to the frame when a user presses on the track pad
34. Any suitable mechanical, electrical and/or optical switch or
sensor may be used. For example, tact switches, force sensitive
resistors, pressure sensors, proximity sensors and the like may be
used.
[0067] Track pads 10 and 30 shown in FIGS. 1-3 may, in some
embodiments, be multi-touch trackpads. Multi-touch consists of a
touch surface (screen, table, wall, etc.) or touchpad, as well as
software that recognizes multiple simultaneous touch points, as
opposed to the standard touchscreen (e.g., computer touchpad, ATM),
which recognizes only one touch point. This effect is achieved
through a variety of means, including but not limited to:
capacitive sensing, resistive sensing, surface acoustic wave
sensing, heat, finger pressure, high capture rate cameras, infrared
light, optic capture, tuned electromagnetic induction, and shadow
capture. An example of a multi-touch mobile phone is the iPhone
produced by Apple Inc. of Cupertino, Calif. An example of a
multi-touch media device is the iPod Touch produced by Apple Inc.
Examples of laptop computers having multi-touch track pads are the
MacBook Air and MacBook Pro produced by Apple Inc. All of the input
devices described herein may employ multi-touch technology in some
embodiments; alternatively the input devices described herein may
employ single touch track pads.
[0068] FIG. 4 is a simplified block diagram of a computing system
39, in accordance with one embodiment of the present invention. The
computing system generally includes an input device 40 operatively
connected to a computing device 42. By way of example, the input
device 40 may generally correspond to the input device 30 shown in
FIGS. 2 and 3, and the computing device 42 may correspond to a
laptop computer, desktop computer, PDA, media player, mobile phone,
smart phone, video game or the like. As shown, input device 40
includes a depressible track pad 44 and one or more movement
indicators 46. Track pad 44 is configured to generate tracking
signals and movement indicator 46 is configured to generate a
button signal when the track pad 44 is depressed. Although track
pad 44 may be widely varied, in this embodiment, track pad 44
includes capacitance sensors 48 and a control system 50 for
acquiring the position signals from sensors 48 and supplying the
signals to computing device 42. Control system 50 may include an
application specific integrated circuit (ASIC) that is configured
to monitor the signals from sensors 48, to compute the location
(Cartesian or angular), direction, speed and acceleration of the
monitored signals and to report this information to a processor of
computing device 42. Movement indicator 46 may also be widely
varied. In this embodiment, however, movement indicator 46 takes
the form of a switch that generates a button signal when track pad
44 is depressed. Switch 46 may correspond to a mechanical,
electrical or optical style switch. In one particular
implementation, switch 46 is a mechanical style switch that
includes a protruding actuator 52 that may be pushed by track pad
44 to generate the button signal. By way of example, the switch may
be a tact switch or tactile dome.
[0069] Both track pad 44 and switch 46 are operatively coupled to
computing device 42 through a communication interface 54. The
communication interface provides a connection point for direct or
indirect connection between the input device and the electronic
device. Communication interface 54 may be wired (wires, cables,
connectors) or wireless (e.g., transmitter/receiver).
[0070] Computing device 42 generally includes a processor 55 (e.g.,
CPU or microprocessor) configured to execute instructions and to
carry out operations associated with the computing device 42. For
example, using instructions retrieved for example from memory, the
processor may control the reception and manipulation of input and
output data between components of the computing device 42. In most
cases, processor 55 executes instruction under the control of an
operating system or other software. Processor 55 can be a
single-chip processor or can be implemented with multiple
components.
[0071] Computing device 42 also includes an input/output (I/O)
controller 56 that is operatively coupled to processor 55. I/O
controller 56 may be integrated with processor 55 or it may be a
separate component, as shown. I/O controller 56 is generally
configured to control interactions with one or more I/O devices
that can be coupled to computing device 42, for example, input
device 40. I/O controller 56 generally operates by exchanging data
between computing device 42 and I/O devices that desire to
communicate with computing device 42.
[0072] Computing device 42 also includes a display controller 58
that is operatively coupled to processor 55. Display controller 58
may be integrated with processor 55 or it may be a separate
component, as shown. Display controller 58 is configured to process
display commands to produce text and graphics on a display screen
60. By way of example, display screen 60 may be a monochrome
display, color graphics adapter (CGA) display, enhanced graphics
adapter (EGA) display, variable-graphics-array (VGA) display, super
VGA display, liquid crystal display (LCD) (e.g., active matrix,
passive matrix and the like), cathode ray tube (CRT), plasma
displays, backlit light-emitting diode (LED) LCD displays, or the
like.
[0073] In one embodiment (not shown), track pad 44 can comprise a
glass surface functioning not only as a touch-sensitive surface,
but also as a display screen; in this case display screen 60 shown
in FIG. 4 would be integrated with the glass surface of the track
pad 44. This could be useful in computing devices (e.g., media
players or mobile phones) having touch sensitive displays. An
example of a media player having a touch sensitive display is the
iPod Touch produced by Apple Inc. of Cupertino Calif. An example of
a mobile phone having a touch sensitive display is the iPhone
produced by Apple Inc. of Cupertino Calif.
[0074] In most cases, processor 55 together with an operating
system operates to execute computer code and produce and use data.
The computer code and data may reside within a program storage area
62 that is operatively coupled to processor 55. Program storage
area 62 generally provides a place to hold data that is being used
by computing device 42. By way of example, the program storage area
may include Read-Only Memory (ROM), Random-Access Memory (RAM),
hard disk drive and/or the like. The computer code and data could
also reside on a removable program medium and loaded or installed
onto the computing device when needed. In one embodiment, program
storage area 62 is configured to store information for controlling
how the tracking and button signals generated by input device 40
are used by computing device 42.
[0075] FIG. 5 shows one embodiment of an input device, generally
shown at 70, comprising a track pad 72 connected to a frame 76.
Frame 76 may be a housing for a stand alone input device, or it may
be a casing for another device which incorporates track pad 72, for
example a laptop computer, desktop computer, hand held media
device, PDA, mobile phone, smart phone, etc. Track pad 72 includes
various layers including an outer touch-sensitive track surface for
tracking finger movements. Track surface 74 may also provide a low
friction cosmetic surface. In one embodiment, track pad 72 is based
on capacitive sensing; therefore, it includes an electrode layer
80, which, for example, may be implemented on a PCB. In the case of
capacitive sensing, track surface 74 is a dielectric material. A
stiffener 84 is located below electrode layer 80. Stiffener 84 is
shown in FIG. 5 and FIG. 6, but in some embodiments may be omitted.
Stiffener 84 may be used to compensate for the inherent flexibility
of electrode layer 80. Electrode layer 80 responds to finger
movements along track surface 74 by sending signals to sensor 82.
In the case of capacitive sensing, electrode layer 80 registers
changes in capacitance based on finger movements and sensor 82 is a
capacitive sensor. In this way, track pad 72 incorporates a touch
sensor arrangement. Sensor 82 is shown disposed on the bottom of
electrode layer 80, but it may be located elsewhere in other
embodiments. If, as in the illustrated embodiment, sensor 82 is
located on a movable part of track pad 72, the input device may
incorporate a flexible electrical connection (not shown) capable of
moving with the system.
[0076] A movement indicator 78 is disposed on the bottom of track
pad 72. Movement indicator 78 may be widely varied, however, in
this embodiment it takes the form of a mechanical switch, which is
typically disposed between the track pad 72 and the frame 76. In
other embodiments, movement indicator 78 may be a sensor, for
example an electrical sensor. Movement indicator 78 may be attached
to frame 76 or to track pad 72. In the illustrated embodiment,
movement indicator 78 is attached to the bottom side of electrode
layer 80. By way of example, if electrode layer 80 is located on a
PCB, movement indicator 78 may be located on the bottom of the PCB.
In another example, movement indicator 78 may take the form of a
tact switch and more particularly, may be an SMT dome switch (dome
switch packaged for SMT).
[0077] Track pad 72 is shown in its neutral position in FIG. 5,
where movement sensor 78 is not in contact with frame 76. When a
user applies a downward pressure to track surface 74, track pad 72
may move downward causing movement sensor 78 to register this
change in position. In the illustrated embodiment, movement sensor
78 (a tact switch) would contact either frame 76, or in this case
set screw 88. Set screw 88 may be manually adjusted to alter the
distance between the neutral and activate positions. In one
embodiment (not shown), set screw 88 may directly abut movement
sensor 78 in the neutral position, such that there is no slack or
pre-travel in the system. A flexure hinge 86 connects track pad 72
with frame 76. Flexure hinge 86 is a resilient material that flexes
when a force is applied, but exerts a restoring force so as to urge
track pad 72 back towards the neutral position. In one embodiment,
flexure hinge 86 may be thin spring steel.
[0078] As shown in FIG. 6, flexure hinge 86 will flex when a user
pushes down on track surface 74. Flexure 86 also urges track pad 72
towards its neutral position, which in the illustrated embodiment
shown in FIG. 5 is horizontal. In this way, a user can press down
virtually anywhere on track surface 74 and cause a "pick," meaning
that movement indicator 78 will register this depression. This is
in contrast to prior track pads which incorporate separate track
zones and pick zones. Being able to pick anywhere on track surface
74 will provide the user with a more intuitive and pleasurable
interface. For example, a user may be able to generate tracking and
button signals with a single finger without ever having to remove
the finger from track surface 74. In contrast, a user operating a
track pad with separate track and pick zones may, for example, use
a right hand for tracking and a left hand for picking, or a
forefinger for tracking and a thumb for picking.
[0079] A shoulder 90, which may be an extension of frame 76 or a
discrete member, blocks track pad 72 from traveling past its
neutral position by contacting a part of track pad 72, for example
stiffener 84. In this way, track surface 74 may be kept
substantially flush with a top surface of frame 76. There may be a
shock absorber or upstop (not shown) incorporated in conjunction
with shoulder 90 to cushion contact between track pad 72 and
shoulder 90.
[0080] As should be appreciated, the pick generated by pressing on
track surface 74 may include selecting an item on the screen,
opening a file or document, executing instructions, starting a
program, viewing a menu, and/or the like. The button functions may
also include functions that make it easier to navigate through the
electronic system, as for example, zoom, scroll, open different
menus, home the input pointer, perform keyboard related actions
such as enter, delete, insert, page up/down, and the like.
[0081] Flexure hinge 86 allows for a movable track pad in the
minimum vertical space possible. Minimum vertical space is achieved
because flexure hinge 86 is thin and is generally situated parallel
to a bottom layer of track pad 72, consequently, flexure hinge 86
does not appreciably add to the thickness of track pad 72.
Therefore, this arrangement is feasible for use in ultrathin laptop
computers (or other ultrathin devices). In such ultrathin laptop
computer applications, vertical space is extremely limited. In the
past, the size of electrical components was often the limiting
feature as to how small electrical devices could be made. Today,
electrical components are increasingly miniaturized, meaning that
mechanical components (e.g., movable track pads) may now be the
critical size-limiting components. With this understanding, it is
easy to appreciate why linear-actuation (e.g., supporting a movable
track pad by coil springs or the like) is not ideal in some
applications. Furthermore, using springs may add unnecessary
complexity (increased part count, higher cost, higher failure
rates, etc.) to the manufacturing process. Another disadvantage of
springs is that in some embodiments springs may mask or compromise
the tactile switch force profile. In contrast, flexure 86 can
deliver a substantially consistent feel across track surface 74,
and give the user a more faithful representation of the tactile
switch force profile.
[0082] Referring now to FIG. 6, according to one embodiment of the
present invention, when a user presses on track surface 74 of track
pad 72, track pad 72 pivots downwardly and activates switch 78
disposed underneath. When activated, switch 78 generates button
signals that may be used by an electronic device connected to input
device 70. Flexure 86 can constrain track pad 72 to move
substantially about only one axis. This can be accomplished by, for
example, using multiple flexures arranged along an axis on one side
of track pad 72, such as the rear side. Furthermore, if track pad
72 is made stiff (for example, by inclusion of stiffener 84 if
necessary), a leveling architecture is achieved. The coupling of a
stiff track pad 72 to flexure hinge 86 allows track pad 72 to
remain level when articulated off-center.
[0083] FIG. 7 and FIG. 8 show an input device 100, in accordance
with one embodiment of the present invention. FIG. 7 is a
perspective view of an input device 100 shown in use with a laptop
computer. FIG. 8 is an exploded perspective view of a disassembled
track pad 101 used in input device 100.
[0084] Input device, shown generally at 100 in FIG. 7 is a
depressible touch-sensitive track pad 101 disposed in a laptop
computer frame 104. As installed in computer frame 104, the only
portion of input device 100 visible to the user is track surface
102, which may be flush with computer frame 104. In the illustrated
embodiment, track surface 102 is glass. Glass provides a
dielectric, low-friction, durable, cosmetic surface. In one
embodiment, track surface 102 is made of slightly frosted glass. In
other embodiments, track surface 102 may be ceramic, plastic, or
the like. If input device 100 is based on capacitive sensing, track
surface 102 must be a dielectric material. The front end (i.e.,
nearest the user) of track surface 102 has a mid point 201 and a
corner 203. Track surface 102 moves approximately 0.2 mm when
picked at the mid point of the extreme front end 201. Due to the
leveling architecture and stiffness of the illustrated embodiment,
track surface 102 moves only approximately 0.4 mm when picked in
the extreme left or right corner of the front end 203, making input
device 100 suitable for use with ultrathin laptops or other
ultrathin applications where a depressible track pad is
desirable.
[0085] As best seen in FIG. 8, immediately below glass 102 is a
layer of ink 106. Ink 106 is for cosmetic purposes, and may be
color-matched to the color of computer frame 104. Alternatively,
ink 106 may be a different color than computer frame 104, for
example, a different shade of a similar color or a contrasting
color. A layer of pressure-sensitive adhesive (PSA) 108 attaches
glass 102 to the top surface of PCB 110. A second layer of PSA 112
attaches the bottom surface of PCB 110 to the top surface of
stiffener 114.
[0086] In the illustrated embodiment, PSA layers 110 and 112 are
shown as sheets shaped to match with the adjacent layers 106, 110,
and 114. Modifications can be made, for example cutting holes in
layers 110 and 112 to accommodate rigid posts or epoxy glue or the
like in order to control shear between adjacent layers.
Alternatively, PSA layers 110 and 112 can be cut back at their
perimeters in order to make room for an entire perimeter of glue.
These modifications may strengthen the bond between adjacent layers
when subjected to high shear loads. PSA is described herein by way
of example; other means of attaching layers could be used, for
example, double-sided tape, glue, or cement.
[0087] PCBs generally have some inherent flex to them, which
stiffener 114 substantially corrects for in order to add rigidity
to track pad 101. Stiffener 114 may have cutouts 116 a to
selectively reduce its weight, and or to selectively adjust its
stiffness. Other cutouts, for example 118 a, not only serve to
reduce weight (or to modulate stiffness) but also to allow
electrical contact between PCB 110 and sensors incorporated on flex
120, as will be discussed below. Overlying PSA layer 112 has
corresponding cutouts 116b and 118b.
[0088] In general, stiffener 114 should be stiff, light (i.e., low
density), and thin enough for use in space-sensitive applications
(e.g., ultrathin laptops, media devices, mobile phones, smart
phones or the like). An ideal stiffener would be very stiff, very
light, while at the same time very thin. However, these three
qualities (stiffness, light weight, thin) can be considered as
tradeoffs; for example, there is generally a tradeoff between
stiffness and weight for a given material. In the illustrated
embodiment, stiffener 114 is made of steel. Steel is a compromise
material because it is moderately heavy, but is very stiff. Because
of its high stiffness, a stiffener 114 constructed of steel can be
made relatively thin. Other metals may be used, for example,
aluminum or titanium. Titanium is very light but may be more
expensive than steel.
[0089] In other embodiments clad stiffeners may be used, in
particular clad metallic stiffeners formed from various metals or
other materials. An exemplary clad metallic stiffener 115 is shown
in FIG. 9 consisting of, for example, an aluminum core 117
surrounded by an upper steel layer 119 and a lower steel layer 121.
Steel has a higher elastic modulus (also known as modulus of
elasticity) than inner core 117 of aluminum. An elastic modulus is
the mathematical description of an object or substance's tendency
to be deformed elastically (i.e., non-permanently) when a force is
applied to it. A material with a higher elastic modulus (e.g.,
steel) is stiffer than a material with a lower elastic modulus
(e.g. aluminum). This is important because, under certain
conditions, the deflection of a stiffener is inversely proportional
to the product of the elastic modulus and the second moment of
area. This means that a stiffener made exclusively of aluminum of
the same size and shape as stiffener 115, which has an aluminum
core and steel outer layers, would be lighter but would not be as
stiff.
[0090] The clad effect (i.e., increasing stiffness by using high
modulus materials as outer layers on a lightweight core) is similar
to what happens with I-beams in constructing buildings; but in
I-beams the second moment of area is adjusted instead of the
elastic modulus. This is why beams with higher area moments of
inertia, such as I-beams, are so often seen in building
construction as opposed to other beams with the same area.
[0091] In other embodiments, stiffeners can be made of any suitable
structural material, including but not limited to glass, ceramics,
tungsten carbide, carbon fiber composites, and metal matrix
composites. Such structural materials are very light and thin,
making them desirable for use as stiffeners in thin, lightweight
portable electronic devices.
[0092] PCB 110 includes an electrode layer (not shown) on the top
surface and a movement sensor 126 on the bottom surface. In the
illustrated embodiment, movement sensor 126 is a mechanical switch
(see FIGS. 8 and 11). Movement sensor 126 may be widely varied.
Generally, tact switches may be used. More particularly, it may be
a bare, packaged or encased metal dome switch. When a user presses
down on track surface 102, flexure hinge 122 allows for
displacement of track pad 101, thereby allowing movement sensor 126
to contact set screw 128. Since switch 126 is electrically
connected to other parts of the system (e.g., it is mounted on PCB
110 ), a pick signal will be registered and processed each time the
user presses down sufficiently far to actuate sensor 126.
[0093] Set screw 128 can be adjusted to increase or completely
eliminate any offset displacement from movement sensor 126 in the
neutral position. As shown in FIG. 11, there may be a small offset
between movement sensor 126 and set screw 128 in the neutral
position. In another embodiment (not shown), set screw 128 may
directly abut switch 126 in the neutral position.
[0094] Flexure 122 will now be discussed with reference to FIGS. 8,
10, and 12. In the illustrated embodiment, two flexures 122 are
attached along a side of track pad 101 opposite sensor 126. This
arrangement constrains track pad 101 to move generally as a pivot
about an axis defined by the location of the flexures 122. The
physical separation of the flexures 122 help to establish a
leveling architecture. However, some amount of twist about a
perpendicular axis (e.g., an axis on the midline of the track
surface and perpendicular to the axis defined by the location of
flexures 122 ) will also be possible if a user presses down on
track surface 102 off center. This twist is partly from inherent
flexibility in track pad 101 (even if stiffener 114 is used) and
partly from variable bending of flexures 122. This twist could be
at least partially compensated by, for example, a more robust
stiffener and/or using more or stiffer flexures. As previously
mentioned, in the illustrated embodiment, track surface 102 moves
approximately 0.4 mm when pressed off center (e.g., at corner 203
in FIG. 7) and only approximately 0.2 mm when pressed on its
centerline (e.g., at 201 in FIG. 7). This extremely small amount of
twist does not degrade the performance of track pad 101.
[0095] Flexure 122 has a top flexure portion 130 and a bottom
flexure stiffener portion 132. Flexure portion 130 may be made of a
thin resilient material, for example thin spring steel. When a
flexible component is subject to bending stress, an instability can
occur that manifests itself as a buckling. To relieve this
instability, flexure members 130 have slots 134, generally oriented
substantially parallel to the axis about which they are most likely
to be bent. Flexure stiffeners 132 stiffen flexures 122 in the area
where they are attached to frame 104. In the illustrated
embodiment, each flexure 122 has three fasteners 136 which thread
through holes 136 a in flexure member 130 and holes 136 b in
stiffener 114. In the illustrated embodiment, each flexure 122 also
has two more rear fasteners 138 which thread through holes 138 a in
flexure 122 and 138 b in frame 104 to secure flexures 122 to frame
104. While three fasteners 136 and two rear fasteners 138 are
shown, the type and number of fasteners can be varied.
[0096] As shown in FIGS. 8 and 13, two upstops 140 are positioned
above extensions 146 of stiffener 114 and below an extension or
shoulder of frame 104. This arrangement prevents track pad 101 from
overshooting the neutral position after a depression cycle,
maintaining track surface 102 substantially flush with a surface of
frame 104. PSA 144 can be used to attach upstop 140 to frame 104.
Alternatively, PSA 144 can be used to attach upstop 140 to
stiffener 114. After a depression cycle, flexures 122 urge track
pad 101 back towards the neutral position. In the illustrated
embodiment, extensions 146 of stiffener 114 come into contact with
upstop 140, which is positioned underneath frame 104. Upstop 140
acts as a mild shock absorber, preventing stiffener 114 from
actually contacting frame 104, which may be substantially rigid.
Suitable materials for upstop 140 include plastic, foam, rubber,
biaxially-oriented polyethylene terephthalate (boPET) polyester
film, which is known by the trade mark Mylar.RTM., and the like. By
absorbing the impact between stiffener 114 and frame 104 when the
track pad 101 rebounds to neutral, upstop 140 can selectively
dampen undesirable acoustic noise after a depression cycle. Upstop
140 serves the dual function of shock absorption and limiting an
upper range of motion of track pad 101 to coincide with the neutral
position, which may be substantially flush with frame 104. While
two upstops 140 are shown, more or fewer may be used.
[0097] Flex 120 can best be seen in FIGS. 8 and 14. Since track pad
101 is movable, flex 120 must be able to travel with track pad 101
as it moves. This is accomplished by providing a flexible
electrical connection 150, which runs between a computer connection
152 configured to communicate with the electronic device in which
input device 100 is housed in, for example a laptop computer, and a
sensor connection 154 configured to communicate with PCB 110.
Integrated circuits 156 are located on the top surface of flex 120.
Integrated circuits 156 receive and process data from the electrode
layer on PCB 110 to form the heart of a capacitive sensor,
providing functions such as reading when a user's finger, for
example, is in contact with track surface 102, and for determining
finger movement. A PCB-based sensor is discussed by way of example,
and not by way of limitation. Non-PCB sensors such as stamped
sheetmetal, flex circuits (e.g., polyimide), conductive ink printed
on substrates, e.g., polyethylene terephthalate (PET) substrates,
indium tin oxide (ITO) on glass, and the like can also be used in
the present invention. A cosmetic label 124 covers flex 120 from
below. The assembled input device 100 is seen from below in FIG.
10.
[0098] Although not shown, input device 100 may be back lit. For
example, PCB 110 can be populated with light emitting diodes (LEDs)
on either side to enable a user to more easily see input device 100
in low light.
[0099] The input devices described herein may be integrated into an
electronic device or they may be separate stand alone devices. One
example of an input device integrated into a laptop computer is
shown in FIG. 7 and previously discussed; FIG. 15 shows an input
device 200 integrated into a media player 202 while FIG. 16 shows
an input device 207 integrated into a mobile phone. FIGS. 17 and
18, on the other hand, show some implementations of input device
200 as a stand alone unit. In FIG. 17, input device 200 is a
peripheral device that is connected to a desktop computer 206. In
FIG. 18, the input device 200 is a remote control that wirelessly
connects to a docking station 208 with a media player 210 docked
therein. It should be noted, however, that remote control 200 can
also be configured to interact with media player 210 (or other
electronic device) directly thereby eliminating the need for a
docking station. An example of a docking station for a media player
with which the present invention may be used can be found in U.S.
patent application Ser. No. 10/423,490, "MEDIA PLAYER SYSTEM,"
filed Apr. 25, 2003, which is herein incorporated in its entirety
by reference thereto. It should be noted that these particular
embodiments are not a limitation and that many other devices and
configurations may be used.
[0100] Referring to FIG. 15, the media player 202 will be discussed
in greater detail. 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.
[0101] In one embodiment, the media player 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. In the illustrated embodiment, the
media player 202 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 40,000 CD-quality songs). By way of example, the MP3
music player may correspond to one of the iPod family of MP3
players manufactured by Apple Inc. of Cupertino, Calif. Although
used primarily for storing and playing music and/or video, 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.
[0102] As shown in FIG. 15, the media player 202 includes a housing
222 that encloses internally various electrical components
(including integrated circuit chips and other circuitry) to provide
computing operations for the media player 202. In addition, the
housing 222 may also define the shape or form of the media player
202. That is, the contour of the housing 222 may embody the outward
physical appearance of the media player 202. The integrated circuit
chips and other circuitry contained within the housing 222 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 compimentary
oxide semiconductor (CMOS)) or optics (e.g., lenses, splitters,
filters).
[0103] In the illustrated embodiment, the media player 202 includes
a hard drive thereby giving the media player massive storage
capacity. For example, a 160 GB hard drive can store up to 40,000
songs, approximately 200 hours of video, or up to 25,000 photos. 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., 8, 16, 80, 160 GB, etc.). In addition to the hard
drive, the media player 202 shown herein also includes a battery
such as a rechargeable lithium ion battery. These type of batteries
are capable of offering about 30 hours of continuous music playtime
to the media player or 5 hours of video playtime.
[0104] The media player 202 also includes a display screen 224 and
related circuitry. The display screen 224 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 224 may be a liquid crystal display (LCD). In one particular
embodiment, the display screen corresponds to a 320 -by-240 -pixel
high-resolution display LCD display, with LED backlight to give
clear visibility in daylight as well as low-light conditions. As
shown, the display screen 224 is visible to a user of the media
player 202 through an opening 225 in the housing 222, and through a
transparent wall 226 that is disposed in front of the opening 225.
Although transparent, the transparent wall 226 may be considered
part of the housing 222 since it helps to define the shape or form
of the media player 202.
[0105] The media player 202 also includes the touch pad 200 such as
any of those previously described. The touch pad 200 generally
consists of a touchable outer surface 231 for receiving a finger
for manipulation on the touch pad 230. In the illustrated
embodiment, touch pad 200 is circular, but its shape can be widely
varied, e.g., rectangular, square, etc. Although not shown in FIG.
15, beneath the touchable outer surface 231 is a sensor
arrangement. The sensor arrangement includes a plurality of sensors
that are configured to activate as the finger sits on, taps on or
passes over them. In the simplest case, an electrical signal is
produced each time the finger is positioned over a sensor. 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 an electronic interface
that converts the number, combination and frequency of the signals
into location, direction, speed and acceleration information. This
information may then be used by the media player 202 to perform the
desired control function on the display screen 224. For example, a
user may easily scroll through a list of songs by swirling the
finger around the touch pad 200.
[0106] In addition to above, the touch pad may also include a
movable button configured to provide one or more dedicated control
functions for making selections or issuing commands associated with
operating the media player 202. By way of example, in the case of
an MP 3 music player, the button functions may be associated with
opening a menu, playing a song, fast forwarding a song, seeking
through a menu, making selections and the like. In most cases, the
button functions are implemented via a mechanical clicking
action.
[0107] The position of the touch pad 200 relative to the housing
222 may be widely varied. For example, the touch pad 200 may be
placed at any external surface (e.g., top, side, front, or back) of
the housing 222 that is accessible to a user during manipulation of
the media player 202. In most cases, the touch sensitive surface
231 of the touch pad 200 is completely exposed to the user. In the
illustrated embodiment, the touch pad 200 is located in a lower,
front area of the housing 222. Furthermore, the touch pad 230 may
be recessed below, level with, or extend above the surface of the
housing 222. In the illustrated embodiment, the touch sensitive
surface 231 of the touch pad 200 is substantially flush with the
external surface of the housing 222.
[0108] The shape of touch pad 200 may also be widely varied.
Although shown as circular, the touch pad may also be annular,
rectangular, triangular, and the like.
[0109] Media player 202 may also include a hold switch 234. The
hold switch 234 is configured to activate or deactivate the touch
pad and/or buttons associated therewith. 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.
[0110] Moreover, the media player 202 may also include one or more
headphone jacks 236 and one or more data ports 238. The headphone
jack 236 is capable of receiving a headphone connector associated
with headphones configured for listening to sound being outputted
by the media device 202. The data port 238, 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 238 may be used to
upload or down load audio, video and other images to and from the
media device 202. 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.
[0111] The data port 238 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
238 may be a radio frequency (RF) link or optical infrared (IR)
link to eliminate the need for a cable. Although not shown in FIG.
12, the media player 202 may also include a power port that
receives a power connector/cable assembly configured for delivering
powering to the media player 202. In some cases, the data port 238
may serve as both a data and power port. In the illustrated
embodiment, the data port 238 is a Firewire port having both data
and power capabilities.
[0112] Although only one data port is shown, 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. 15. They may be positioned almost anywhere on the housing
(e.g., front, back, sides, top, bottom), or even be absent in some
embodiments. For example, the data port may be positioned on the
bottom surface of the housing rather than the top surface as
shown.
[0113] Referring back FIG. 16, mobile phone 207 will be discussed
in greater detail. Phone 207 may be a smart phone. Mobile phone 207
comprises a frame 209 and a touch sensitive screen 211.
Touch-sensitive screen 211, which may be a multi-touch screen,
similar to that used on the iPhone produced by Apple Inc. of
Cupertino, Calif. can be made clickable by allowing it to displace
relative to frame 209 when pressed on. In this way a button
functionality like the previously described depressible input
devices of the present invention can be incorporated to phone 207.
In some embodiments, tactile and/or aural feedback may be
incorporated with the button function. For example, pressing down
on screen 211 not only activates some function, but may also
produce an audible clicking sound. The clicking sound may be
mechanically produced (for example by the mechanical switch itself)
and/or may be electrically produced (for example through a speaker
which is activated whenever the user presses down far enough).
Moreover, tactile feedback can be generated, for example the
mechanical feedback generated by positively clicking a mechanical
switch or a vibration which is triggered whenever a pick is
detected. Although specifically discussed with reference to mobile
phone 207, tactile and/or aural feedback may be incorporated with
the button function of any embodiment discussed herein (e.g.,
laptop track pad, media player track pad or screen, remote control
track pad, etc.).
[0114] In another embodiment (not shown) a mobile phone can
incorporate a non-touch sensitive screen (i.e., a traditional
screen) in conjunction with a touch-sensitive, depressible track
pad, such as the track pads previously described herein. In this
embodiment, the screen functions as the display, while the track
pad can, for example, move a cursor on the display and also
incorporate a button function. In other words, a depressible track
pad can be used on a mobile phone in conjunction with a separate
screen instead of depressing the screen itself, as was the case
with the embodiment discussed in reference to FIG. 16.
[0115] Turning to FIG. 19, a simplified block diagram of a remote
control 280 incorporating an input device 282 therein, in
accordance with another embodiment of the present invention is
shown. By way of example, input device 282 may correspond to any of
the previously described input devices of the present invention.
Input device 282 includes a touch pad 284 and switch 286. Touch pad
284 and switch 286 are operatively coupled to a wireless
transmitter 288, configured to transmit information over a wireless
communication link so that an electronic device having receiving
capabilities may receive the information over the wireless
communication link The wireless transmitter 288 may be widely
varied. For example, it may be based on wireless technologies such
as FM, RF, Bluetooth, 802.11 UWB (ultra wide band), infrared (IR),
magnetic link (induction) and/or the like. In the illustrated
embodiment, the wireless transmitter 288 is based on IR. IR
generally refers wireless technologies that convey data through
infrared radiation. As such, the wireless transmitter 288 generally
includes an IR controller 290. The IR controller 290 takes the
information reported from the touch pad 284 and switches 286 and
converts this information into infrared radiation as for example
using a light emitting diode 292.
[0116] As previously noted, the track surface of the present
invention may be made of glass. Besides providing a low friction,
durable, cosmetic surface, glass provides for options that opaque
surfaces (e.g., plastic, ceramic, and the like) do not provide. For
example, in one embodiment, track pad 101 can be delineated into
separate zones, using, for example, lights, textured glass, or
combinations thereof. Each zone can have a different function. For
example, one zone may be a track zone (which may move a cursor)
while another zone may be a pick zone (which may be depressible to
activate a button function.)
[0117] FIGS. 20a -20e show exemplary delineation options for track
pad 300. FIG. 20a shows transparent or semi-transparent track pad
300 made of glass with a single zone 302, i.e., the entire track
surface is depressible to activate a button function. FIG. 20b
shows track pad 300 with an upper track surface 304 and a single
pick zone 306. The line 308 which separates track surface 304 from
pick zone 306 can be created by a textured glass surface with LED
side lighting, IR ink with LED side lighting, electro-luminescence,
magnetic ink, two-tone rolling wire, or the like. FIG. 20c shows an
alternate embodiment having two pick zones 310 and 312. These zones
can be associated with separate button functions, for example "left
click" and "right click." FIG. 20d shows two track zones that are
left-biased, i.e., left pick zone 314 is larger than right pick
zone 316. FIG. 20e shows two track zones that are right-biased,
i.e. left pick zone 318 is smaller than right pick zone 320. FIG.
20f shows three pick zones 322. The delineation options shown in
FIG. 20 are given by way of example, and not by way of
limitation.
[0118] In one embodiment, track and pick zones can be
user-selectable. For example, the user can turn off the delineation
line(s), such that the track pad is like that shown in FIG. 20a
corresponding to a track pad that can be picked anywhere on its
track surface, which now functions similar to the embodiment shown
in FIG. 7. If the user later desires a more traditional track pad
having left and right pick zones, he can configure the track pad to
appear as shown in FIG. 20c , with a corresponding change in
functionality of the track pad.
[0119] As shown in FIG. 21, in addition to displaying delineation
lines on the track pad, a track pad 324 with a glass (or otherwise
transparent or semi-transparent) track surface 326 can even
function as a full pixel display. In one embodiment, track surface
326 can be an active matrix display, for example using electronic
paper/electronic ink, LCD, thin film transistor liquid crystal
display (TFT-LCD), etc.
[0120] E ink.RTM. is the trade mark for one type of electronic
paper developed by E Ink Corporation of Cambridge, MA. The
principal components of E ink.RTM. are millions of tiny
microcapsules 327, about the diameter of a human hair. In one
embodiment, shown in FIG. 22, each microcapsule contains positively
charged white particles 328 and negatively charged black particles
330 suspended in a clear fluid 332. When a negative electric field
334 is applied, the white particles move to the top of the
microcapsule to become visible to the reader. This makes the
surface appear white at that spot. At the same time, an opposite
electric field 336 pulls the black particles to the bottom of the
microcapsules where they are hidden. By reversing this process, the
black particles appear at the top of the capsule, which now makes
the surface appear dark at that spot. The top 338 and/or bottom 340
electrodes are transparent so that a user can see the colored
particles.
[0121] To form an E Ink.RTM. electronic display, the ink is printed
onto a sheet of plastic film that is laminated to a layer of
circuitry. The circuitry forms a pattern of pixels that can then be
controlled by a display driver. These microcapsules are suspended
in a liquid "carrier medium" allowing them to be printed using
existing screen printing processes onto virtually any surface,
including glass, plastic, fabric and even paper. An exemplary E
ink.RTM. display was unveiled in February 2004 by Polymer Vision
Ltd. This display is an organics-based quarter VGA (QVGA) (i.e.,
320.times.240 pixels) active matrix display with a diagonal of five
inches, a resolution of 85 dpi and a bending radius of 2 cm. The
display combined a 25 micron thick active-matrix back pane
containing the polymer electronics-based pixel driving, with a 200
micron front plane of reflective E Ink.RTM..
[0122] As discussed, a glass surface can be used as a track surface
in some embodiments of the present invention. Ideally, such a glass
surface should have a low coefficient of friction, should be clean
with high clarity, should not readily pick up smudges, readily
scratch, or be abrasive to skin, and finally should be mechanically
robust in order to survive thousands of cycles of track pad
depressions.
[0123] One disadvantage of conventional glass structures is that
they do not have all of these attributes simultaneously, e.g.,
conventional glass may be very clear, but it has a high coefficient
of friction. Low friction is important in track pads (e.g., track
pads on laptop computers) because overcoming excessive frictional
forces between the glass and a user's finger, for example, can
cause user discomfort or could cause inadvertent picks in the case
of a depressible track pad. The preferred glass surface is one that
is silky-smooth and highly optically clear.
[0124] There are various known methods to treat glass including,
for example, blasting, laser etching, honing, and chemical etching.
These conventional methods are normally applied to a piece of raw
glass. The surface of raw glass may appear smooth to the naked eye,
but its smoothness actually increases the coefficient of friction
because the finger (or other surface) is in direct contact with
glass over a large percentage of surface area. To correct for this,
treatments (etching, etc.) are sometimes applied to smooth surface
344 in order to decrease friction or change the optical properties
of the glass. Etching glass produces microscopic bumps or peaks
which reduces the smoothness of the raw glass; this lowers the
coefficient of friction by reducing the surface area that a finger
is in contact with the glass. In other words, a finger rubbed
across a piece of etched glass will have to overcome frictional
forces associated with directly contacting the bumps or peaks on
the etched glass surface, but the finger will experience greatly
reduced friction in areas between the bumps or peaks, which is
essentially just air.
[0125] Producing a final piece of treated glass (e.g., for use in
an LCD) has commonly been done in one step. For example, the raw
glass is chemically etched. However, this single-step method does
not yield a glass surface that has all of the desirable attributes
mentioned above. For example, the glass surface may have lower
friction, but is often associated with decreased clarity or
decreased smudge resistance. Efforts to process the glass in
multiple steps (e.g., mechanical abrasion followed by chemical
post-processing) has also not been previously successful; the glass
surfaces produced in multiple steps suffer the same disadvantages
as those produced in a single step.
[0126] In the present invention, raw glass may be processed in a
two step method to produce a much improved glass.
[0127] In the first step, a piece of raw glass 342 is processed
mechanically or chemically to create a "seed surface" with a fine
pitch. Tailoring the seed surface to have a very fine pitch (i.e.,
a very rough surface) would enable a subsequent liquid-polishing
(i.e., in the second step) so as to produce a final glass surface
having all of the desirable attributes. The seed surface is best
seen in FIG. 24A where the processed glass has a bumpy surface 346
characterized by a peak-to-peak ratio 348 and an amplitude 350.
This is the seed surface. A fine pitch seed surface, such as 346,
will have a very low transmittance (ratio of transmitted to
incident light), on the order of 30%.
[0128] The first step of processing the glass may be performed
using chemical etching, for example using ammonium BiFlouride cream
mixed with an inert carrier. This chemical etching cream is applied
to the surface and left there for a period of time, for example 30
minutes. FIG. 24B shows the seed surface 346 at the conclusion of
the first step. The seed surface is shown at 1,000 magnification.
The scale at the bottom of FIG. 24B is scaled to 10 .mu.m.
[0129] In the second step, the seed surface is exposed to a
hydrofluoric acid (HF) solution incorporating a secondary acid.
This is a wet application, meaning that HF could be sprayed onto
the seed surface, or the seed surface could be dipped into HF. In
one embodiment, the solution consists of HF and hydrochloric acid,
i.e., HF HCl. In another embodiment, the solution consists of HF
and sulfuric acid, i.e., HF+H.sub.2SO.sub.4. In either of these
embodiments, the acid solution may be mixed with water. The higher
the concentration of HF the faster the process will occur, but the
net result will be the same. In one embodiment, the solution may
consist of approximately 5% HF with approximately 10% HCl and
approximately 85% H.sub.20. The primary acid is HF, while the
secondary acid (HCl or H.sub.2SO.sub.4) functions to remove
residuals from the glass surface to let the HF react with the
glass. The HF reacts with seed surface 346 produced during the
first step and changes its topography, which in turn changes the
relevant properties of the glass (e.g., transmittance, coefficient
of friction). The resulting final glass surface 356 is shown in
FIG. 25. Surface 356 has an amplitude 352 roughly equal to
amplitude 350 of the seed surface, but a peak-to-peak ratio 354
that is roughly an order of magnitude larger (e.g., eight to twelve
times) than the peak-to-peak ratio 348 of seed surface 346. Testing
has shown that the amplitude is not significantly correlated to the
relevant glass properties; the peak-to-peak ratio is the dominant
characteristic. In other words, varying the amplitude of the final
glass surface did not affect the relevant glass properties, while
independently varying the peak-to-peak ratio drastically affected
the relevant properties.
[0130] When seen from above, as in FIG. 26, which is magnified 1000
times, the final surface 356 has a matrix of divots 358, resembling
a metal surface that has been randomly struck by a ball peen hammer
The resulting glass has all of the desirable attributes (low
friction, clear, durability, smudge-resistant, etc.), and has an
appearance that is "lively" and "sparkly." The transmittance of
this glass is on the order of 90%.
[0131] The final surface 356 is a low friction surface. The
coefficient of friction, .mu., of a surface is the ratio of a
normal force, FN , from an object on that surface to the frictional
force, FF , that must be overcome in order to move the object
relative to the surface, i.e.,
.mu. = F N F f . ##EQU00001##
The frictional force is further classified into static and dynamic
friction. Static friction, Fs , is the force that must be overcome
when two objects are not moving relative to each other, while
dynamic friction, FD , is the frictional force between two objects
in relative motion. Static friction is typically higher than
dynamic friction, i.e., it normally takes a larger force to get an
object moving relative to another surface when they were initially
stationary, but a smaller force to keep the object in motion. The
coefficients of static .mu..sub.s and dynamic .mu..sub.Dfriction
are therefore defined as:
.mu. s = F N F s and .mu. D = F N F D . ##EQU00002##
[0132] To demonstrate the frictional qualities of surfaces like
final surface 356, a 1-inch diameter neoprene disk with a roughened
surface using 320 -grit sandpaper was loaded with a normal force
and pulled along various samples of surfaces like 356. Tests were
performed on various samples, and the neoprene disk was either
pulled at 50 mm/min or 500 mm/min, and was loaded at either 71.4
grams or 295.9 grains. The surface was lubricated with squalene
during some tests and not lubricated during the other tests. Table
1 summarizes the testing data:
TABLE-US-00001 TABLE 1 Friction Data FN Test 1 Test 2 Test 3
Standard Standard Sample (gram) Lubrication (grams) (grams) (grams)
No deviation .mu..sub.s/.mu..sub.D deviation 1 71.4 Yes 32.37 33.27
32.41 0.46 0.01 1.07 0.01 1 295.9 Yes 106.46 105.85 111.39 0.36
0.01 1.04 0.01 1 71.4 Yes 38.58 37.35 39.07 0.54 0.01 1.16 0.06 1
295.9 Yes 115.5 115.63 116.35 0.39 0.00 1.08 0.03 1 71.4 No 77.77
78.17 76.58 1.09 0.01 1.03 0.00 1 295.9 No 284.24 268.88 260.79
0.92 0.04 1 71.4 No 58.9 58.68 56.4 0.81 0.02 1.31 0.04 1 295.9 No
250.52 246.24 244.39 0.83 0.01 1.09 0.05 2 71.4 Yes 25.3 24.65
25.25 0.35 0.01 1.13 0.08 2 295.9 Yes 81.75 81.83 83.2 0.28 0.00
1.10 0.02 2 71.4 Yes 40.35 37.02 35.47 0.53 0.03 1.15 0.02 2 295.9
Yes 111.77 112.91 110.12 0.38 0.00 1.05 0.01 2 71.4 No 94.67 92.67
87.71 1.28 0.05 1.05 0.02 2 295.9 No n/a n/a n/a n/a n/a n/a n/a 2
71.4 No 81.52 81.89 80.82 1.14 0.01 1.21 0.04 2 295.9 No 341.19
332.56 324.6 1.12 0.03 1.06 0.01 3 71.4 Yes 24 24.58 25.08 0.34
0.01 1.07 0.02 3 295.9 Yes 78.22 78.63 78.78 0.27 0.00 1.04 0.02 3
71.4 Yes 33.49 34.48 36.04 0.49 0.02 1.10 0.01 3 295.9 Yes 102.95
102.49 103.29 0.35 0.00 1.03 0.00 3 71.4 No 82.32 90.8 85.67 1.21
0.06 1.18 0.09 3 295.9 No n/a n/a n/a n/a n/a n/a n/a 3 71.4 No 101
98.1 96.93 1.38 0.03 1.10 0.01 3 295.9 No 371.08 368.13 365.01 1.24
0.01 1.01 0.00
[0133] FIG. 27 shows the peak-to-peak ratio produced in the second
step of the glass treatment process as a function of time. The
peak-to-peak ratio rapidly increases before a critical time Tcrit
360, at which point it proceeds basically asymptotically. This is
important in manufacturing the glass because the process window of
the second step is very large. In other words, the second step
chemical treatment process is not time sensitive; the treatment can
be applied and left on the glass for either a shorter time (near
Tcrit 360 ) or for a much longer time to still get a relatively
constant peak-to-peak ratio. This means that the time does not have
to be carefully controlled; therefore, defective parts that would
have needed to be scrapped if the peak-to-peak ratio were incorrect
are reduced or eliminated. While the peak-to-peak ratio stays
substantially constant in the asymptotic part of the peak-to-peak
curve, the overall thickness of the glass is constantly decreasing
during this process because the HF thins the glass.
[0134] In an alternate process, the first step can employ a
mechanical treatment in lieu of the chemical treatment described
above. For example, the glass can be treated with a fine grit
(e.g., cerium oxide) and then mechanically honed. In some cases
though, this may create micro fractures and/or give the final glass
a lower four-point bending strength. As noted, the glass should be
robust in order to survive thousands of pick cycles when used with
a track pad; therefore, a chemical treatment, as described above,
may be preferred to mechanical honing.
[0135] The two-step process of the present invention can be
performed on a large sheet of glass, which is then subsequently cut
into the desired shape, such as a rectangle. Alternatively, the raw
glass can be cut into the desired shape first, and then treated.
Cutting the glass into smaller shapes can introduce imperfections
into the glass (e g , small chips) which the chemical treatment can
subsequently mask; therefore, in some embodiments it is desirable
to cut the raw glass before treating it.
[0136] As shown in FIG. 28, PCB 110 can serve as the flexure hinge
in an alternate embodiment. This has the advantage of requiring
fewer parts. In this embodiment, track surface 102 and stiffener
114 surround PCB 110 except for a cantilevered portion 105 attached
to computer frame 104. In this way, a gap 105a is formed which
serves as the flexure hinge. When a user presses down on track5
surface 102, the track pad will pivot about 105a as cantilevered
PCB 110 flexes in the area of 105a. When pressure from the user is
relieved, PCB 110 will urge the track pad back to the neutral
position, which in the illustrated embodiment is shown as
horizontal. In another embodiment (not shown), gap 106 may be
eliminated.
[0137] FIG. 29 shows another embodiment where a flexure hinge is
made entirely from stiffener 114. In this embodiment, stiffener 114
has a cantilevered end 107 that is thinner than the main body of
stiffener 114. End 107 is attached to computer frame 104 in an
opening 109 in frame 104. When a user presses down on track surface
102, the track pad will pivot as end 107 flexes along gap 105 a.
When pressure from the user is relieved, end 107 of stiffener 114
will urge the track pad back to the neutral position, which in the
illustrated embodiment is shown as horizontal.
[0138] FIG. 30 shows a flexure hinge made from a clad stiffener
123. Like clad stiffener 115 described above with reference to FIG.
9, clad stiffener 123 has, for example, and aluminum core 125
surrounded by an upper steel layer 127 and a lower steel layer 129.
However, unlike clad stiffener 115, upper layer 127 has a
cantilever extension 131 which is attached to computer frame 104 in
an opening 109 in frame 104. When a user presses down on track
surface 102, the track pad will pivot as extension 131 flexes along
gap 105a. When pressure from the user is relieved, extension 131
will urge the track pad back to the neutral position, which in the
illustrated embodiment is shown as horizontal. Instead of upper
layer 127 having a cantilevered extension 131, core 125 or lower
steel layer 129 may have a cantilever extension (not shown) to
connect to frame 104 and act as a flexure hinge. Materials other
than aluminum and steel may be used in a clad stiffener, provided
they are stiff (i.e., high elastic modulus), thin, and are low
density (i.e., lightweight).
[0139] Turning now to FIG. 31, another embodiment is shown in which
stiffener 133 is unitary with computer frame 104. When a user
presses down on track surface 102, the track pad will pivot as
stiffener 133 flexes. When pressure from the user is relieved,
stiffener 133 will urge the track pad back to the neutral position,
which in the illustrated embodiment is shown as horizontal. In this
embodiment, stiffener 133 and housing may be made of aluminum, for
example.
[0140] Another input device 135 according to the present invention
is shown in FIGS. 32 and 33. In this embodiment, input device 135
has a track surface 137, an electrode (or PCB) layer 139, and a
stiffener 141. Stiffener 141 partially extends into a cavity 143 of
computer frame 145. A trap 147 is attached to the underside of
frame 145. Trap 147 has an X-Y alignment post 151 which extends
into a notch 153 in stiffener 141. X-Y alignment post 151 fits
inside of notch 153 and prevents stiffener 141 from moving in its
own plane. Offset 155 extends along the front edge or pivot edge
157 of trap 147 and an area 159 between notch 153 and the maximum
thickness of stiffener 141. When a user presses down on track
surface 137, stiffener 141 rotates about pivot edge 157. The
presence of offset 155 and stiffener thickness transition 159
enables one-way rotation downward of input device 135. One-way
rotation is desirable to retain input device 135 inside of frame
145 and to keep track surface 137 flush to the outside of frame 145
in the nominal state as represented in FIG. 32.
[0141] As can be appreciated, all of the various flexure hinges
described herein do not appreciably add to the thickness of the
depressible track pads. Therefore, any of the flexure hinges of the
present invention are particularly suitable for use in ultrathin
applications (laptops, media devices, mobile phones, game players,
etc.).
[0142] In the various track pads discussed above, inherent
flexibility of various flexure hinges serves to urge the track pads
back to their neutral positions whenever the user is not depressing
the track pad to activate the button function. In other words, the
track pads discussed above are biased to the neutral position by
way of inherent flexibility. It is possible to use magnetic forces
to bias a track pad to the neutral position. Magnetic force can be
the sole biasing mechanism, or it can enhance existing biasing due
to inherent flexibility. In other words, magnets can be used on any
of the previously discussed input devices to supplement the bias
provided from the various flexure hinges discussed.
[0143] In the various track pads discussed above, a mechanical dome
switch serves as the primary restorative member to urge the track
pads back to their neutral positions whenever the user is not
depressing the track pad to activate the button function. Inherent
flexibility in the various flexure hinges described above also
urges the track pads back to their neutral positions. The
mechanical dome is also responsible for providing tactile feedback
to a user for a pick event. It is possible to use magnetic forces
to bias a track pad to the neutral position and or to provide
tactile feedback to the user. Magnetic force can be the sole
biasing and tactile mechanism, or it can enhance existing biasing
and tactile feel due to the mechanical dome switch and inherent
flexibility from flexure hinges. In other words, magnets can be
used on any of the previously discussed input devices to supplement
the bias and tactile feel to the neutral position.
[0144] Turning to FIG. 34a, an input device 161 using magnetic
forces is shown. Input device 161 has a track pad 163 having a
track surface 165. Like the other track pads discussed herein,
track pad 163 has a sensor arrangement to detect and process finger
movements on track surface 165. For example, track pad 163 may
employ capacitive sensing. To this end, track pad 163 has an
electrode layer 167 (which may be on a PCB) for capacitive sensing.
In the illustrated embodiment, track pad 163 has a pick zone 169
which is separated from track surface 165. In this case, a user
moves his finger relative to track s urface 165 in order to perform
tracking operations (e.g., move a cursor) but depresses pick zone
169 in order to activate a button functionality.
[0145] Input device 161 is shown in the neutral position in FIG.
34a. Magnetic attractive forces between magnet 179 and flange 177
biases the pick zone 169 to the neutral position and allows for
movement to an activate position (to activate a button function)
whenever a user depresses pick zone 169. Button assembly 171
consists of a leveling plate 173, flexure attachment 175, flange
177 and pick zone 169. Leveling plate 173 is composed of a
relatively stiff material, for example, steel, which is also
optimally thin and lightweight. Leveling plate 173 is connected to
track pad 163 by flexure attachment 175, which may be, for example,
a thin piece of steel attached with screws. Flexure attachment 175
is capable of bending, similar to flexure hinge 122 discussed in
relation to FIGS. 8, 10, and 12. In another implementation, flexure
attachment 175 can be a pivot pin assembly. When depressed at pick
zone 169, button assembly 171 hinges or pivots at flexure
attachment 175 causing a movement sensor (not shown) to activate.
The movement sensor may be capacitive, proximity, Hall-effect,
optical, mechanical membrane or a plurality of sensors. Input
device 161 is shown in the activate position in FIG. 34b .
[0146] Magnet 179 may be positioned anywhere, but in the
illustrated embodiment, flange 177 is located on an end of leveling
plate 173 and is situated directly below magnet 179 which is
opposite the pivot point defined by flexure attachment 175. Flange
177 may be a ferrous metal or other material capable of being
attracted magnetically. Magnet 179 may be, for example, a permanent
magnet, or electromagnet. In the illustrated embodiment magnet 179
is fixedly connected to the housing (not shown) of input device
161. In another embodiment, 179 may be fixed to the housing (not
shown) of an electronic device in which input device 161 is
incorporated. In this case, magnet 179 would not move, but flange
177 would move with leveling plate 173 when the magnetic force
attraction between magnet 179 and flange 177 is overcome by the
user depressing pick zone 169. In another embodiment (not shown)
the magnet may move with leveling plate 173 while the metal portion
stays fixed; in other words, magnet 179 and flange 177 can be the
reverse of what is shown in FIG. 34. In such an embodiment, flange
177 may be a separate component from or it may integral with the
housing (not shown). The magnetic force between magnet 179 and
flange 177 can be controlled to obtain the desired click feel, for
example by using a stronger or weaker permanent magnet, by varying
the size or separation of magnet 179 and or flange 177, or by using
an adjustable electromagnet.
[0147] Although input device 161 is shown in FIG. 34 as having a
track surface 165 that is separate from a pick zone 169, magnetic
biasing can be used on a track pad having a depressible track
surface, such as those described above. In other words, magnets can
be used to bias depressible track pads to their neutral position.
For example, magnets can be used with track pad 100 shown in FIG.
7, or with the various flexure hinges shown in FIGS. 28-32.
[0148] While this invention has been described in terms of several
embodiments, there are alterations, permutations, and equivalents,
which fall within the scope of this invention. It should also be
noted that there are many alternative ways of implementing the
methods and apparatuses of the present invention. 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.
* * * * *