U.S. patent application number 14/913916 was filed with the patent office on 2016-07-14 for remote control device.
This patent application is currently assigned to Apple Inc.. The applicant listed for this patent is APPLE INC.. Invention is credited to Jeremy D. Bataillou, John M. Brock, Ryan P. Brooks, Keith J. Hendren, Wayne W. Huang, Nicholaus Lubinski.
Application Number | 20160203710 14/913916 |
Document ID | / |
Family ID | 51619266 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160203710 |
Kind Code |
A1 |
Bataillou; Jeremy D. ; et
al. |
July 14, 2016 |
REMOTE CONTROL DEVICE
Abstract
A remote control device includes a housing and an upper element.
The top surface of the upper element can be partitioned to include
different frictionally engaging surfaces. At least one frictionally
engaging surface can be used as an input surface that receives user
inputs such as touch or force inputs. An input device, such as a
force sensing switch, can be positioned in the housing and used in
determining an amount of force applied to the input surface. The
bottom surface of the upper element below the second surface can be
affixed to the housing in a manner that permits the input surface
to bend based on the applied force.
Inventors: |
Bataillou; Jeremy D.;
(Cupertino, CA) ; Hendren; Keith J.; (San
Francisco, CA) ; Lubinski; Nicholaus; (San Francisco,
CA) ; Brooks; Ryan P.; (Cupertino, CA) ;
Brock; John M.; (Menlo Park, CA) ; Huang; Wayne
W.; (Cupertino, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
APPLE INC. |
Cupertino |
CA |
US |
|
|
Assignee: |
Apple Inc.
Cupertino
CA
|
Family ID: |
51619266 |
Appl. No.: |
14/913916 |
Filed: |
August 22, 2014 |
PCT Filed: |
August 22, 2014 |
PCT NO: |
PCT/US14/52413 |
371 Date: |
February 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13974620 |
Aug 23, 2013 |
|
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14913916 |
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Current U.S.
Class: |
340/12.55 ;
29/592 |
Current CPC
Class: |
H01H 13/785 20130101;
H01H 2201/036 20130101; G08C 19/28 20130101; H03K 17/9625 20130101;
G08C 17/02 20130101 |
International
Class: |
G08C 19/28 20060101
G08C019/28 |
Claims
1. A remote control device, comprising: a housing comprising a
bottom surface coupled to adjoining side walls extending up from
the bottom surface to form an interior cavity; an upper element
connected to the housing and configured to cover the interior
cavity, wherein only a portion of a bottom surface of the upper
element is connected to the housing to permit the upper element to
bend based on an applied force; and a force sensing switch disposed
in the interior cavity, wherein the force sensing switch comprises:
a dome switch disposed over a top surface of a deflectable beam;
and a strain gauge disposed over a surface of the deflectable
beam.
2. The remote control device as in claim 1, wherein a top surface
of the upper element comprises at least two different frictionally
engaging surfaces, wherein at least one frictionally engaging
surface comprises a textured surface and the force sensing switch
is positioned under the textured surface.
3. The remote control device as in claim 1, wherein only a bottom
surface of the upper element under the second surface is affixed to
the housing so that the first textured surface bends in response to
an applied force.
4. The remote control device as in claim 1, further comprising a
processing device operatively connected to the dome switch.
5. The remote control device as in claim 4, wherein the strain
gauge is operatively connected to the processing device.
6. The remote control device as in claim 5, further comprising at
least one additional strain gauge disposed over a surface of the
deflectable beam, wherein each additional strain gauge is
operatively connected to the processing device.
7. The remote control device as in claim 1, wherein the upper
element comprises a glass upper element.
8. The remote control device as in claim 1, further comprising a
trim extending out from the sidewalls into the interior cavity,
wherein only a bottom surface of the upper element under the second
surface is affixed to the trim so that the first textured surface
bends based on an applied force.
9. The remote control device as in claim 1, wherein the upper
element includes a second textured surface and an input device is
disposed in the interior cavity below the second textured
surface.
10. The remote control device as in claim 9, wherein the input
device comprises a trackpad.
11. The remote control device as in claim 9, wherein the input
device comprises a touchscreen display assembly and the second
textured surface comprises a transparent upper element glass.
12. The remote control device as in claim 1, further comprising one
or more input buttons disposed in respective openings formed
through the upper element.
13. The remote control device as in claim 1, further comprising one
or more microphones disposed in the interior cavity.
14. The remote control device as in claim 1, further comprising one
or more fasteners formed on an underside of the glass upper element
below the first textured surface, the one or more fasteners being
configured to mechanically engage with the housing.
15. A method of producing a remote control device, comprising:
providing a force sensing switch in an interior cavity of a
housing; and providing an upper element over the interior cavity,
the upper element comprising at least one textured surface and a
second surface, the force sensing switch being located below a
first textured surface.
16. The method as in claim 15, wherein providing an upper element
over the interior cavity comprises affixing only a bottom surface
of an upper element under the second surface to the housing so that
the first textured surface bends based on an applied force.
17. The method as in claim 15, further comprising: providing an
input device in the interior cavity of the housing below a second
textured surface; and providing a processing device in the interior
cavity operatively connected to the force sensing switch and the
input device.
18. The method as in claim 15, wherein providing a force sensing
switch in an interior cavity of a housing comprises: providing a
dome switch and a deflectable beam, wherein the dome switch is
disposed over a top surface of the deflectable beam and the dome
switch includes a deformable structure configured to deform when a
force is applied to the first textured surface; and providing a
strain gauge over a surface of the deflectable beam.
19. A method of producing a glass upper element for a remote
control device, the method comprising: applying a first masking
material to a top surface of the glass upper element to define a
first surface not covered by the first masking material and a
second surface covered by the first masking material; producing a
first textured surface by etching the first surface; removing the
first masking material; and forming one or more openings through
the glass upper element, at least one opening being configured to
receive an input button.
20. The method as in claim 19, wherein the at least one opening
being configured to receive the input button is formed through the
second surface of the glass upper element.
21. The method as in claim 19, further comprising forming at least
one fastener on an underside of the glass upper element below the
first textured surface.
22. The method as in claim 19, wherein producing a first textured
surface by etching the first surface comprises producing a first
textured surface by sandblasting the first surface.
23. The method as in claim 19, wherein producing a first textured
surface by etching the first surface comprises producing a first
textured surface by chemically etching the first surface.
24. The method as in claim 19, further comprising: prior to forming
the one or more openings, applying a second masking material to an
area of the second surface of the glass upper element to define a
third surface not covered by the second masking material; producing
a second textured surface by etching the third surface; and
removing the second masking material.
25. A method for producing a roughness in a surface of a glass
upper element of a remote control device, the method comprising:
producing the roughness in a portion of the surface of the glass
upper element by abrasively etching the portion with a mixture of
glass beads and a liquid; and polishing the portion to modify the
roughness in the portion of the surface of the glass upper
element.
26. A remote control device, comprising: a housing comprising a
bottom surface coupled to adjoining side walls extending up from
the bottom surface to form an interior cavity; an upper element
connected to the housing and configured to cover the interior
cavity, wherein only a portion of a bottom surface of the upper
element is connected to the housing to permit the upper element to
bend based on an applied force; and a force sensing switch disposed
in the interior cavity, wherein the force sensing switch comprises:
a deflectable beam; a dome switch disposed over a top surface of
the deflectable beam; and an electrode disposed under a bottom
surface of the deflectable beam, wherein the bottom surface of the
deflectable beam and the electrode form a capacitive sensing
element.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This Patent Cooperation Treaty patent application claims
priority to U.S. non-provisional application Ser. No. 13/974,620,
filed Aug. 23, 2013, and titled "Remote Control Device," the
contents of which are incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates to input devices, and more
particularly to remote control devices for controlling an
electronic device. Still more particularly, the present invention
relates to a remote control device that includes one or more input
devices.
BACKGROUND
[0003] Remote control devices are used to control various
electronic devices such as televisions, DVD players, stereos, and
game consoles. Typically, the remote control device includes
multiple buttons that can be pressed by a user to interact with the
electronic device, or to interact with a program or application
displayed on the electronic device itself or on a second electronic
device connected to the electronic device. Many of these buttons
provide a binary input for user interaction in that the buttons
either register an input or they do not. Some applications and
remote control devices may benefit from additional inputs beyond
that provided strictly by binary input devices. For example, it may
be advantageous for a user to be able to indicate an amount of
force applied to a touch input surface of a remote control device.
For instance, a user could manipulate a screen element or other
object in a first way with a relatively light touch or in a second
way with a relatively more forceful touch.
SUMMARY
[0004] In one aspect, a remote control device includes a housing
comprising a bottom surface coupled to adjoining side walls
extending up from the bottom surface to form an interior cavity,
and an upper element configured to upper element the interior
cavity.
[0005] The upper element can include a top surface that includes
different frictionally engaging surfaces, including at least one
textured surface and a second surface. One or more input devices
can be disposed in the interior cavity. For example, a force
sensing switch can be positioned in the interior cavity under
either a textured surface or the second surface. The force sensing
switch can include a dome switch disposed over a top surface of a
deflectable beam, where the dome switch includes a deformable
structure configured to deform when a force is applied to the first
textured surface or to the second surface. One or more strain
gauges can be positioned over at least one surface of the
deflectable beam and configured to sense a strain in the
deflectable beam based on the force applied to the textured
surface. For example, a strain gauge can be placed over the top
surface and the bottom surface of the beam, or four strain gauges
can be disposed over the top surface of the deflectable beam. A
processing device can determine the amount of force applied to the
textured surface based on at least one strain measurement received
from a strain gauge or gauges. In some embodiments, only a portion
of the bottom surface of the upper element is connected to the
housing to permit the textured surface to bend based on a force
applied to the textured surface. For example, only the bottom
surface under the second surface can be connected to the
housing.
[0006] In another aspect, a method of producing the remote control
device can include providing at least one input device in an
interior cavity of the housing. The input device is a force sensing
switch in some embodiments. An upper element is provided over the
interior cavity. The upper element can include a top surface that
includes different frictionally engaging surfaces, including at
least one textured surface and a second surface. An input device
can be located under the textured surface. A portion of the bottom
surface of the upper element can be affixed to the housing so that
the textured surface is able to bend based on a force applied to
the textured surface. For example, in some embodiments, only the
bottom surface under the second surface can be connected to the
housing.
[0007] In yet another aspect, a method of producing an upper
element for the remote control device can include applying a first
masking material to a top surface of the upper element to define a
first surface not covered by the first masking material and a
second surface covered by the first masking material. A first
textured surface is then produced in the first surface. For
example, the first surface can be etched and polished or a
mechanical polishing can be used to produce the first textured
surface. The first masking material can be removed and one or more
openings can be formed through the glass upper element. At least
one of the one or more openings is configured to receive an input
button. When the upper element is to include more than one textured
surface, prior to forming the opening(s), a second masking material
can be applied to an area of the second surface of the glass upper
element to define a third surface not covered by the second masking
material. A second textured surface then can be produced and the
second masking material removed.
[0008] In another aspect, a method for producing a roughness in a
surface of a glass upper element of a remote control device can
include producing the roughness in a portion of the surface of the
glass upper element by abrasively etching the portion with a
mixture of glass beads and a liquid, and polishing the portion to
modify the roughness in the portion of the surface of the glass
upper element.
[0009] And in yet another aspect, a remote control device includes
a housing comprising a bottom surface coupled to adjoining side
walls extending up from the bottom surface to form an interior
cavity, and an upper element configured to upper element the
interior cavity. The upper element can include a top surface that
includes different frictionally engaging surfaces, including at
least one textured surface and a second surface. One or more input
devices can be disposed in the interior cavity. For example, a
force sensing switch can be positioned in the interior cavity under
either a textured surface or the second surface. The force sensing
switch can include a dome switch disposed over a top surface of a
deflectable beam, where the dome switch includes a deformable
structure configured to deform when a force is applied to the first
textured surface or to the second surface. An electrode can be
positioned below a bottom surface of the deflectable beam, where
the bottom surface of the deflectable beam and the electrode form a
capacitive sensing element. A processing device can determine the
amount of force applied to the textured surface based on at least
one capacitance measurement.
[0010] In some embodiments, only a portion of the bottom surface of
the upper element is connected to the housing to permit the
textured surface to bend based on a force applied to the textured
surface. For example, only the bottom surface under the second
surface can be connected to the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments are better understood with reference to the
following drawings. The elements of the drawings are not
necessarily to scale relative to each other.
[0012] Identical reference numerals have been used, where possible,
to designate identical features that are common to the figures.
[0013] FIG. 1 is an isometric view of one example of a remote
control device that can include one or more force sensing
switches;
[0014] FIG. 2 is a block diagram of the remote control device shown
in FIG. 1;
[0015] FIG. 3 is a simplified cross-section view of one example of
a dome switch;
[0016] FIG. 4 is a simplified cross-section view of one example of
a force sensing switch in a non-actuated state;
[0017] FIG. 5 is a simplified cross-section view of the force
sensing switch 401 in an actuated state;
[0018] FIGS. 6-8 are circuit diagrams of different types of strain
gauge configurations that can be used in a force sensing
switch;
[0019] FIG. 9 is a top view of a force sensing switch;
[0020] FIG. 10 is a view of the remote control device of FIG. 1
with the glass upper element 104 detached from the housing 102;
[0021] FIG. 11 is a view of one example of a bottom surface of the
glass upper element 104 shown in FIG. 10;
[0022] FIG. 12 is a view of another example of a remote control
device with the glass upper element detached from the housing;
[0023] FIG. 13 is a flowchart of a method for producing the glass
upper element shown in FIGS. 10-12;
[0024] FIG. 14 is a flowchart of a method for producing a textured
surface in block 1308 of FIG. 13;
[0025] FIG. 15 depicts a glass upper element after block 1306 in
FIG. 13 is performed;
[0026] FIG. 16 illustrates the glass upper element 1502 after block
1310 in FIG. 13 is performed;
[0027] FIG. 17 depicts a method for abrasively etching a glass
upper element;
[0028] FIG. 18 illustrates the glass upper element after the
abrasive etch is performed;
[0029] FIGS. 19-20 are simplified cross-section views of another
example of a force sensing switch suitable for use in a remote
control device; and
[0030] FIG. 21 is a block diagram of one example of a
self-capacitance sensing system suitable for use with the force
sensing switch shown in FIGS. 19-20.
DETAILED DESCRIPTION
[0031] Embodiments described herein provide a remote control device
that can be used with networked devices, such as computers, tablet
computing devices, and video streaming media devices. One suitable
non-limiting example of a networked device is a streaming media
player. The remote control device includes an upper element having
different frictionally engaging surfaces, including at least one
textured surface and a second surface. The at least one textured
surface can receive user inputs, such as a touch and/or force
input. A force sensing switch can be positioned in a housing of the
remote control device and provide an analog input based on the
amount of applied force. In other words, the force sensing switch
is not binary in that the force sensing switch does not register an
input or not register an input. The force sensing switch can have
multiple output states or signal levels based on the amount of
force applied to the upper element.
[0032] A force sensing switch can include one or more dome switches
and one or more strain gauges disposed over a top surface of a
deflectable beam. When a downward force is applied to an input
surface, the downward force is also applied to the dome switch and
to the deflectable beam. The force can cause a deformable structure
in the dome switch to compress, which in turn causes the
deflectable beam to deflect or strain based on the applied force.
The amount of beam strain can vary depending on the amount of force
applied to the input surface. The strain gauge(s) can measure the
amount of beam strain, and a processing device operatively
connected to the one or more strain gauges can determine the amount
of force applied to the input surface based on a strain measurement
received from at least one strain gauge.
[0033] A portion of the bottom surface of the upper element can be
affixed to the housing in a manner that permits the textured
surface to bend based on the applied force. For example, only the
bottom surface under the second surface can be affixed to the
housing, or to a trim within the housing. The textured surface is
therefore able to bend at or near an interface between the affixed
and non-affixed bottom surface in response to an applied force.
[0034] The upper element can further include one or more input
buttons. The input buttons can provide for a variety of user
inputs, such as volume control, channel control, a home button, a
select button, navigation buttons, pause or play buttons, and a
device or mode button. The input buttons can be flush with the
surface, can protrude or extend beyond the surface, can be recessed
with respect to the surface, or a combination of both in that some
input buttons are flush or recessed while other input buttons
protrude. Additionally or alternatively, the input buttons can have
any given shape and/or surface to aid a user in identifying an
input button and its function.
[0035] In some embodiments, the upper element of the remote control
device includes multiple textured surfaces. A force sensing switch
can be positioned below one textured surface and another input
device, such as a trackpad, can be located under another textured
surface.
[0036] Referring now to FIG. 1, there is shown a perspective view
of a remote control device that can include one or more force
sensing switches. The remote control device 100 includes a housing
102 and a glass upper element 104. Although the upper element 104
is described herein as a glass upper element, other embodiments can
form the upper element with a different material or combination of
materials, such as with a plastic, a metal, or various combinations
of a glass, a plastic, or a metal.
[0037] The housing 102 is formed such that an interior cavity (not
shown) is disposed between the bottom surface and the sidewalls of
the housing 102. The interior cavity can include various
structural, electrical and/or mechanical components. For example,
the interior cavity can include a power source, a processing
device, one or more microphones, a memory or data storage device,
one or more wireless communication devices, and one or more
connector ports. The housing 102 can be made of any suitable
material or materials, such as a metal, a plastic, or a combination
of materials.
[0038] The top surface of the glass upper element 104 can be
partitioned to include at least two different frictionally engaging
surfaces, including a textured surface 106 and a second surface
108. The textured surface 106 and the second surface 108 can have
substantially the same dimensions, or the two surfaces can have
different dimensions. Additionally, the textured surface 106 and
the second surface 108 can be positioned at locations different
from the locations shown in FIG. 1.
[0039] The second surface 108 can be smooth or include some
texturing or covering. The textured surface 106 can be used for
user inputs, such as a touch and/or a force input. A user's finger
can move or slide more easily on or over the textured surface
because the finger contacts a lesser amount of surface compared to
a smooth surface. Additionally or alternatively, the second surface
can be used for user inputs.
[0040] Openings (not shown) can extend through the second surface
108 and/or the textured surface 106 to provide for one or more
input buttons 110. The input buttons can provide for a variety of
user inputs, such as volume control, channel control, a home
button, a select button, navigation buttons, pause or play buttons,
and a device or mode button. The input buttons 110 can be formed
with any suitable material, including metal or plastic. The input
buttons can be flush with the surface, can be recessed with respect
to the surface, can protrude or extend beyond the surface, or a
combination of these configurations. For example, in some
embodiments, the input buttons are flush while other input buttons
protrude. Additionally or alternatively, the input buttons can have
any given shape and/or surface. For example, an input button can
have a textured, concave or convex surface while another input
button has a smooth or flat surface. The input buttons can be
shaped differently to assist a user in identifying the input
buttons from one another. Raised symbols can be formed in the
button surface; or the input buttons or an area around the input
buttons can be illuminated to aid a user in identifying an input
button and its function.
[0041] The glass upper element 104 can include one or more openings
112 for a microphone or speaker(s). Additionally or alternatively,
the housing 102 can include an opening or openings (not shown) for
a microphone or one or more speakers.
[0042] FIG. 2 is a block diagram of the remote control device shown
in FIG. 1. The remote control device 100 can include one or more
processing devices 200, one or more data storage devices 202,
input/output (I/O) device(s) 204, a power source 206, and one or
more sensors 208. The one or more processing devices 200 can
control some or all of the operations of the remote control device
100. The processing device(s) 200 can communicate, either directly
or indirectly, with substantially all of the components of the
remote control device 100. For example, one or more system buses or
signal lines 210 or other communication mechanisms can provide
communication between the processing device(s) 200, the data
storage device(s) 202, the I/O device(s) 204, the power source 206,
and/or the sensor(s). The processing device(s) 200 can be
implemented as any electronic device capable of processing,
receiving, or transmitting data or instructions. For example, the
one or more processing devices 200 can be a microprocessor, a
central processing unit (CPU), an application-specific integrated
circuit (ASIC), a digital signal processor (DSP), or combinations
of multiple such devices. As described herein, the term "processing
device" is meant to encompass a single processor or processing
unit, multiple processors, multiple processing units, or other
suitably configured computing element or elements.
[0043] The data storage device(s) 202 can store electronic data
that can be used by the remote control device 100. For example, a
data storage device can store electrical data or content such as,
for example, audio files, settings and user preferences, and timing
signals. The data storage device(s) 202 can be configured as any
type of memory. By way of example only, the memory can be
implemented as random access memory, read-only memory, Flash
memory, removable memory, or other types of storage elements, in
any combination.
[0044] The input/output device(s) 204 can receive data from a user
or one or more other electronic devices. Additionally, the
input/output device(s) 204 can facilitate transmission of data to a
user or to other electronic devices. For example, an I/O device 204
can transmit electronic signals via a wireless or wired connection.
Examples of wireless and wired connections include, but are not
limited to, WiFi, Bluetooth, infrared, and Ethernet.
[0045] In other embodiments, the I/O device(s) 204 can include a
display, a touch sensing input surface such as a trackpad, one or
more buttons, one or more microphones or speakers, a keyboard,
and/or a force sensing switch or switches. For example, a force
sensing switch can be included in a button, the keys on a keyboard,
and/or an input surface of the remote control device.
[0046] The power source 206 can be implemented with any device
capable of providing energy to the remote control device 100. For
example, the power source 206 can be one or more batteries or
rechargeable batteries, or a connection cable that connects the
remote control device to another power source such as a wall
outlet.
[0047] The one or more sensors 208 can include any suitable type of
sensor or sensors, such as a motion sensor, a proximity sensor, an
orientation sensor (e.g., gyroscope), and/or an accelerometer.
[0048] Referring now to FIG. 3, there is s own a simplified view of
one example of a dome switch in an unactuated or relaxed position.
The dome switch 300 includes a substrate 302, conductive traces 304
and 306 disposed within the substrate 302, an inner conductive
contact 308, and an outer conductive ring 310. The substrate 302
can be any suitable type of substrate, such as a flexible circuit,
a printed circuit board, a frame structure, or a housing wall. In
the illustrated embodiment, the substrate is a flexible circuit.
The conductive trace 304 is connected to the inner conductive
contact 308 while the conductive trace 306 is connected to the
outer conductive ring 310.
[0049] The dome switch 300 further includes a deformable structure
312. The deformable structure 312 is shaped as a dome in the
illustrated embodiment, but other embodiments can shape the
deformable structure differently. The deformable structure 312 can
include a flexible outer material 314 and an adhesive 316 that
connects the deformable structure 312 to the substrate 302. The
flexible outer material can be made of any suitable flexible
material, such as polyethylene terephthalate ("PET"). The underside
of the flexible outer material 314 is coated with a conductive
material 318 such as graphite or gold that is connected to the
outer conductive ring 310. A contact structure 320 can be disposed
between the underside of the textured surface 106 (FIG. 1) and the
flexible outer material 314.
[0050] While in the unactuated state, the conductive material 318,
the inner contact 308, and the outer contact ring 310 are not in
contact with each other, causing the dome switch to be in an "open"
or "off" state because a circuit formed through the conductive
material 318, the inner contact 308, and the outer contact ring 310
is not complete. When a finger 322 presses down on the textured
surface 106, the contact structure 320 pushes down on the
deformable structure 312, which in turn causes the deformable
structure 312 to compress such that the conductive material 318
makes contact with both the inner conductive contact 308 and the
outer conductive ring 310. This action completes the circuit formed
through the conductive material 318, the inner contact 308, and the
outer contact ring 310 and places the dome switch in an actuated or
"on" state.
[0051] Other embodiments can construct the dome switch 300
differently. For example, a deformable structure, such as a dome,
can be arranged in an inverted position such that the base of the
dome connects to an outer conductive ring affixed to an underside
of an input surface. An inner conductive contact is also positioned
on the underside of the input surface under the dome. An inner
surface of the dome can be lined with a conductive material. In the
unactuated state, the switch is in an "open" or "off" state because
the dome is not collapsed and the conductive material inside the
dome is not in contact with both the inner conductive contact and
the outer conductive ring. The dome switch is actuated when a user
presses down on the input surface and the inverted dome compresses
such that the inner conductive contact and the outer conductive
ring both make contact with the conductive material lining the
inside of the dome. This action closes the circuit and places the
switch in an "on" state.
[0052] Alternatively, in other embodiments, the dome switch can
include a rubber dome positioned over a metal dome. The rubber dome
can include a plunger portion that extends downward from the center
of the underside of the rubber dome. The plunger portion is
positioned over the center of the top of the metal dome. A membrane
is disposed under the metal dome, and conductive contact pads are
embedded in the membrane. In an unactuated state, the conductive
contact pads are not in contact with each other and the switch is
in an "off" state. To place the dome switch in an "on" state, a
user presses down on an input surface to compress the rubber dome
such that the plunger portion contacts and pushes down on the
center of the top of the metal dome, which in turn causes the metal
dome to collapse and push down on the membrane. The conductive
contact pads connect and close the switch when the metal dome
presses down on the membrane.
[0053] Embodiments of a force sensing switch include at least one
dome switch, such as the dome switch 300. FIG. 4 depicts a
simplified view of one example of a force sensing switch in an
unactuated state, and FIG. 5 illustrates the force sensing switch
401 in an actuated state. The dome switch 300 is disposed over a
top surface of a deflectable beam 400 (FIG. 4). Although only one
dome switch is shown in the figures, embodiments can position one
or more dome switches over the top surface of the deflectable
beam.
[0054] In one embodiment, the deflectable beam 400 is shaped
similar to a table or stool with support structures 402 extending
out and under the deflectable beam and connecting to a component or
surface in the electronic device. In other embodiments, the
deflectable beam can be constructed differently. By way of example
only, the deflectable beam can be configured as a cantilevered
beam.
[0055] The deflectable beam 400 is affixed to a structure 403. By
way of example only, the structure 403 can be a surface of a frame
or enclosure, or the structure can be a separate element that is
affixed to the frame or enclosure. Any suitable method can be used
to affix the deflectable beam 400 to the structure 403, such as,
for example, an adhesive or a fastener. In some embodiments, the
deflectable beam 400 can be molded with the enclosure such that the
enclosure and deflectable beam are one piece.
[0056] One or more strain gauges 404 can be disposed over the top
surface of the deflectable beam adjacent to, or around the dome
switch 300. Additionally or alternatively, in other embodiments one
or more strain gauges 404 can be placed over other surfaces of the
deflectable beam 400. For example, one or more strain gauges can be
disposed over the bottom surface of the deflectable beam between
the two support structures 602. In such embodiments, a strain gauge
or gauges can also be located over the top surface of the
deflectable beam 400.
[0057] As described earlier, the substrate 302 is a flexible
circuit or a printed circuit board in some embodiments. In the
illustrated embodiment, a conductive connector 406 can operatively
connect the strain gauge 404 to the flexible circuit or printed
circuit board substrate 302. Another flexible circuit 408 can be
disposed over the top surface of the deflectable beam in one
embodiment. A second conductive connector 410 can operatively
connect the flexible circuit substrate 302 of the dome switch to
the flexible circuit 408. The flexible circuit 408 can connect to a
processing device or a main logic board (not shown). In other
embodiments, a main logic board that includes a processing device
can be positioned over the top surface of the deflectable beam 400,
and the second conductive connector 410 can operatively connect the
flexible circuit substrate 302 of the dome switch to the main logic
board. And in other embodiments, the flexible circuit 408 can be
omitted and the flexible circuit substrate 302 can connect to a
processing device or main logic board.
[0058] When a downward force (represented by arrow 500) is applied
to the textured surface (not shown) of the remote control device,
the downward force is also applied to the deformable structure 312
and to the deflectable beam 400. The downward force can be
sufficient to collapse the deformable structure 312 and actuate the
dome switch, or the force can be insufficient to actuate the dome
switch but still compress the deformable structure 312. Either way,
the deflectable beam 400 deflects based on the applied force.
Different amounts of beam deflection are represented by dashed
lines 502 and 504. Dashed line 502 represents a small amount of
beam deflection while dashed line 504 a greater amount of beam
deflection. The strain gauge or gauges 404 can be used to measure
the amount of beam strain. For example, each strain gauge can
output a signal representative of the amount of beam strain
measured by the strain gauge.
[0059] The signal or signals from the one or more strain gauges can
be transmitted to a processing device or the main logic board using
the conductive connector 406, the flexible circuit 302, the
conductive connector 410, and the flexible circuit 408. The
processing device can determine an amount of force that was applied
to the textured surface based on the amount of strain measured by
at least one strain gauge 404. Embodiments can use any suitable
type of strain gauge, including a mechanical, a resistive, a
capacitive, and an optical strain gauge. By way of example only, a
semiconductor strain gauge or a bonded metallic strain gauge can be
used. FIGS. 6-8 illustrate different types of strain gauges that
can be used in a force sensing switch in one or more
embodiments.
[0060] In some embodiments, the dome switch 300 can be used to test
and/or calibrate the force sensing switch 401. For example, the
dome switch may collapse at a known and reproducible force. When a
collapse of the dome switch is detected by the force sensing switch
changing from the "off" state to the "on" state, the strain
measured by at least one strain gauge can then be calibrated at
this force. Since strain gauges are largely linear, strain readings
at zero load and at the dome switch collapse force are sufficient
to calibrate the force sensing switch 401.
[0061] In some embodiment, the force sensing switch is not operable
unless the dome switch 300 is actuated. Once the dome switch is
actuated, the processing device determines the amount of applied
force based on a signal received from at least one strain gauge. In
other embodiments, the force sensing switch operates regardless of
whether the dome switch is actuated or not. Based on the applied
force, the dome switch either compresses (no actuation) or is
actuated, and in both cases the processing device determines the
amount of applied force based on a signal received from at least
one strain gauge.
[0062] The deflectable beam 400 can be formed of a material or a
combination of materials that allow the beam to strain only to a
maximum point (e.g., dashed line 504), thereby preventing the
deflectable beam from straining too far and breaking or becoming
inoperable. For example, the deflectable beam 400 can be made of
steel, aluminum, glass, and/or a plastic. Additionally or
alternatively, a structure (not shown) having a height that is less
than the underside of the deflectable beam can be positioned below
the beam 400 to prevent the deflectable beam from deflecting too
far. The underside of the deflectable beam can strain only as far
as the top surface of the structure under the beam. Thus, the
deflectable beam 400 can have a maximum amount of deflection, which
means each strain gauge has a limit on the amount of strain the
gauge can measure. Once the deflectable beam reaches maximum
deflection, the strain gauge or gauges will not measure any more
strain, even when additional force (more force than needed to reach
maximum deflection) is applied to the input surface.
[0063] FIGS. 6-8 are circuit diagrams of different types of strain
gauge configurations that can be used in a force sensing switch. In
FIG. 6, a strain gauge S1 and three constant resistors R are
connected in a full Wheatstone bridge. A Wheatstone bridge is an
electrical circuit used to measure an unknown electrical resistance
by balancing two legs of a bridge circuit. One leg includes an
unknown component and three legs are formed by a resistor having a
known electrical resistance. In the illustrated embodiment, an
output voltage V.sub.OUT is generated when a voltage supply
V.sub.EX is applied to the circuit. When a force is applied to the
deflectable beam and the beam deflects, a strain is generated that
changes the resistance of the strain gauge S1 and changes the
output voltage V.sub.OUT.
[0064] FIG. 7 shows a circuit diagram of another type of strain
gauge configuration. Four strain gauges S.sub.1A, S.sub.1B,
S.sub.2A, and S.sub.2B are electrically connected in a full
Wheatstone bridge. In this configuration, the four strain gauges
replace the three known resistors and the one unknown component.
Instead of balancing the resistors to get a nearly zero output, a
voltage output V.sub.OUT is generated with the resistances of the
strain gauges S.sub.1A, S.sub.1B, S.sub.2A, S.sub.2B. A force
applied to the deflectable beam introduces a strain that changes
the resistance in each strain gauge. The output voltage V.sub.OUT
produced when a voltage supply V.sub.EX is applied to the circuit
changes when the resistances in the strain gauges changes.
[0065] The strain gauges can be arranged as shown in area 700. The
strain gauges can be co-located such that S.sub.1A and S.sub.1B
detect the strain parallel to one axis (e.g., central X-axis 916 in
FIG. 9) and S.sub.2A and S.sub.2B detect the Poisson strain
generated by the strain parallel to the X-axis.
[0066] In FIG. 8, a strain gauge S.sub.1 and a constant resistor
R.sub.1 are connected in series. This configuration is commonly
called a half-bridge. The resistor R.sub.1 is chosen to be nearly
equal to the resistance of the strain gauge S.sub.1 so that the
output voltage V.sub.OUT generally lies midway between V+ and V-.
When a force is applied to the force sensing switch, the
deflectable beam deflects and a strain is generated at the strain
gauge S.sub.1. The strain at the strain gauge S.sub.1 changes the
resistance of the strain gauge S.sub.1, and this in turn changes
the output voltage V.sub.OUT.
[0067] Referring now to FIG. 9, there is shown atop view of a force
sensing switch. The force sensing switch 900 includes four strain
gauges S.sub.1A, S.sub.1B, S.sub.2A, S.sub.2B formed on a common
carrier 902. The common carrier 902 can be affixed to the top
surface 904 of the deflectable beam 906. In other embodiments, two
of the strain gauges can be disposed over the top surface 904 while
the other two strain gauges are placed over the bottom surface of
the deflectable beam.
[0068] A flexible circuit 908 is disposed over the top surface 904
of the deflectable beam 906, and a deformable structure 910 is
disposed over the flexible circuit 908. As described earlier, the
deformable structure 910 and the flexible circuit 908 are
configured as a dome switch. Support structures 912 are shown as
dashed lines in FIG. 9 since the support structures are not visible
when viewing the force sensing switch from above.
[0069] A conductive connector 914 electrically connects V.sub.OUT,
V.sub.EX, and the four strain gauges S.sub.1A, S.sub.1B, S.sub.2A,
and S.sub.2B to the flexible circuit 908. The common carrier 902 is
aligned with the central X-axis 916 of the deflectable beam 906.
The common carrier 902 is placed on the top surface 904 such that
the electrical contact pads 918 are closer to an edge of the
deflectable beam 906 and further away from the center of the beam.
It may be useful to have the electrical contact pads 918 positioned
away from the loading position to avoid damage to the pads,
although it should be understood that alternative embodiments may
orient the common carrier and/or the strain gauges differently.
[0070] In the illustrated embodiment, electrical contact pads 918
are connected to nodes 702, 704, 706, 708 shown in FIG. 7, the
positive input voltage V.sub.EX+ is connected to S.sub.1A and
S.sub.2B, and the negative input voltage V.sub.EX- is connected to
S.sub.1B and S.sub.2A. One side of the differential output,
negative output V.sub.OUT-, is connected between S.sub.1A and
S.sub.2A. The other side of the differential output, positive
output V.sub.OUT+, is connected between S.sub.1B and S.sub.2B.
[0071] FIG. 10 is a view of the remote control device 100 of FIG. 1
with the glass upper element 104 detached from the housing 102. The
housing 102 is formed such that an interior cavity 1000 is disposed
between the bottom 1002 and the sidewalls 1004 of the housing 1002.
The housing 102 can be made of any suitable material or materials,
such as a metal or a plastic. The interior cavity 1000 can include
various structural, electrical and/or mechanical components. For
example, the interior cavity 1000 can include a power source such
as one or more batteries or rechargeable batteries 1006 and a main
logic board 1008. The main logic board can include various
integrated circuits in addition to one or more processing devices.
For example, the main logic board can include a data storage
device, one or more microphones, and other support circuits. One or
more wireless communication devices such as an infrared,
Bluetooth.RTM., WiFi, or RE device can be included in the interior
cavity 1000.
[0072] A connector port 1010 can receive an electrical cord or
cable 1012 that connects the remote control device 100 to a power
source, such as a wall outlet, to charge a rechargeable battery.
Additionally or alternatively, the remote control device 100 can be
connected to a charging dock to recharge the power source.
[0073] A trim 1014 can extend or protrude out along the interior
edges of the sidewalls 1004. In some embodiments, a portion of the
underside of the glass upper element 104 can be connected to the
trim 1014. For example, the bottom surface of the upper element 104
below the second surface 108 can be connected to the housing. The
glass upper element 104 can be connected in any suitable manner.
For example, an adhesive can be used to affix the glass upper
element 104 to the trim 1014. In other embodiments, the underside
of the glass upper element can be affixed to the housing in other
configurations, such as below the second surface and at least a
part of the textured surface.
[0074] The underside of the glass upper element 104 below the
textured surface 106 is not connected to the trim 1014 in one
embodiment. This allows the glass upper element 104 to bend when a
force is applied to the textured surface 106. Since a portion of
the underside of the upper element is affixed to the housing, the
upper element does not pivot but rather bends at or near the
interface between the affixed bottom surface and the non-affixed
bottom surface. The type of glass or materials used in the glass
upper element may limit the bending range such that when a user
presses down on the textured surface, the user may not detect any
movement in the surface. A force sensing switch 1016 can be
disposed on the bottom 1002 of the housing 102 below the textured
surface 106. When a force is applied to the textured surface, such
as when a finger presses down on the surface, the textured surface
bends and the force sensing switch 1016 senses the strain in the
deflectable beam. A processing device on the main logic board 1008
can determine the amount of force applied to the textured surface
106 based on a signal or signals produced by one or more strain
gauges on the deflectable beam. Although only one force sensing
switch is shown, other embodiments can include multiple force
sensing switches. For example, a force sensing switch can be
positioned under the textured surface 106 and another force sensing
switch can be used in combination with at least one input button
110. Additionally or alternatively, two or more force sensing
switches can be disposed under the textured surface 106.
[0075] Referring now to FIG. 11, there is shown a view of a bottom
surface of the glass upper element 104 shown in FIG. 10. A support
layer 1100 can be connected to the bottom surface of the glass
upper element 104. The support layer 1100 can be made of any
suitable material or materials. In one embodiment, the support
layer 1100 is made of different plastics. The corner regions 1102
can be formed with a softer plastic, such as, for example, a
plastic having a durometer hardness of 50. The remaining areas 1104
of the support layer 1100 can be formed with a harder plastic, such
as a glass-filled nylon. The softer corner regions 1102 can provide
support and absorb external forces when the remote control device
forcibly strikes a surface, such as when the remote control device
is dropped.
[0076] A button assembly 1106 can be assembled to the underside of
the glass upper element 104, between the glass upper element and
the support layer 1100. The button assembly 1106 can include the
input buttons (110 in FIGS. 1 and 10) and all of the circuitry and
components needed for the input buttons to operate. The button
assembly 1106 can also assist in positioning and controlling the
input buttons relative to the top surface of the glass upper
element 104.
[0077] An opening 1108 can be formed in the support layer 1100 to
thin the support layer 1100 or to expose the underside of the glass
upper element 104. The opening 1108 can allow the dome switch of
the force sensing switch to be positioned closer to the glass upper
element 104. The opening 1108 can also permit the textured surface
located above the opening 1108 to more easily bend in response to
the force applied to the textured surface.
[0078] Since the textured surface 106 is bendable and not affixed
to the trim 1014 in some embodiments, fasteners 1110 can be molded
or formed on the support layer 1100 to mechanically engage with the
trim 1014 or housing 102 and prevent the textured surface 106 from
being lifted or pulled away from the housing 102. For example, the
fasteners 1110 can include a hook shape that engages with the edge
of the trim, or that is received by openings in the trim 1014.
Other embodiments can use fewer or more fasteners, and the
fasteners can be configured in any given shape. Additionally or
alternatively, the fasteners can be formed with the housing and
engage with the support layer 1100.
[0079] Referring now to FIG. 12, there is shown a view of another
example of a remote control device with the glass upper element
detached from the housing. The remote control device 1200 can
include some of the same elements and components as the remote
control device 1000 in FIG. 10. For simplicity, reference numbers
identical to those in FIG. 10 are used for the like element and
components, and these features are not described in detail with
respect to FIG. 12.
[0080] The remote control device 1200 includes a housing 1202 and a
glass upper element 1204. Although the upper element 1204 is
described as a glass upper element, other embodiments can form the
upper element with a different material or combination of
materials. The glass upper element 1204 is partitioned to include
three different frictionally engaging surfaces, including a first
textured surface 1206, a second textured surface 1208, and the
second surface 108. The first and second textured surfaces can have
substantially the same dimensions, or the two surfaces can have
different dimensions. Additionally, the second surface 108 can have
the same or different dimensions as one or both textured surfaces.
The first textured surface 1206, the second textured surface 1208,
and the second surface 108 can be positioned at locations other
than the locations shown in FIG. 12.
[0081] The first and second textured surfaces 1206 and 1208 can be
used for user inputs, such as a touch and/or a force input. An
input device 1212 can be positioned under one of the textured
surfaces, such as the first textured surface 1206, while a force
sensing switch 1016 can be positioned under the other textured
surface (e.g., surface 1208). For example, in one embodiment, the
input device 1212 can be a trackpad that a user interacts with
using the first textured surface 1206. In another embodiment, the
input device 1212 can be any suitable type of touchscreen with the
first textured surface 1206 being a transparent upper element glass
that a user touches to interact with icons, buttons, or menus
displayed on the screen. And in a third embodiment, the force
sensing switch 1012 can be omitted and two different input devices,
such as a trackpad and a touchscreen, can be included in the remote
control device 1200.
[0082] FIG. 13 is a flowchart of a method for producing the remote
control device shown in FIGS. 10-12. Initially, the glass upper
element is formed and shaped, as shown in block 1300. The glass
upper element can be made of an aluminum silicate composite
material in one or more embodiments. The openings for the one or
more input buttons can then be formed through the glass upper
element (block 1302). Next, as shown in block 1304, an edge profile
can be created around the side edges of the glass upper element. In
some embodiments, the side edges of the glass upper element are
fully exposed in that a housing or frame does not surround the
glass upper element. Thus, the side edges can be shaped to create
an edge profile. For example, the side edges can be cut by a
cutting tool to have a rounded edge profile, similar in shape to
one or more parentheses "( )" or the letter "c" in one or more
embodiments.
[0083] A masking material is then applied to the area of the top
surface of the glass upper element that will not be subsequently
textured (block 1306). A textured surface can be produced in any
given shape and at any location, and the masking material can be
used to define the shape and/or location of the textured surface.
Next, as shown in block 1308, the exposed area of the top surface
of the glass upper element not covered by the masking material is
then etched to form a textured surface.
[0084] The type of masking material used in block 1306 may depend
on the etching process used in block 1308. By way of example only,
if a sandblasting method is used to produce the textured surface,
the masking material can be a removable vinyl adhesive.
Alternatively, if a chemical etch process is used as the etching
process, the masking material can be a resist material, such as a
photoresist.
[0085] After the textured surface is formed, the masking material
is removed, as shown in block 1310. As described in conjunction
with FIG. 12, the remote control device can include multiple
textured surfaces. In some embodiments, the textured surfaces can
be implemented as textured surfaces that have substantially the
same texture or feel to a user. In these embodiments, the masking
material applied at block 1306 can be applied in a manner that
exposes the areas and locations that will be the textured surfaces
having the same texture or feel.
[0086] In other embodiments, the multiple textured surfaces can
have a different texture or feel to the user. Distinct textured
surfaces that feel different to a user can assist the user in
identifying the input device positioned below a respective textured
surface. In these embodiments, the method can include a
determination at block 1312 as to whether or not another area of
the top surface of the glass upper element is to be a textured
surface having a different texture or feel. If so, the method
returns to block 1306. Blocks 1306, 1308, and 1310 repeat until all
of the textured surfaces have been formed.
[0087] When all of the textured surfaces have been produced, the
process passes to block 1314 where the glass upper element is
chemically strengthened. Chemically strengthening the glass upper
element can help prevent cracks from forming in the glass upper
element, and can reduce the probability that the glass upper
element will chip or break. Next, as shown in block 1316, the
button assembly and/or the support layer can then be attached to
the glass upper element. If both are to be attached to the glass
upper element, the button assembly can be attached first followed
by the support layer.
[0088] The glass upper element is then affixed to the housing to
produce the remote control device. As described earlier, only a
portion of the bottom surface of the glass upper element can be
affixed to the housing, or to the trim in the housing in some
embodiments. Connecting only the underside of the second surface to
the housing allows the textured surface to bend in response to an
applied surface. In other embodiments, the underside of the glass
upper element can be connected to the housing differently. For
example, the bottom surface of the glass upper element below the
second surface and below at least a portion of the textured surface
can be affixed to the trim or housing.
[0089] The method shown in FIG. 13 can be performed differently in
other embodiments. Blocks can be added or deleted, or performed in
a different order. By way of example only, block 1312 can be
omitted in embodiments where only one textured surface is formed,
or when multiple textured surfaces having the same texture are
formed on the top surface of the glass upper element.
Alternatively, block 1312 can be omitted in embodiments where the
upper element is made of a material other than glass.
[0090] FIG. 14 is a flowchart of a method for producing a textured
surface in block 1308 of FIG. 13.
[0091] The illustrated process comprises a two-step process. In the
first step, the exposed area is etched to produce a roughness in
the surface of the exposed area (block 1400). The rough surface is
then polished, as shown in block 1402, to modify the roughness. For
example, the polish can smooth out the roughness such that the
sharpness of the irregular surface is reduced to lower the friction
coefficients.
[0092] FIG. 15 depicts a masking material 1500 applied to a port on
of the top surface of the glass upper element 104. The exposed
portion 1502 is an area of the glass upper element that will be a
textured surface. In a prior art method, a chemical etch is used in
block 1400 (FIG. 14) to etch the exposed portion 1502 and produce a
roughness 1600 in the surface of the exposed portion. However, as
shown in FIG. 16, the chemical etch also etches or removes some of
the glass upper element 104 in the exposed portion 1502, resulting
in a noticeable step S1 between the top surface of the exposed
portion 1502 and the top surface of the portion 1602 that was
protected by the masking material. The step S1 can be noticeable to
a user, and in some situations, may be objectionable to the user as
the user handles or moves his or her fingers over the glass upper
element.
[0093] Instead of using a chemical etch in block 1400, one
embodiment described herein uses an abrasive etch that includes
abrasive particles. The abrasive particles can be mixed in with a
liquid. The liquid is the carrier for the abrasive particles and
applies the abrasive particles against the surface of the exposed
portion at the desired amount of pressure. FIG. 17 illustrates a
method for abrasively etching a glass upper element. The masking
material 1500 is applied to a portion of the top surface of the
glass upper element 104. A mixture 1700 of the liquid and the
abrasive particles 1702 can be applied to the exposed portion of
the top surface to produce a roughness in the top surface. By way
of example only, the abrasive particles can be glass beads, the
liquid may be water, and the mixture can be jetted from a nozzle
onto the exposed portion of the top surface. The diameter of the
glass beads can be based on the desired roughness. For example, the
diameter of the glass beads can be an ultra-fine micro-grit with an
average particle diameter of 10.3 or a 1000 grit designation. In
one embodiment, the ultra-fine micro-grit glass beads produce a
surface roughness of less than 100 Ra, where Ra is the average
roughness expressed in nanometers. In other embodiments, the
diameter of the glass beads can be larger to produce a different
surface roughness Ra. For example, larger diameter glass beads can
be used to formed a surface roughness of 500-1000 in a surface.
[0094] The amount of abrasive particles and the amount of liquid in
a mixture can be based on the desired roughness to be formed in a
surface, and/or on the amount of polish to be used in block 1402 of
FIG. 14. Additionally or alternatively, the size and the shape of
the abrasive particles can be different in other embodiments.
[0095] In some embodiments, at least a portion of the abrasive
particles (e.g., the glass beads) can be recycled and used again
when producing one or more additional glass upper elements. For
example, the glass beads can be separated from the water with a
filter and a percentage of previously-used glass beads can be mixed
in with new glass beads when forming another glass upper
element.
[0096] In another embodiment, a mechanical polish can be used in
block 1400 of FIG. 14 instead of the abrasive etch to produce a
desired surface roughness. For example, a compound can be applied
to the exposed surface of the glass upper element with a pad. The
combination of the pad and the compound can produce the roughness
in the surface.
[0097] FIG. 18 illustrates the glass upper element after the
abrasive etch is performed. A roughness 1800 is formed in a portion
of the top surface of the glass upper element 104, and the upper
element has a smaller step S2 than the step S1 shown in FIG. 16.
The smaller step S2 may not be noticeable, or may be less
noticeable to a user than the step S1.
[0098] Although a glass upper element has been used to describe
various techniques for forming a roughness in the surface of the
glass upper element, other embodiments are not limited to this
construction. A roughness can be produced in different types of
materials or surfaces. By way of example only, a roughness can be
formed in a plastic or metal surface, or the surface can be used in
a different type of product, such as, for example, in the exterior
surface of a trackpad, the keys in a keyboard, input buttons, a
surface of a mouse, or any other surface that a user interacts
with.
[0099] Referring now to FIGS. 19 and 20, there are shown simplified
cross-section views of another example of a force sensing switch
that is suitable for use in a remote control device. FIG. 19
depicts the force sensing switch in an unactuated state. Some of
the elements included in the force sensing switch 1900 are the same
elements that are shown in FIG. 4. For simplicity, these identical
elements are not described in detail.
[0100] The force sensing switch 1900 detects force by measuring
capacitance changes between the bottom surface 1902 of the
deflectable beam 400 and an electrode 1904 disposed under the
deflectable beam and over the support structure 403. The electrode
1904 can be made of any suitable material, such as, for example, a
metal. The combination of the bottom surface 1902 of the
deflectable beam 400 and the electrode 1904 forms a capacitive
sensing element.
[0101] The gap or distance between the bottom surface 1902 and the
electrode 1904 is D1 when the force sensing switch is in an
unactuated state. When a downward force (represented by arrow 2000
in FIG. 20) is applied to an input surface (not shown), the
downward force is also applied to the deformable structure 312 and
to the deflectable beam 400. The downward force can be sufficient
to collapse the deformable structure 312 and actuate the dome
switch, or the force can be insufficient to actuate the dome switch
but still compress the deformable structure 312. Either way, the
deformable structure 312 compresses and the deflectable beam 400
deflects based on the applied force. The beam deflection changes
the distance between the bottom surface 1902 of the deflectable
beam and the electrode 1904. In the illustrated embodiment, the
distance decreases to D2. The change in distance results in a
capacitance change between the bottom surface 1902 and the
electrode 1904. The measured capacitance can be calibrated as a
function of applied force and used as a force sensor.
[0102] The capacitive sensing element formed by the bottom surface
1902 and the electrode 1904 can operate in a self-capacitance mode
or in a mutual capacitance mode. In a mutual capacitance mode, the
electrode 1904 can be driven with an excitation signal and a sense
line connected to the electrode 1904 scanned to measure the
capacitance between the bottom surface 1902 and the electrode 1904.
When the capacitive sensing element operates in a self-capacitance
mode, the capacitance is measured with respect to a reference
signal or voltage. FIG. 21 is a block diagram of a self-capacitance
sensing system that is suitable for use with the force sensing
switch shown in FIGS. 19-20. The electrode 1904 can be connected to
a reference voltage, such as ground. A sense circuit scans a sense
line 2100 connected to the electrode to measure the capacitance
between the bottom surface 1902 and the electrode 1904. A
processing device connected to the sense circuit can direct the
sense circuit to scan, and can receive the measurement from the
sense circuit and determine the amount of force applied to the
input surface based on the measurement.
[0103] Various embodiments have been described in detail with
particular reference to certain features thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the disclosure. For example, an input
device such as a force sensing switch has been described as being
positioned below a textured surface. Other embodiments are not
limited to this configuration, and an input device can be disposed
under the second surface. As another example, a processing device
may not be included in a remote control device having one or more
force sensing switches. Instead, the remote control device can be
operatively connected to a processing device and the strain
measurements by a force sensing switch or switches can be
transmitted to the processing device using a wired or wireless
connection. Additionally or alternatively, other embodiments can
include additional structural, electrical and/or mechanical
components in a remote control device. For example, a stiffener
plate can be disposed between the glass upper element and the
bottom of the housing to provide additional structural support.
[0104] Even though specific embodiments have been described herein,
it should be noted that the application is not limited to these
embodiments. In particular, any features described with respect to
one embodiment may also be used in other embodiments, where
compatible. Likewise, the features of the different embodiments may
be exchanged, where compatible.
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