U.S. patent application number 16/369074 was filed with the patent office on 2019-07-25 for method and apparatus for controlling generation of electrostatic friction effects for a plurality of electrodes.
The applicant listed for this patent is Immersion Corporation. Invention is credited to Juan Manuel CRUZ HERNANDEZ, Vincent LEVESQUE, Ali MODARRES, Mohammadreza MOTAMEDI, Kaniyalal SHAH.
Application Number | 20190228620 16/369074 |
Document ID | / |
Family ID | 61007601 |
Filed Date | 2019-07-25 |
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United States Patent
Application |
20190228620 |
Kind Code |
A1 |
LEVESQUE; Vincent ; et
al. |
July 25, 2019 |
METHOD AND APPARATUS FOR CONTROLLING GENERATION OF ELECTROSTATIC
FRICTION EFFECTS FOR A PLURALITY OF ELECTRODES
Abstract
An interface device configured to provide an electrostatic
friction (ESF) effect is disclosed. The interface device comprises
a plurality of electrodes disposed at a surface of the interface
device. It further comprises a signal generating circuit configured
to generate a first drive signal at an output of the signal
generating circuit, and comprises a plurality of frequency filter
units or delay elements electrically connected to the signal
generating circuit and to the plurality of electrodes. The
interface device further comprises a control unit configured to use
the plurality of frequency filter units or delay elements: (i) to
cause only a subset of one or more electrodes of the plurality of
electrodes to output one or more respective ESF effects with the
first drive signal, or (ii) to cause at least two electrodes to
output respective ESF effects with the first drive signal in
different respective manners.
Inventors: |
LEVESQUE; Vincent;
(Montreal, CA) ; CRUZ HERNANDEZ; Juan Manuel;
(Montreal, CA) ; MOTAMEDI; Mohammadreza;
(Montreal, CA) ; SHAH; Kaniyalal; (Fremont,
CA) ; MODARRES; Ali; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Immersion Corporation |
San Jose |
CA |
US |
|
|
Family ID: |
61007601 |
Appl. No.: |
16/369074 |
Filed: |
March 29, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15916397 |
Mar 9, 2018 |
10249157 |
|
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16369074 |
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|
15415137 |
Jan 25, 2017 |
9928700 |
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15916397 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G08B 6/00 20130101; G06F
3/016 20130101 |
International
Class: |
G08B 6/00 20060101
G08B006/00; G06F 3/01 20060101 G06F003/01 |
Claims
1-18. (canceled)
19. An interface device configured to provide an electrostatic
friction (ESF) effect, the interface device comprising: a signal
generating circuit configured to generate a first drive signal at
an output of the signal generating circuit; a first electrode
disposed at a surface of the interface device and permanently
electrically connected to a source of ground potential; a second
set of electrodes disposed at the surface of the interface device,
wherein the first electrode is not part of the second set of
electrodes; a plurality of gating elements, wherein each gating
element of the plurality of gating elements comprises at least one
switch and is configured to switch between (a) electronically
connecting a respective electrode of the second set of electrodes
to the output of the signal generating circuit and (b) electrically
connecting the respective electrode to the source of ground
potential or leaving the respective electrode in an electrically
floating state; a control circuit configured to select one or more
electrodes of the second set of electrodes to output the ESF effect
with the first drive signal, to control the plurality of gating
elements to electrically connect the one or more electrodes that
have been selected to the output of the signal generating circuit,
and to control the plurality of gating elements to either:
electrically connect all unselected electrodes of the second set of
electrodes to the source of ground potential, or leave all
unselected electrodes of the second set of electrodes in the
electrically floating state.
20. The interface device of claim 19, wherein the signal generating
circuit comprises a signal processor and an amplifier, wherein the
signal processor is configured to generate an initial drive signal,
and the amplifier is configured to amplify the initial drive signal
to generate the first drive signal, and wherein each gating element
of the plurality of gating elements is electrically connected to an
output of the amplifier.
21. The interface device of claim 20, wherein the amplifier is
configured to generate the first drive signal with an amplitude of
at least 1 kV.
22. The interface device of claim 21, wherein the signal generating
circuit is configured to generate the first drive signal as a pulse
with the amplitude of at least 1 kV.
23. The interface device of claim 21, wherein the amplifier is the
only amplifier of the signal generating circuit for amplifying any
signal from the signal processor.
24. The interface device of claim 23, wherein each electrode of the
second set of electrodes is an insulated electrode.
25. The interface device of claim 24, wherein the first electrode
is an exposed electrode.
26. The interface device of claim 20, wherein the at least one
switch of a respective gating element of the plurality of gating
elements is a relay switch or a transistor.
27. The interface device of claim 19, wherein the control circuit
is configured to select only one electrode of the second set of
electrodes to generate the ESF effect with the first drive signal,
to control the plurality of gating elements to electrically connect
only the one electrode that is selected to the output of the signal
generating circuit, and to control the plurality of gating elements
to electrically connect all unselected electrodes of the second set
of electrodes to the source of ground potential.
28. The interface device of claim 19, wherein the interface device
is a wearable device having a band, wherein the surface of the
interface device includes a surface of the band, and wherein the
plurality of electrodes are disposed at the surface of the
band.
29. The interface device of claim 28, wherein each electrode of the
second set of electrodes is shaped as a strip.
30. The interface device of claim 19, wherein the second set of
electrodes are arranged as a two-dimensional array.
31. The interface device of claim 19, wherein the control circuit
is configured to determine a spatial relationship between a
location of an object or event and a location of the interface
device, wherein the control circuit is configured to select the one
or more electrodes of the second set of electrodes based on the
spatial relationship between the location of the object or event
and the location of the interface device.
32. The interface device of claim 19, wherein the control circuit
is configured to determine a temporal relationship between a time
of an event and a current time, wherein the control circuit is
configured to select the one or more electrodes of the second set
of electrodes based on the temporal relationship between the time
of the event and the current time.
33. The interface device of claim 19, wherein each gating element
of the plurality of gating elements comprises a first switch and a
second switch, wherein the first switch is configured to switch
between electrically connecting a respective electrode of the
second set of electrodes to the output of the signal generating
circuit and leaving the respective electrode in the electrically
floating state, and wherein the second switch is configured to
switch between electrically connecting the respective electrode to
the source of ground potential and leaving the respective electrode
in the electrically floating state.
34. The interface device of claim 19, wherein the control circuit
is configured to select the one or more electrodes from among a
subset of the second set of electrodes, the subset of electrodes
receiving user contact, such that some electrodes of the second set
of electrodes receiving user contact are not selected to generate a
respective ESF effect with the first drive signal.
35. The interface device of claim 19, wherein the interface device
is a mobile device, and the second set of electrodes are disposed
on a back surface of the mobile device.
36. The interface device of claim 35, wherein each electrode of the
second set of electrodes is shaped as a circle or as a square.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to a method and apparatus
for controlling generation of electrostatic friction effects for a
plurality of electrodes, and has application in wearables, user
interfaces, gaming, automotive, virtual reality or augmented
reality, and consumer electronics.
BACKGROUND
[0002] As computer-based systems become more prevalent, the quality
of the interfaces through which humans interact with these systems
is becoming increasingly important. Haptic feedback, or more
generally haptic effects, can improve the quality of the interfaces
by providing cues to users, providing alerts of specific events, or
providing realistic feedback to create greater sensory immersion
within a virtual environment.
[0003] Examples of haptic effects include kinesthetic haptic
effects (such as active and resistive force feedback), vibrotactile
haptic effects, and electrostatic friction haptic effects. In
electrostatic friction haptic effects, a current may be provided to
an electrode. The electrode may then exert an attractive force on
the skin of a user, who may perceive this force as electrostatic
friction.
SUMMARY
[0004] One aspect of the embodiments herein relates to an interface
device configured to provide an electrostatic friction (ESF)
effect. The interface device comprises a plurality of electrodes, a
signal generating circuit, a plurality of frequency filter units or
delay elements, and a control unit. The plurality of electrodes are
disposed at a surface of the interface device. The signal
generating circuit is configured to generate a first drive signal
at an output of the signal generating circuit. The plurality of
frequency filter units or delay elements are electrically connected
to the signal generating circuit and to the plurality of
electrodes, such that each electrode of the plurality of electrodes
is electrically connected to an output of a respective frequency
filter unit or delay element. An input of the respective frequency
filter unit or delay element is electrically connected to the
output of the signal generating circuit. The control unit is
configured to use the plurality of frequency filter units or delay
elements: (i) to cause only a subset of one or more electrodes of
the plurality of electrodes to output one or more respective ESF
effects with the first drive signal, or (ii) to cause at least two
electrodes of the plurality of electrodes to output respective ESF
effects with the first drive signal in different respective
manners.
[0005] In an embodiment, the interface device comprises the
plurality of frequency filter units. Each of the plurality of
frequency filter units has a respective pass-through frequency band
or a respective set of pass-through frequency bands, and is
configured to block any frequency component of the first drive
signal which is outside the respective pass-through frequency band
or respective set of pass-through frequency bands. The respective
pass-through frequency bands or respective sets of pass-through
frequency bands of the plurality of frequency filter units do not
overlap in frequency, or only partially overlap in frequency.
[0006] In an embodiment, the control unit is configured to cause
the signal generating circuit to generate the first drive signal
with only a frequency component that is (i) within the respective
pass-through frequency band or respective set of pass-through
frequency bands of a respective frequency filter unit of a first
electrode and (ii) outside the respective pass-through frequency
bands or respective sets of pass-through frequency bands of the
remainder of the plurality of frequency filter units of the
remainder of the plurality of electrodes of the interface device,
such that the plurality of frequency filter units causes only the
first electrode of the plurality of electrodes to output an ESF
effect with the first drive signal.
[0007] In an embodiment, each of the plurality of frequency filter
units has only a single respective pass-through frequency band, and
the respective pass-through frequency bands of the plurality of
frequency filter units do not overlap in frequency, or each of the
plurality of frequency filter units has a respective set of
pass-through frequency bands, and the respective sets of
pass-through frequency bands of the plurality of frequency filter
units have partial overlap in frequency.
[0008] In an embodiment, the plurality of frequency filter units
comprise a first frequency filter unit configured to pass the first
drive signal to a first electrode of the plurality of electrodes
with a first attenuation level, and comprises a second frequency
filter unit configured to pass the first drive signal to a second
electrode of the plurality of electrodes with a second attenuation
level different than the first attenuation level. The interface
device is configured to cause the first electrode and the second
electrode to output respective ESF effect with the first drive
signal with different respective intensity levels.
[0009] In an embodiment, the plurality of frequency filter units
comprise a first frequency filter unit configured to pass the first
drive signal to a first electrode of the plurality of electrodes
with a first phase shift that creates a first period of delay, and
comprises a second frequency filter unit configured to pass the
first drive signal to a second electrode of the plurality of
electrodes with a second phase shift that creates a second period
of delay different than the first period of delay, and wherein the
interface device is configured to cause the first electrode and the
second electrode to output respective ESF effects with the first
drive signal at different respective times.
[0010] In an embodiment, the control unit is configured to
determine a spatial relationship between the interface device and a
determined location, or to determine a temporal relationship
between a current time and a determined event, and is configured to
select the subset of one or more electrodes to convey the spatial
relationship or the temporal relationship.
[0011] In an embodiment, the interface device comprises the
plurality of frequency filter units. The first drive signal is one
of a plurality of drive signals the signal generating circuit is
configured to generate in different respective time periods or in
response to different signal generating commands. The control unit
is configured to cause the plurality of frequency filter units to
pass the plurality of drive signals to different respective
electrodes of the plurality of electrodes.
[0012] In an embodiment, the plurality of electrodes are arranged
as an array. The control unit is configured to use the plurality of
frequency filter units to cause the array of electrodes to
sequentially output respective ESF effects with the respective
drive signals to create an impression of flow along the array of
electrodes.
[0013] In an embodiment, the interface device comprises the
plurality of delay elements, wherein the plurality of delay
elements are configured to control a timing by which each electrode
of the plurality of electrodes will output an ESF effect by
introducing different respective periods of delay of the first
drive signal from an input of the respective delay element to an
output of the respective delay element.
[0014] In an embodiment, the plurality of electrodes is arranged in
an array in which the plurality of electrodes has uniform spacing
between adjacent electrodes.
[0015] In an embodiment, the array is a two-dimensional array.
[0016] In an embodiment, the interface device is a wearable
device.
[0017] In an embodiment, the signal generating circuit comprises an
amplifier circuit configured to amplify a first signal to the first
drive signal, wherein the amplifier circuit is the only amplifier
circuit in the interface device for amplifying the first signal to
the first drive signal.
[0018] In an embodiment, the control unit is configured to select
the subset of one or more electrodes from among a set of electrodes
of the plurality of electrodes that are receiving user contact,
such that some electrodes receiving user contact are not selected
to generate a respective static ESF effect with the first drive
signal.
[0019] One aspect of the embodiments herein relates to an interface
device configured to provide an electrostatic friction (ESF)
effect. The interface device comprises a signal generating circuit,
a plurality of delay elements, and a plurality of electrodes. The
signal generating circuit is configured to generate a first drive
signal at an output of the signal generating circuit. The plurality
of delay elements are configured to introduce respective periods of
delay to the first drive signal from an input of the respective
delay element to an output of the respective delay element. The
plurality of electrodes correspond to the plurality of delay
elements, wherein each of the plurality of electrodes is connected
to an output of a respective delay element and is configured to
generate a respective ESF effect with the first drive signal. The
plurality of delay elements and their respective electrodes form a
plurality of respective pairs that each includes a respective delay
element and a respective electrode. The plurality of pairs of delay
elements and their respective electrodes are electrically connected
in series such that an input of a delay element of a first pair in
the series is connected to an output of the signal generating
circuit, and an input of a delay element of all other pairs in the
series is electrically connected to an electrode of a previous pair
in the series.
[0020] In an embodiment, the respective periods of delay introduced
by the plurality of delay elements are the same.
[0021] In an embodiment, the respective periods of delay introduced
by the plurality of delay elements are all different. Features,
objects, and advantages of embodiments hereof will become apparent
to those skilled in the art by reading the following detailed
description where references will be made to the appended
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The foregoing and other features and advantages of the
invention will be apparent from the following description of
embodiments hereof as illustrated in the accompanying drawings. The
accompanying drawings, which are incorporated herein and form a
part of the specification, further serve to explain the principles
of the invention and to enable a person skilled in the pertinent
art to make and use the invention. The drawings are not to
scale.
[0023] FIG. 1A is a depiction of a wearable device having a
plurality of electrodes disposed at an outer surface thereof to
generate electrostatic friction effects, according to an embodiment
herein.
[0024] FIG. 1B is a depiction of a wearable device having a
plurality of electrodes disposed at an outer surface thereof to
generate electrostatic friction effects, according to an embodiment
herein.
[0025] FIG. 2 is a depiction of a mobile device having a plurality
of electrodes disposed at an outer surface thereof to generate
electrostatic friction effects, according to an embodiment
herein.
[0026] FIG. 3 is a depiction of a laptop having a plurality of
electrodes disposed at an outer surface thereof to generate
electrostatic friction effects, according to an embodiment
herein.
[0027] FIGS. 4A and 4B are schematic representations of a plurality
of gating elements disposed between a driving circuit and
respective electrodes, according to an embodiment herein.
[0028] FIGS. 5A and 5B are schematic representations of a plurality
of gating elements that are frequency filter units, according to an
embodiment herein.
[0029] FIG. 6A is a schematic representation of a plurality of
delay elements connected to a signal generating circuit in a
parallel fashion, according to an embodiment herein.
[0030] FIG. 6B is a schematic representation of a plurality of
delay elements connected to each other in a series fashion,
according to an embodiment herein.
[0031] FIG. 7 is a schematic representation of a plurality of
gating elements that are relay switches, according to an embodiment
herein.
[0032] FIGS. 8A and 8B are schematic representations of an
interface device having a plurality of gating elements connected
between respective electrodes and a ground potential, according to
an embodiment herein.
[0033] FIG. 9 is a schematic representation of a plurality of
shielding elements of a shielding layer that are configured to
shield respective electrodes from a surface of an interface device,
according to an embodiment herein.
[0034] FIG. 10 is a schematic representation of a plurality of
shielding elements that are configured to shield respective
electrodes from a surface of an interface device, according to an
embodiment herein.
[0035] FIGS. 11A and 11B illustrate a plurality of electrodes being
used to convey a spatial or temporal relationship, according to an
embodiment herein.
[0036] FIG. 12 illustrates an example layout of a plurality of
electrodes for generating respective ESF effects, according to an
embodiment herein.
[0037] FIG. 13 illustrates an example layout of a plurality of
electrodes for generating respective ESF effects, according to an
embodiment herein.
DETAILED DESCRIPTION
[0038] The following detailed description is merely exemplary in
nature and is not intended to limit the invention or the
application and uses of the invention. Furthermore, there is no
intention to be bound by any expressed or implied theory presented
in the preceding technical field, background, brief summary or the
following detailed description.
[0039] Embodiments hereof relate to implementing a haptic enabled
interface device (e.g., a handheld or otherwise graspable device
such as a mobile device or game console controller, a wearable
device, a laptop) which includes a plurality of electrodes for
producing (e.g., generating) electrostatic friction (ESF) effects,
and is configured to control which subset of one or more electrodes
will generate one or more respective ESF effects with a drive
signal, and/or is configured to vary how different electrodes
generate respective ESF effects with the drive signal. For example,
the haptic enabled interface device may include frequency filter
units or relay switches which are configured to block the drive
signal from reaching certain electrodes, or include shielding
elements which are configured to electrically shield those
electrodes from a surface of the device, so that those electrodes
do not generate any ESF effect with the drive signal at the
surface. In another example, the haptic enabled interface device
may be configured to pass a drive signal to multiple electrodes,
but may attenuate or delay the drive signal by different
amounts/periods for different electrodes, so that the different
electrodes generate respective ESF effects with the drive signal in
different manners. The frequency filter units, delay elements, and
relay switches may be different types of gating elements.
[0040] In an embodiment, the haptic enabled interface device may be
configured to control which electrodes output respective ESF
effects with a drive signal and/or how those electrodes output the
ESF effects with the drive signal in order to convey a spatial
relationship, a temporal relationship, a spatio-temporal
relationship (e.g., a combination of a spatial relationship and a
temporal relationship), and/or other information to a user. In an
embodiment, the plurality of electrodes may sequentially output
respective ESF effects to create an impression of flow along the
electrodes. For instance, if the electrodes are arranged in a
one-dimensional array (e.g., a line) or a two-dimensional array,
the sequential output of the respective ESF effects along the array
may create an impression of flow along the array. This impression
of flow may be used to provide navigation instructions for a user,
indicate progress of an operation, a passage of time, or for any
other purpose.
[0041] In an embodiment, the plurality of electrodes may be used to
produce (e.g., generate) static ESF effects. As discussed in more
detail below, dynamic ESF effects may require a user to move a part
of his or her body (e.g., finger tip) across an electrode, while
static ESF effects allow the user's body (e.g., finger tip) to
remain stationary. In some cases, static ESF effects may use a much
higher voltage (e.g., 1.5 kV) than that used with dynamic ESF
effects (e.g., 10 V). Thus, in some instances, a signal generating
circuit of the haptic enabled device may use one or more amplifier
circuits that include high-voltage electronics to generate a
high-voltage drive signal for static ESF. For example, the drive
signal may be an amplified signal with an amplitude (e.g., >1
kV) suitable for static ESF effects. In an embodiment, the haptic
enabled interface device may include multiple amplifier circuits,
with one amplifier circuit assigned to each electrode, so that the
output of ESF effects can be separately controlled at each
individual electrode. In another embodiment, the haptic enabled
interface device may include only one amplifier circuit for
generating any drive signal. The sole amplifier circuit may be
included in the signal generating circuit. In this embodiment, the
amplifier circuit outputs a drive signal that can be shared among
the plurality of electrodes, which may produce respective ESF
effects using the same drive signal. For instance, a plurality of
individually controllable gating elements (e.g., switches,
frequency filter units, or delay elements) may be placed between
the single amplifier circuit and the respective electrodes to
control ESF effects at those electrodes, or a plurality of
shielding elements may be placed between the respective electrodes
and a ground potential to control ESF effects at those electrodes.
The gating elements or shielding elements may, e.g., cause only a
subset of one or more electrodes of a plurality of electrodes to
output respective one or more ESF effects with a first drive
signal, or may cause at least two electrodes of the plurality of
electrodes to output respective ESF effects with the first drive
signal, but to do so in different manners. In another instance, a
plurality of delay elements may be arranged in a series
configuration to form a chain of delay elements, with each delay
element gating a respective electrode. This series arrangement may
cause a drive signal to sequentially propagate through the chain of
delay elements and their respective electrodes to create the
impression of flow, for instance.
[0042] FIGS. 1A and 1B are depictions of a wearable interface
device (e.g., an activity tracker wristband or smart watch)
configured to provide an electrostatic friction (ESF) effect to a
user. FIG. 1A depicts a wearable interface device 100 that has a
band 101 with a first surface 101a and a second, opposite surface
101b. The first surface 101a may, e.g., be a top outer surface
intended to be visible and/or accessible when worn, and the second
surface 101b may be, e.g., a bottom outer surface intended to
contact a user's wrist when worn. The second surface 101b may be
referred to as a contact surface. In FIG. 1A, the second surface
101b of the band 101 may have a plurality of electrodes 103a-103h
disposed at the surface 101b. In an embodiment, the first surface
101a may have a display device (e.g., touch screen) and/or a
physical user input component (e.g., a button) mounted thereon, or
may alternatively have none of those devices (e.g., as a simpler
activity tracker). In an embodiment, the wearable interface device
100 may include another haptic device. For instance, the wearable
interface device 100 may include a piezoelectric actuator embedded
within the band 101 to produce a vibrotactile haptic effect for the
whole band 101, or a layer of shape memory alloy disposed on the
first surface 101a to produce a deformation haptic effect at the
first surface 101a.
[0043] The electrodes used to produce ESF effects (which may be
referred to as ESF electrodes) may have a variety of sizes and
shapes, such as squares, dots, and strips. For instance, FIG. 1B
depicts another wearable interface device 200 that has a plurality
of electrodes 203a-203e on a band 201, which are different in size
and shape than the electrodes 103a-103h in FIG. 1A. More
specifically, the electrodes 203a-203e may each have the form of a
long strip having a length substantially equal to a length of the
band 201. In some cases, an electrode shaped as a long strip may be
more advantageous compared to some other shapes because an ESF
effect for some users may be more optimal when their skin does not
completely cover an electrode. An electrode having the long strip
shape may be less likely to be completely covered by the skin of a
user. The electrodes in the embodiments herein may also be arranged
in a variety of orientations. For instance, the electrodes
103a-103h may be lined up along a length of the band 101, while the
electrodes 203a-203e may be rotated 90 degrees from as shown in
FIG. 1B to be lined up along a width of the band 201. In an
embodiment, these two orientations may be combined, with some
electrodes lined up along a length of a band (FIG. 1B), while some
electrodes are lined up along a width of the band.
[0044] As discussed above, the electrodes 103a-103h or the
electrodes 203a-203e may be used to create spatial and/or temporal
feedback, such as to create an impression of flow of ESF effects
along the electrodes, or to convey a spatial direction for a user
to follow. With respect to FIG. 1A, sequential ESF effects, or the
flow of ESF effects, along the electrodes 103a-103h may be used to
direct a user in a leftward direction of a rightward direction.
With respect to FIG. 1B, sequential ESF effects, or the flow of ESF
effects, along the electrodes 203a-203e may be used to direct a
user in a forward or a backward direction. The arrangement of
electrodes in FIG. 1A may be combined with the arrangement of
electrodes in FIG. 1B to allow a haptic enabled interface device to
direct a user in a forward, backward, leftward, or rightward
direction.
[0045] In another example, the electrodes 103a-103h or the
electrodes 203a-203e may be used to indicate a spatial orientation
of the corresponding haptic enabled interface device (and of a user
wearing the device) relative to a location of interest. For
example, electrode 103d or 103e may be designated as a center
electrode that represents a current location of the device, while
electrode 103b may be determined to fall on a left side of the
center electrode when the strap 101 is worn, and electrode 103g may
be determined to fall on a right side of the center electrode when
strap 101 is worn. When a desired destination or object is to the
left of the device's current location, a drive signal may be
directed to the electrode 103b to output an ESF effect. When the
desired destination or object is to the right of the device's
current location, the drive signal may be directed to the electrode
103g to output an ESF effect.
[0046] In another example, the electrodes 103a-103h may be used to
convey a temporal relationship between a current time and an event
of interest. For example, each of the electrodes 103a-103h may
correspond to different amounts of time (e.g., 15 minutes, 30
minutes, etc.) before a meeting, and may be selectively activated
to indicate a current duration of time before a meeting. In yet
another example, the electrodes 103a-103h may be used to indicate
progress of an operation, such as a data transfer operation. For
instance, electrodes 103a-103h may correspond to different
percentages (e.g., 0%, 10%, 20%, etc.), and may be selectively
activated to indicate what percentage of the data transfer
operation is currently complete.
[0047] FIGS. 2 and 3 depict examples of other interface devices
having ESF electrodes for producing (e.g., generating) an ESF
effect. FIG. 2 shows an example of a mobile interface device 300
(e.g., smartphone or tablet computer) having a plurality of
electrodes 303a-303g disposed at a contact surface 301 (e.g., a
back surface) thereof. The contact surface of the device 300 may be
a surface that is expected to receive user contact from a hand when
the device 300 is held by that hand. The electrodes 303a-303g may
each be shaped as a circle (e.g., a dot), and may be arranged in a
two-dimensional array (e.g., four rows by two columns). The
electrodes may be placed, e.g., at locations on the contact surface
301 where a user's finger is most likely to touch when holding the
mobile interface device 300. FIG. 3 depicts an example of a laptop
400 having a plurality of electrodes 403a-403f on a contact surface
(e.g., palm rest, touch pad 409, hand print scanner) thereof. The
contact surface of the device 400 may be a surface that is expected
to receive user contact during typing or other use of the device
400. The electrodes 403a-403f may be arranged as a first
one-dimensional array 413 and a second one-dimensional array 423.
The first one-dimensional array 413 is located on one side of a
touch pad 409, and the second one-dimensional array 423 is located
on an opposite side of the touch pad 409. These locations may
correspond to areas where a user's wrist is likely to come to rest
and contact the laptop 400, allowing the ESF effect to be generated
at the user's wrist. In an embodiment, the ESF electrodes described
herein may be disposed at a surface of a display screen of device
300, device 400, or of any other device having a display screen. In
an embodiment where a plurality of electrodes (e.g., 103a-103h) are
arranged as an array, the plurality of electrodes may have uniform
spacing between adjacent electrodes.
[0048] The electrodes 103a-103h, 203a-203e, 303a-303h, 403a-403f
may be configured to generate an ESF effect, and may be referred to
as ESF electrodes. In an embodiment, each electrode may be a
conductive (e.g., metal) pad. In an embodiment, the plurality of
electrodes 103a-103h, 203a-203e, 303a-303h, 403a-403f may be
exposed electrodes and/or insulated electrodes. Some haptic enabled
interface devices may include only exposed ESF electrodes, include
only insulated ESF electrodes, or include a mixture of exposed ESF
electrodes and insulated ESF electrodes. An exposed electrode may
be disposed at a respective portion of a surface of an interface
device (e.g., surface 101b), and more specifically may form the
respective portion of the surface. The exposed electrode may, e.g.,
be configured to be directly electrically coupled to a user upon
the user making contact with the exposed electrode (or disposed
over the exposed electrode with only a very small air gap
therebetween) at the respective portion of the surface. The contact
may refer to contact with, e.g., the user's skin. More generally
speaking, the contact may refer to contact in which a drive signal
can create an electrostatic friction effect on the user's body. In
one example, an exposed electrode may be a conductive pad adhered
on top of a body of the interface device (e.g., on top of a body of
band 101). In one example, the exposed electrode may be a
conductive pad exposed through an opening in a body, a housing or
other structural element of the interface device (e.g., through an
opening in a casing of a mobile phone).
[0049] In an embodiment, an insulated electrode may be disposed at
a respective portion of an outer surface (e.g., surface 101b) of an
interface device, and more specifically may be disposed behind the
respective portion of the outer surface. The insulated electrode
may, e.g., be separated from the surface by a thin insulating
layer, such as a layer of dielectric material. The insulated layer
may be configured to be capacitively electrically coupled to a user
upon the user making contact with the insulated electrode's
respective portion of the surface. In one example, an insulated
electrode may be embedded within a plastic outer cover of a mobile
phone or game console controller, or embedded within a band of a
smart watch, such that there is an electrically insulating material
(e.g., a dielectric material) between the electrode and the outer
surface of the mobile phone, game console controller, or smart
watch. In another example, the insulated electrodes may be a
conductive material placed on a body of the smart phone, smart
watch, or game console controller, and may have then been covered
with an insulating material (e.g., a layer of Kapton.RTM.
tape).
[0050] In an embodiment, the multiple electrodes may be used, e.g.,
to generate a static ESF effect or a dynamic ESF effect. Dynamic
ESF effects may involve exerting electrostatic forces on a finger
or other part of the user's body while the finger or other part of
the user's body is moving on a surface of the interface device. The
electrostatic forces may be created by applying a time-varying
signal to an electrode. The electrostatic forces may attract the
finger, and may be perceived as friction during the movement of the
finger. Static ESF effects may be generated while the user's finger
or other body part remains stationary relative to and contacting a
surface of the interface device. Static ESF effects may also
involve applying a time-varying signal to an electrode to create
electrostatic forces. In some cases, static ESF may involve a
higher voltage level for the time-varying signal compared to that
for dynamic ESF.
[0051] In an embodiment, the handheld interface device 100 includes
electrodes which are signal electrodes or switchable to being
signal electrodes, and includes electrodes which are ground
electrodes or switchable to being ground electrodes. For example,
FIG. 4A shows an embodiment in which electrodes 103a and 103h are
both ground electrodes, and electrodes 103b-103g are signal
electrodes or switchable by gating elements 105b-105g to being
signal electrodes. In an embodiment, a signal electrode may be an
electrode that receives a drive signal from a signal generating
circuit, and may be configured to produce an ESF effect with the
drive signal. In an embodiment, a ground electrode may be an
electrode electrically connected to a ground potential (e.g., a
ground potential as being equal to a potential of a negative
terminal of a battery or other power source of the interface device
100). Because electrodes 103a and 103h have a permanent electrical
connection to ground, they may be referred to as dedicated ground
electrodes in FIG. 4A. Because electrodes 103a and 103h are
dedicated ground electrodes, they have no corresponding gating
elements (i.e., no gating element 105) in FIG. 4A. Generally
speaking, a gating element for an electrode may be an element
(e.g., circuit) which controls whether a signal can reach the
electrode, or a manner in which the signal reaches the electrode
(e.g., a level of attenuation or amplification, or a period of
delay). In some examples in which static ESF effects are generated,
only an insulated electrode(s) is used as a signal electrode, while
an insulated electrode or an exposed electrode (if any) may be used
as a ground electrode. In some cases, an insulated electrode is
switchable between being a signal electrode and a ground electrode
(e.g., interchangeably used as a signal electrode at one point in
time (a first instance) or as a ground electrode at another point
in time (a second instance).
[0052] Returning to FIG. 4A, the figure is a schematic
representation of the wearable interface device 100, which includes
a signal generating circuit 104 that includes a signal processor
106 and an amplifier 108. The signal processor 106 may be
configured to generate, e.g., a sinusoidal or other time-varying
signal for producing an ESF effect. The signal generated by the
signal processor 106 may be an analog or digital signal. In an
embodiment, the interface device 100 may include a control unit 110
(e.g., a microprocessor or FPGA circuit) that is configured to
control the signal generated by the signal processor 106. The
amplifier 108 may be configured to amplify the signal from the
signal processor 106 to generate a drive signal at an output of the
signal generating circuit 104. For instance, the signal generated
by the signal processor 106 may be a rectangular pulse having an
amplitude that is in a range of 5 V to 10 V, and the amplifier 108
may amplify this signal to generate a drive signal that is a
rectangular pulse with an amplitude of about 1 kV for producing a
static ESF effect. In an embodiment, the amplifier 108 may be the
only amplifier in the interface device 100 for amplifying any
signal from the signal processor 106.
[0053] In an embodiment, the signal generating circuit 104 may
output a first drive signal and a second drive signal which
correspond to separate time periods, or separate signal generating
commands. For example, a voltage waveform that is output by the
signal generating circuit 104 in a first time period (e.g., first
1-second window) may be considered a first drive signal, while a
voltage waveform that is output by the signal generating circuit
104 in a second time period (e.g., a subsequent 1-second window)
may be considered a second drive signal. In another example, a
voltage waveform that is output by the signal generating circuit
104 in response to a first signal generating command from a
software application (e.g., device driver) or application
programming interface (API) controlling control unit 110 may be
considered a first drive signal, while a voltage waveform that is
output by the signal generating circuit 104 in response to a second
signal generating command may be considered a second drive signal.
In an embodiment, a first electrode that receives a drive signal
may be considered to be generating a first ESF effect, while a
second electrode that receives the same drive signal may be
considered to be producing a second ESF effect. The two electrodes
may receive the same version of the drive signal (e.g., same
intensity, same phase, and same frequency components) or different
versions (e.g., different intensities, different phases, or
different frequency components) of the same drive signal.
[0054] In an embodiment, a plurality of gating elements 105b-105g
may be disposed between respective electrodes 103b-103g and an
output of the signal generating circuit 104, to control which of
the electrodes 103b-103g will be signal electrodes. Examples of a
gating element include a frequency filter, a delay element, and a
switch (e.g., a high-voltage relay switch or high-voltage
transistor). The plurality of gating elements 105b-105g may be
configured to control which electrode(s) of the electrodes
103b-103g will receive a drive signal from the output of the signal
generating circuit 104, and/or control a manner in which the drive
signal reaches an electrode, such as an attenuation level or period
of delay (e.g., from a phase shift) of the drive signal in reaching
the electrode. In an embodiment, the relay switches or high-voltage
transistors may form a high-voltage multiplexer that electrically
connect a drive signal to exactly one electrode of electrodes
103b-103g, which may be selected under software control.
[0055] In FIG. 4A, the properties of the gating elements 105b-105g
may be fixed. For instance, if the gating elements are frequency
filters, each of the frequency filters may have a fixed
pass-through frequency band(s). If the gating elements are delay
elements, each of the delay elements may have a fixed time delay by
which it delays a drive signal from the signal generating circuit
104. FIG. 4B depicts gating elements that are re-configurable. More
specifically, FIG. 4B also depicts an interface device 100 having a
plurality of gating elements 105b'-105g' disposed between an output
of the signal generating circuit 104 and respective electrodes
103b-103g. In FIG. 4B, the properties of the gating elements
105b'-105g' may be reconfigured by the control unit 110 through
respective CTRL input lines. For instance, if in an embodiment the
gating elements are frequency filters, the control unit may be
configured to communicate a command to a CTRL input line of at
least one of the frequency filters to re-configure a pass-through
frequency band(s) of the frequency filter. If in an embodiment the
gating elements are delay elements, the control unit 110 may be
configured to communicate a command to a CTRL input line of at
least one of the delay elements to re-configure a period of delay
that the delay element will introduce to a signal. If in an
embodiment the gating elements are a plurality of switches (e.g.,
relay switches), the control unit 110 may be configured to control
(e.g., open or close) each of the switches via respective CTRL
input lines.
[0056] In an embodiment, the control unit 110 is configured to
select a subset of one or more electrodes from the set of
electrodes 103a-103h, or from the set of electrodes 103b-103g that
are switchable to being signal electrodes, for outputting an ESF
effect with a drive signal. The control unit may be configured to
select a subset of one or more electrodes (e.g., 103b) from among a
set of electrodes (e.g., 103b, 103c, 103d) that are receiving user
contact, such that the electrodes receiving user contact are not
selected to produce a respective static ESF effect with a drive
signal.
[0057] FIG. 5A is a schematic representation of an embodiment
having gating elements that are a plurality of frequency filter
units (e.g., analog or digital frequency filter units) 1105b,
1105c, 1105d, respectively. In an embodiment, each of the frequency
filter units 1105b, 1105c, 1105d may be configured to have a
different respective pass-through frequency band. As shown in FIG.
5A, frequency filter unit 1105b may have only a single pass-through
frequency band that is centered around 50 Hz. Frequency filter unit
1105c may have only a single pass-through frequency band that is
centered around 100 Hz. Frequency filter unit 1105d may have only a
single pass-through frequency band that is centered around 200 Hz.
Each of the frequency filter units 1105b, 1105c, and 1105d may be
configured to block any frequency component of a drive signal which
is outside of its respective pass-through frequency band. For
instance, a drive signal which is a weighted sum of a 50 Hz
sinusoidal signal and a 100 Hz sinusoidal signal will be blocked by
frequency filter unit 1105d, because the frequency filter unit
1105d has only the single pass-through band centered around 200
Hz.
[0058] In an embodiment, a frequency filter unit may be configured
to attenuate a frequency component of a signal that falls within a
pass-through band of the frequency filter unit. For a drive signal
that is a weighted sum of a 50 Hz sinusoidal signal and a 100 Hz
sinusoidal signal, for example, the frequency filter unit 1105b may
attenuate the 50 Hz sinusoidal signal by 50% (while completely
blocking the 100 Hz component of the drive signal), and the
frequency filter unit 1105c may attenuate the 100 Hz sinusoidal
signal by 25% (while completely blocking the 50 Hz component of the
drive signal). In an embodiment, each of the frequency filter units
may be configured to introduce a phase shift into a frequency
component of a signal that falls within a pass-through band of the
frequency filter unit. The phase shift may introduce a delay by
which the drive signal reaches a respective electrode connected to
the frequency filter unit.
[0059] In an embodiment, the frequency filter units of a haptic
enabled interface device may have pass-through bands with the same
bandwidth, or with different respective bandwidths. In an
embodiment, a bandwidth for each pass-through band may be nonzero
(e.g., 20 Hz). In an embodiment, a bandwidth for a pass-through
band may be small enough such that the pass-through band may be
treated as a pass-through frequency (e.g., a pass-through frequency
of 50 Hz, 100 Hz, or 200 Hz). The pass-through frequency may be
associated with a digital frequency filter unit that performs
digital signal processing (e.g., a Fourier transform) to perform
filtering.
[0060] In the embodiment of FIG. 5A, the respective pass-through
frequency bands of frequency filter units 1105b (one band centered
around 50 Hz), 1105c (one band centered around 100 Hz), and 1105d
(one band centered around 200 Hz) do not overlap. This embodiment
allows the control unit 110 to create a first drive signal that
reaches only one ESF electrode. For example, the control unit may
cause the first drive signal to have a frequency component of only
50 Hz, such that only frequency filter unit 1105b will pass the
first drive signal to electrode 103b, and only electrode 103b will
produce or generate an ESF effect based on the first drive signal.
However, the control unit may also cause a second drive signal in
this embodiment to reach multiple electrodes, by including multiple
frequency components (e.g., 50 Hz and 100 Hz) in the second drive
signal. In another embodiment, the respective pass-through
frequency bands of a plurality of frequency filter units may have
some overlap.
[0061] FIG. 5B shows an embodiment in which some frequency filter
units may have respective sets of pass-through frequency bands.
More specifically, the embodiment of FIG. 5 includes a frequency
filter unit 2105b that has a respective set of pass-through
frequency bands that includes a band centered around 50 Hz, a band
centered around 100 Hz, and a band centered around 200 Hz.
Frequency filter unit 2105d has a respective set of pass-through
frequency bands that includes a band also centered around 100 Hz
and another band also centered around 200 Hz. Frequency filter unit
2105c has a single respective pass-through frequency band also
centered around 100 Hz. In the embodiment depicted in FIG. 5B, the
respective pass-through frequency band (of filter unit 2105c) or
respective sets of pass-through frequency bands (of filter units
2105b and 2105d) have partial overlap in frequency (e.g., at 100 Hz
and 200 Hz). In another embodiment, a plurality of frequency filter
units may have respective pass-through frequency bands or
respective sets of pass-through frequency bands that do not overlap
in frequency.
[0062] In an embodiment, control unit 110 may be configured to use
the frequency filter units 2105b, 2105c, and 2105d to cause only a
subset of one or more electrodes of the set of electrodes 103b,
103c, and 103d to output one or more respective ESF effects with a
first drive signal. For instance, the control unit may generate the
first drive signal with only a frequency component of 200 Hz. In
that instance, only electrodes 103b and 103d will output respective
ESF effects with the first drive signal. In an embodiment, the
control unit may be configured to cause at least two electrodes of
electrodes 103b, 103c, and 103d to output respective ESF effects
with the first drive signal, but to do so in different manners. For
instance, the first drive signal with the 200 Hz frequency
component may be attenuated by 70% by frequency filter unit 2105b,
and may be attenuated by 50% by frequency filter unit 2105d. Thus,
the two respective electrodes 103b and 103d may receive the first
drive signal with different levels of attenuation, and thus output
respective ESF effects with the first drive signal in different
manners. In another example, the first drive signal may include
frequency components of only 100 Hz and 200 Hz. As shown in FIG.
5B, the frequency filter unit 2105c will filter out the 200 Hz
component of the first drive signal, while the frequency filter
units 2105b and 2105d will not. Accordingly, electrodes 103b and
103d are driven by the 100 Hz and the 200 Hz frequency components
of the first drive signal, while electrode 103c is driven by only
the 100 Hz frequency component of the first drive signal. Thus, the
three electrodes 103b, 103c and 103d may output respective ESF
effects with the first drive signal in different manners, because
the three electrodes are driven by different combinations of
frequency components and provide different levels of
attenuation.
[0063] FIG. 6A depicts an embodiment in which gating elements
thereof are a plurality of delay elements 3105b-3105d,
respectively. Each delay element of delay elements 3105b-3105d may
be configured to control a timing by which a respective electrode
of electrodes 103b-103d will output a respective ESF effect. A
delay element may control this timing by introducing a different
respective period of delay of a drive signal from an output of the
signal generating circuit 104 to the respective electrode. In an
embodiment, each of the delay elements may be an analog delay
element, such as an inductive and/or capacitive filter (e.g., a LC
filter). In another embodiment, each of the delay elements may be a
digital delay element, such as a buffer. In FIG. 6A, delay element
3105b may be configured to introduce a delay "d1" (e.g., 500 msec),
delay element 3105c may be configured to introduce a delay "d2"
(e.g., 700 msec), and delay element 3105d may be configured to
introduce a delay "d3" (e.g., 900 msec) to a drive signal. In the
embodiment of FIG. 6A, a delay in traversing a physical distance
from the signal generating circuit 104 to a particular electrode
may be considered negligible. The delay elements 3105b, 3105c, and
3105d may be configured to cause the electrodes 103b, 103c, and
103d to output respective ESF effects in a sequence, at t.sub.0+d1,
t.sub.0+d2, and at t.sub.0+d3, respectively. In an embodiment, d1,
d2, and d3 increase in value in a linear fashion. For instance,
d2=2.times.d1, while d3=3.times.d1. The delay elements 3105b,
3105c, and 3105d may then cause the electrodes 103b, 103c, and 103d
to output respective ESF effects in a sequence, at t.sub.0+d1,
t.sub.0+2d1, and at t.sub.0+3d1. The sequential output of ESF
effects across electrodes 103b, 103c, and 103d may provide the
sensation of flow described above.
[0064] While FIG. 6A illustrates an embodiment in which a plurality
of delay elements 3105b, 3105c, and 3105d may each be connected to
an output of the signal generating circuit 104 in a parallel
configuration, FIG. 6B illustrates an embodiment in which a
plurality of delay elements 4105b, 4105c, and 4105d are connected
to each other in a series fashion to form a chain of delay elements
so that a drive signal propagates through the chain of delay
elements. More specifically, FIG. 6B depicts an interface device
that includes delay elements 4105b, 4105c, and 4105d and respective
ESF electrodes 103b, 103c, and 103d that operably correspond to the
delay elements. Delay elements 4105b, 4105c, and 4105d may be
configured to introduce delays of d1, d2, and d3, respectively,
from an input of the delay element to an output of the delay
element. The delay elements may be spatially arranged as a line or
other array of delay elements, and the electrodes may be spatially
arranged as a line or other array of electrodes. Each of the
electrodes 103b, 103c, 103d may be electrically connected to an
output of a respective delay element. FIG. 6B further includes a
signal generating circuit 104 that is configured to generate a
drive signal.
[0065] As shown in FIG. 6B, the delay elements 4105b, 4105c, and
4105d and their respective electrodes 103b, 103c, 103d may form or
otherwise be grouped into respective pairs that each includes a
respective delay element and a respective electrode. For instance,
delay element 4105b and electrode 103b may form a pair 1, delay
element 4105c and electrode 103c may form a pair 2, and delay
element 4105d and electrode 103d may form a pair 3. The pairs of
delay elements and electrodes (e.g., pair 1, pair 2, and pair 3)
may be electrically connected in series. In an embodiment, the pair
1 may be a first pair in the series, the pair 2 may be a second
pair in the series, and the pair 3 may be a third pair in the
series. By being connected in series, an input of a delay element
of a first pair in the series (i.e., an input of delay element
4105b) may be connected to an output of the signal generating
circuit 104, while an input of a delay element of all other pairs
in the series is electrically connected to an electrode of a
previous pair in the series. Thus, an input of a delay element of
the second pair in the series (input of delay element 4105c) may be
connected to an electrode of the first pair in the series
(electrode 103b), while an input of a delay element of the third
pair in the series (input of delay element 4105d) may be connected
to an electrode of the second pair in the series (electrode 103c).
With this arrangement, a drive signal may propagate through the
series of delay elements and electrodes to sequentially output ESF
effects along the electrodes. Each electrode may experience a
cumulative delay of its delay element and of delay elements in
previous pair of the series. Thus, electrode 103b may experience a
delay of d1, electrode 103c may experience a delay of d2+d1, and
electrode 103d may experience a delay of d3+d2+d1. In an
embodiment, d1=d2=d3. In an embodiment, at least some or all of d1,
d2, and d3 have different values.
[0066] In an embodiment, each of the delay elements in FIGS. 6A and
6B is configured to introduce a respective period of delay, a time
delay or period of delay, to a drive signal from an input of the
delay element to an output of the delay element. The delay elements
may be configured to introduce the same period of delay, or to
introduce different respective periods of delay.
[0067] In an embodiment, each of the delay elements in FIGS. 6A and
6B may have a fixed delay, or may have a reconfigurable delay. For
instance, each delay element may be a capacitor with a fixed
capacitance, or a reconfigurable capacitance.
[0068] FIG. 7 depicts an embodiment in which a plurality of gating
elements are relay switches 5105b-5105d. The relay switches may be
controlled by, e.g., the control unit 110 in FIG. 4A. In an
embodiment, the control unit 110 may be configured to close only
one relay switch of all the relay switches that are being used as
gating elements, and to leave all other relay switches open. In an
embodiment, the control unit 110 may be configured to close
multiple relay switches at the same time, and to leave open other
relay switches being used as gating elements. In an embodiment,
each of the relay switches 5105b-5105c may be a high voltage relay
switch configured to withstand a voltage (e.g., 1 kV) used to
generate static ESF effects. When a particular switch is in an open
state as shown in FIG. 7, an electrode connected to the switch may
be in an electrically floating state.
[0069] As discussed above, generating an ESF effect may involve a
signal electrode and a ground electrode. An insulated electrode may
be usable as a signal electrode at one point in time by being
electrically connected to an output of a signal generating circuit,
and as a ground electrode at another point in time by being
electrically connected to a ground potential. FIG. 8A schematically
represents an embodiment in which each electrode of electrodes
103a-103g may be an insulated electrode switchable between being a
signal electrode and being a ground electrode. More specifically,
FIG. 8A shows a signal generating circuit 104, a control unit 110,
a plurality of electrodes 103a-103g (e.g., insulated electrodes),
and gating elements 105a-105h, similar to FIG. 4A. However, FIG. 8A
further shows a plurality of gating elements 115a-115h that are
each electrically connected to a ground potential. In one example,
while gating elements 105a-105h may control which subset of
electrodes will receive a drive signal from the signal generating
circuit 104, the gating elements 115a-115h may be configured to
ground those electrodes that are not receiving a drive signal or
not intended to receive the drive signal.
[0070] In an embodiment depicted in FIG. 8B, an electrode may be
grounded rather than be left in an electrically floating state when
its respective gating element is in an open state. In the
embodiment of FIG. 8B, the gating elements 5115a-5115h are relay
switches, and more particularly, include a first plurality of relay
switches 5105b, 5105c, 5105d, and a second plurality of relay
switches 5115b, 5115c, 5115d. The gating elements may form pairs,
such as a first pair of switches 5105b, 5115b, a second pair of
switches 5105c, 5115c, and a third pair of switches 5105d, 5115d.
In an embodiment, each of the relay switches may be controlled by
the control unit 110. Each of the relay switches 5105b, 5105c,
5105d may be operably controlled to selectively connect a
corresponding electrode to an output of the signal generating
circuit 104, while each of the relay switches 5115b, 5115c, and
5115d may be operably controlled to selectively connect the
corresponding electrode to ground. The pairs of relay switches may
be configured or controlled so that exactly one relay switch in
each pair will be closed during operation of the haptic interface
device. This way, if an electrode is not electrically connected to
the output of a signal generating circuit, the electrode is
grounded rather than left in an electrically floating state.
[0071] FIG. 9 provides an embodiment in which a plurality of
shielding elements 113a-113h may control which electrodes 103a-103h
output an ESF effect with a first drive signal. The shielding
elements 113a-113h may be combined with the gating elements
105a-105h in FIG. 4A, but also allows such gating elements to be
omitted such that each of the electrodes 103a-103h receives a drive
signal(s) from the signal generating circuit 104. In an embodiment,
each of the electrodes 103a-103h may be an insulated electrode that
is disposed behind an outer surface of a haptic enabled interface
device. The plurality of shielding elements 113a-113h may be
disposed in front of (on top of or above) respective electrodes
103a-103h, such that the shielding elements 113a-113h are located
between the electrodes 103a-103h and an outer surface of the
interface device. For example, the shielding element 113a-113h may
be conductive pads (e.g., metal pads) buried slightly behind
(below) an outer surface of the interface device, but at a
shallower depth compared to the electrodes 103a-103h. In an
embodiment, each shielding element of the shielding elements
113a-113h may have the same dimensions as a respective electrode of
the electrodes 103a-103h, and may be disposed directly in front of
(e.g., directly above) the respective electrode.
[0072] In an embodiment, each shielding element of the shielding
elements 113a-113h is switchably connectable to ground, via a
respective gating element (e.g., switch) of the gating elements
115a-115h, which may be controlled by the control unit 110. In this
embodiment, each of the electrodes 103a-103h may be electrically
connected to an output of a signal generating circuit 104. Each of
the electrodes 103a-103h may generate an electric field based on
the drive signal. A shielding element (e.g., 113b) of the shielding
elements 113a-113h may suppress the electric field emanating from a
respective electrode (e.g., 103b) by being switchably connected to
ground, such as via a respective gating element (e.g., 115b) of the
gating elements 115a-115h. When the shielding element is
electrically connected to ground, it may block the electric field
of a respective electrode from reaching an outer surface of the
interface device. Thus, this shielding element may prevent the
corresponding electrode (e.g., 103b) from generating an ESF effect
with the drive signal. Another electrode (e.g., 103c) may be
allowed to generate an ESF effect with the drive signal by having
its respective shielding element (e.g., 113c) electrically
disconnected from ground. Shielding elements are discussed in more
detail in U.S. application Ser. No. 15/239,464 (Atty Dkt. No.
IMM627), filed on Aug. 17, 2016, the content of which is
incorporated by reference herein in its entirety.
[0073] FIG. 10 depicts an embodiment in which the gating elements
that switchably connect shielding elements to ground are relay
switches 5115b-5115d, respectively. Any of the relay switches may
be closed to electrically connect a respective shielding element to
ground, or may be opened to electrically disconnect the respective
shielding element from ground.
[0074] FIGS. 11A and 11B depict embodiments in which the plurality
of electrodes shown above (e.g., electrodes 103a-103h or 203a-203e)
are used to provide spatial feedback and/or temporal feedback
(which may be referred to generally as spatio-temporal feedback)
with ESF effects. In an embodiment, spatial feedback may indicate a
spatial orientation of a haptic interface device relative to a
location of interest. The location of interest may be a particular
final destination (e.g., a friend's house) or intermediate
destination (e.g., a highway on-ramp), a location of an event
(e.g., a concert), or any other location of interest, such as a
location of an object (e.g., a car). The spatial feedback may
indicate, for instance, a direction of a location of interest
relative to a haptic enabled interface device (or relative to a
user wearing the device). For example, FIG. 11A shows a haptic
enabled interface device 100' which may include at least electrodes
103b and 103g from FIG. 1A and electrode 203a from FIG. 1B. If the
location of interest is to the left of (or, e.g., to the west of)
the device 100', electrode 103b may output an ESF effect with a
drive signal. If the location of interest is to the front of (or,
e.g., to the north of) the device 100', electrode 203a may output
an ESF effect with the drive signal. If the location of interest is
to the right (or, e.g., to the east of) the device 100', electrode
103g may output an ESF effect with the drive signal. In an
embodiment, a direction that constitutes front (or left or right)
may be based on a direction that a user is facing. The direction
that the user is facing may be determined when the device 100' is
worn or being held. This determination may use, e.g., any
integrated motion sensor (e.g., accelerometer or gyroscope), any
integrated compass, or any integrated global positioning system
(GPS). In an embodiment, the selection of which electrode(s) will
represent a particular direction or orientation may be
predetermined and fixed. In an embodiment, such a selection may be
re-configurable, and may be based on how the device (e.g., 100') is
worn or held.
[0075] FIG. 11B depicts an embodiment of producing spatial feedback
that may be sensed as a flow. More specifically, FIG. 11B depicts
the wearable interface device 100 of FIG. 1A that includes at least
electrodes 103b, 103c, 103d, and 103e spatially arranged in a line
or other array. The electrodes 103b, 103c, 103d, and 103e may
sequentially output respective ESF effects in a clockwise order
around a user's wrist, or in a counterclockwise order around the
user's wrist to provide a feeling of flow to the user in
corresponding clockwise or counterclockwise direction. The
clockwise direction may indicate, e.g., a rightward direction
(e.g., the user needs to move to the right), while the
counterclockwise direction may indicate, e.g., a leftward direction
(e.g., the user needs to move to the left).
[0076] In an embodiment, the sense of flow may be created with one
drive signal, or with multiple drive signals. For example, the
sense of flow may be created with one drive signal and the multiple
delay elements shown in FIG. 6A or 6B. The delay elements may allow
a drive signal to propagate to electrode 103b at a first time
(e.g., t.sub.0+d) to generate a first ESF effect, allow the drive
signal to propagate to electrode 103c at a second time (e.g.,
t.sub.0+2d) to generate a second ESF effect, allow the drive signal
to propagate to electrode 103d at a third time (e.g., t.sub.0+3d)
to generate a third ESF effect, and to propagate to electrode 103e
at a fourth time (e.g., t.sub.0+4d) to generate a fourth haptic
effect.
[0077] In another example, the sense of flow may be created with
multiple drive signals and the frequency filter units or relay
switches shown in FIGS. 5A, 5B, and FIG. 7. For instance, a first
drive signal may be generated at a first time (e.g., t.sub.0+d) and
be applied to only electrode 103b by blocking the first drive
signal from all other electrodes, using the frequency filter units
or relay switches. Then, a second drive signal may be generated at
a second time (e.g., t.sub.0+2d) and be applied to only electrode
103c by blocking the second drive signal from all other electrodes.
This process may be repeated for at least a third drive signal
(applied to only electrode 103d) and a fourth drive signal (applied
to only electrode 103e).
[0078] In an embodiment, creating or producing a sense of flow may
be used to convey a temporal relationship between a current time
and an event of interest (e.g., a temporal relationship between a
current time and a meeting), as discussed above. In an embodiment,
creating or producing a sense of flow may be used to convey
information such as the status of an operation.
[0079] In an embodiment, the gating elements discussed above may be
used to create particular ESF effects by implementing a sequence of
at least a first electrode, a second electrode, and a third
electrode, in which the second electrode is a middle electrode, and
the first and third electrodes are immediately next to the middle
electrode and on opposite sides of the middle electrode. For
instance, in order to generate a particular ESF effect, the gating
elements may allow a drive signal to reach the first electrode and
the second electrode, but not the third electrode.
[0080] FIGS. 12 and 13 illustrate other embodiments of shapes and
arrangements of electrodes (e.g., static ESF electrodes) used to
generate ESF effects for a haptic interface device. FIG. 12 shows a
haptic enabled interface device 500 that is an armband. The device
500 may include an electrode 503a shaped as an ellipse that is
disposed at a surface of the device 500, and an electrode 503b
shaped as a line or bar that is disposed at the surface of the
device 500. As shown in FIG. 12, the electrode 503a may surround
the electrode 503b. FIG. 13 shows a haptic interface device 600
that has a plurality of electrodes 603a, 603b, 603c, 603d that are
arranged as concentric circles and disposed at a surface of the
haptic enabled interface device 600. The arrangement of the
electrodes may allow them to sequentially create respective ESF
effects that create an impression of inward or outward flow.
[0081] As discussed above, the array of static ESF electrodes may
have a variety of shapes and arrangements, such as long strips
(e.g., disposed over the length of a bracelet), small dots (e.g.,
all over the surface of a phone), or a 2D array of large squares
(e.g., on the back of a tablet computer). In an embodiment, long
strips and larger pads may provide better static ESF effects than
smaller electrodes, because they are less likely to be completely
covered by a user's skin.
[0082] Embodiments herein may be used for a mobile phone, gaming,
automotive, augmented reality (AR), virtual reality (VR), or
wearables application. For example, the handheld interface device
may be a controller for a VR or AR application. In an embodiment,
the electrodes may be used to expand the expressivity of static ESF
feedback by producing a variety of spatial and/or temporal
effects.
[0083] Embodiments herein may be used for dynamic ESF effects or
static ESF effects. For static ESF effects, the drive signal
applied to the selected subset of the plurality of electrodes may
have an amplitude of at least 1 kV.
[0084] While various embodiments have been described above, it
should be understood that they have been presented only as
illustrations and examples of the present invention, and not by way
of limitation. It will be apparent to persons skilled in the
relevant art that various changes in form and detail can be made
therein without departing from the spirit and scope of the
invention. Thus, the breadth and scope of the present invention
should not be limited by any of the above-described exemplary
embodiments, but should be defined only in accordance with the
appended claims and their equivalents. It will also be understood
that each feature of each embodiment discussed herein, and of each
reference cited herein, can be used in combination with the
features of any other embodiment. All patents and publications
discussed herein are incorporated by reference herein in their
entirety.
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