Mobile communications device with adaptive friction of the housing

A mobile communication device (10) adjusts a level of friction between a surface of the device and one or more other objects (22a, 22b, 24) that may be in contact with the device (10), such as receipts, credit cards, keys, money, the user's hand or fingers, and the like. To adjust the friction, the device (10) first determines its current environmental context, such as whether it is inside the user's pocket (20) or lying on a table surface, for example. Then, based on that context, the device (10) varies a coefficient of friction to increase or decrease the friction between the surface of the device (10) and the surfaces of the other objects (22a, 22b, 24). Varying the friction allows a user to grip the device (10) easier and/or reduce the chance that the other objects (22a, 22b, 24) in contact with the device (10) are also inadvertently removed from the storage location with the device.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a 35 U.S.C. § 371 National Stage of International Patent Application No. PCT/SE2014/051103, filed Sep. 25, 2014, designating the United States, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to mobile communications devices configured to vary friction between its surface and the surface of another object in contact with the mobile communications device, and methods thereof.

BACKGROUND

Mobile communications devices, such as cellular telephones, are popular and very commonplace. Their popularity among users is due not only to the variety of functions they offer, but also to their size. Particularly, the size of such devices allows users to hold them comfortably, and place the device into a storage location, such as a pocket, a handbag, or similar location, when not in use. This permits the users of these devices to always keep their devices close at hand.

However, manufacturers continue to reduce the size of their devices. And as the devices get smaller and thinner, their surfaces become smoother. Further, some of the locations into which the user may place the device, such as in a pocket or handbag, are relatively small when compared to the user's hand. Thus, it is becoming increasingly more difficult for users to easily grip the device and remove it from such locations. Further compounding this issue is that other objects, such as receipts, keys, credit cards, money, other devices, or notes, for example, may also be in the same storage location proximate the device. Therefore, when a user removes his or her device from that location, the friction that exists between the surface of the user's device and these objects often times inadvertently causes the objects to be pulled out with the device. The user may not want to remove these other objects from the storage location when they remove their mobile communications device the storage location.

SUMMARY

Embodiments of the present disclosure provide a method and corresponding mobile communications device for adjusting a level of friction between the surface of the mobile communication device and the surfaces of one or more other objects (e.g., receipts, credit cards, keys, money, the user's hand or fingers, etc.) adjacent the device. Particularly, the device is configured to determine its current environmental context—i.e., its current environment or surroundings, such as whether it is inside the user's pocket or lying on a table surface, for example. Based on the determined environmental context, the device varies a coefficient of friction to increase or decrease the level of friction between the surface of the device and the surfaces of the other objects. Varying the level friction allows a user to grip the device easier and/or reduce the chance that a receipt, paper, or other such object adjacent the device is removed from the storage location when the user removes the device from that location.

In one embodiment, the present disclosure provides a method for varying a level of friction between a surface of a mobile communications device and one or more other surfaces. The method comprises determining an environmental context for a mobile communications device, and controlling the mobile communications device to vary a coefficient of friction based on the environmental context to increase or decrease the friction between the surface of the mobile communications device and the one or more other surfaces.

In some embodiments, the method also comprises detecting a predetermined event that occurs at the mobile communications device. For example, the device may detect that the user has gripped the device, and if so, where on the device the user is gripping, or detect the receipt of an incoming call.

Additionally, the method may further comprise determining an environmental context, such as a current surrounding environment, for the mobile communications device, and based on that environmental context, selecting a predefined friction profile. In such embodiments, the predetermined friction profile comprises information that defines a coefficient of friction for the given context. However, the predefined friction profile may also be selected based on other criteria as well, such as an event type for the predetermined event or on an identity of the user. Thus, in some embodiments, the method further calls for authenticating the user of the mobile communications device.

In one embodiment, the mobile communications device is controlled to vary a coefficient of friction based on the environmental context by increasing or decreasing the coefficient of friction based on where on the surface of the mobile communications device the user is gripping. This may comprise, for example, switching an operating mode of the mobile communications device to one of a hi-friction mode and a low-friction mode based on the environmental context of the device. Further, the coefficient of friction may be varied at different locations across the surface of the device.

In some embodiments, controlling the mobile communications device to vary a coefficient of friction based on the environmental context comprises controlling the device to vary the coefficient of friction at different locations across the surface of the mobile communications device based on the environmental context. For example, the mobile communications device may be controlled to alter the surface of the wireless communications device to increase or decrease the coefficient of friction based on the environmental context, or on one or more objects that are adjacent to the device.

In addition, the present disclosure also provides a mobile communications device. In this embodiment, the mobile communications device comprises a context sensor configured to sense a current environment of the mobile communications device, a haptic interface configured to vary a level of friction between a surface of the mobile communications device and one or more other surfaces, and a processing circuit. In one embodiment, the processing circuit is configured to determine an environmental context based on the current environment sensed by the context sensor, and control the haptic interface to vary the coefficient of friction based on the environmental context to increase or decrease the friction between the surface of the mobile communications device and the one or more other surfaces.

In some embodiments, the processing circuit is further configured to detect a predetermined event occurring at the mobile communications device, and to control the context sensor to determine the current environment responsive to detecting the predetermined event.

The device may also comprise other sensor devices, such as a grip sensor. In these embodiments, the grip sensor is configured to detect the user gripping the mobile communications device, and send signals to the processing circuit indicating the detection. In some aspects, the processing may also be able to determine where on the surface of the mobile communications device the user is gripping based on signals received from the grip sensor.

In at least one embodiment, the device further comprises a communications interface circuit. The device is configured to detect a predetermined event, such as the receipt of an incoming call via such an interface.

Additionally, in some aspects, the device further comprises a memory circuit configured to store one or more friction profiles. Each friction profile comprises information defining a corresponding coefficient of friction between the surface of the mobile communications device and one or more other surfaces. In these cases, the processing circuit is configured to select a friction profile from the one or more friction profiles stored in the memory circuit, and control the haptic interface to vary the coefficient of friction according to the information in the selected friction profile.

In some cases, the processing circuit is further configured to select the friction profile based on one or more of a detected user event, an environmental context determined for the mobile communications device, and an identity of the user of the mobile communications device. In some embodiments, the processing circuit is further configured to authenticate the user of the mobile communications device.

In some aspects of the disclosure, the device is configured to control the haptic interface to vary the coefficient of friction based on where on the surface of the mobile communications device the user is gripping.

The processing circuit is configured to control the haptic interface to vary the coefficient of friction in various ways. In one embodiment, for example, the processing circuit is configured to control the haptic interface to switch between a hi-friction mode and a low-friction mode. In other embodiments, however, the processing circuit is configured to control the haptic interface to vary the coefficient of friction at different locations of the surface of the mobile communications device, and/or to alter the surface of the mobile communications device to increase or decrease the friction between the surface of the mobile communications device and the one or more other surfaces.

In some embodiments, the device also comprises an object sensor. The object sensor is configured to detect one or more objects contacting the surface of the mobile communications device, and based on those signals, determine the environmental context of the mobile communications device.

A still further embodiment provides a mobile communications device comprising one or more modules for varying a coefficient of friction to vary a level of friction between a surface of the mobile communication and the surface(s) of one or more objects. Such functional modules include, for example, a sensing module for sensing a current environment of the mobile communications device, a haptic interface module for varying a level of friction between a surface of the mobile communications device and one or more other surfaces, and a processing module. The processing module is operative to determine an environmental context based on the current environment sensed by the sensing module, and to control the haptic interface module to vary the coefficient of friction based on the environmental context to increase or decrease the friction between the surface of the mobile communications device and the one or more other surfaces.

DETAILED DESCRIPTION

Generally, the term “haptics” refers to the science of tactile feedback—i.e., non-verbal communications involving touch. For example, when a user's mobile device receives an incoming call or text message, the device may vibrate. Typically, the vibration is achieved by controlling an inertial actuator within the device to vibrate the entire device. The vibration serves to alert the user to the incoming communication or to some other event. However, while such feedback is useful, there is another type of haptic technology that is also becoming popular. This technology is referred to as “high-definition haptics.”

High-definition haptics allows the user to feel a greater variety of spatially or temporally separated effects, which may then be used to enhance the granularity of the effects that are produced. For example, rather than control a single inertial actuator within the device to vibrate the entire device as a whole, specific selected parts of the device may be controlled to vibrate to enhance the user's experience when using the device. APPLE'S MULTI-TIERED HAPTICS SYSTEM and MICROSOFT'S VACUUMTOUCH, for example, each utilize high-definition haptic techniques to simulate the presence of individual keys on a keyboard or create other surface effects.

Embodiments of the present disclosure utilize high-definition haptics technology to control the level of friction between a surface of a mobile communications device and the surfaces of one or more other objects (e.g., receipts, credit cards, keys, money, the user's hand or fingers, etc.) that may be in contact with the device. More particularly, a device configured according to embodiments of the present disclosure will determine its current environmental context—i.e., its current environment or surroundings using one or more sensors. By way of example, the device may be configured to detect where the device is currently located, such as whether the device is inside the user's pocket or lying on a table, as well as whether other objects, such as receipts, money, or the user's fingers, are adjacent to or in contact with the surface of the device. Based on the determined environmental context, the device controls a haptic interface to increase and/or decrease the level of friction between the surface of the device and the surfaces of the other objects. So adjusted, the embodiments of the present disclosure allow the user to more easily grip the device to remove the device from a given location, while also helping to prevent the inadvertent removal of other objects that may be adjacent to, or in contact with, the device in the location.

Turning now to the drawings,FIG. 1is a view of a mobile communications device10configured according to one embodiment of the present disclosure. As seen inFIG. 1, device10is a cellular telephone that comprises a housing12and a display14. While device10is shown herein as being a cellular telephone, those of ordinary skill in the art should readily appreciate that this is for illustrative purposes only. The present disclosure is not limited only to cellular telephone applications. Rather, other consumer devices that may be handled by a user, such as laptop and tablet computing devices, for example, may also be configured according to the present disclosure to increase and/or decrease the friction between its surface and the surface of one or more other objects that are adjacent to, or in contact with, such devices. By way of example only, embodiments of the present disclosure may also utilize high-definition haptics technology to vary a level of friction between a surface of such a laptop or tablet computing device in a carrying case or a pouch, and the surfaces of one or more papers, books, cards, and the like, that may also be in the case or pouch in contact with the device.

To adjust the level of friction between it and one or more other objects, device10varies a coefficient of friction based on its current environmental surroundings. For example, as seen inFIGS. 2A-2B, device10is in a shirt pocket20of a user. One or more other objects22a,22b, such as paper, money, cards, or receipts, and the like, are also inside pocket20and in contact with the housing12of device10. As seen inFIG. 2B, the user may grip the housing12of the device10with his/her fingers24to remove the device10from pocket20; however, the user would not want the objects22a,22bto be removed with device10. By varying the coefficient of friction in accordance with the present disclosure, a device10is able to increase the level of friction between the surface of housing12and the user's fingers24allowing the user to better grip the device10when removing the device10from pocket20. Additionally, or alternatively, however, varying the coefficient of friction decreases the level of friction between the surface of housing12and the one or more other objects22a,22bthereby avoiding the inadvertent removal of objects22a,22bfrom the pocket20along with device10.

FIG. 3is a block diagram illustrating some of the functional modules or components contained within the housing12of device10according to one embodiment of the present disclosure. As seen inFIG. 3, device10comprises a processor, such as a processing circuit30, a memory circuit32, a user I/O interface34, a grip sensor36, a context sensor38, an object sensor42, and a communications interface circuit44configured to send and receive information and data with one or more remote devices via a communications network. The user I/O interface further comprises the display14, which may be a touch-sensitive display, for example, and a haptic interface40. As those of ordinary skill in the art will readily appreciate, device10may or may not comprise other components not specifically illustrated herein.

The processor comprises means for performing the functions described in the present disclosure. For example, as seen inFIG. 3, the processor may comprise a processing circuit30configured to execute instructions and code stored in memory32to perform the functions described herein. The memory circuit32and the processing circuit30may, as is illustrated herein, comprise separate components that communicate with each other via a bus, for example. However, those of ordinary skill in the art should readily appreciate that the present disclosure is not so limited. In some embodiments, the processor may incorporate memory32as a unitary module or circuit.

Processing circuit30, which may comprise one or more microprocessors, microcontrollers, hardware circuits, or a combination thereof, generally controls the operation of device10according to logic and data stored in memory circuit32. As seen inFIG. 3, processing circuit32particularly processes signals and data received from the communications interface circuit44, as well as from each of the sensors36,38, and42, and controls the components of device10accordingly. More specifically, processing circuit30controls haptic interface40to vary a coefficient of friction thereby increasing and/or decreasing the level of friction between the surface of housing12and the surface of one or more other objects22a,22b,24, that may be in contact with, the surface of housing12.

Memory circuit32stores the program code and data needed by the processing circuit30to operate as herein described. Memory circuit32may comprise a combination of volatile and non-volatile memory devices, and may include discrete memory devices as well as internal memory. Program code executed by the processing circuit32is typically stored in a non-volatile memory such as a read-only memory (ROM) or flash memory, while temporary data generated during operation of device10may be stored in a volatile memory, such as a random access memory (RAM).

In one embodiment of the present disclosure, memory circuit32stores a plurality of friction profiles46. Each friction profile46comprises information that controls how the processing circuit30controls the haptic interface40to vary a coefficient of friction, and may be associated with a user, a detected event, one or more predetermined environmental contextual states, or a combination thereof. The friction profiles may be predefined by a manufacturer of the device10, or by the user of device10, for example, and indicate the level of friction between the surface of housing12and the one or more other objects22a,22b,24under specifically sensed circumstances.

By way of example only, a friction profile46may contain values that define the level of friction that should be present between the surface of housing12and the one or more other objects22a,22b,24, responsive to detecting that the user picked up the device10to be in-use (IU). Additionally or alternatively, friction profile46may contain values that define the level of friction that should be present between the surface of housing12and the one or more other objects22a,22b,24, responsive to detecting that the user is placing device10into pocket20(i.e., Transition To Storage—TTS), or removing device10from pocket20(i.e., Transition Away from Storage—TAS).

The values used to define the level of friction may be any values in any format needed or desired. However, in some embodiments, the values in the friction profiles46are simply binary values (e.g., ‘1’ or ‘0’). The value ‘1’ when processed by the processing circuit30, causes the processing circuit30to maximize the level of friction between the surface of housing12and another object. The increased or maximized level of friction in this “high-friction mode” may make it easier for the user to grip the housing12of device10with his/her fingers24without inadvertently dropping device10. In contrast, the value ‘0’, when processed by the processing circuit30, causes the processing circuit30to minimize the level of friction between the surface of housing12and other objects. This decreased or minimal level of friction in this “low-friction mode” may make it easier for the user to remove the device10from pocket20, for example, without also inadvertently removing these other objects, such as objects22a,22b, from pocket20.

In other embodiments, the friction profiles46contain a plurality of different values defining varying levels of friction to be applied across different parts of the surface of housing12. Thus, by way of example only, a given friction profile46may contain a first value (e.g., ‘1’) that causes the processing circuit30to maximize the level of friction over a first surface area of housing12typically gripped by the user with his/her fingers24when removing the device10from pocket20, and a second value (e.g. ‘0’) that minimizes the level of friction over a second area of housing12that is not typically gripped by the user when removing the device10. Varying the friction differently over different areas of device10would allow the user to safely remove device10from pocket20without also inadvertently removing the objects22a,22bthat are also inside of the user's pocket20.

Regardless of the particular value or values that are stored in the friction profiles46, however, each friction profile46may, as described in more detail below, be associated with a particular user, and/or a predefined user-driven event (e.g., “In-Use (IU),” “Transition Away from Storage (TAS),” “Transition To Storage (TTS)”), and/or with a particular environmental context sensed by one or more of the sensors36,38,42.

Regarding the sensors, which may also comprise modules, Grip Sensor (GS)36comprises circuitry configured to detect the locations on housing12where the user's fingers24are gripping device10. By way of example, the GS36may, in one embodiment, comprise a touch sensor, such as a capacitive touch screen, that detects when and where the user is touching the display of device10. Signals indicating the detected position may be sent to the processing circuit30for processing. Additionally, or alternatively, GS36may comprise circuitry distributed over the surface of device10that detects a change in impedance over one or more different areas of the housing12of device10. The changes in impedance are caused by the user's touch. Thus, when processed by processing circuit30, the signals output by GS36may indicate whether a user has touched a mobile device in a predetermined manner or pattern, and in accordance with a resolution of the GS36, identify the particular areas on device10that are currently being touched by the user.

In another embodiment, GS36may comprise one or more spatially separated transducers, such as microphones, for example, that are distributed across the housing12of device10and configured to detect the user's touch as audible sound. These sounds are also reported as signals to the processing circuit30, which then computes an acoustic signature representing the locations where the user is touching device10. For example, the processing circuit30may employ a beam-forming algorithm, as is known in the art, to compute the acoustic signature representing the locations of the user's touch on device10based on signals reported from some or all of the microphones.

The Context Sensor (CS)38comprises circuitry configured to sense the current environment of device10. As stated above, such environments include, but are not limited to, the inside of a pocket20or handbag, or out in the open on a table, for example. In operation, CS38is configured to sense the current environment of device10based on various aspects such as a detected motion of device10, a detected illumination level, and the like, as well as where device10is being used. Additionally, CS38may be utilized to sense whether a direction and trajectory of a user's hand gesture (e.g., detecting that the user's hand is approaching device10) indicate that the user intends to grip or pick up device10. To accomplish these functions, CS38may include a suitable sensor such as a gyroscope, a light sensor (e.g., a camera), an accelerometer, or the like, and may comprise a combination of such components.

According to embodiments of the present disclosure, CS38provides signals and/or data regarding the sensed environment to the processing circuit30. Upon receipt, the processing circuit30utilizes those signals and/or data in one or more well-known algorithms to determine whether the user intends to perform such actions as pick-up or grab device10from inside a storage location such as pocket20or a table, take a picture, place an outgoing call or text, view images or video, play games, or place device10into the same or different storage location.

For example, where CS38comprises light and motion detection capabilities, CS38may provide signals indicating a detected level of light and motion to the processing circuit30. If a low level of light is indicated, and the detected motion corresponds to the user's likely gait, the processing circuit30may determine that device10is in the user's pocket20. If CS38also senses that the user's hand is approaching device10, then CS38may also provide signals to processing circuit30indicating the user's intention to grip or pick-up device10. These signals may also be used by processing circuit30to determine that device10is about to be removed from pocket20, or placed back into pocket20.

In another example, CS38may sense and provide signals indicating that a certain level of light has been detected (e.g., daylight). In such cases, if CS38also detects the user's eyes (e.g., using a forward facing camera associated with device10), and senses that the user is gazing at display14, then the processing circuit30may determine, based on the signals from CS38, that device10is in use by the user. In some cases, the signals from multiple sensors may be used. For example, if the signals from GS36and CS38indicate that the user is gripping device10and moving device10to an area with low illumination, but is still in proximity to the user, then processing circuit30may determine that the user is placing device10back into pocket20or other storage location.

As those skilled in the art will readily appreciate, these are but some examples of the functions performed by the component(s) that comprise CS38. However, regardless of the particular components and what they are configured to sense, the signal or signals output from CS38indicate any of a variety of different states for device10that correspond to user driven events. Such states include, but are not limited to:(1) Transition Away from Storage (TAS)—where CS38senses that the user is removing device10from a storage location, such as pocket20or a table, for example;(2) In Use (IU)—where the CS38senses that the user is currently using device10for some function such as placing a call or text, viewing images or video, taking a picture, playing a game, and the like; and(3) Transition To Storage (TTS)—where the CS38senses that the user is placing device10into a storage location such as pocket20.
Based on the signals indicating these states, and others like them, processing circuit30can determine the environmental context of device10.

The Haptic interface (HI)40comprises circuitry configured to adjust the friction between the surface of housing12and one or more other objects22a,22b,24that are in contact with the housing12of device10. As previously described, HI40performs this function by selectively controlling a coefficient of friction in accordance with the values identified in one or more of the friction profiles46. That is, controlling the haptic components of device10to operate according to these values sufficiently alters the coefficient of friction such that the level friction between the surface of device10and the one or more other objects22a,22b,24is effectively increased or decreased. Some HIs40will increase the coefficient of friction, thereby increasing the level of friction between the two surfaces, while other HIs40will decrease the coefficient of friction, thereby decreasing the level of friction between the two surfaces. In some embodiments, the HI40can selectively increase the coefficient of friction over some surface areas of device10, while selectively decreasing the coefficient of friction over other surface areas of device10. With this latter aspect, the HI40can both increase and decrease the level of friction over different surface areas of device10.

In more detail, HI40comprises, in one embodiment, the existing haptic components of device10, such as one or more tactile generator. However, in other embodiments, HI40comprises other components in addition to, or in lieu of, these existing components, such as interface panels and vacuum mechanisms, for example. Regardless, the components that comprise HI40are controlled by processing circuit30such that the coefficient of friction is increased or decreased.

By way of example only, HI40may comprise an interface panel in which selected elements are raised or lowered by a piezoelectric or other electrically operated actuator. Such elements include, for example, portions or parts of the housing12that alter or change a texture of the surface of housing12. In another embodiment, HI40comprises a small motor connected to the interface panel. In use, the motor may be actuated to create a vacuum at certain points across the panel surface, and/or to a “negative vacuum” at other points across the surface of the panel. In such embodiments, the panel or housing12may comprise small holes communicatively connected to the motor. The holes may be selectively opened and closed to create varying levels of suction across selected areas of the panel or housing12(e.g., where ever the user is currently touching the surface of panel or housing12) to increase friction, and/or create a positive airflow from the holes to decrease friction and gently push objects that are in contact with housing12away from housing12.

In another embodiment, HI40may comprise an interface panel and/or other component configured to vibrate selected portions of housing12(or the entire housing) such that the force required by the user to move device10over the surface of another object is reduced. Such vibrations may be ultrasonic oscillations generated using techniques described in the article to W. Littmann, et. al., entitled “Sliding friction in the presence of ultrasonic oscillations: superposition of longitudinal oscillations,” published in August of 2001 in the Archive of Applied Mechanics, Vol. 71, Issue 8, pp. 549-554, or in the paper authored by W. Littmann et. al., entitled, “Reduction of friction using piezoelectrically excited ultrasonic vibrations,” published in Conference Proceedings of SPIE—The International Society for Optical Engineering, Vol. 4331, Smart Structures and Materials 2001: Damping and Isolation, 302 on Jul. 2, 2001. In some embodiments, HI40comprises a variable friction device, such as the device described in the paper authored by Chubb, et. al., entitled, “ShiverPad: A device capable of controlling shear force on a bare finger,” published in the Third Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pp. 18-23, Salt Lake City, Utah, USA, Mar. 18-20, 2009. The technology described in this paper generates a lateral (i.e., shear) force by vibrating a surface in contact with another object in two directions simultaneously. The first direction is in an “in-plane” direction (i.e., a lateral direction), while the second direction is an “out-of-plane” direction (i.e., a direction normal to the in-plane direction). Each of these papers is incorporated herein by reference in their entirety.

Those of ordinary skill in the art will readily appreciate that the particularly identified technologies are not the only technologies suitable for use with the present disclosure. Rather, other technologies, devices, and methods not specifically mentioned here may also be suitable for use with one or more embodiments. Regardless of how the HI40is controlled, however, controlling the HI40in accordance with the present disclosure varies the coefficient of friction thereby increasing or decreasing the level of friction between the surface of device10and the surface or surfaces of one or more other objects22a,22b,24that are in contact with the surface of device10.

Object Sensor (OS)42comprises circuitry configured to detect other objects that may be in contact with device10, and to provide that information to the processing circuit30for processing. By way of example only, OS42, in one embodiment, comprises multiple microphones that capture audible sound caused by an object, such as a stylus or finger, for example, as it is drawn across a surface of device10. Based on the sounds, the processing circuit30generates an acoustic signature utilizing any well-known beam-forming algorithm to compute the location of the object that is in contact with the device10. Based on this location, the processing circuit30may control the HI40, as stated above, to adjust the friction between the surface of device10and another object in contact with device10at that location.

In another embodiment, OS42comprises circuitry (e.g., capacitance-based circuitry) distributed across the surface of housing12. In this embodiment, similar to GS36, the circuitry of OS42is configured to detect whether the housing12is being contacted by another object (e.g., a paper receipt). Such detection may be performed using capacitive sensors, for example, in which the presence of an object in contact with the housing12varies the capacitance of the circuitry that comprises OS42. These changes in capacitance are reported to the processing circuit30, which in turn, uses that information to determine where on housing12the object is in contact with device10. So informed, the processing circuit30can vary a coefficient of friction to minimize or decrease the level of friction that exists between that area of housing12and a surface of the object.

Those of ordinary skill in the art should readily appreciate that such circuitry for use as the OS42is exemplary only, and that other circuits and sensor technologies may be utilized to perform this function. Such sensing technologies include, but are not limited to, inductive and ultrasonic sensing technologies, such as those described in the article authored by Thomas A. Kinny and entitled, “Proximity sensors compared: Inductive, capacitive, photoelectric, and ultrasonic”, published on Sep. 1, 2001 on the Machine Design website, and which is incorporated herein by reference in its entirety.

Those of ordinary skill in the art should appreciate that the circuitry comprising OS42may be separate from the circuitry that comprises the GS36. Thus, while the functionality of each sensor may overlap in some embodiments, their functions can also be different. Accordingly, embodiments of the present disclosure may comprise sensors that are capable of detecting the grip or touch of a user, as well as the touch of other objects.

The User Identification System Sensor (UISS)48comprises circuitry configured to identify a user. For example, in one embodiment, the UISS48comprises a biometric sensor that measures, for example, the user's heartbeat and identifies the user from that heartbeat. Some suitable devices for such a sensor include, but are not limited to, conductive leads, fingerprint sensors, and optical sensors that measure biometrics with respect to the user's iris. Based on the information gathered by such devices, the processing circuit30can identify the user as being an authorized, or unauthorized, user of device10.

In another embodiment, the UISS48comprises an optical sensor, such as a forward or rear facing camera, that is triggered to capture an image of a user when the user touches or picks-up device10. The image may be image processed by the processing circuit30, using any algorithm known in the art, and the results compared against data representing an authorized user. Provided the comparison results in a match, the user is authorized to use the device10. In some embodiments, authorizing the user in this manner, or in another manner, allows the device10to select an appropriate friction profile46for the user, as stated above.

Regardless of the type of sensor used, or the method used to determine whether a given user is or is not authorized, the processing circuit30is configured to control HI40to adjust the level of friction between device10and the objects and users based on the signals provided by the UISS48.

The communications interface circuit44may comprise a receiver and transmitter interface for communicating with one or more other remotely located devices over a communications network. The communications interface circuit44may effect such communications using one or more communication protocols known in the art or that may be developed, such as IMS/SIP, Diameter, HTTP, RTP, RTCP, HTTPs, SRTP, CAP, DCCP, Ethernet, TCP/IP, SONET, ATM, or the like. The communication interface circuit44implements receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like), and the transmitter and receiver functions may share circuit components and/or software, or alternatively may be implemented separately.

In one embodiment, the communications interface circuit44comprises a radio transceiver configured to communicate with remote parties and devices via a wireless communications network, such as a mobile communications network. For example, the communications interface circuit44may be configured to communicate across an air interface with at least one base station (BS) utilizing any well-known protocol or that may be developed. Some exemplary protocols include, but are not limited to, protocols according to IEEE 802.xx, CDMA, WCDMA, GSM, EDGE, LTE, UTRAN, E-UTRAN, WiMax, and the like.

FIG. 4is a flow diagram illustrating a method50for varying the level of friction between device10and one or more other objects that are in contact with device10, such as objects22a,22band the user's finger24. In this embodiment, the flow diagram for method50begins with device10identifying or authorizing the user (box52). This particular function is not required for device10to properly vary the level of friction; however, when device10does identify or authorize the user, it may do so using any known means or method. In one embodiment, device10utilizes the UISS48to measure a biometric characteristic of the user, as described above. Regardless of whether device10performs the identification function, the user will typically place device10in a storage location, such as pocket20, when not actively using device10.

Thereafter, device10will detect the occurrence of a predetermined event (box54). As stated above, such predetermined events include the receipt of incoming calls or messages from a network, in response to which the user is likely to retrieve device10from its storage location20, which but also include a determination that the user intends to grip or has gripped device10based on signals sent by one or more of the sensors36,38,42. In response to detecting a predetermined event, device10determines its current environmental context (box56). By way of example only, processing circuit30may determine whether device10is currently inside or outside of pocket20using the signals and/or data received from one or more of the sensors36,38,42. So determined, device10may then select an appropriate friction profile46stored in the memory circuit32(box58), and vary the level of friction between the surface of device10and one or more objects22a,22b,24in contact with device10in accordance with the values in the selected friction profile (box60).

In some embodiments, for example, the friction profiles46are associated with the particularly identified events. In simple embodiments, the values within the friction profiles46may indicate a simplistic “binary” operation wherein the processing circuit30will either increase the level of friction to a predefined level (i.e., a so-called “high-friction mode”), or decrease the level of friction to a predefined level (i.e., a so-called “low-friction mode”) responsive to detecting the event. In these cases, the processing circuit30may control HI40to vary the coefficient of friction in a predetermined manner, and thus, the level of friction between the surface of device10and the surface(s) of other objects, similarly over the entire surface of device10.

In other more complex embodiments, however, the friction profiles46have a plurality of different values to be applied across different surfaces of the device10. For example, upon detecting an incoming call or message, device10may determine that it is inside the user's pocket20, and further, that one or more pieces of paper such as receipts or money (22aand22b) are also inside pocket20contacting device10. As stated above, this information is detected by the one or more of the sensors36,38,42. In these situations, the values contained in the friction profile46may cause the processing circuit30to control HI40to vary the coefficient of friction across different portions of the device10such that the level of friction is increased in areas where the user will, or is likely to, grip the device10to pull device10out of pocket20to answer the call, while simultaneously decreased in those areas in contact with the papers or receipts to help prevent those objects from being inadvertently removed from pocket20along with the device10. In some of these embodiments, the friction profile46may also be uniquely associated with a user such that he or she may customize the values, while in other embodiments, the values may be altered by the processing circuit30as it “learns” where the user typically grips device10in certain situations over time.

FIG. 5is a flow diagram illustrating another embodiment of the present disclosure. In this embodiment, the processing circuit30utilizes the identification of the user, as well as the current environmental context of device10, to determine how to vary the coefficient of friction, and thus, the friction between the surface of device10and one or more other objects, such as the user's fingers24.

As seen inFIG. 5, method70identifies the user of device10(box72). As previously stated, such identification and/or authorization may be accomplished using the UISS48. When device10detects a predetermined event (box74), device10determines it current environmental context using information and data sensed by one or more of the sensors36,38,42(box76). Device10then determines whether the user is an authorized user based on the results if the earlier user identification (box78). If the user is authorized, the device10will control the HI40to enter the high-friction mode (box80). In this mode, the processing circuit30controls the HI40to vary the coefficient of friction to maximize the level of friction between the surface of device10and the user's fingers24(box84). This assists an authorized user in gripping the device10when in use. If, however, the user is not an authorized user (box78), the processing circuit30will control the HI40to enter the lo-friction mode (box82). In this mode, the processing circuit30controls the HI40to vary the coefficient of friction to minimize the level of friction between the surface of device10and the user's fingers24(box84). In this mode, the unauthorized user would have a more difficult time gripping device10.

In addition to the above embodiments, device10may also be configured to control HI40in real-time, or near real-time, in accordance with data sensed by one or more of the sensors36,38,42. For example,FIG. 6is a flow diagram illustrating a method90for varyingly controlling HI40based on the feedback data from one or more of the sensors36,38,42. Particularly, device10varies the level of friction based on whether the user has an adequate grip of device10with his/her fingers24. For example, the user's hands may be sweaty or there may be some substance on the housing12that makes it difficult for the user to properly grip device10.

As seen inFIG. 6, the processing circuit30receives signals from the grip sensor36that indicate the user's changing or varying grip (box92). Such signals may be used by processing circuit30to determine, for example, whether device10is slipping from the user's hands, or is stable within the user's hands. If device10is slipping (box94), processing circuit30will control HI40to increase the level of friction between the device10and the user's fingers24to assist the user in obtaining a better grip (box96). By way of example, the processing circuit30may control HI40in a stepwise fashion to increase the friction in predetermined increments until it can detect that the user has a good hold on device10. Conversely, if device10is not slipping through the user's hands (box94), the processing circuit30simply continues to receive the signals (box92).

FIG. 7is a functional block diagram illustrating some functional modules of a mobile communications device10according to one embodiment. Each module100,102,104, and106may comprise dedicated hardware, programmable hardware together with appropriate firmware, or one or more processors together with appropriate computer program modules.

As seen inFIG. 7, the modules comprise a sensing module100, a processing module102, a haptic interface module104, and a communications module106. The sensing module100is operative to sense a current environment of the mobile communications device10, as previously described, and to report that environment to the processing module102via signaling. Thus, in at least one embodiment, the sensing module100performs the functions described previously with respect to the context sensor38. In other embodiments, however, the sensing module is further operative to perform the functions previously described with respect to one of more of the GS36, the OS42, and the UIS48. Thus, the sensing module100may be operative in various embodiments to sense a variety of different objects and events (e.g., the user's grip and/or the surface(s) of papers or cards, as previously described), and to report such detections to the processing module102.

The processing module102, which may or may not comprise memory32and friction profiles46, receives signals from the sensing module100, and in response, generates control signals to control the haptic interface module104. The control signals generated by the processing module102may be based on one or more values included in the friction profiles46, as previously described. That is, the processing module102will control the haptic interface module104to vary a coefficient of friction thereby increasing and/or decreasing a level of friction between a surface of the mobile communications device10and the surfaces of the other objects (e.g., the user's fingers24, papers22aand22b, and the like) that are in contact with the device10.

The haptic interface module104is operative to vary a coefficient of friction responsive to receiving the control signals from the processing module102. As stated above, varying a coefficient of friction may comprise the haptic interface module104altering one or more areas over a surface of the device10, or controlling the device10to vary a level of friction between the entire surface of device10and the surfaces of the other objects sensed by the sensing module100. In these latter cases, the haptic interface104may be controlled by the processing module102to increase or decrease the coefficient of friction so as to maximize or minimize the level friction between the surface of device10and the surfaces of the other objects sensed by the sensing module100.

The communications module106is operative to send and receive signals and data to one or more remote parties via a network, as is known in the art. The communications module, which is operatively connected to the processing module30, may communicate with such remote parties using any known communications protocols known in the art. In one embodiment, the communications module106comprises, for example, an interface for performing receiver and transmitter functions. In other embodiments, however, the communications module comprises radio transceiver circuitry configured to facilitate communications between the device10and one or more other devices via a mobile communications network and one or more BSs. Regardless of the embodiment, however, the communications module106includes transmitter and receiver functionality that may share circuit components and/or software, or alternatively may be implemented separately as independent components.