Thermal Haptic Effects

[0001] One embodiment of the present invention is directed to a haptic feedback system. More particularly, one embodiment of the present invention is directed to a thermal haptic feedback system.

[0002] Electronic device manufacturers strive to produce a rich interface for users. Conventional devices use visual and auditory cues to provide feedback to a user. In some interface devices, kinesthetic feedback (such as active and resistive force feedback) and/or tactile feedback (such as vibration, texture, and heat) is also provided to the user, more generally known collectively as “haptic feedback” or “haptic effects”.

[0003] Some known haptic feedback systems use heating or cooling haptic effects (collectively, “thermal haptics effects”) in addition to force feedback effects. However, the known uses of thermal haptic effects is fairly basic and is only able to impart minimal information to the user, especially when compared to other known haptic effects such as vibration based haptic effects.

[0004] Based on the foregoing, there is a need for an improved system and method for generating thermal haptic effects.

[0005] One embodiment is a thermal haptic feedback device that includes a plurality of cells coupled to a processor. The processor controls each of the cells so that each cell can independently generate heating or cooling effects. Unique haptic effects, such as a simulated wind effect, can be generated by causing some cells to be hot or cold, or changing some of the cells from hot to cold.

[0008] One embodiment is a thermal haptic system that can provide both heat and cold to a user in localized areas to provide complex haptic effects.

[0009] FIG. 1 is a block diagram of a thermal haptic system 10 in accordance with one embodiment. System 10 includes a garment or wearable object 20 that is designed to be worn by a user or otherwise located near a user so that it is touching the user's skin. Coupled to garment 20 is a processor 24, and memory 22. Processor 24 may be any general purpose processor or controller, or any device that can execute instructions. Memory 22 is any type of storage media that can store instructions and other data. Garment 20, for example, may be a glove, sleeve, pant leg, neck covering, shoe, hat, etc. Garment 20 may be embedded within a larger garment or clothing. Garment 20 may be flexible so it can be wrapped around a portion of a user's body. Processor 24 is coupled to garment 20 through one or more wires 23.

[0010] Garment 20 includes multiple cells, for example cells 12-16. Each cell can provide heating or cooling in a generally isolated area that is approximately the size of the cell. Each cell can be independently controlled, allowing for the generation of complex thermal haptic patterns for generating haptic effects, as disclosed below. In one embodiment, the size of each cell is related to the haptic resolution of the contacting body surface. In one embodiment, in addition to thermal haptic effects, each cell can include force feedback type haptic effects generated by, for example, actuators. In one embodiment, processor 24 is connected by at least one wire to each of the cells of garment 20 so that each cell can be separately controlled and can independently generate hot or cold.

[0011] In one embodiment, each cell 12-16 is formed from two dissimilar metals or semiconductors (n-type and p-type) and the Peltier effect occurs at the junction between the n and p materials. As a current flows from the p to n materials, the junction is cooled. When the current is reversed the junction heats. If two junctions are implemented, one junction heats while one junction cools. In one embodiment, a p-n junction is used to both cool and heat, keeping the complexity down. In another embodiment, the p-n junction is only used for cooling, and the heating is generated using another type of available heating element for efficiency purposes.

[0012] In another embodiment, each cell 12-16 of garment 20 includes a container for compressed carbon dioxide or other gas. Processor 24, by controlling whether gas is released or compressed into the container, creates a heating or cooling effect. The compressing of the gas generates heat and the uncompressing of the gas produces cooling. Each cell 12-16 may be individually connected to a compressor and the compression/release of gas may be controlled to produce thermal haptic effects of the garment. In one embodiment, the container is made of metal or some other thermally conductive material that can be the portion of the cell that is applied to the skin portion of the user's body. For example, carbon dioxide (“CO₂”) metal containers become cold when the compressed gas is released and the CO₂ container may touch the skin of a user.

[0013] In one embodiment, the compressed air or atmosphere is used to generate a cooling sensation by blowing the substance through a semi-permeable layer of garment 20 onto the skin of the user. The effect may be increased if the garment 20 is damp. Air warmed by a heater element may be used to create heating effects. Garment 20 can include individually controlled gas spigot lines to allow for greater granularity of control in the heating and cooling.

[0014] In another embodiment, garment 20 includes a closed “water loop system” that includes a thermally conductive latex liner where hot and cold water is pumped to cells 12-16 within garment 20 to flush to the liner and to create a sensation of hot and cold. In another embodiment, garment 20 includes a main line for cooling and heating liquids and valves that control which type of liquid is being pumped through a particular cell of garment 20. In another embodiment, an “open water” system is implemented by using garment 20 as a wicking material that draws waters away from the skin. Jets of hot and cold water are directed at the skin and then “wicked away” to allow for the recirculation of fluid.

[0015] System 10, when controlled by processor 24, can be used to generate many novel types of haptic effects because the large number of cells can create a variety of thermal patterns. For example, in one embodiment garment 20 is in the form of a sleeve worn by a user. A haptic effect can be created that would allow the user to feel as if someone is touching them on their arm by creating the shape of a hand thermally imprinted by heating a pattern of cells 12-16 that form the shape of a hand. The change in temperature may be combined with an applied force or other haptic effect, again in the shape of a hand in the form of pressure rather than heat, to create a completely immersive experience of somebody touching or grabbing the user's arm.

[0016] System 10 may be used to enhance virtual reality by simulating a texture of a surface and a thermal behavior of an object. For example, to simulate a piece of metal, garment 20 will apply cold effects, while wood may be neutral. In a medical simulator, surgeons can determine if organs are infected by way of temperature. In virtual reality mechanical design simulations, individual parts and components could feel cool or warm to the touch depending on results.

[0017] Rapid cycling from cold to hot can be used to simulate environmental conditions. For example, wind can be simulated by rapidly cycling cells 12-16 between hot and cold, and different types of wind can be simulated by altering the cycling pattern, such as steady, gusting, breezy, etc. Waves can also be simulated through rapid cycling.

[0018] FIG. 2 is a flow diagram of the functionality of system 10 in accordance with one embodiment when a thermal haptic effect that simulates a specific object, such as a hand, is created on garment 20. In one embodiment, the functionality of the flow diagram of FIG. 2 is implemented by software stored in memory and executed by a processor. In other embodiments, the functionality can be performed by hardware, or any combination of hardware and software.

[0019] At 102, processor 24 receives information regarding the object to be simulated (e.g., a hand) and determines a group of cells having the appropriate pattern out of all the cells of garment 20 that forms the shape of the object.

[0020] At 104, processor 24 changes the thermal properties of the determined cells by generating signals to the determined group of cells to either cool or heat the cells, depending on the desired thermal effect. As a result, the user will “feel” the object against their skin.

[0021] Several embodiments of the present invention are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.

[0022] For example, embodiments may include combining one method of heating with another method of cooling. For example, heated water can be used to create the heating sensation and provide a damp surface for the injection of compressed gas for cooling.