Thermal haptic effects

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.

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”.

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.

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

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.

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.

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.

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.

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.

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.