Apparatus and method for providing a user interface to an information processing system

Abstract

An apparatus for use as an output device of a user interface to an information processing system includes at least one device for generating a synthetic jet. The device is capable of producing outputs with different modalities. Examples of different modalities that are possible include airflows, vibration and sound.

Claims

1. A method of controlling an output device comprising first and second spaced apart transducers coupled to a cavity enclosed within a housing, said output device being adapted to produce a plurality of different perceptible output modalities for conveying information to a user in response to respective drive signals applied to at least one of said transducers, said method comprising: applying a first drive signal having a frequency range effective for forcing a synthetic fluid jet through an opening in communication with the cavity to operate said transducers in anti-phase with respect to each other to effect production of an adjustable airflow modality; and applying a second drive signal to operate said transducers in-phase with respect to each other to produce a vibration modality.

2. The method as claimed in claim 1, wherein the vibration modality comprises sound.

3. The method as claimed in claim 1, wherein the first drive signal comprises a component having a carrier frequency that is amplitude modulated in accordance with an envelope signal.

4. The method as claimed in claim 1 wherein said first and second drive signals are applied simultaneously to the first and second transducers to effect said first output modality simultaneously with said second output modality.

5. The method as claimed in claim 4, wherein the output according to the vibration modality is adjustable independently of the output according to the airflow modality.

6. A computer program embodied in a non-transitory computer-readable medium for causing a computer, executing the computer program, to perform a method of controlling an output device comprising first and second spaced apart transducers both coupled to a cavity enclosed within a housing, said output device being adapted to produce a plurality of different perceptible output modalities for conveying information to a user in response to respective drive signals applied to at least one of said first and second transducers, said method comprising: applying a first drive signal having a frequency range effective for forcing a synthetic fluid jet through an opening in communication with the cavity to operate said first and second transducers in anti-phase with respect to each other to effect production of an adjustable airflow modality; and applying a second drive signal to operate said transducers in-phase with respect to each other to produce a vibration modality.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in further detail with reference to the accompanying drawings, in which:

(2) FIG. 1 is a very schematic illustration of an information processing system with a user interface comprising an apparatus including devices for generating synthetic jets;

(3) FIG. 2 is a schematic cross-section of a first device for generating a synthetic jet; and

(4) FIG. 3 is a schematic cross-section of a second device for generating a synthetic jet.

DETAILED DESCRIPTION

(5) An example of an information processing system is discussed here for illustrative purposes and comprises a computing device 1 for rendering audiovisual media in perceptible form, which has a user interface that also includes means for providing haptic feedback and feedback in the form of airflows. A user interface with such means for providing haptic feedback and/or output in the form of airflows could also be used in conjunction with other types of information processing systems, including systems fitted to vehicles, e.g. navigation systems, and systems for operating industrial equipment.

(6) The computing device 1 comprises a central processing unit 2 and memory 3 enabling it to execute software that includes software for controlling the user interface. This software enables the computing device 1 to determine the appropriate outputs, and to provide the required control signals to the output devices of the user interface, as will be explained. The software is generally stored on a mass storage device 4.

(7) The computing device 1 obtains data, such as audiovisual content data through a network interface 5 or from a data carrier inserted in a read unit 6. Image data is rendered by means of a video codec 7, display driver 8 and display device 9.

(8) The computing device 1 is also provided with an interface 10 to a head-set 11. The interface 10 can be suitable for establishing a wireless or wired link to the head-set 11, depending on the implementation. In an alternative embodiment, the interface 10 is adapted to establish a link to each of a number of head-sets 11 and the computing device 1 is configured to provide individual, and potentially different, control signals to each of the head-sets 11, e.g. in accordance with personal settings for the users wearing the head-sets 11.

(9) In the illustrated embodiment, the head-set 11 includes a head-band 12 for placement of the head-set 11 over the head, but any alternative carrier means may be used. Left and right ear pads 13,14 each include a device 15 (FIG. 2) for generating a synthetic jet, which also renders the audio signal conveyed to the head-set by the computing device 1. Left and right tubes 16,17 are configured such that, with the head-set 11 in place, any airflows generated by the devices 15 are directed to the opposite sides of the wearer's face, e.g. to the cheeks.

(10) In the illustrated embodiment, the head-set 11 further includes a brace 18 for placing a housing 19 of a further device 20 (FIG. 3) for generating a synthetic jet against the wearer's neck. This device 20 is further configured to provide haptic feedback to the wearer of the head-set 11 in the form of vibrations. A tube 21 for directing the airflow generated by the device 20 extends from the housing 19. In alternative embodiments, there can be two tubes, directed to opposite sides of the user's body (throat and neck, left side and right side of the neck, etc.). The tube 21 could also be directed upwards.

(11) Although the head-set 11 is used here as an advantageous example of an apparatus for use as an output device of a user interface for an information processing system, alternative embodiments of such an apparatus are conceivable. For example, such an apparatus may be provided as one of a pair for attachment to the user's person by means of wrist-bands, with the air flows directed to the user's hands, for example.

(12) It is further noted that the illustrated head-set 11 has both types of devices 15,20 for generating a synthetic jet and providing output of a second modality. An alternative embodiment could have one or more devices of only one of these types.

(13) Turning to FIG. 2, the first device 15 for generating a synthetic jet, which first device 15 also renders sound, is illustrated. The first device 15 comprises an enclosure defined by a cavity 22 and a conduit 23. The conduit 23 connects to the cavity 22 at one end and terminates in an orifice 24 at the opposite end. It has a length L.sub.1 between the two ends. Incidentally, although the conduit 23 is cylindrical in the illustrated embodiment, this is not an absolute requirement. The conduit 23 can moreover have any cross-sectional shape (circular, square, rectangular, etc.).

(14) The first device 15 further includes a transducer in the shape of a permanent magnet 25 and a voice coil 26. Movement of the magnet 25 is guided by a rod 27, which is attached to a housing 28 of the device by means of a suspension in the form of blade springs 29a-d. An airtight flexible suspension rim 30 is provided to close off the cavity 22. The combination of magnet 25 and suspension rim 30 forms an airtight movable boundary of the cavity 22, which is otherwise defined by walls 31-33 of the housing 28. The movable boundary is located on an opposite side of the cavity 22 to the wall 33 in which an opening is provided for connecting the conduit 23 to the cavity 22. Because the area of the movable boundary actuated by the transducer is much larger than that of the opening in the wall 33 a jet with a relatively large momentum can be created even where the stroke of the movable boundary is relatively small. The lateral dimensions of the movable boundary are in the order of 10 cm, for example between 1 and 20 cm.

(15) The separation between the movable boundary and the wall 33 is such that the volume V.sub.1 of the cavity 22 is, in one embodiment, small enough to prevent fluid in the cavity 22 from acting as a spring in a resonating mass-spring system at the working frequencies of the transducer. In that case, the acoustic compliance of the cavity 22 is small enough that the Helmholtz frequency of the cavity 22 and conduit 23 is well above the operating frequency f.sub.w of the device 15. The acoustic flow in the cavity 22 is therefore incompressible at the operating frequency f.sub.w. It is also possible to choose the working frequency f.sub.w such as to correspond essentially to the Helmholtz frequency. The conduit 23 can have a length L.sub.1 smaller than one-tenth the wavelength of the pressure waves at the working frequency f.sub.w. Alternatively, it can be dimensioned to function as a transmission line. To this end, its length L.sub.1 is greater than one-tenth the wavelength of the pressure waves at the working frequency f.sub.w. For resonance, L.sub.1.sup.(2n+1)/4.

(16) The working frequency f.sub.w is chosen to lie in the range below 200 Hz, more generally below 100 Hz, at around 50 Hz, so that the generation of synthetic jets is independent of the generation of sound. The dimensions of the cavity 22 and conduit 23 are adjusted to the working frequency, specifically to ensure that the velocity of the fluid flow at the orifice 24 has at least a local maximum on the frequency scale at a frequency approximately equal to the working frequency f.sub.w. Furthermore, the electrical impedance of the device 15 (i.e. the impedance of transducer in combination with the cavity 22, conduit 23 and orifice 24) also has a (local) maximum, preferably the first local maximum, at a frequency approximately equal to the working frequency f.sub.w.

(17) The driving signal for the transducer thus has two components: the analogue sound signal and the signal at the working frequency f.sub.w selected for generating a synthetic jet. To achieve better separation, the sound signal is equalized by the computing device 1 or an equalizer included in the head-set 11. The equalization removes components below a cut-off frequency equal to or higher than the working frequency f.sub.w.

(18) The signal at the working frequency f.sub.w is amplitude-modulated in accordance with an envelope signal. This envelope signal is generated or caused to be generated by the computing device 1, and is adjusted in accordance with at least one of a user control signal and characteristics of the audio and/or video signal being rendered by the information processing system. The user control signal is a signal provided in response to manipulation of at least one user control by the user, in a manner similar to volume control of the audio signal.

(19) The characteristics of the audio and/or video signal are, in one embodiment, determined by the computing device 1 by analyzing the audio and/or video data. In another embodiment, metadata or scripts representative of characteristics of the audio and/or video data are provided with the content data. This data or script is then mapped to generate the envelope signal.

(20) Turning to FIG. 3, the second device 20 for generating a synthetic jet, which also provides haptic feedback, will now be explained. The second device 20 comprises an enclosure defined by a cavity 34 and a conduit 35. The conduit 35 connects to the cavity 34 at one end and terminates in an orifice 36 at the opposite end. It has a length L.sub.2 between the two ends. Like the conduit 23 of the first device 15, the conduit 35 of the second device 20 need not be cylindrical and can have any cross-sectional shape (circular, square, rectangular, etc.).

(21) The second device 20 includes two transducers in the shape of respective permanent magnets 37,38 and voice coils 39,40. The magnets 37,38 in some embodiments are combined with additional non-magnetic masses. Movements of the magnets 37,38 are guided by rods 41,42, which are attached to an inner housing 43 of the device 20 by means of suspensions in the form of blade springs 44a-h. Airtight flexible suspension rims 45,46 are provided to close off the cavity 34.

(22) Each combination of a magnet 37,38 and a suspension rim 45,46 forms one of two generally opposite airtight movable boundaries of the cavity 34, which is otherwise defined by the inner housing 43. An opening is provided for connecting the conduit 35 to the cavity 34.

(23) The area of each movable boundary is much larger than that of the opening. In fact, the lateral dimensions of the movable boundaries are each in the order of cm, at least 1 cm. The volume V.sub.2 of the cavity 34 is, in one embodiment, small enough to prevent fluid in the cavity 34 from acting as a spring in a resonating mass-spring system at the working frequencies of the transducer. The acoustic compliance of the cavity 34 is preferably small enough that the Helmholtz frequency of the cavity 34 and conduit 35 can be well above the operating frequency f.sub.w of the device 20. The acoustic flow in the cavity 34 is therefore incompressible at the operating frequency f.sub.w. In one embodiment, the conduit 35 has a length generally smaller than one-tenth the wavelength of the pressure waves at the working frequency f.sub.w. In another embodiment, the conduit 35 functions as a transmission line. To this end, its length L.sub.2 is greater than one-tenth the wavelength of the pressure waves at the working frequency f.sub.w. For resonance, L.sub.1.sup.(2n+1)/4.

(24) The dimensions of the cavity 34 and conduit 35 are adjusted to the working frequency, specifically to ensure that the velocity of the fluid flow at the orifice 36 has at least a local maximum on the frequency scale at a frequency approximately equal to the working frequency. Furthermore, the electrical impedance of the device 20 (i.e. the impedance of a transducer in combination with the cavity 34, conduit 35 and orifice 36) also has a (local) maximum, preferably the first local maximum, at a frequency approximately equal to the working frequency, when the movable boundaries are moving in anti-phase (and the device 20 is thus producing a synthetic jet), i.e. alternately towards and away from each other.

(25) To generate vibrations, the magnets 37,38 are made to move in phase. To enable the synthetic jet to be controlled independently of the vibrations, the working frequency f.sub.w is generally outside the frequency range within which the vibration frequency lies. Thus, the driving signal to the two transducers is a superposition of the signal at the working frequency f.sub.w, where the respective components have a phase difference such as to cause the magnets 37,38 to move in anti-phase, and a signal at the vibration frequency, where the respective components are such as to cause the magnets 37,38 to move in phase.

(26) The computing device 1 provides the appropriate amplitudes of the respective components. Alternatively, the computing device 1 can provide the target signals, which are translated to driving signals by e.g. a digital signal processor (not shown) in the outer housing 19.

(27) The conduit 35 directs the synthetic jet towards the user. The vibrations are conveyed to the user through a wall 47 of the outer housing.

(28) Thus, the second device 20, like the first device 15 allows output of two modalities to be provided independently using a single device. This is done by providing a composite driving signal to each transducer, with the components adjusted in accordance with the desired level of the respective types of output.

(29) It should be noted that the above-mentioned embodiments illustrate, rather than limit, the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word comprising does not exclude the presence of elements or steps other than those listed in a claim. The word a or an preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

(30) In an alternative embodiment of the devices 15,20, a different type of actuator is used. An alternative actuator can comprises a stationary permanent magnet and moving mass with voice coil. Other alternatives include electrostatic drivers, electret drivers and magnetostatic drivers, all known from the field of loudspeaker technology.

(31) The computing device 1 may be portable and of a slightly simpler construction than illustrated, e.g. forming a portable media player. Furthermore, even where the appropriate software or scripts for providing immersive effects to accompany other types of perceptible output are not available, the apparatus described herein may be used to provide a continuous air flow to cool the person using it.