Patent Application
20100133436
Infrared (IR) sources and receivers provide useful and low-cost wireless links between devices. Wireless infrared links may be useful wherever short range wireless communications are desired. For example, a common infrared device is a remote controller used to send commands to a display device or audio device, or to select a desired receiver device from among several potential receiver devices. Other common infrared devices include personal digital assistants and smartphones where the IR link is used for easy and quick data transmission.
As multi-function wireless devices proliferate, new applications for wireless IR links will arise. As a result, there is a need for improved methods and systems for infrared devices.
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements.
Methods and apparatuses for infrared power control supporting multi-use functionality are disclosed. The following description is presented to enable any person skilled in the art to make and use the invention. Descriptions of specific embodiments and applications are provided only as examples and various modifications will be readily apparent to those skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed herein. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
Various aspects of this patent application have resulted from the Applicant's identification of unmet needs. For example, Applicant has identified that it would be useful to have a wireless infrared link serve as an out-of-band-link for simple pairing between two Bluetooth devices, providing a quick and secure pairing method. As a further example, Applicant has identified that it would be useful to determine whether a user is facing or not facing a display device based on whether an IR link is detected or not detected.
In the prior art, devices using infrared links typically utilize the link to perform only a single function, where the transmit power level of the infrared light source is at a fixed level to implement the single function. Applicant has further identified that it would be useful to have infrared devices that are capable of performing multiple functions using an infrared link. For example, since headsets are easily worn or carried, it would be useful to have a headset performing several infrared related functions. It would also be useful in a variety of applications to determine the proximity of the infrared link devices to each other.
In one example, the transmit power level of an infrared (IR) light source on a headset having multiple functional states is controlled based on the headset function state. In one example, the transmit power level is cycled to determine the proximity between the headset and a receiver device such as a base station. Use of IR power control based on headset function allows the headset's IR subsystem to be used for multiple purposes, such as device simple pairing, facing/no facing presence detection, near/far determination, and remote control. Use of IR power control can also improve device performance for individual functions, such as improved performance in simple pairing and remote control. Furthermore, use of IR power control also enables new methods for determining near/far status.
In one example, an IR device includes an IR light source to output an IR signal, a power control means for controlling an IR signal power level of the IR signal, a processor, and a computer readable memory. The computer readable memory stores a first set of instructions that when executed by the processor cause the multi-function IR device to enter a first device function state and stores a second set of instructions that when executed by the processor cause the multi-function IR device to enter a second device function state, where the IR signal power level is adjusted responsive to whether the multi-function IR device is in the first device function state or the second device function state.
In one example, a method for determining proximity between an IR source device and an IR receiver device includes cycling a power level of an IR signal transmitted from an IR source device to an IR receiver device. The method includes receiving a notification from the IR receiver device that detection of the IR signal at the receiver device has been lost, and identifying a lost detection power level at which detection of the IR signal at the receiver device was lost. The method further includes determining a proximity between the IR source device and the IR receiver device utilizing the lost detection power level.
In one example, a method for determining proximity between an IR source device and an IR receiver device includes receiving a series of IR signals at an IR receiver device transmitted from an IR source device, each successive IR signal of the series of IR signals transmitted from the IR source device having a decreasing power level from a prior IR signal. Each IR signal includes associated transmit power level data. The method further includes identifying at the IR receiver device when detection of the series of IR signals is lost, and decoding at the IR receiver device the associated transmit power level of the prior IR signal received. The method further includes determining a proximity between the IR source device and the IR receiver device utilizing the associated transmit power level of the prior IR signal received.
In one example, a method for operating a multi-function IR light output device includes providing a multi-function IR light output device having two or more user selectable operating function states, and receiving at the multifunction IR light output device a user selected operating function state. The method further includes selectively adjusting a power level of an IR light source output responsive to the user selected operating function state.
In one example, a method for selecting a desired IR receiver from among several potential IR receivers includes outputting a first IR function request signal from an IR source device, and receiving notification from two or more IR receivers that the IR function request signal was detected by the two or more IR receivers. The method further includes outputting a second IR function request signal from the source device having a selectively decreased power level from the first IR function request signal, and receiving notification from a single IR receiver that the second IR function request signal was detected by the single IR receiver.
In one example, IR source 4 is a light emitting diode used to output an IR signal. Infrared power control 6 in communication with processor 10 controls the power level of the IR signal. In further examples, multifunction IR device 2 may also include a radio frequency transceiver or an IR light signal detector. The IR source 4 can be optionally modulated by a data stream from the processor 10. The data stream can be used to transmit, for example, data identifying the source, data describing the functionality desired by the signal, and the IR source power level.
When executed by processor 10, function 1 application 12, function 2 application 14, and function 3 application 16 cause the multifunction IR device 2 to enter a function 1 device state, function 2 device state, and function 3 device state, respectively. The power level of the IR signal is adjusted responsive to whether the multifunction IR device 2 is in a function 1 device state, function 2 device state, or function 3 device state. In one example, a user selects the device operating state using user-interface 18. Although illustrated as having three function applications, one of ordinary skill in the art will recognize that the multifunction IR device 2 may have fewer or a greater number of device functions for which the power level of the output IR signal is adjusted.
The multifunction IR device 2 device states may vary. For example, the device states may include a pairing state, a receiver device selection state, a facing/no facing presence detection state, and a remote function control state. In a remote function control state (i.e., when operated as a remote controller), data is communicated via the IR link. At a minimum, the data communicated is the function to be executed. Generally, remote function control is desired to be done at a distance, often as far away as possible from the receiver, thus requiring a higher or maximum IR source transmit power level.
In a pairing state, the devices to be paired are placed in close proximity. This allows the user to indicate the desire to pair specific devices without having to select from a list, thereby simplifying the task of pairing. Since pairing is done at close proximity, a lower IR source transmit power level is required.
In a receiver device selection state, the multifunction IR device is used to select a desired receiver from among several potential receivers. Selection of a desired receiver requires the user also bring the multifunction IR device within close proximity to the desired receiver so that undesired receiver devices do not detect an IR transmission. Since receiver device selection is done at close proximity, a lower IR source transmit power level is possible, further enhancing selection of the device by reducing the chances of another device picking up the IR transmissions.
In a facing/no facing presence detection state, the IR signal is used to determine whether the wearer of the multifunction IR device is facing a particular object, such as his or her computer monitor. Facing status is a useful input for unified communications presence applications. Establishment of an IR link indicates the person is facing the object of interest, and the IR signal is typically made directional for this purpose. Further discussion of facing/no facing and presence detection can be found in pending U.S. patent application Ser. No. 12/211,701 filed Sep. 16, 2008, entitled “Infrared Derived User Presence and Associated Remote Control”, assigned to the present Applicant Plantronics Inc., the full disclosure of which is hereby incorporated by reference for all purposes. In facing/no facing presence detection applications, the user is typically anywhere from 1 to 10 feet or more away from the receiver device (typically a base station in headset presence applications). Generally, to achieve the farther distances a mid-range IR source transmit power level is used, as facing is not a useful indication when the user is extremely far away from the receiver device. Furthermore, by allowing the user to adjust the IR power level to the minimum necessary for their environment, false facing-detection which might occur at a more distant user position from the base can be reduced.
The power control of the IR source may be discrete or continuous. One of ordinary skill in the art will recognize that a variety of power control circuits may be used to control the IR source transmit power level.
In one example, a multifunction IR device 2 includes a head mounted device housing such as a headset or ear-piece in which the IR source 4 is oriented to emit the IR signal in a desired direction. The multifunction IR device 2 may also include additional IR light sources oriented in the head mounted device housing to emit additional IR signals in different desired directions. In one example, four IR light sources are used and oriented within the head mounted device housing to emit IR signals in directions 90 degrees apart. This could be useful for determining the user orientation based on the which source (each with unique coded data) was detected.
At block 1102, an IR light signal at a power level P is sent from device 1 to device 2. At decision block 1104, it is determined whether the IR light signal was detected at device 2. If “yes” at decision block 1104, at block 1106 the power level P is decreased by an increment. Following block 1106, the process returns to block 1102. In this manner, the power level P is cycled. If “no” at decision block 1104, at block 1108 notification is received at device 1 from device 2 that IR light signal detection has been lost. If device 1 is the multifunction IR device 72 shown in
At block 1110 the power level P of the IR light signal at which IR light signal detection was lost is identified. At block 1112 the proximity between device 1 and device 2 is determined utilizing the identified power level P at which signal detection was lost.
In one example, determining the proximity between device 1 and device 2 involves determining whether device 1 is in a near status or a far status with respect to device 2. Near status and far status are further discussed, for example, in pending U.S. patent application Ser. No. 12/211,701 filed Sep. 16, 2008, entitled “Infrared Derived User Presence and Associated Remote Control”, the disclosure having been incorporated by reference above. In one example, near status or far status is determined by comparing the lost detection power level to a pre-determined near/far boundary power level. In further examples, determining proximity may involve calculating a distance between device 1 and device 2 or other relative proximity.
At decision block 1306, it is determined whether the IR light signal was detected at device 2. If “yes” at decision block 1306, at block 1308 the power level P is decreased by an increment. Following block 1308, the process returns to block 1304. In this manner, the power level P is cycled. If “no” at decision block 1306, at block 1310 notification is received at device 1 from device 2 that IR light signal detection has been lost. If device 1 is the multifunction IR device 72 shown in
At block 1312 the power level P of the IR light signal at which IR light signal detection was lost is identified. At block 1314, the near/far boundary power level is set using the identified lost to detection power level. In a further example, an initial near/far boundary power level is pre-determined and set by the device manufacturer.
The method described in
At block 1202, a series of IR light signals with a cycling power level P are sent from device 1 to device 2, where each IR light signal sent includes encoded data corresponding to the value of the power level P at which the IR light signal is sent. Each successive IR light signal of this series is sent with an incrementally decreasing power level P. At decision block 1204, it is determined whether the IR light signal has been detected at device 2. If “yes” at decision block 1204, at block 1206 the next IR light signal is received at device 2 and the process returns to decision block 1204. If “no” at decision block 1204, at block 1208 the last detected IR light signal is processed to identify the value of power level P prior to which IR signal detection was lost. For example, the IR light signal is decoded to identify the power level P. At block 1210 the proximity between device 1 and device 2 is determined utilizing the identified transmit power level of the last detected IR light signal at block 1208. In a further example, each successive IR light signal of this series is sent with an incrementally increasing power level P and the value of the power level P of the first detected IR signal is identified.
In one example, determining the proximity between device 1 and device 2 involves determining whether device 1 is in a near status or a far status with respect to device 2. In one example, near status or far status is determined by comparing the lost detection power level to a pre-determined near/far boundary power level. In one example, the near/far boundary power level is determined without using a communication backchannel by performing the process illustrated in
In one example the IR light signal transmitted from device 1 to device 2 includes a source identifier to distinguish the IR source from other IR sources at device 1. The source identifier is decoded from the IR light signal received at device 2. Where each IR light source at device 1 is associated with a particular user orientation, the decoded source identifier may be used to identify a current user physical orientation with respect to device 2.
In one example, device 2 includes a plurality of IR photodetectors disposed at different orientations within the device housing. For example, four photodetectors may be disposed 90° apart. Where each photodetector at device 2 is associated with a particular user orientation, the photodetector at which an IR light signal is received may be used to identify a current user physical orientation (i.e., device 1 orientation). In one example, device 2 is a head mounted device with a plurality of photodetectors or a base station with a plurality of photodetectors.
In addition to providing information used to identify a current user physical orientation, multiple IR light sources at device 1 or multiple photodetectors at device 2 may assist in determining a more accurate near/far state. Where only a single IR light source and photodetector is used, a person not facing may undesirably provide a false near/far state due to a premature loss of signal while measurement is occurring or as a reflected detection causing a reduction in received power level. However, the potential for a false far state can be reduced by using multiple sources or receivers. In this way, a direct line of sight is more likely to be maintained so that as the power is lowered, a reflected reception will drop out at a higher power level than the power level for the direct line of site, thereby ensuring the direct line of sight is used for the near/far determination.
To determine the near status 900 usage state, an IR light signal 92 having a power level PN at which receiver device 74 or 82 loses detection is sent from multifunction IR device 72 or 80 to receiver device 74 or 82. Upon loss of IR light signal detection, receiver device 74 or 82 transmits a lost IR signal detection notification 94 to multifunction IR device 72 or 80. Where multifunction IR device 72 is used, lost IR signal detection notification 94 is transmitted over a radiofrequency link. Where multifunction IR device 80 is used, lost IR signal detection notification 94 is transmitted over an IR link. The power level PN is identified at multifunction IR device 72 or 80 and compared to a pre-determined near far boundary power level PNFboundary to determine near status 900. In near status 900, power level PN is less than the pre-determined near far boundary power level PNFboundary.
To determine the far status 902 usage state, an IR light signal 98 having a power level PF at which receiver device 74 or 82 loses detection is sent from multifunction IR device 72 or 80 to receiver device 74 or 82. Upon loss of IR light signal detection, receiver device 74 or 82 transmits a lost IR signal detection notification 100 to multifunction IR device 72 or 80. Where multifunction IR device 72 is used, lost IR signal detection notification 100 is transmitted over a radiofrequency link. Where multifunction IR device 80 is used, lost IR signal detection notification 100 is transmitted over an IR link. The power level PF is identified at multifunction IR device 72 or 80 and compared to a pre-determined near far boundary power level PNFboundary to determine far status 902. In far status 902, power level PF is less than the pre-determined near far boundary power level PNFboundary.
To determine the near status 1000 usage state, an IR light signal 104 having a power level PN at which receiver device 68 loses detection is sent from multifunction IR device 2 to receiver device 68. IR light signal 104 includes the value of power level PN encoded as data. Upon loss of IR light signal detection, receiver device 68 processes the last received IR light signal 104 to decode the value of power level Plast encoded in the last received IR light signal 104. The power level Plast is compared to a pre-determined near far boundary power level to determine near status 1000. In near status 1000, power level Plast is less than the pre-determined near far boundary power level.
To determine the far status 1002 usage state, an IR light signal 108 having a power level PF at which receiver device 68 loses detection is sent from multifunction IR device 2 to receiver device 68. IR light signal 108 includes the value of power level PF encoded as data. Upon loss of IR light signal detection, receiver device 68 processes the last received IR light signal 104 to decode the value of power level Plast encoded in the last received IR light signal 104. The power level Plast is compared to a pre-determined near far boundary power level to determine far status 1002. In far status 1002, power level Plast is greater than the pre-determined near far boundary power level.
Referring again to
As described earlier, in a receiver device selection state, the multifunction IR device is used to select a desired receiver from among several potential receivers. Selection of a desired receiver requires the user also bring the multifunction IR device within close proximity to the desired receiver so that undesired receiver devices do not detect an IR transmission. Since receiver device selection is done at close proximity, a lower IR source transmit power level is possible, further enhancing selection of the device by reducing the chances of another device picking up the IR transmissions. However, in certain instances, multiple receivers may still detect the IR transmission. In one example solution to this scenario, the IR source transmit power level of an IR device is lowered and the IR device brought closer to a desired device until the correct device is selected. The IR device may be a multifunction IR device as described, or may be any IR device capable of outputting an IR light signal at an adjustable power level P.
For example, notification may be received at the IR source device via a communication backchannel from the IR receiver devices to the IR source device. This communication backchannel may be an IR channel or a RF channel. Alternatively, each receiver device may indicate via an output user interface indicator that it received the function request IR signal, where the user of the IR source device views the indicator. For example, the output user interface indicator may be a LED or display on the IR receiver devices. At block 1410, the power level P of the next function request IR signal is decreased. For example, the power level P may be decreased automatically by the IR source device or manually by the IR source device user. At block 1412, a repositioning of the IR source device is received. For example, the user may walk towards the desired IR receiver. Following block 1412, the process returns to block 1402.
The various examples described above are provided by way of illustration only and should not be construed to limit the invention. Based on the above discussion and illustrations, those skilled in the art will readily recognize that various modifications and changes may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein. Such changes may include, but are not necessarily limited to: the number and type of functions performed by the multi-function IR device; the values of the transmit power level of the IR source for each function performed by the multi-function IR device; the methods for controlling the transmit power level of the IR source. Furthermore, the functionality associated with any blocks described above may be centralized or distributed. It is also understood that one or more blocks of the headset may be performed by hardware, firmware or software, or some combinations thereof. Such modifications and changes do not depart from the true spirit and scope of the present invention that is set forth in the following claims.
While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative and that modifications can be made to these embodiments without departing from the spirit and scope of the invention. Thus, the scope of the invention is intended to be defined only in terms of the following claims as may be amended, with each claim being expressly incorporated into this Description of Specific Embodiments as an embodiment of the invention.
