Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s amendments, filed 12/03/2025, with respect to prior 35 USC 101 and 112 rejections of claims have been fully considered and are persuasive. The 35 USC 101 and 112 rejections of claims has been withdrawn.
Applicant's arguments filed 12/03/2025 have been fully considered but they are not persuasive.
Applicant argues that Oliver does not disclose “identifying magnetometer calibration constants based on a difference between the first estimate of the derivative of the external magnetic field and the second estimate of the derivative of the external magnetic field” and instead merely align rotation axis.
Examiner respectfully disagrees as Oliver first determines a magnetic field from excessive magnetometer readings, where the change from magnetometer reading from M1 to M2 reflects a corresponding change in orientation [0060], this constitutes a first estimate of magnetic field (i.e. derivative of the magnetic field vector). Independently, Oliver determines a gyroscope based rotation axis and angle [0063] and models M2 as a rotation of M1 based on the gyroscope derived rotation [0064]. This modeling provides a second estimate of magnetic field based on angular velocity measurements. Oliver then computes a rotation axis derived from both magnetometer derived change vector and the gyroscope derived rotation [0067], and determines a calibration parameter based on properties of those rotation axis [0058]. Because the rotation axis is computed from both magnetic field change estimates, and the calibration parameter is determined from that axis calibration parameter is necessarily identified based on the difference between magnetometer derived and gyroscope derived magnetic field change estimates. Applicants’ characterization that Oliver merely “align axes” overlooks that the axis in [0067] as mathematically derived from disagreement between two independently determined magnetic field change vectors. The claim does not require a particular derivative formula, only two magnetic field change estimates and identification of calibration constants based on their difference. Olive expressly discloses this sequence.
Claim Rejections - 35 USC § 103
3. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-11 and 13-20 are rejected under 35 U.S.C. 103 as being unpatentable over Oliver (U.S. Publication 20130320966) in view of Lyren (U.S. Publication 20190297442).
Regarding claim 1, Oliver discloses a method for calibrating magnetometers for motion tracking devices (“a method of calibrating a magnetometer on a mobile device” [0021]), comprising:
obtaining a sequence of gyroscope measurements from one or more gyroscopes (fig. 5 via 24) and a sequence of magnetometer measurements from one or more magnetometers (fig. 5 via 25) “the magnetometer calibration 700 checks whether a sufficient number of magnetometer readings have been obtained. In one example, the magnetometer calibration 700 requires a minimum of two pairs of magnetometer readings and thus 702 to 706 are repeated to obtain {right arrow over (M)}.sub.3, thus also obtaining another pair of magnetometer readings comprising {right arrow over (M)}.sub.2 and {right arrow over (M)}.sub.3 (FIG. 10). The rotation axis direction {circumflex over (r)}.sub.23 and rotation angle .theta..sub.23 can be obtained from the gyroscope 24” [0071]);
determining a sequence of angular velocity estimates based on the sequence of gyroscope measurements (“At 704, a rotation axis direction and a rotation angle are determined. The rotation axis direction and rotation angle correspond to the change in orientation of the mobile device 10 between obtaining the first magnetometer reading and obtaining the second magnetometer reading of the pair of magnetometer readings. In the example configuration of the mobile device 10 of FIG. 5, the magnetometer calibration module 26 can obtain the rotation axis direction and rotation angle from a rotational sensor such as the gyroscope 24” [0061, 71]);
determining a first estimate of a derivative of an external magnetic field based on the sequence of magnetometer measurements (“The magnetometer reading {right arrow over M1 is obtained first, and then after a sample period, magnetometer reading {right arrow over M2 is obtained. The change from magnetometer reading {right arrow over M1 to {right arrow over M2 reflects a corresponding change in the orientation” [0060] derivative corresponds to change in estimated magnetic field);
determining a second estimate of the derivative of the external magnetic field based on the sequence of angular velocity estimates (“the angular velocity about each axis of the gyroscope sensor 48 over the time period between obtaining the first magnetometer reading {right arrow over (M)}.sub.1 and the second magnetometer reading {right arrow over (M)}.sub.2” [0063],.., the magnetometer reading {right arrow over (M)}.sub.2 can be modelled as a rotation of the magnetometer reading {right arrow over (M)}.sub.1 about an axis {right arrow over (R)}.sub.12 by the rotation angle .theta..sub.12, where the axis {right arrow over (R)}.sub.12 is in the direction of the rotation axis direction {circumflex over (r)}.sub.12 and passing through the constant bias {right arrow over (E)} [0064] derivative corresponds to change in estimated magnetic field); and
identifying magnetometer calibration constants based on a difference between the first estimate of the derivative of the external magnetic field and the second estimate of the derivative of the external magnetic field, wherein the identified magnetometer calibration constants are usable for calibrating an orientation tracking system has not been obtained, 702 to 706 are repeated. In one example, two pairs of magnetometer readings (i.e. a minimum of three unique magnetometer readings) are used to perform the magnetometer calibration 700. Once a sufficient number of magnetometer readings are obtained, at 710, a calibration parameter is determined based on at least one property of one or more rotation axes” [0058, 0072] which clearly states identifying the calibration readings reflecting orientation changes).
Oliver does not explicitly teach wherein the one or more gyroscopes and the one or more magnetometers are disposed in or on headphones or a head- mounted display.
Lyren teaching a system using magnetometer that assists in calibration against orientation drift teaching wherein the one or more gyroscopes and the one or more magnetometers are disposed in or on headphones or a head- mounted display (fig. 17 (WEG 1750 having 1752 “WEG 1750 localizes binaural sound to a location that is proximate to but away from a wearer of the WEG. Sensors 1752 include a specific or customized sensor with a MEMS-based inertial measurement unit (IMU). This IMU includes a microcontroller, one or more accelerometers and gyroscopes that detect changes in various attributes (like pitch, roll, and yaw) and a magnetometer that assists in calibration against orientation drift” [0255, 0258])).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to incorporate the teaching of Lyren in Oliver to gain the advantage of improved assists in calibration against orientation drift [Lyren[0258]].
PNG
media_image1.png
573
595
media_image1.png
Greyscale
Regarding claim 2, Oliver further discloses wherein the sequence of gyroscope measurements and the sequence of magnetometer measurements are obtained during movement of the orientation tracking system (“For each pair of magnetometer readings, the method also includes determining a rotation axis direction and a rotation angle corresponding to a change in orientation of the mobile device between obtaining the first reading and the second reading and determining a rotation axis for the pair of magnetometer readings using the rotation axis direction and rotation angle” [0021]).
Regarding claim 3, Oliver further discloses wherein identifying the magnetometer calibration constants comprises identifying the magnetometer calibration constants that minimize the difference between the first estimate of the derivative of the external magnetic field and the second estimate of the derivative of the external magnetic field (“calibrating a magnetometer 25 on a mobile device 10 to address the constant bias. In an example configuration of the mobile device 10 of FIG. 5, the magnetometer calibration 700 may be executed by the magnetometer calibration module 26. At 702, a pair of magnetometer readings is obtained. At 704, a rotation axis direction and a rotation angle corresponding to a change in an orientation of the mobile device 10 are determined. At 706, a rotation axis is determined using the rotation axis direction and the rotation angle. At 708, a check is performed to determine whether a sufficient number of magnetometer readings has been obtained. If a sufficient number of magnetometer readings has not been obtained, 702 to 706 are repeated. In one example, two pairs of magnetometer readings (i.e. a minimum of three unique magnetometer readings) are used to perform the magnetometer calibration 700. Once a sufficient number of magnetometer readings are obtained, at 710, a calibration parameter is determined based on at least one property of one or more rotation axes”[0058, 0072] which clearly states identifying the calibration readings reflecting orientation changes).
Regarding claim 4, Oliver further discloses determining the first estimate of the derivative of the external magnetic field comprises determining a difference between at least two magnetometer measurements of the sequence of magnetometer measurements (“The magnetometer reading {right arrow over M1 is obtained first, and then after a sample period, magnetometer reading {right arrow over M2 is obtained. The change from magnetometer reading {right arrow over M1 to {right arrow over M2 reflects a corresponding change in the orientation” [0060] derivative corresponds to change in estimated magnetic field).
Regarding claim 5, Oliver further discloses wherein the at least two magnetometer measurements span a time duration within a range of about 80 milliseconds - 120 milliseconds (“The gyroscope 24, when operable, obtains or otherwise acquires readings including the rate of change of angular displacement with respect to time (i.e. angular velocity) of the mobile device 10 about an axis of the gyroscope 24 using a rotation or gyroscope sensor 48” [0031]).
Regarding claim 6, Oliver further discloses wherein determining the second estimate of the derivative of the external magnetic field comprises determining a product of a matrix indicating magnetic field vector represented by the sequence of magnetometer measurements (determining a rotation axis direction and rotation angle based on gyroscope measurement [0063], modeling magnetometer reading M2 as a rotation of magnetometer reading M1 based on the gyroscope derived rotation [0064] “an error indicator can be a rotational quality indicator which measures the difference between the angular movement of a magnetic field measured by a calibrated magnetometer 25 and the angular movement measured by a rotational sensor, such as the gyroscope 24” [0099]. A three dimensional rotation of a vector is mathematically implemented as multiplication of a rotation matrix (derived from angular velocity or axis angle parameter) by a vector. Thus, modeling M2 as a rotation of M1 inherently corresponds to determining a product of a matrix indicating aa change in angular velocity estimates and a magnetic field vector).
Regarding claim 7, Oliver further discloses identifying the magnetometer calibration constants comprises identifying an eigenvector corresponding to a smallest eigenvalue of a matrix representative of the difference between the first estimate of the derivative of the external magnetic field and the second estimate of the derivative of the external magnetic field, and wherein elements of the eigenvector correspond to the magnetometer calibration constants (“calibrating a magnetometer 25 on a mobile device 10 to address the constant bias. In an example configuration of the mobile device 10 of FIG. 5, the magnetometer calibration 700 may be executed by the magnetometer calibration module 26. At 702, a pair of magnetometer readings is obtained. At 704, a rotation axis direction and a rotation angle corresponding to a change in an orientation of the mobile device 10 are determined. At 706, a rotation axis is determined using the rotation axis direction and the rotation angle. At 708, a check is performed to determine whether a sufficient number of magnetometer readings has been obtained. If a sufficient number of magnetometer readings has not been obtained, 702 to 706 are repeated. In one example, two pairs of magnetometer readings (i.e. a minimum of three unique magnetometer readings) are used to perform the magnetometer calibration 700. Once a sufficient number of magnetometer readings are obtained, at 710, a calibration parameter is determined based on at least one property of one or more rotation axes”[0058, 0072] which clearly states identifying the calibration readings reflecting orientation changes).
Regarding claim 9, Oliver further discloses wherein the sequence of angular velocity estimates is determined using the sequence of gyroscope measurements adjusted using gyroscope calibration constants, and wherein the gyroscope calibration constants are determined based on gyroscope measurements obtained while the orientation tracking system is held stationary (“The gyroscope 24, when operable, obtains or otherwise acquires readings including the rate of change of angular displacement with respect to time (i.e. angular velocity) of the mobile device 10 about an axis of the gyroscope 24 using a rotation or gyroscope sensor 48. Such readings are stored in a gyroscope sensor readings data store 42. The gyroscope 44 in this example embodiment also comprises or otherwise has access to a gyroscope calibration module 44 which can be used to calibrate the gyroscope sensor 48 to improve the quality of the gyroscope sensor readings 42. Various applications 36 may utilize the readings in the data store 42, e.g. text-based communication applications, gaming applications, etc. The applications 36 may then use such readings to provide and/or update a user interface (UI) using a display module 40. The gyroscope readings 42 can also be used by the magnetometer calibration module 26, as will be discussed below” inherently measurements starts from stationary position [0031]).
Regarding claim 10, Oliver further discloses wherein the sequence of angular velocity estimates is determined using an initial set of gyroscope calibration constants, and wherein the method further comprises: determining a calibration error of the magnetometer calibration constants identified using the initial set of gyroscope calibration constants; updating the initial set of gyroscope calibration constants based on the calibration error to generate an updated set of gyroscope calibration constants; and determining updated magnetometer calibration constants using the updated set of gyroscope calibration constants (“the mobile device 10 can incorporate gyroscope readings from the gyroscope 24 of the mobile device 10 to compute the orientation matrix 35,.., mobile device 10 is experiencing linear acceleration such that the accelerometer vector is not aligned perfectly with the direction of the Earth's gravity and/or there is magnetic interference near the mobile device 10 such that the magnetometer reading does not consist only of the Earth's magnetic field. During such times, the accelerometer vector and/or magnetometer vector may be ignored and the gyroscope readings can be used to update a previous reliable orientation matrix 35,.., number of different types of error indicators can be determined for a magnetometer 25, each of which can have different criteria for defining error. For example, calibration quality indicator can be based on consistency in a value of a magnetometer reading, irrespective of the correctness of the value generated, whereas a magnetometer accuracy indicator can be based on the correctness of the magnetometer reading. Therefore, providing an application 36 or 38 of the mobile device 10 with a plurality of types of error indicators may enable the application 36 or 38 to respond more effectively to magnetic influences” [0036, 0101]).
Regarding claim 11, Oliver further discloses wherein the updated set of gyroscope calibration constants are determined using gradient descent to minimize an error of the updated magnetometer calibration constants (determining calibration parameters based on disagreement between magnetometer derived magnetic field change and gyroscope derived rotation [0058, 72] and further determining error indicators that measure the difference between angular movement of the magnetic field measured by the magnetometer and angular movement measured by the gyroscope [0099] determining calibration constants that reduce disagreement between predicted and measured magnetic field change constitute minimizing and error between two estimates of magnetic field change further “one or more calibration parameters are available for the current state, such that the module 26 can load the appropriate parameters for the new K value whenever K changes, or generate new calibration parameters for a known state K that does not currently have a set of calibration parameters, or determine that a new state exists and generate a new K value and a corresponding set of calibration parameters” [0110]).
Regarding claim 13-14, Oliver does not explicitly teach that the calibrated sensor system in implemented in a headphone or head mounted display system.
Lyren teaching a system using magnetometer that assists in calibration against orientation drift teaching headphones and head mounted displays incorporating inertial measurement units including gyroscopes and magnetometers for determining head orientation and improving audio rendering and tracking performance [0255, 0258].
Is It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention to incorporate the teaching of Lyren in Oliver to gain the advantage of improved assists in calibration against orientation drift, thereby improving orientation accuracy and reduced drift [Lyren[0258]].
PNG
media_image2.png
740
554
media_image2.png
Greyscale
Regarding claim 15, Oliver further discloses wherein the one or more gyroscopes are configured to measure rotation along three axes, and the one or more magnetometers are configured to measure magnetic field along the three axes (“a 3-axis magnetometer may have an offset in any one or more of the three magnetometer axes. The constant bias is the magnetometer axes' measurement point of intersection origin, and is usually non-zero, as the constant bias typically includes magnetic interference due to the net effect of hard iron inside a mobile device. As such, a calibration of the magnetometer can be performed to improve its accuracy by compensating for the effect of the constant bias” [0020]).
Regarding claim 16, Oliver further discloses determining a calibration error of the identified magnetometer calibration constants; and causing an indication of the calibration error to be presented in a user interface (“an error indicator can be a rotational quality indicator which measures the difference between the angular movement of a magnetic field measured by a calibrated magnetometer 25 and the angular movement measured by a rotational sensor, such as the gyroscope 24” [0099]).
Regarding claim 18, Oliver further discloses obtaining a second sequence of gyroscope measurements and a second sequence of magnetometer measurements; identifying updated magnetometer calibration constants of the second sequence of gyroscope measurements and the second sequence of magnetometer measurements; determining a second calibration error associated with the updated magnetometer calibration constants; and updating the user interface with an indication of the second calibration error (“the mobile device 10 can incorporate gyroscope readings from the gyroscope 24 of the mobile device 10 to compute the orientation matrix 35,.., mobile device 10 is experiencing linear acceleration such that the accelerometer vector is not aligned perfectly with the direction of the Earth's gravity and/or there is magnetic interference near the mobile device 10 such that the magnetometer reading does not consist only of the Earth's magnetic field. During such times, the accelerometer vector and/or magnetometer vector may be ignored and the gyroscope readings can be used to update a previous reliable orientation matrix 35,.., number of different types of error indicators can be determined for a magnetometer 25, each of which can have different criteria for defining error. For example, calibration quality indicator can be based on consistency in a value of a magnetometer reading, irrespective of the correctness of the value generated, whereas a magnetometer accuracy indicator can be based on the correctness of the magnetometer reading. Therefore, providing an application 36 or 38 of the mobile device 10 with a plurality of types of error indicators may enable the application 36 or 38 to respond more effectively to magnetic influences” [0036, 0101]).
Regarding claim 19, the structure recited is intrinsic to the method recited in claim 1, as disclosed Oliver (U.S. Publication 20130320966) as the recited structure will be used during the normal operation of the method, as discussed above with regard to claim 1.
Regarding claim 20, the method recited is intrinsic to the apparatus recited in claim 1, as disclosed by Oliver (U.S. Publication 20130320966) [0057] as the recited method steps will be performed during the normal operation of the apparatus, as discussed above with regard to claim 1.
Allowable Subject Matter
4. Claim 8, 17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims, provided it overcome all rejections/objections presented above.
The following is a statement of reasons for the indication of allowable subject matter:
None of the prior art of record discloses or teaches the claimed combinations, or feature the following:
Regarding claims 8, 17, determining a second smallest eigenvalue of the matrix representative of the difference between the first estimate of the derivative of the external magnetic field and the second estimate of the derivative of the external magnetic field; and determining that a second sequence of gyroscope measurements and a second sequence of magnetometer measurements are to be obtained based on a ratio of the smallest eigenvalue to the second smallest eigenvalue.
Conclusion
5. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAQI R NASIR whose telephone number is (571)270-1425. The examiner can normally be reached 9AM-5PM EST M-F.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lee Rodak can be reached at (571) 270-5628. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/TAQI R NASIR/Examiner, Art Unit 2858
/LEE E RODAK/Supervisory Patent Examiner, Art Unit 2858