DETAILED ACTION
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 Amendment
The following addresses applicant’s remarks/amendments dated August 12, 2025.
Claim 1 was amended. Claim 3 was cancelled. New claims 9-10 were added. Therefore, claims 1 and 4-10 are currently pending in the current application and are addressed below.
Response to Arguments
Applicant’s arguments, see page 6 of the Remarks, filed August 12, 2025, with respect to the rejection of claim 1 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Thurner, US 20180106891 A1 ("Thurner") in view of Bamji et al., US 20080007709 A1 (“Bamji”).
Claim Rejections - 35 USC § 103
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, 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 4-5, 7, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Bamji et al., US 20080007709 A1 (“Bamji”) in view of Patil et al., US 20170041589 A1 (“Patil”).
Regarding claim 1, Bamji discloses a method of correcting a nonlinear distance error of a 3- dimensional distance measuring camera using a pulse phase shift, the method comprising:
a distance estimating step of generating an estimated distance between a subject and the 3- dimensional distance measuring camera by a control unit (Fig. 2, controller unit 160, TOF system 200, target 20, Paragraphs [0005] and [0053]) such that the estimated actual distance is matched to a time length of one period (T) of a modulation frequency of an output light pulse output from a light-emitting unit (Figs. 1B-C shows how to obtain depth information from phase difference between emitted and returned light, Paragraph [0008]; See also: Fig. 2, clock generator 280 and Paragraphs [0059]);
a phase adjusting step of delaying a phase of the output light pulse, output from the light-emitting unit and modulated by the control unit , by T/n, to be proportional to the estimated distance, where n is a natural number greater than 1 (Fig. 3C-D, discrete sweep phase shifts of emitted light waveforms related to increase in distance, Paragraph [0058]-[0060]);
a light emitting step of outputting the phase-delayed output light pulse to a subject by the light-emitting unit (Fig. 2, light source 120, Paragraph [0058]);
a light receiving step of receiving a reflected-light pulse reflected from the subject by a light-receiving unit (Fig. 2, detector array 130, Paragraph [0053]);
a distance-error correction value calculating/storing step of calculating a measured distance to the subject using a time difference between a time point at which the phase-delayed output light pulse is output and a time point at which the reflected-light pulse is received (Fig. 2, memory 170, look-up table 210, Paragraph [0053]: TOF system 200 simulates multiple distances with calibration phase timing signals and stores calibration data in look-up table, See also: Paragraph [0008]), and calculating and storing a distance- error correction value for correcting a difference between the estimated distance and the measured distance, by the control unit (Fig. 2, memory 170, calibration look-up table 210, Paragraph [0053]).
Bamji does not teach: and a measurement completion-determining step of determining whether the measurement is completed on the basis of whether the phase of the phase-delayed output light pulse is the same as a preset completion reference phase, by the control unit, after performing the distance error correction value calculating/storing step, wherein, based on determining in the measurement completion-determining step that the phase of the phase-delayed output light pulse is not the same as the completion reference phase, the measurement completion-determining step is switched to the phase adjusting step.
However, Patil does teach a method of calibrating correction information based on distances simulated by phase shifts wherein after acquiring correction information for one set of phase differences and storing this in a look-up table, the system checks whether a predetermined number of phase differences have been measured, and if not adjusts the phase difference to the next step (Fig. 3, steps 306-310, Paragraphs [0028]-[0030], See also Fig. 1, corrector block 132, [0021]).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of this invention to modify Bamji’s method of calibrating the TOF system taught with the Patil’s calibration method that checks if a predetermined number of phases have been measured to complete the calibration process. One of ordinary skill in the art would have been motivated to make this modification in order to “compensate for non-linearity errors in TOF camera systems”, as suggested by Patil (Paragraph [0003]).
Regarding claim 4, Bamji, as modified in view of Patil, discloses the method of claim 1, wherein, in the distance-error correction value calculating/storing step, the control unit stores the distance-error correction value in a look-up table format (Bamji, Fig. 2, calibration look-up table 210, Paragraph [0053]).
Regarding claim 5, Bamji, as modified in view of Patil, discloses the method of claim 1, wherein the phase adjusting step, the light emitting step, the light receiving step, the distance-error correction value calculating/storing step, and the measurement completion-determining step are performed in a state in which a position of the 3-dimensional distance measuring camera is fixed (Bamji, Fig. 3B, TOF system 200, stationary target object 20, fixed distance Zf, Paragraph [0057], [0059]).
Regarding claim 7, Bamji, as modified in view of Patil, discloses the method of claim 1, wherein, after the measurement completion- determining step is switched to the phase adjusting step (Patil, Fig. 3, steps 306-310, Paragraphs [0028]-[0030]), the phase adjusting step, the light emitting step, the light receiving step, the distance-error correction value calculating/storing step, and the measurement completion-determining step are performed again (Bamji, Fig. 3C-D, distance measurement taken as each phase shift, Paragraph [0058]-[0060]).
Regarding claim 10, Bamji, as modified in view of Patil, discloses the method of claim 1, wherein a time taken for the phase-delayed output light pulse to be reflected from the subject and returned back to the light-receiving unit is changed compared to a time taken for the output light pulse to be reflected from the subject and returned back to the light-receiving unit without changing a distance between the 3-dimensional distance measuring camera and the subject (Bamji, Fig. 3B, TOF system 200, stationary target object 20, fixed distance Zf, Paragraph [0057], Fig. 3D, Paragraph [0059]: TOF system simulates relocation of target object 20 through phase sweep).
Claims 6 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Bamji, as modified in view of Patil, in further view of Thurner, US 20180106891 A1 (“Thurner”).
Regarding claim 6, Bamji, as modified in view of Patil, discloses the method of claim 1.
Bamji, as modified in view of Patil, does not teach: wherein the control unit is embedded in the 3- dimensional distance measuring camera as a FPGA IP (field-programmable gate array intellectual property), or is provided outside the 3-dimensional distance measuring camera and connected to the 3-dimensional distance measuring camera.
However, Thurner teaches a host controller, which may be an FPGA, that is connected to a depth camera (Fig. 1, 3D depth camera 1 and host controller 2, Paragraphs [0022]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the controller unit, disclosed by Bamji and Patil, by substituting the microprocessor with the FPGA, which is disclosed by Thurner. One of ordinary skill in the art could have substituted one known controller for another, and the results of the substitution would have been predictable.
Regarding claim 8, Bamji, as modified in view of Patil, discloses the method of claim 1.
Bamji, as modified in view of Patil, does not explicitly teach: wherein the maximum measurement distance is expressed by Equation 1 below, Equation 1: maximum measurement distance = C/(2f), where C (luminous flux) = 3x1011 mm, and f is the modulation frequency.
However, Thurner teaches a depth camera that calculates a depth measurement according to Δzmax = c / (2fmod), where Δzmax is an unambiguity range, fmod is the modulation frequency, and c is the speed of light (Paragraph [0024]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to modify the TOF system calibration, as disclosed by Bamji and Patil, to explicitly include the maximum distance measurement as taught by Thurner which would “utilize phase difference estimations (or depth estimations) from one or more modulation frequencies for deriving the final (combined) depth measurement over an possibly extended unambiguity range” (Thurner, Paragraph [0024]).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Bamji, as modified in view of Patil, in further view of Dorrington et al., US 20170205497 A1 (“Dorrington”)
Regarding claim 9, Bamji, as modified in view of Patil, discloses the method of claim 1, wherein the 3-dimensional distance measuring camera is fixed at a specific point (Bamji, Fig. 3B, TOF system 200, stationary target object 20, fixed distance Zf, Paragraph [0057], Fig. 3D, Paragraph [0059])
Bamji, as modified in view of Patil, does not teach: the fixed distance being a specific point in which the reflected-light pulse is not saturated in an image sensor of the light-receiving unit.
However, Dorrington teaches a time of flight camera system where the camera is arranged to view a target such that the pixels avoid saturation (Fig. 1, camera 1, image sensor 2, scene, Paragraph [0079]).
It would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the placement of the TOF system as taught by Bamji, as modified in view of Patil, by placing the system such that none of the detector pixels are saturated, as taught by Dorrington for the purpose of having “adequate signal quality” (Dorrington, Paragraph [0079]).
Conclusion
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/RACHEL NGUYEN/Examiner, Art Unit 3645
/JONATHAN MALIKASIM/Supervisory Patent Examiner, Art Unit 4100