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 .
Examiner’s Note
Applicant has not submitted the Application Data Sheet. The document that applicant has submitted in place of the ADS just displays a “Please wait…” message.
Information Disclosure Statement
The information disclosure statement filed 8/01/2022 fails to comply with 37 CFR 1.98(a)(1), which requires the following: (1) a list of all patents, publications, applications, or other information submitted for consideration by the Office; (2) U.S. patents and U.S. patent application publications listed in a section separately from citations of other documents; (3) the application number of the application in which the information disclosure statement is being submitted on each page of the list; (4) a column that provides a blank space next to each document to be considered, for the examiner’s initials; and (5) a heading that clearly indicates that the list is an information disclosure statement. The information disclosure statement has been placed in the application file, but the information referred to therein has not been considered. The document that has been submitted in place of the IDS just displays a “Please wait…” message, just like the document submitted in place of the ADS. There are no references to consider.
Claim Objections
Claims 4, 5, and 19 are objected to because of the following informalities:
Regarding Claim 4: line 2 of the claim recites “the reference photon events is larger than…” and should be corrected to --the reference photon events being larger than…--. Line 4 of the claim recites “the reference photon events is smaller than…” and should be corrected to --the reference photon events being smaller than…--. Line 6 of the claim recites “the reference photon events is equal to…” and should be corrected to --the reference photon events being equal to…--.
Regarding Claim 5: Line 5 recites “a number of photon events of at the peak” and should be corrected to --a number of photon events at the peak--.
Regarding Claim 19: the last line recites the limitation “the rest sampling periods are…”. This appears to be a drafting oversight that could be corrected to recite --the rest of the sampling periods are--. However, if “rest sampling periods” is a new limitation, there is lack of antecedent basis for this limitation.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 15-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Takemoto (US 20180329063 A1).
Regarding Claim 15: Takemoto discloses an optical sensor (Fig. 1, distance measuring device 10) comprising:
a light source (Fig. 1, light emitter 101), configured to illuminate light according to a light source driving signal to cause the light source to have a lighting interval shorter than an extinction interval within one operation period (Figs. 4 and 10, the light signals P11, P12, and P13, in frame 1, are shorter than their respective measurement time ranges. The time that the light is not being emitted is longer than the duration of the light pulse);
a pixel (Fig. 1, light receiver 102), configured to respectively acquire photon events within at least three sampling periods according to a sampling signal (Fig. 4, each frame has three cycle periods where the exposure time is when the pixel acquires charge; Fig. 10, in Frame 1, there are three cycle periods, in Frame 2 there are many sampling periods, where one time duration corresponding to Exposure A and Exposure B is one sampling period); and
a processor configured to calculate at least two object distances respectively according to a ratio of numbers of the photon events of two adjacent sampling periods among the at least three sampling periods ([0114] the controller 103 divides the second measurement time range, in frame 2, into three segments. For each segment, a distance measurement operation is performed; Fig. 4(c), during the second and third cycle periods, the received light is detected during the exposure period, illustrated by the shading. These second and third cycle periods are adjacent sampling periods; Fig. 10, and [0185] based on the ratios of intensity in the exposure sequences, a distance is calculated. There are many cycles of exposure periods in Frame 2 where distance can be calculated).
Regarding Claim 16: Takemoto discloses the optical sensor as claimed in claim 15. Takemoto further discloses wherein a number of the sampling periods is determined according to an expected detection distance range of the optical sensor ([0171] “The number of times of integration increases in distance measurement in a range including a distant location because the number of photons that were reflected by a measurement target and returns decreases. For this reason, it is important to shorten the cycle of an emission light pulse, and to increase the number of times of integration”).
Regarding Claim 17: Takemoto discloses the optical sensor as claimed in claim 15. Takemoto further discloses wherein the processor is configured to change lengths of the lighting interval and the sampling periods to calibrate a distance resolution ([0186-0191] and Fig. 10, the length and timings of the lighting and exposure periods are different in Frame 1 vs Frame 2).
Regarding Claim 18: Takemoto discloses the optical sensor as claimed in claim 15. Takemoto further discloses wherein among the at least three sampling periods, a start of a later sampling period is aligned with an end of a previous sampling period (Fig. 10, in both frames 1 and 2, the subsequent cycle periods start immediately after current cycle period ends. There is no waiting time between cycle periods).
Regarding Claim 19: Takemoto discloses the optical sensor as claimed in claim 15. Takemoto further discloses wherein among the at least three sampling periods, a first sampling period is corresponding to the lighting interval, and the rest of the sampling periods are corresponding to the extinction interval (Fig. 10, in both Frames 1 and 2, there is an exposure period that corresponds with the time segment in which the light is emitted; Fig. 4, in the first cycle period of frame 1 the exposure time is at the same time segment where light is emitted).
Regarding Claim 20: Takemoto discloses the optical sensor as claimed in claim 15. Takemoto further discloses wherein the processor is further configured to add a delay distance in calculating the object distance using the two adjacent sampling periods behind a first sampling period among the at least three sampling periods ([0186-0191] since frame 2 is more accurate, but there is an unambiguous distance, frame 1 is used to disambiguate. When the distance of the object corresponds to a time that is longer than the duration of a single time period, the delay distance can be added because it was determined within the first frame and a unique distance can be determined).
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.
Claims 1, 2, 6, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Sano (US 20220146648 A1) in view of Yeruhami (US 20200249354 A1).
Regarding Claim 1: Sano discloses an optical sensor (Fig. 2, distance measuring device 1), comprising:
a light source (Fig. 2, light source 20), configured to illuminate light according to a light source driving signal ([0073] the automatic exposure (AE) control unit 40 controls the light source 20 to emit light according to a cycle);
a light sensor, recorded with an event threshold corresponding to an exposure interval (Fig. 2, light detection unit 30; Fig. 9, there is a threshold where reflected light can be distinguished from ambient light and internal system noise) and comprising:
a first pixel, configured to sample according to a sampling signal (Fig. 3, two-tap pixel 34; Fig. 5, there are two accumulation timings (second and third graph) for detecting reflected light),
the light sensor also is configured to respectively acquire reference photon events using multiple of the exposure intervals ([0102] and Fig. 5, the bottom graph shows accumulation timing that spans multiple exposure intervals and the acquired signal n2 is ambient light that is accumulated and integrated), and
a processor (Fig. 2, AE control unit 40) configured to
compare a number of the reference photon events of each of the multiple exposure intervals with the event threshold to generate a random code ([0074] based on current frame information, the next frame light emission exposure calculation and control units 41 and 42 determine the exposure of the light emission in the next frame; Fig. 10, current frame information has the amount of charge in tap A and B, and the exposure and timing control is modulated such that the charge amount is as close to the saturation threshold as possible, without exceeding it), and
modulate the light source driving signal and the sampling signal using the random code (([0074] based on current frame information, the next frame light emission exposure calculation and control units 41 and 42 determine the exposure of the light emission in the next frame).
Sano does not expressly teach that there is a second pixel, separate from the first pixel, that is configured to acquire ambient light/noise.
However, Yeruhami teaches an optical sensor (Fig. 8A, LIDAR system 802) that has a light source (Fig. 8A, light source 812), and a light sensor (Fig. 8A, sensors 806 and 808). In Fig. 8A, a first light sensor, 806, detects light from the field of view 820. Yeruhami further teaches a second pixel, configured to acquire reference photon events ([0219] and Fig. 8A, sensor 808 senses ambient light, like internally reflected light 850).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the sensor disclosed by Sano, such that the ambient light is detected by a separate sensor, as taught by Yeruhami. Sano, in paragraph [0121] explains that the ambient light acquired is separate from the reflected light and that it can be acquired individually. A person of ordinary skill in the art would then be motivated to make this modification because having a separate sensor for detecting ambient light enables the system to simultaneously measure light from the environment and internal light, and then subtract the contribution of internally reflected light from the same detection cycle (Yeruhami, [0219]).
Regarding Claim 2: Sano, in view of Yeruhami, teaches the optical sensor as claimed in claim 1. In this combination, Yeruhami further teaches further comprising a package (Fig. 8A, the housing encloses the LIDAR device 802), wherein
the second pixel is configured to receive reflected light form an inner surface of the package illuminated by the light source ([0219] and Fig. 8A, calibration pixel 808 only receives internally reflected light 850 reflected off the housing), and
the first pixel is configured to receive reflected light from an object outside the package illuminated by the light source ([0219] and Fig. 8A, sensor 806 detects light 822 that has been reflected back from the field of view 820).
Regarding Claim 6: Sano, in view of Yeruhami, teaches the optical sensor as claimed in claim 1. Sano further discloses wherein the processor is configured to modulate the light source driving signal and the sampling signal using phase shift keying according to the random code ([0074] the next frame light emission/exposure condition calculation and control units 41 and 42 control the timing and duration of the light emission in the next frame).
Regarding Claim 7: Sano, in view of Yeruhami, teaches the optical sensor as claimed in claim 1. Sano further discloses wherein the random code has one bit ([0101] and Fig. 5, one whole cycle is 4 x Tp, and within this cycle, light is transmitted at 0 and 180 degrees). According to applicant’s specifications on page 7 lines 10-18, a modulation of zero phase shift and 180 degree phase shift “can be used as a modulation scheme” that corresponds to a random code with one bit.
In this current combination, Yeruhami teaches that the second pixel comprises one single photon avalanche diode (Fig. 8C, [0233] and [0242] the calibration sensor 887, which only detects internally reflected light, may be a single sensor element such as a SPAD, or a group of detection elements). Since “comprises” is open ended, the second pixel is not limited to being only one single photon avalanche diode.
Claims 9, 11, 12, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Kawahito (US 20230367019 A1) in view of Sano.
Regarding Claim 9: Kawahito discloses an optical sensor (Fig. 1, device 1), comprising:
a light source, configured to illuminate light according to a light source driving signal to cause the light source to have a lighting interval and an extinction interval within one operation period (Fig. 1, light source 1; [0076] light source 1 has a semiconductor light emitting element and a driving circuit);
a pixel, configured to acquire photon events according to a sampling signal corresponding to the lighting interval and the extinction interval (Fig. 1 photodiode 11; Fig. 5, there are two taps SG1 and SG2, which sample at different time intervals to acquire photon events); and
a processor, configured to calculate an object distance according to the photon events using indirect time of flight ([0072-0073] distance is determined in an indirect time of flight method based on a flight time), and upon the object distance being larger than a predetermined distance, change the extinction interval to be longer than the lighting interval ([0050] The timing of the exposure periods of the first and second transfer control gates G1 and G2 are variable with respect to the emission timing of the irradiation light L1; Fig. 5, the return pulse L2 is at a distance that is ‘far’ and the exposure periods are given a time delay, extending the time of the measurement period. Because the timing and duration of the emitted light pulse is constant, the extinction interval becomes longer once this time delay in the exposure intervals is introduced).
Kawahito is silent on the lighting interval and the extinction interval identical to each other.
Sano teaches an optical sensor (Fig. 2, distance measuring device 1), comprising: a light source (Fig. 2, light source 20), configured to illuminate light according to a light source driving signal to cause the light source to have a lighting interval and an extinction interval within one operation period ([0073] the automatic exposure (AE) control unit 40 controls the light source 20 to emit light according to a cycle);
a pixel, configured to acquire photon events according to a sampling signal corresponding to the lighting interval and the extinction interval, identical to each other (Fig. 5, during one cycle, which is 4 x Tp, there are two dime intervals where light is emitted, one at 0 degrees and one at 180 degrees. There are two time intervals, one at 90 degrees and one at 270 degrees, where light is not irradiated. This means the time that the light is irradiated is the same as the time that it is ’off’).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the sensor disclosed by Kawahito, such that the time periods for detecting and emitting light are the same length in the beginning, and that there is no wait time between measurement periods, as taught by Sano. When there is no wait time between measurement periods, but a time delay is introduced, as taught by Kawahito, this extends the time during which the laser is ‘off’ and extends the extinction interval. Since the Kawahito reference is silent on whether there is a wait time between successive periods, this would be a combination of prior art elements according to known methods to yield the predictable result of distance measurement. See MPEP 2141.III KSR Rationale A.
Regarding Claim 11: Kawahito, in view of Sano, teaches the optical sensor as claimed in claim 9. In this current combination, Kawahito as modified by Sano does not teach wherein when the object distance is smaller than the predetermined distance, the processor is configured to subtract a predetermined calibration value from the photon events.
Sano further teaches when the object distance is smaller than the predetermined distance, the processor is configured to subtract a predetermined calibration value from the photon events ([0102-0103] and Equation 1, the ambient light component, N2, is removed from the detected signal to remove the influence of ambient light and only leave the reflected light component; Fig. 5, the bottom graph illustrates the accumulation of ambient light).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to further modify the sensor taught by Kawahito and Sano, by including a measurement of ambient light and removing it from the detected signal as taught by Sano. This would be beneficial because the sensor also detects ambient light in addition to reflected light, and removing the ambient light component will yield a better distance measurement by improving SNR(Sano, [0102-0103] and [0115]).
Regarding Claim 12: Kawahito, as modified by Sano, teaches the optical sensor as claimed in claim 11. In this combination, Sano further teaches wherein the processor is further configured to control the pixel to acquire calibration photon events corresponding to the lighting interval using another sampling signal, and updating the predetermined calibration value using the calibration photon events (Fig. 5 and [0102], ambient light is detected as signal n2, and the ambient light component that is used in distance calculation is N2, the sum of signals n2. Because there are multiple time intervals during which ambient light is sampled, the value of N2 is updated as signals n2 are acquired).
Regarding Claim 14: Kawahito, as modified by Sano, teaches the optical sensor as claimed in claim 9. Kawahito further discloses wherein the processor is configured to extend the extinction interval without changing the lighting interval (Fig.5 and [0055-0056] in each of the cycles of operation, only delay time is changed, and illumination time has not changed).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Kawahito, in view of Sano, further in view of Takemoto. Kawahito, as modified by Sano, teaches the optical sensor as claimed in claim 9. However, they do not expressly teach wherein the extinction interval is changed to be longer than 2 times of the lighting interval.
Takemoto teaches a sensor where the extinction interval is longer than 2 times the lighting interval (Fig. 22, there are two cycle periods where light is transmitted at the start of the cycle period. The time between emitted pulses is longer than 2 times the duration of the transmitted pulse).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the sensor taught by Kawahito and Sano, such that the extinction interval is changed to be longer than twice the duration of the lighting interval, as taught by Takemoto. This would be a mere variation in pulse duration and period duration, which would be motivated by design incentives, other market forces, or other known work (MPEP Section 2141.III KSR Rationale F).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Kawahito, in view of Sano, further in view of Yeruhami. Kawahito, as modified by Sano, teaches the optical sensor as claimed in claim 11. They do not expressly teach further comprising a protection cover in front of the light source and the pixel, wherein the predetermined calibration value is a number of photon events contributed by reflected light from the protection cover.
However, Yeruhami teaches this limitation in Fig. 8A and in the specifications in paragraph [0219]. The sensor 802 has a housing that contains the light source 812 and the sensors 806 and 808. The calibration sensor 808 detects light that has been internally reflected 850, and uses this to remove extraneous detections from the output of sensor 806, which also detects light that has been reflected back from the environment.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to further modify the sensor taught by Kawahito and Sano, by incorporating a housing that contains all the elements of the sensor as taught by Yeruhami. The predetermined calibration value is the ambient light that is detected by the sensor and does not contain a reflected light signal from the environment. This means, with the modification made in view of Yeruhami, the ambient light that is detected will include light that has been internally reflected, since this is not a signal that has been reflected back from the environment. Since Kawahito and Sano are silent on including a housing, this modification would be a combination of prior art elements according to known methods to yield predictable results (MPEP Section 2141.III KSR Rationale A).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Sano, in view of Yeruhami, further in view of Ono (US 20220137215 A1). Sano, in view of Yeruhami, teaches the optical sensor as claimed in claim 1. In this combination, Yeruhami teaches that the second pixel comprises two single photon avalanche diodes (Fig. 8C, [0233] and [0242] the calibration sensor 887, which only detects internally reflected light, may be a SPAD and can be two or more pixels). Since “comprises” is open ended, the second pixel is not limited to being only two single photon avalanche diodes.
However, Sano and Yeruhami do not teach the random code has two bits.
Ono teaches a two-tap lidar system where the random code has two bits (Figs. 12-15, showing detecting signals where the irradiation light has phase delay of 0, 90, 180, and 270 degrees respectively). According to applicant’s specifications on page 7 lines 10-18, a modulation of zero phase shift and 180-degree phase shift “can be used as a modulation scheme” that corresponds to a random code with one bit. Since a 0 and 180 degree phase shift corresponds to one bit, an additional phase shift of 90 and 270 degrees can correspond to two bits.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the sensor taught by Sano and Yeruhami, by employing the 2-tap 4-phase measurement scheme, as taught by Ono. This is a design modification that would have been predictable to a person having ordinary skill in the art because Ono describes that their detection scheme can be applied in a case where the distance is determined in a 2-tap 2-phase scheme, as well as the 2-tap 4-phase scheme illustrated in Figs. 12-15. “Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art” (MPEP Section 2141.III KSR Rationale F).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Sano, in view of Yeruhami, further in view of Pacala (US 20230176223 A1). Sano, in view of Yeruhami, teaches the optical sensor as claimed in claim 1. They do not teach wherein the event threshold is a number of photon events of a peak of a probability distribution of multiple photon events previously acquired by the second pixel using multiple of the exposure intervals.
However, Pacala teaches this limitation with Fig. 37 and paragraph [0298]. In Fig. 37, the noise threshold 3712 is calculated based on a standard deviation of the number of photon counts in the background time bins. This is determined by a standard deviation analysis of the histogram data.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to further modify the sensor taught by Sano and Yeruhami, such that a standard deviation analysis of the noise measurements is used as the threshold, as taught by Pacala. Standard deviation analyses are performed on probability distributions because the standard deviation is a measure of how close data points are to the average/mean. This would be applying a known technique to a known device ready for improvement to yield the predictable result of being able to determine a threshold for internally reflected light noise (MPEP 2141.III KSR Rationale C).
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Sano, in view of Yeruhami, further in view of Pacala, further in view of Takemoto.
Regarding Claim 4: Sano, in view of Yeruhami and Pacala, teach the optical sensor as claimed in claim 3. Sano further teaches upon the number of the reference photon events being smaller than the event threshold, the random code is set as 0 ([0115] and Fig. 10, if the control target for having signals above a threshold are not met, the next frame is adjusted. This means if the target is met, the current frame does not need to be adjusted. Since ambient light is also controllable, this is also included in the consideration of adjusting the subsequent frame) and
upon the number of the reference photon events being equal to the event threshold, the random code is not generated ([0115] and Fig. 10, if the control target for having signals above a threshold are not met, the next frame is adjusted. This means if the target is met, nothing happens, and there is no change).
They do not expressly teach wherein upon the number of the reference photon events is larger than the event threshold, the random code is set as 1.
Takemoto teaches upon the number of the reference photon events is larger than the event threshold, the random code is set as 1 ([0112] and [0068] and Fig. 4, in the first measurement time frame of Frame 1, only background noise is detected, and this background noise can exceed the event threshold. Since no reflected light is detected, the timing of the transmission and exposure is changed until the reflected light signal is detected).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to further modify the sensor taught by Sano, Yeruhami, and Pacala, by incorporating the teaching suggested by Takemoto, where the transmission and exposure timing is modulated until a reflected signal is detected. This is beneficial because determining whether light has been detected and in what segment it has been detected can be simplified and made more efficient by simply checking if there is a presence or absence of a signal, and the magnitude of the signal strength would not have to be saved (Takemoto, [0070-0071]).
Regarding Claim 5: Sano, in view of Yeruhami, Pacala, and Takemoto, teaches the optical sensor as claimed in claim 4. With this combination, Sano further teaches wherein the exposure interval is selected based on a number of photon events at the peak minus a 3 times of standard deviation in the probability distribution being larger than 0 ([0118] and Figs. 11 and 12, the exposure timings of the subsequent frames are controlled to maximize a confidence value without exceeding the saturation threshold, while still meeting a target saturation threshold, where the amount of reflected light needs to be larger than the ambient light threshold by a minimum confidence level. In Fig. 12, the amount of reflected light in tap A is more than three times the reflected noise offset), and
a number of photon events at the peak plus a 3 times of standard deviation in the probability distribution being smaller than a saturation of the second pixel ([0115] exposure timing is controlled in order to obtain a maximum SNR. If the maximum number of detected photons is too close to the ambient light noise and the minimum confidence level has not been met, the exposure timing will be modulated).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ISABELLE LIN BOEGHOLM whose telephone number is (571)270-0570. The examiner can normally be reached Monday-Thursday 7:30am-5pm, Fridays 8am-12pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Yuqing Xiao can be reached at (571) 270-3603. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ISABELLE LIN BOEGHOLM/Examiner, Art Unit 3645
/YUQING XIAO/Supervisory Patent Examiner, Art Unit 3645
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