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 .
Drawings
1. The drawings are objected to as failing to comply with 37 CFR 1.84(p)(4)
because Fig. 6, has unlabeled boxes which according to the specification are intended to depict “individual steps of a process that implements the proposed principle”. The lack of information in the drawing is unclear. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections – 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
2. Claims 1 & 11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
3. Regarding Claim 1:
The claim language “wherein an intensity of the portion of the frequency-modulated single-mode laser beam generated by the laser device is higher than a maximum detected amplitude of the amplitude- and frequency-modulated single-mode laser beam reflected from the object” in claim 11 is comparing the intensity of one portion of the beam with the amplitude of another portion of the beam, while these terms are related, they are not directly comparable since they have different units. This renders the claim indefinite.
4. Dependent Claims 2-15 fail to remedy this issue, thus are summarily rejected under 35 USC 112 (b).
5. Regarding Claim 11:
The term “a few” in claim 11 is a relative term which renders the claim indefinite. The term “a few” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The term a few can have several meanings since there is no standard definition for an exact number that “a few” defines. This makes the scope of the claim indefinite.
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.
6. Claims 1-2, 4, 9-10, 12-14, & 16-22 are rejected under 35 U.S.C. 103 as being
unpatentable over Behzadi et al (US 11435453 B1), hereinafter Behzadi, in view of Dietz et al (EP 3822658 A1), hereinafter Dietz, and further in view of Muenster et al (“FMCW: The future of lidar”), hereinafter Muenster.
7. Regarding Claims 1 & 16:
Behzadi teaches an optical measuring device, for a motor vehicle, ([Col. 3, Lines 33-43]: According to some examples, the described LIDAR system may be implemented in any sensing market, such as, but not limited to, transportation, manufacturing, metrology, medical, augmented reality, virtual reality, and security systems. According to some examples, the described LIDAR system is implemented as part of a front-end of frequency modulated continuous-wave (FMCW) device that assists with spatial awareness for automated driver assist systems or self-driving vehicles, such as part of an automobile, motorcycle, bicycle, scooter, helicopter, or plane, or other vehicle). Behzadi teaches a laser device designed to generate a single-mode laser beam whose frequency can be modulated, ([Col. 23, Lines 54-57]: System 1800 represents a system that generates a scanning beam that includes both FM and AM modulation. FM laser 1810 represents the FMCW signal with FM modulation).
One of ordinary skill in the art at the time of filling would understand that a single-mode laser is a basic requirement of FMCW Lidar systems, since such systems rely on coherent detection and measuring the beat frequency. The use of a multi-mode laser would destroy the distinct phase and frequency characteristics needed to extract distance and velocity information.
Behzadi teaches a controllable optical modulator designed for an adjustable amplitude modulation of the frequency-modulated single-mode laser beam generated by the laser device, ([Col. 23, Lines 54-63]: System 1800 represents a system with that generates a scanning beam that includes both FM and AM modulation. FM laser 1810 represents the FMCW signal with FM modulation. The signal can be split with splitter 1820 to provide AM modulation 1830 on the FM modulated signal, to generate an FM and AM modulated signal, which could also be referred to as a frequency and power modulated signal. AM modulation 1830 can be active modulation in accordance with embodiments of active modulation of the present disclosure). Behzadi teaches a detector device designed to receive a portion of the frequency-modulated single-mode laser beam generated by the laser device for superposition with an amplitude- and frequency-modulated single-mode laser beam reflected by an object, ([Col. 24, Lines 3-14]: System 1800 can provide an additional estimate of the range of the target with time domain processing as well as the frequency domain processing. Circulator 1840 can provide a received signal or signal reflection of the transmitted power and frequency modulated signal to I/Q (in-phase/quadrature) processor 1850, component, or other signal processor. The processor can use the frequency modulated signal from splitter 1820 as a reference to compare with the received signal from circulator 1840. In one example, I/Q processor 1850 has a balanced PD (photodetector) stage followed by an ADC stage). Behzadi further teaches, ([Col. 24, Lines 15-24]: In one example, I/Q processor 1850 includes two paths, one for AM modulation and another for FM modulation. Balanced PD 1862 can feed to ADC 1872 to generate an ‘x’ component. Balanced PD 1864 can feed to ADC 1874 to generate a ‘y’ component. The combined processed signal allows improvement of the traditional FMCW signal information with additional range information from AM signaling, which can improve the target point estimates. System 1800 can provide simultaneous detection of range and velocity from the signal). Behzadi goes on to teach, ([Fig. 18]: Shows detector device 1864 receiving a portion of the FM beam while detector device 1862 receives the AM & FM signal reflected by an object for superposition with the FM reference). Behzadi teaches an evaluation circuit for transmitting the signal superimposed by the detector device into the frequency domain and determining the distance and speed of an object reflecting the single-mode laser beam, ([Col. 30, Lines 4-13]: The AM information can enable processor 3070 to compute information related to time of flight or signal delay information. Thus, AM processing 3074 can generate a range value corresponding to a signal propagation delay between the LIDAR system and target 3040. Processor 3070 can compute or determine a target range value for target 3040 based on the AM range value. Processor 3070 can compute or determine a target velocity value for target 3040 based on a difference between the Doppler-adjusted range value and the AM range value). Behzadi further teaches, ([Col. 30, Lines 35-47]: In general with respect to the descriptions herein, in one example, a light detection and ranging (LIDAR) system includes: a frequency modulation (FM) modulator to FM modulate a light signal as an FM modulated signal; an active modulator to provide time of flight (TOF) signal information with the FM modulated signal as a power and frequency modulated signal; an emitter to emit the power and frequency modulated signal; and a detector to receive a reflection of the power and frequency modulated signal and provide a detected signal for signal processing to generate a target point set, including frequency processing to generate target points based on range and Doppler information, and TOF processing to provide TOF range information).
Behzadi teaches a beam splitter which is arranged in the beam path between the laser device and the controllable optical modulator, ([Fig. 18]: shows a beam splitter 1820 between the frequency modulated laser and controllable optical modulator, AM MOD 1830). Behzadi teaches the beam splitter is designed to direct a part of the frequency-modulated single-mode laser beam generated by the laser device onto the detector device as a local oscillator signal, ([Col. 24, Lines 27-37]: FIG. 19 illustrates an example of a LIDAR system that provides FM and AM modulation on a LIDAR signal. System 1900 provides an example of system 1800. FMCW laser 1910 can be a laser transmission system in accordance with any example herein that provides a light signal for both FM and AM modulation. The modulation can be or include active AM modulation or passive AM modulation. Optical components 1920 provide the modulation and optics to transmit TX signal 1912 to target 1930 and receive the reflection signal represented by RX signal 1932). Behzadi further teaches, ([Col. 24, Lines 38-41]: Photodetector 1940 can receive RX signal 1932 from optical components 1920 from target 1930, and LO signal 1914 from optical components 1920 from FMCW laser 1910).
Behzadi does not teach the controllable optical modulator is designed to change a frequency of the amplitude modulation during a duration of a cycle of a frequency modulation, in particular after half of the duration.
However, Dietz teaches, ([0036]: The signal exposition time for each pixel has to guarantee a sufficient signal to noise ratio (SNR), but does not need any waiting time due to marking each pixel signal with an amplitude modulation. This is illustrated in figure 3b where the laser signal for each pixel is amplitude modulated (in addition to the frequency modulation) with a different characteristic frequency fAM. These frequencies can be identified with an fast Fourier transform of the detected mixing signal as sidebands surrounding each beat signal. This method guarantees that each received signal can be assigned to the corresponding pixel n, even when it is detected in a time window corresponding to pixel n+1. The frequency and amplitude modulation for up- and down chirp can be chosen differently to decrease the ambiguity between signals stemming from different pixels). Dietz further teaches, ([0038]: The electric field equations of up- down chirp for pixel n are, therefore, given by:
Eup,n=1+cos2πfAM,1int⋅cosφup
Edown,n=1+cos2πfAM,2int⋅cosφdown[AltContent: rect]
with i and n indicating that the amplitude frequencies for up- down chirp and each pixel can be chosen differently, ϕ being the phase delay between the emitted and received laser signals). Dietz goes on to teach, ([Figs. 3a & 3b]: Show a change in frequency for the amplitude modulation at 1/3 and again at 2/3 of the chirp duration).
It would have been obvious for one of ordinary skill in the art at the time of filling to modify Behzadi with Dietz to include a change in frequency of the amplitude modulation since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi with Dietz since, by superimposing an AM chirp (varying the amplitude modulation frequency) onto the FM laser, the LiDAR system imparts a unique time-varying “signature” or coded sequence onto the optical wave. At the receiver, decoding this AM pattern allows the system to distinguish the true return from ambiguous, overlapping chirps, extending the maximum unambiguous detection range without physically slowing down the laser sweep rate. In addition, such techniques create high processing gain. It allows the LiDAR to achieve sharp depth precision and spatial resolution while significantly relaxing the required sampling rates of the system's analog-to-digital converters.
Behzadi does not teach an intensity of the portion of the frequency-modulated single-mode laser beam generated by the laser device is higher than a maximum detected amplitude of the amplitude- and frequency-modulated single-mode laser beam reflected from the object.
It is not possible to directly compare the intensity with the amplitude, see section 3 of this office action, under claim rejections 112. In the interest of compact prosecution Examiner has compared the amplitude of the portion of the frequency modulated beam with the amplitude of the reflected beam.
However, Muenster teaches, ([P. 3]: This diagram illustrates the concept of coherent amplification. The local oscillator, branched off from the blue transmit signal, interferes constructively with the weak purple receive signal and generates a new green strong beat frequency signal. The strong beat frequency signal is then fed back into and detected by the photodetector). Muenster further teaches, ([P. 3, diagram]: shows the local oscillator signal is higher than the signal reflected by the object).
It would have been obvious for one of ordinary skill in the art at the time of filling to modify Behzadi with Muenster to include a reference beam with higher amplitude than the beam reflected by the object, since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi with Muenster since, this configuration yields a shot-noise-limited system, providing maximized SNR, optimal detection sensitivity, and passive noise suppression.
8. Regarding Claim 16:
Behzadi teaches a method, ([Col. 31, Lines 18-28]: In general with respect to the descriptions herein, in one example, a method includes: modulating a light signal with frequency modulation (FM) to generate an FM modulated signal; encoding the FM modulated signal with a time of flight (TOF) signal with an active modulator to generate an FM and AM modulated signal; emitting the FM and AM modulated signal; and processing to a reflection of the FM and AM modulated signal to generate a target point set, including frequency processing to generate target points based on range and Doppler information, and TOF processing to provide TOF range information). Behzadi teaches a beat frequency, ([Col. 21, Lines 46-53]: As the beam comes back from the target, the RX signal will be offset in time (Δt) with a value corresponding to the range of the object. Measuring the total time of flight TToF (Δt) provides a range measurement that is not a function of Doppler, while the beat frequency from the frequency modulated signal is a function of Range and Doppler. Combining the information of the TToF and beat frequency allows for range and doppler calculation within a single measurement).
9. Regarding Claim 2:
Behzadi teaches the controllable optical modulator comprises a controllable electro-optical modulator, in particular selected from a group operating on the basis of
the Franz-Keldysh effect or the Quantum-Confined-Stark effect; or wherein the controllable optical modulator comprises a Mach-Zehnder modulator, ([Col. 3, Lines 33-43]: For active modulation, the system can provide modulation using a Mach-Zehnder modulator (MZM), modulating optical amplifier gain signal, amplifier gain signal, an optical attenuator, attenuator, laser AM modulation, saturable absorber, optical switch, or other active modulator).
10. Regarding Claim 4:
Behzadi teaches a light optics which is arranged downstream of the controllable optical modulator in a beam path and is configured to direct a portion of the frequency- and amplitude-modulated single-mode laser beam reflected by the object onto the detector device, ([Col. 23, Lines 54-67 & Col. 24, Line 1]: System 1800 represents a system with that generates a scanning beam that includes both FM and AM modulation. FM laser 1810 represents the FMCW signal with FM modulation. The signal can be split with splitter 1820 to provide AM modulation 1830 on the FM modulated signal, to generate an FM and AM modulated signal, which could also be referred to as a frequency and power modulated signal. AM modulation 1830 can be active modulation in accordance with embodiments of active modulation of the present disclosure. AM modulation 1830 can be passive modulation in accordance with embodiments of passive modulation of the present disclosure. Circulator 1840 can provide the modulated signal to lens system 1842 and scanner 1844 to transmit and receive signal reflections of targets in a scanned environment). Behzadi further teaches, ([Fig. 18]: Shows detectors 1862 & 1864 which receive a portion of the frequency- and amplitude-modulated single-mode laser beam reflected by the object, directed by lens system 1842 and scanner 1844).
11. Regarding Claims 9 & 17:
Behzadi teaches the evaluation circuit is designed for a complex Fourier transformation of the signal superimposed by the detector device, ([Col. 24, Lines 60-67, & Col. 25, Lines 1-3]: Generally, in an FMCW DSP (digital signal processing) chain, samples from the ADC go through time domain filters for signal conditioning. Following time domain conditioning, a time-to-frequency domain conversion block (for example, an FFT (fast Fourier transform)) converts the time domain samples to frequency domain samples). Behzadi further teaches, ([Col. 23, Lines 42-47]: I/Q detection enables completely separating out AM and FM components of a received signal. The X path is the In Phase signal (such as I/Q 1850 to balanced PD 1862 to ADC 1872 of system 1800) and the Quadrature signal is the Y path (such as I/Q 1850 to balanced PD 1864 to ADC 1874 of system 1800). The in-phase signal is received at ADC 2010 which generates the X component, which can be provided to compute block 2030 and compute block 2040. The quadrature signal is received at ADC 2020 which generates the Y component, which can be provided to compute block 2030 and compute block 2040).
12. Regarding Claims 10 & 19:
Behzadi teaches a frequency for amplitude modulation of the controllable optical modulator is greater than a difference frequency resulting from a frequency of the amplitude and frequency modulated single-mode laser beam reflected from an object received by the detecting device at a time and the portion of the frequency modulated single-mode laser beam generated by the laser device received in the detecting device at said time, ([Col. 12, Lines 54-62]: FIG. 7 illustrates an example of modulation signals for on/off modulation. On/off modulation refers to modulation that changes from a baseline modulation power to a low modulation power state or the modulation power is reduced (which may be reduced all the way to zero power). Diagram 702 represents an example of a signal (TX) and the reflection (RX) of the signal. Diagram 702 represents time of flight signaling by way of selectively reducing modulation power for a period or by turning modulation frequency off). Behzadi further teaches, ([Col. 13, Lines 5-16]: Diagram 704 provides a representation of the modulation signal of diagram 702. In diagram 702, the T_low time at 710 corresponds to T_low time 720 of the TX signal. Similarly, the T_low time at 712 corresponds to T_low time 730 of the TX signal. As the beam comes back from the target, the T_low will be offset in time (ΔT) with a value corresponding to the range of the object. Measuring the total time of flight TToF (ΔT) provides a range measurement that is not a function of Doppler, while the beat frequency from the frequency modulated signal is a function of Range and Doppler). Behzadi goes on to teach, ([Figs. 6, 7, & 8]: Show the frequency of amplitude modulation is greater than the beat frequency).
13. Regarding Claim 12:
Behzadi teaches the duration of one cycle of a frequency modulation is greater than twice a light propagation time of a maximum predetermined path length, ([Fig. 7]: Shows the duration of one cycle of a frequency modulation is greater than twice a light propagation time of a maximum predetermined path length).
14. Regarding Claim 13:
Behzadi teaches the evaluation circuit is adapted to determine a distance and relative velocity of an object based on a frequency modulation and an amplitude modulation of the light reflected from the object during a pass of the frequency modulation from a first frequency to a second frequency, ([Col. 3, Lines 12-18]: As described herein, a frequency-modulated continuous-wave (FMCW) light detection and ranging (LIDAR) system provides amplitude modulation (AM) or time of flight (TOF) signaling to a frequency modulation (FM) modulated light signal. The application of AM modulation or TOF signaling to the FMCW signal enables range and velocity measurement simultaneously from the return signal). Behzadi further teaches, ([Col. 24, Lines 37-48]: Photodetector 1940 can receive RX signal 1932 from optical components 1920 from target 1930, and LO signal 1914 from optical components 1920 from FMCW laser 1910. System 1900 can condition the signal with ADC 1950 and provide the conditioned signal for digital signal processing 1960. In one example, digital signal processing 1960 generates point cloud 1962, which can represent a group of points of estimates of target information. A point cloud can refer to a group of target estimate values that have corresponding coordinate information to spatially map the points relative to each other). Behzadi goes on to teach, ([Col. 24, Lines 37-48]: I/Q detection enables completely separating out AM and FM components of a received signal. The X path is the In Phase signal (such as I/Q 1850 to balanced PD 1862 to ADC 1872 of system 1800) and the Quadrature signal is the Y path (such as I/Q 1850 to balanced PD 1864 to ADC 1874 of system 1800). The in-phase signal is received at ADC 2010 which generates the X component, which can be provided to compute block 2030 and compute block 2040. The quadrature signal is received at ADC 2020 which generates the Y component, which can be provided to compute block 2030 and compute block 2040). Behzadi continues to teach, ([Fig. 16]: Shows a pass of the frequency modulation from a first frequency to a second frequency).
15. Regarding Claim 14:
Behzadi does not teach the evaluation circuit is configured to conduct a first Fourier transformation during the duration of the frequency of the amplitude modulation
and a second Fourier transformation during a duration of the changed frequency of the amplitude modulation.
However, Dietz teaches, ([0016]: Advantageously, the calculating unit carries out a Fast Fourier Transform (to the mixed modulated reflected laser signal), to distinguish the reflected laser signals of two adjacent pixels. Such Fast Fourier Transform provides a reliable method for distinguishing the reflected signals on the basis of the amplitude modulation, as the side bands will show specific frequencies for each pixel and up and down chirp). Dietz further teaches, ([0038]: The electric field equations of up- down chirp for pixel n are, therefore, given by:
Eup,n=1+cos2πfAM,1int⋅cosφup
Edown,n=1+cos2πfAM,2int⋅cosφdown
with i and n indicating that the amplitude frequencies for up- down chirp and each pixel can be chosen differently, ϕ being the phase delay between the emitted and received laser signals).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Muenster with Dietz to include first Fourier transformation during the duration of the frequency of the amplitude modulation and a second Fourier transformation during a duration of the changed frequency of the amplitude modulation. since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Muenster with Dietz since, (Dietz: [0036]: The signal exposition time for each pixel has to guarantee a sufficient signal to noise ratio (SNR), but does not need any waiting time due to marking each pixel signal with an amplitude modulation. This is illustrated in figure 3b where the laser signal for each pixel is amplitude modulated (in addition to the frequency modulation) with a different characteristic frequency fAM. These frequencies can be identified with a fast Fourier transform of the detected mixing signal as sidebands surrounding each beat signal. This method guarantees that each received signal can be assigned to the corresponding pixel n, even when it is detected in a time window corresponding to pixel n+1. The frequency and amplitude modulation for up- and down chirp can be chosen differently to decrease the ambiguity between signals stemming from different pixels).
16. Regarding Claim 18:
Behzadi teaches generating a complex Fourier transform from the acquired signal, with a first frequency component which corresponds substantially to
a frequency of the beat and a second frequency component which corresponds substantially to an amplitude modulation frequency of the amplitude modulation signal;
the method further comprising: - calculating a distance from the signal with the first frequency component and/or a phase position of the signal with the second frequency component; - calculating a relative velocity from the signal with the first frequency component on the basis of a phase position of the signal with the second frequency component, ([Col. 3, Lines 12-18]: As described herein, a frequency-modulated continuous-wave (FMCW) light detection and ranging (LIDAR) system provides amplitude modulation (AM) or time of flight (TOF) signaling to a frequency modulation (FM) modulated light signal. The application of AM modulation or TOF signaling to the FMCW signal enables range and velocity measurement simultaneously from the return signal). Behzadi further teaches, ([Col. 24, Lines 14-26]: In one example, I/Q processor 1850 includes two paths, one for AM modulation and another for FM modulation. Balanced PD 1862 can feed to ADC 1872 to generate an ‘x’ component. Balanced PD 1864 can feed to ADC 1874 to generate a ‘y’ component. The combined processed signal allows improvement of the traditional FMCW signal information with additional range information from AM signaling, which can improve the target point estimates. System 1800 can provide simultaneous detection of range and velocity from the signal. System 1800 represents the AM signal component with the combiner after the ADC stage, with the signal represented as the combination of x2+y2). Behzadi continues to teach, ([Col. 21, Lines 46-53]: As the beam comes back from the target, the RX signal will be offset in time (Δt) with a value corresponding to the range of the object. Measuring the total time of flight TToF (Δt) provides a range measurement that is not a function of Doppler, while the beat frequency from the frequency modulated signal is a function of Range and Doppler. Combining the information of the TToF and beat frequency allows for range and doppler calculation within a single measurement).
17. Regarding Claim 20:
Behzadi teaches, a modulation frequency of the frequency-modulated laser beam increases from a first frequency value to a second frequency value linearly,
during a period of time, and the period of time is greater than a predetermined value corresponding to a maximum measuring distance, ([Col. 21, Lines 37-45]: FIG. 16 illustrates an example an AM signal based on passive modulation to provide a combined FM and AM signal. Diagram 1602 represents time of flight signaling by way of providing passive AM modulation. Signal 1610 is represented by a solid line triangle signal, which represents the transmit signal TX. The TX signal has FM modulation and AM modulation. Signal 1620 is represented by a dashed line triangle signal, which represents the reflection signal RX). Behzadi further teaches, ([Col. 21, Lines 37-45]: As the beam comes back from the target, the RX signal will be offset in time (Δt) with a value corresponding to the range of the object). Behzadi continues to teach, ([Fig. 16]: shows the frequency-modulated laser beam increases from a first frequency value to a second frequency value linearly, during a period of time, and the period of time is greater than Δt, corresponding to a maximum measuring distance).
18. Regarding Claim 21:
Behzadi teaches, receiving and generating the beat is performed during the time period, ([Fig. 8]: Shows both generating and receiving the beat is performed during the time period).
19. Regarding Claim 22:
Behzadi teaches, deflecting the frequency- and amplitude-modulated laser beam by a defined amount at regular intervals, in particular at times when no reception is taking place; or deflecting of the frequency- and amplitude-modulated laser beam in an essentially continuous manner, ([Col. 8, Lines 26-33]: In one example, while the data samples from the ADC may be continuous, the subsequent digital processing described below may be partitioned into “time segments” that can be associated with some periodicity in the LIDAR system. In one example, and without limitation, a time segment might correspond to a predetermined number of chirp periods T, or a number of full rotations in azimuth by the optical scanner). Behzadi further teaches, ([Col. 23, Lines 54-67 & Col. 24, Line 1]: System 1800 represents a system with that generates a scanning beam that includes both FM and AM modulation. FM laser 1810 represents the FMCW signal with FM modulation. The signal can be split with splitter 1820 to provide AM modulation 1830 on the FM modulated signal, to generate an FM and AM modulated signal, which could also be referred to as a frequency and power modulated signal. AM modulation 1830 can be active modulation in accordance with embodiments of active modulation of the present disclosure. AM modulation 1830 can be passive modulation in accordance with embodiments of passive modulation of the present disclosure. Circulator 1840 can provide the modulated signal to lens system 1842 and scanner 1844 to transmit and receive signal reflections of targets in a scanned environment).
20. Claims 3, 5, & 23 are rejected under 35 U.S.C. 103 as being
unpatentable over Behzadi et al (US 11435453 B1), hereinafter Behzadi, in view of Dietz et al (EP 3822658 A1), hereinafter Dietz, further in view of Muenster et al (“FMCW: The future of lidar”), hereinafter Muenster, and further in view of Rumala et al (US 20200371212 A1), Hereinafter Rumala.
21. Regarding Claim 3:
Behzadi as modified by Dietz and Muenster does not teach, an optical isolator
which is connected upstream of the controllable optical modulator
and of a beam splitter, and is designed to suppress feedback of a portion of the single-mode laser beam into the laser device.
However, Rumala teaches a Lidar system and method, ([Fig. 5]: Shows an optical isolator connected upstream of a controllable optical modulator and a beam splitter).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz and Muenster with Rumala to include an optical isolator since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz and Muenster with Rumala since, an optical isolator provides superior laser protection, lower insertion loss, and higher reverse isolation than a circulator. It ensures signal integrity by strictly blocking reverse-traveling back-reflections.
22. Regarding Claims 5 & 23:
Behzadi as modified by Dietz and Muenster does not teach, a coherence length of the single-mode laser beam generated by the laser device corresponds to at least twice a distance to the object reflecting the single-mode laser beam.
However, Rumala teaches, ([0084]: where the coherence length of the laser beam 86 should be at least twice the ranging distance).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz and Muenster with Rumala to include a laser with a coherence length of at least twice the ranging distance since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz and Muenster with Rumala since, in coherent LiDAR systems like FMCW, a laser with a coherence length at least twice the maximum ranging distance ensures the emitted and returning light remain in phase. This enables high-precision interference measurements, allowing the system to accurately calculate both distance and velocity simultaneously.
23. Claims 6, 15, & 24 are rejected under 35 U.S.C. 103 as being
unpatentable over Behzadi et al (US 11435453 B1), hereinafter Behzadi, in view of Dietz et al (EP 3822658 A1), hereinafter Dietz, further in view of Muenster et al (“FMCW: The future of lidar”), hereinafter Muenster, and further in view of Boyraz et al (US 20200150250 A1), Hereinafter Boyraz.
24. Regarding Claim 6:
Behzadi as modified by Dietz and Muenster does not teach, the controllable optical modulator is designed to generate a sinusoidal amplitude modulation with a modulation depth in the range from 2% to 60%.
However, Boyraz teaches a Lidar system and method, ([0040]: Several tones can be simultaneously used to modulate the beam, generating a chirped signal which has varying frequency. For a fixed path length, the modulation strength at RF tones can vary sinusoidally. The resulting interference patterns from each tone can be detected apart from one another to allow for simultaneous (rather than successive) measurement of distance). Boyraz further teaches, ([0028]: At the detector, the phase difference of RF tones can convert to intensity changes at the RF domain (i.e. modulation index). However, there can be a trade-off between gain due to heterodyning and modulation depth after unequal interferences of RF tones. Since the scattered light is so weak with respect to the reference arm, gain and modulation depth can be optimized by using a variable optical attenuator placed between the beam splitter 330 and a flat mirror 339 in the reference arm).
Boyraz goes on to teach, ([Fig. 4]: Shows an example modulation depth of over 30%).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz and Muenster with Boyraz to include a sinusoidal amplitude modulation with a modulation depth in the range from 2% to 60 % since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz and Muenster with Boyraz since, such a modulation provides enhanced output stability and linearity, superior eye safety and thermal management, optimized SNR, bandwidth efficiency, and multi-tone ranging, enabling multiple sinusoidal tones on the same carrier frequency without causing excessive harmonic distortion.
25. Regarding Claims 15 & 24:
Behzadi as modified by Dietz and Muenster does not teach, the controllable optical modulator is designed for amplitude modulation of the frequency-modulated single-mode laser beam generated by the laser device, and wherein the frequency of the amplitude modulation resulting from a first modulation signal and a second modulation signal differing therefrom at least in frequency.
However, Boyraz teaches, ([0018]: FIG. 1 shows an apparatus 103 for laser- or LIDAR-based multi-tone continuous wave detection and ranging. A continuous wave (CW) laser source 106 can be modulated by several radiofrequency (RF) tones f.sub.1-f.sub.N simultaneously via a Mach-Zehnder modulator (MZM) 109).
See figure 1.
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz and Muenster with Boyraz to include 2 modulation signals with different frequencies since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz and Muenster with Boyraz since, with rapidly moving objects the Doppler shift can cause range-velocity ambiguity. By adding multiple AM frequencies (e.g., radio-frequency subcarriers), the system can measure the phase shifts of the return signals at these exact frequencies. This gives the Lidar a direct Time-of-Flight (ToF) estimation independent of the Doppler shift, allowing you to mathematically decouple distance and velocity. When multiple targets are present at slightly different distances (or if a target is partially transparent, like smoke or foliage), their beat frequencies can overlap in the receiver. By superimposing distinct AM frequencies on the frequency-modulated chirp, the system creates unique temporal and spatial signatures for each target's reflection. This allows the receiver to isolate and distinguish closely spaced targets that would otherwise blend together into a single blurred return. Applying known amplitude modulations allows the system to act as a dual-mode sensor. The phase difference of the AM envelope can be used to track and subtract phase noise from the FM signal, improving overall depth precision. Using different AM frequencies also allows the Lidar to encode specific "keys" or "codes" onto the beam, preventing interference from other Lidar sensors operating in the same environment. The Lidar can continuously track the environment (measuring range and velocity) while the multiple amplitude modulation frequencies are used simultaneously to transmit digital data to cooperative targets (e.g., vehicles, drones, or satellites) at high speeds.
26. Claim 11 is rejected under 35 U.S.C. 103 as being
unpatentable over Behzadi et al (US 11435453 B1), hereinafter Behzadi, in view of Dietz et al (EP 3822658 A1), hereinafter Dietz, further in view of Muenster et al (“FMCW: The future of lidar”), hereinafter Muenster, further in view of Kreitinger et al (US 20170097302 A1), Hereinafter Kreitinger, and further in view of Nicolaescu et al (JP 2020510882 A), Hereinafter Nicolaescu.
27. Regarding Claim 11:
Behzadi as modified by Dietz and Muenster does not teach, the frequency modulation is in the range of a few 100kHz to a few MHz.
However, Kreitinger teaches a wavelength modulation spectroscopy (WMS) system combined with Lidar, ([0083]: When combined with angle encoder, WMS, and range measurements, the sensor position and orientation can be inputted into direct geo-registration algorithms to construct 3D topographic and gas concentration imagery that is registered to a geographic coordinate system). Kreitinger further teaches, ([0058]: Many of the measurement bias and noise immunity properties of WMS are derived from the fact that the modulation frequency can be made relatively large (kHz to MHz)).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz and Muenster with Kreitinger to include a frequency modulation in the range of a few 100kHz to a few MHz, since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz and Muenster with Kreitinger since, such modulation frequencies can directly boost frame rates, mitigating phase noise, and enabling real-time micro-Doppler and vibration extraction. Because the beat frequency is directly proportional to both distance and velocity, operating at higher modulation rates pushes the intermediate frequency (IF) processing band into the MHz range. This allows the system to capture rapid target movements, engine vibrations, or micro-Doppler signatures, which would otherwise be buried in the low-frequency noise of slower systems. Semiconductor lasers inherently suffer from phase and frequency noise. Faster modulation chirps mean the round-trip time of the light is relatively short compared to the coherence time of the laser. This drastically reduces phase-to-intensity noise conversion in the receiver, cleaning up the signal-to-noise ratio. Because the LiDAR's measurement cycle is tethered to the chirp repetition frequency, running sweeps at higher frequencies enables higher speed point cloud generation. This eliminates motion distortion, which is crucial when tracking high-speed vehicles in automotive applications.
Behzadi as modified by Dietz, Muenster, and Kreitinger does not teach, the amplitude modulation of the controllable optical modulator is greater than 1 MHz.
However, Nicolaescu teaches three-dimensional (3D) optical sensing system for a vehicle, ([0039]: In one case, a charge-controlled Mach-Zehnder configuration may be used to provide an amplitude modulation rate ranging from a few MHz to 25-30 GHz).
It would have been obvious to one of ordinary skill in the art at the time of filling to modify Behzadi as modified by Dietz, Muenster, and Kreitinger, with Nicolaescu to include an amplitude modulation greater than 1 MHz, since it is the same field of endeavor and results would have been predictable. One of ordinary skill in the art at the time of filling would have been motivated to modify Behzadi as modified by Dietz, Muenster, and Kreitinger, with Nicolaescu since, such amplitude modulation frequencies help to overcome ghosting, enable secure vehicle-to-vehicle (V2O) communications, and eliminate velocity-range aliasing without complicating hardware.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 20060098198 A1: Discloses a laser modulator employing the Franz-Keldysh effect.
US 20080267231 A1: Discloses a laser modulator employing the Quantum-Confined-Stark effect.
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/J.W.N./Examiner, Art Unit 3645
/HELAL A ALGAHAIM/SPE , Art Unit 3645
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