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 .
Priority
Acknowledgment is made of Applicant's claim for foreign priority under 35 U.S.C. §§ 119(a)–(d) and 365(b) based on International Application No. PCT/EP2023/076645, filed 27 September 2023, claiming priority to an application filed 28 September 2022.
Information Disclosure Statement
The Information Disclosure Statement filed 27 March 2025 has been considered. An initialed copy of Form PTO/SB/08a is enclosed with this action. Applicant's attention is directed to the fact that the references identified in the IDS as D1 (US 2012/0128374 A1) and D2 (Ahmed et al.) are applied in the rejections set forth below.
Specification
The specification is objected to for the following informalities:
(a) Paragraph [0070] states that the linear polarizer 25a is "arranged upstream of the light source 23." This is inconsistent with paragraph [0019] and with claim 2, both of which recite that the semi-reflective plate is arranged downstream of the luminous module. It is also inconsistent with the operation described in the same paragraph, in which the plate receives and divides light emitted by source 23. A polarizer positioned upstream of the light source cannot polarize light emitted by that source. Correction to "downstream" appears to be required.
(b) Paragraph [0074] refers to "the light from the source 25." Reference numeral 25 designates the linear polarizer device. The intended referent appears to be light source 23.
(c) Paragraph [0028] recites a gain "of the order of 106." In view of the surrounding disclosure regarding avalanche photodiode gain, the intended value appears to be 10⁶. The superscript appears to have been lost in translation or formatting.
(d) Paragraph [0045] states "The luminous module 2 is arranged so that the light beam F1, which it emits..." Reference numeral 2 designates the emission module; the luminous module is designated 21. See paragraph [0044].
Appropriate correction is required.
Claim Objections
Claim 10 is objected to because of the following informality: the claim recites "wherien," which appears to be a typographical error for "wherein."
Appropriate correction is required.
Claim Rejections - 35 U.S.C. § 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.
Claims 1–10 are rejected under 35 U.S.C. § 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 1, element (a), grammatical indefiniteness
Claim 1(a) recites "an emission module including a luminous module able to emit a light beam, the spectrum of the emitted light beam has at least one portion in the visible spectrum, and a linear polarizer device arranged to polarize the emitted light beam in a given polarization direction".
The preliminary amendment deleted the relative pronoun "which" from the phrase "the spectrum of which has at least one portion in the visible spectrum," leaving an independent clause ("the spectrum ... has at least one portion") spliced into what is otherwise a recitation of elements. As amended, it is unclear whether the visible-spectrum limitation is (i) a further characterization of the light beam recited earlier in the element, (ii) a separate positively recited element of the emission module, or (iii) a functional statement of intended result. The scope of the claim cannot be determined with reasonable certainty.
Correction to "the spectrum of the emitted light beam having at least one portion in the visible spectrum" would appear to resolve the ambiguity.
Claim 1, element (b), grammatical indefiniteness
Claim 1(b) recites "a reception module able to receive a light beam, the reception module includes an elementary acquisition module with a photodetector able to convert a light signal that it receives into an electrical signal, and a linear polarizer filter arranged to only transmit the component of the received light beam to the elementary acquisition module that is polarized in the given polarization direction".
The deletion of "wherein" produces the same defect identified above with respect to element (a): the clause "the reception module includes an elementary acquisition module" is an independent clause rather than a recitation of structure.
Claim 1, element (b), ambiguous element membership
Independently of the grammatical defect, the preliminary amendment deleted the phrase "characterized in that the reception module comprises," which had previously identified the linear polarizer filter as an element of the reception module. As amended, the final "and" in element (b) may be read as joining the linear polarizer filter either to "the reception module" or to "an elementary acquisition module." It is therefore unclear whether the linear polarizer filter is a component of the reception module or a component of the elementary acquisition module.
This ambiguity is material to claim scope, because the elementary acquisition module is separately recited and separately relied upon as the destination to which the filter transmits light.
Claim 1, antecedent basis
Claim 1(b) recites "the received light beam." There is insufficient antecedent basis for this limitation. Element (b) earlier recites "a light beam" (received by the reception module) and element (a) recites "a light beam" (emitted by the luminous module). It is unclear which of these two beams "the received light beam" refers to, and no beam has previously been designated a "received light beam."
Claim 1(b) further recites "a light signal that it receives." The antecedent of the pronoun "it" is ambiguous as between the photodetector, the elementary acquisition module, and the reception module.
Claim 1, "elementary acquisition module"
The term "elementary acquisition module" is a relative term which renders the claim indefinite. The specification does not provide a standard for ascertaining what degree of simplicity or subdivision renders an acquisition module "elementary," and the term does not appear to have an established meaning in the art. See paragraphs [0026]–[0027] of the specification, which describe a plurality of such modules forming a sensor but do not define the modifier.
Claim 9, "statutory photometric function"
Claim 9 recites "a predetermined statutory photometric function." The term "statutory" renders the claim indefinite because the scope of the claim depends upon the content of regulations that vary by jurisdiction and that may change over time. It cannot be determined from the claim or the specification which body of regulation defines the recited function, and therefore whether a given photometric function falls within the claim.
See specification paragraph [0034], which offers a daytime running lamp as an example but does not delimit the term.
Claims 2–10 are rejected under 35 U.S.C. § 112(b) as depending from, and incorporating the deficiencies of, claim 1.
Claim Rejections - 35 U.S.C. § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claims 1 and 6 are rejected under 35 U.S.C. § 102(a)(1) as being anticipated by AHMED et al., "Multidomain Suppression of Ambient Light in Visible Light Communication Transceivers," IEEE Transactions on Intelligent Transportation Systems, Vol. 23, No. 10, pp. 18145–18154, date of publication 13 April 2022 (hereinafter "Ahmed").
Ahmed was published 13 April 2022, more than five months before the 28 September 2022 effective filing date, and is therefore prior art under 35 U.S.C. § 102(a)(1). The exception of 35 U.S.C. § 102(b)(1)(A) does not apply, as the subject matter was not obtained directly or indirectly from the inventor or a joint inventor. Applicant identified this reference in the Information Disclosure Statement filed 27 March 2025.
Regarding claim 1, Ahmed discloses a system for an automotive vehicle — Ahmed discloses visible light communication transceivers for vehicular communication, including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) applications (Abstract; Fig. 1; Fig. 6, showing an end-to-end vehicle-to-vehicle VLC system; p. 18145, col. 2). Ahmed further notes that automobiles come pre-fitted with daytime running lamps and parking cameras that may be utilized for VLC communication (p. 18145, col. 2);
an emission module including a luminous module able to emit a light beam, the spectrum of the emitted light beam having at least one portion in the visible spectrum — Ahmed discloses optical front ends Tx1 and Tx2 driven by an encoder and a complementary data generator (Fig. 4; p. 18147, col. 2). The emitted light is visible light; Ahmed identifies the visible light transceivers as operating in the 400–750 nm wavelength band (p. 18150, col. 2) and identifies LED transmitters as the light sources (Fig. 6; p. 18148, col. 2); and
a linear polarizer device arranged to polarize the emitted light beam in a given polarization direction — Ahmed discloses that linear polarization filters are used to polarize the emitted light in order to minimize optical interference, and that the Tx1/Rx1 pair utilizes 0° linear polarization while the Tx2/Rx2 pair utilizes 90° linear polarization (p. 18147, col. 2 through p. 18148, col. 1; Fig. 4, showing 0°-polarized and 90°-polarized paths);
(b) a reception module able to receive a light beam, the reception module including an elementary acquisition module with a photodetector able to convert a light signal that it receives into an electrical signal — Ahmed discloses receiver front ends Rx1 and Rx2 (Fig. 4), and discloses that the two photodiodes at RX1 and RX2 each convert the incident light into differential signal photocurrent (p. 18147, col. 1);and
a linear polarizer filter arranged to only transmit the component of the received light beam to the elementary acquisition module that is polarized in the given polarization direction — Ahmed discloses that the polarization filters are configured between transmitter and receiver such that a communication channel is established between the Tx1/Rx1 pair and the Tx2/Rx2 pair only; the Tx1/Rx1 pair utilizes 0° linear polarization while the Tx2/Rx2 pair utilizes 90° linear polarization; and this configuration ensures that light emitted by Tx1 is blocked by the linear polarizer of Rx2 and light emitted by Tx2 is blocked by the linear polarizer of Rx1 (p. 18148, col. 1). Ahmed thus discloses a receive-side linear polarizer whose transmission axis is matched to the polarization direction imposed at the corresponding transmitter, and which excludes the orthogonal component.
Regarding the preamble. Should Applicant contend that the recitation "for an automotive vehicle" distinguishes over the applied art, that contention is not persuasive. Ahmed is expressly directed to vehicular VLC, including the V2V configuration of Fig. 6 and the head-lamp and tail-lamp transceiver scenarios of Fig. 1. The preamble is therefore met on the merits and it is unnecessary to reach the question of preamble weight. Regarding the recitation of a single emission module and a single reception module. Ahmed discloses a complementary two-channel arrangement (Tx1/Rx1 and Tx2/Rx2). Claim 1 employs the open transitional phrase "comprising" and recites "an emission module" and "a reception module" in the singular. The Tx1/Rx1 pair alone therefore reads on the claim; the presence of an additional Tx2/Rx2 pair does not remove Ahmed from the scope of the claim. See MPEP § 2111.03. Regarding "only transmit." Ahmed describes the cross-channel light as "practically blocked" (p. 18147, col. 1) and as "blocked by the linear polarizer" (p. 18148, col. 1). A linear polarizer necessarily transmits only the component of incident light aligned with its transmission axis and rejects the orthogonal component; this is the inherent operation of the element Ahmed discloses. Ahmed expressly relies on that operation to establish mutually exclusive optical channels. The limitation is therefore met.
Regarding claim 6, Ahmed discloses that the emission module includes a modulation unit able to receive a data sequence and arranged to modulate the emitted light beam from the received data sequence — Ahmed discloses that the stream of incoming binary data is first encoded using a complementary data generator, and that the complementary data is then used to drive the two separate optical front ends Tx1 and Tx2, with Tx1 turned on only when the data bit to be transmitted is a '1' and Tx2 turned on only when the data bit is a '0' (p. 18147, col. 2; Fig. 4, Data → Encoder → Tx1/Tx2). Ahmed further discloses on-off keying as the modulation scheme (p. 18148, col. 2).
Ahmed further discloses that the reception module includes a demodulation unit connected to the photodetector and arranged to extract a data sequence from an electrical signal converted by the photodetector — Ahmed discloses that differential amplification of Rx1 and Rx2 is performed to extract the transmitted data, and discloses a decoder receiving that output and producing the recovered data (p. 18148, col. 1; Fig. 4, Rx1/Rx2 → Differential Amplifier → Decoder → Data).
Alternative Rejection: Claims 1, 3 and 6 are rejected under 35 U.S.C. § 102(a)(1) as being anticipated by YANG et al., US 2012/0128374 A1, published 24 May 2012 (hereinafter "Yang").
Yang was published 24 May 2012 and is prior art under 35 U.S.C. § 102(a)(1). Applicant identified this reference in the Information Disclosure Statement filed 27 March 2025.
Regarding claim 1, Yang discloses (a) an emission module including a luminous module able to emit a light beam, the spectrum of the emitted light beam having at least one portion in the visible spectrum — Yang discloses a transmission apparatus 110 including a light emitting unit 114 which emits visible light under the control of light emission controller 113, and which may include a single LED or an array of multiple LEDs (¶ [0032]; Fig. 1). Yang's system is a visible light communication system throughout (¶¶ [0003], [0006]);and
a linear polarizer device arranged to polarize the emitted light beam in a given polarization direction, Yang discloses a polarizer 116 which converts depolarized visible light emitted from the light emitting unit 114 to polarized visible light, and which may include a linear polarizer (¶ [0034]). Yang further discloses a wire-grid polarizer 510 which passes only electromagnetic waves having a polarization direction 530 perpendicular to the aligned direction of the metallic wires, and which absorbs or reflects the remaining light, the polarization direction 530 also being referred to as a polarization axis (¶¶ [0039]–[0040]; Fig. 5). See also Yang claim 7;
(b) a reception module able to receive a light beam, the reception module including an elementary acquisition module with a photodetector able to convert a light signal that it receives into an electrical signal, Yang discloses a reception apparatus 150 including a visible light receiver 154 which receives the polarized visible light from the analyzer 153 and converts it into an electrical signal, and which may include a photo diode or an image sensor (¶¶ [0051], [0054]; Fig. 1);and
a linear polarizer filter arranged to only transmit the component of the received light beam to the elementary acquisition module that is polarized in the given polarization direction, Yang discloses an analyzer 153 which analyzes received visible light and extracts polarized visible light corresponding to the established channel, transmitting that extracted light to the visible light receiver 154 (¶¶ [0052]–[0053]). Yang discloses that the analyzer may comprise a linear polarizer (Yang claim 16). Yang further discloses that channel information, expressly including polarization direction information for linearly polarized light (¶ [0050]) is broadcast at an interval to synchronize the polarizer 116 and the analyzer 153 (¶¶ [0050], [0059]). Yang therefore discloses that the transmission axis of the receive-side analyzer is set to the same polarization direction imposed by the transmit-side polarizer.
Regarding the preamble "for an automotive vehicle." Yang discloses that the LED has become common in marketplaces for special purpose lighting such as a portable device, an automobile, a traffic light, and a billboard (¶ [0005]). The Examiner notes that this passage appears in Yang's Discussion of the Background and describes the deployment of LEDs generally rather than the deployment of Yang's system in a vehicle.
Accordingly, the preamble recitation "for an automotive vehicle" is treated as a statement of intended use that does not limit the claim. The body of claim 1 recites a structurally complete system — an emission module, a reception module, two polarizing elements and a photodetector — and contains no limitation that is specific to a vehicle or that structurally depends on a vehicle. Deletion of the preamble phrase would not alter the structure recited in the body. The preamble therefore merely states a purpose or intended use and is not entitled to patentable weight. See Catalina Marketing Int'l, Inc. v. Coolsavings.com, Inc., 289 F.3d 801, 808 (Fed. Cir. 2002); MPEP § 2111.02(II).
In the alternative, and should the preamble be accorded patentable weight, see the rejection under 35 U.S.C. § 103 at ¶ 45 below.
Alternative § 103 statement for the preamble. In the alternative, claim 1 is rejected under 35 U.S.C. § 103 as unpatentable over Yang in view of Ahmed. Yang discloses the system as set forth above. Yang further identifies the automobile as a market for LED lighting (¶ [0005]). Ahmed discloses that visible light communication using vehicle LED lamps is among the most attractive use cases for outdoor VLC systems, driven by investment in intelligent transportation systems and autonomous vehicles (p. 18146, col. 1). It would have been obvious to one of ordinary skill in the art before the effective filing date to deploy Yang's polarization-based VLC transceiver pair on an automotive vehicle, because Ahmed identifies vehicular communication as a leading application for precisely this class of system and because Yang itself contemplates automotive LED lighting as a deployment environment. The motivation would have been to obtain the V2V and V2I communication benefits Ahmed describes using the multi-channel polarization scheme Yang provides.
Regarding claim 3, Yang discloses that the linear polarizer device includes a grid polarizer — Yang discloses a wire-grid polarizer 510 including an array of fine parallel metallic wires (¶¶ [0039]–[0040]; Fig. 5).
Regarding claim 6, Yang discloses a modulation unit, signal encoder 112 encodes data to an electrical signal (Manchester coding) and further modulates the electrical signal to a format to be transmitted using visible light communication through the light emitting unit 114, for example using on-off keying (¶ [0030]), and a demodulation unit connected to the photodetector, signal decoder 155 converts the electrical signal from visible light receiver 154 to digital data, and amplifies and demodulates the electrical signal before decoding (¶ [0055]; Fig. 1).
Claim Rejections - 35 U.S.C. § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 2 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of Plant, US 2006/0176558 A1, published 10 August 2006 (hereinafter "Plant").
Ahmed discloses the system of claim 1 as set forth above, but does not expressly disclose that the linear polarizer device includes a semi-reflective plate arranged downstream of the luminous module and inclined at the Brewster angle relative to the emission axis of the luminous module.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the linear polarization filters of Ahmed as Brewster-angle semi-reflective plates as taught by Plant. Ahmed identifies the need for a polarizing element at the transmitter but leaves its physical implementation unspecified; Plant supplies a known implementation. The substitution of one known polarizing structure for another to obtain the predictable result of linearly polarizing an emitted beam is within the ordinary skill in the art. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007); MPEP § 2143(I)(B).
Claim 3 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of Yang.
Ahmed discloses the system of claim 1 as set forth above, but does not expressly disclose that the linear polarizer device includes a grid polarizer.
Yang discloses a wire-grid polarizer 510 including an array of fine parallel metallic wires, which passes only electromagnetic waves having a polarization direction perpendicular to the aligned direction of the wires and absorbs or reflects the remainder, thereby converting electromagnetic waves of mixed polarization into a wave having a defined polarization direction (¶¶ [0039]–[0040]; Fig. 5).
It would have been obvious to one of ordinary skill in the art before the effective filing date to implement Ahmed's linear polarization filters as the wire-grid polarizers of Yang. Both references are directed to polarization-based visible light communication systems, and Yang expressly presents the wire-grid polarizer as a suitable linear polarizer for that purpose. The motivation would have been to obtain a known, compact, planar polarizing element suitable for integration with an LED source.
Claim 4 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of one of the following.
Ahmed discloses the system of claim 1 as set forth above, including a linear polarizer arranged to transmit a portion of the emitted light beam by polarizing it in a given polarization direction (p. 18147, col. 2; p. 18148, col. 1). Ahmed does not expressly disclose that the linear polarizer reflects another portion of the emitted light beam polarized in the other polarization direction, together with an optical delay element arranged to receive that other portion and to polarize it in the given polarization direction.
US 7,097,315 B2, "Polarization conversion and recycling method and apparatus," discloses that an unpolarized light source can be decomposed by a polarizing beam splitter into a linear s-polarization component and an orthogonal p-polarization component; that conventional polarizers without a polarization conversion and recycling device are inefficient because only a maximum of one-half of the available light can be converted to polarized light; and that by introducing a half waveplate one can convert a p-beam into an s-beam or vice versa to recover the otherwise wasted component, with a mirror or prism employed to reflect the converted beam in the same direction as the other beam.
Alternative:
US 6,816,206 B2: a polarization conversion optical system including a half-wave plate that rotates polarization direction by ninety degrees and a polarizing beam splitter prism, in which the P-polarized beam is transmitted, the S-polarized beam is reflected, and the S beam is emitted after reflection at a reflective plane.
US 7,301,701 B2: a polarization conversion system in which light of one polarization state is transmitted, light of the orthogonal state is reflected toward a half wave plate where its polarization state is converted into the first state, and both are delivered to a common output.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the transmit-side linear polarizer of Ahmed to include a polarization conversion and recycling arrangement as taught by the secondary reference. A linear polarizer placed in the output path of an LED emitter necessarily discards approximately half of the emitted flux. In an automotive lighting application, the emitted beam must simultaneously satisfy a photometric requirement, so any loss of luminous flux is a direct design penalty. The secondary reference expressly identifies this loss and expressly provides the remedy: convert the rejected orthogonal component and recombine it with the transmitted component so that substantially all source light exits in a single polarization state. The motivation is the one the secondary reference itself supplies: recovery of the otherwise wasted half of the source output, and the result is predictable.
Applicant's own specification confirms that this is the purpose of the recited arrangement, stating at paragraph [0021] that the arrangement makes it possible to polarize substantially all the light emitted by the luminous module and therefore to maximize the yield of the linear polarizer device. That is the identical rationale set out in the polarization-recycling art.
Claim 5 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed.
Ahmed discloses the system of claim 1 as set forth above. Ahmed discloses that one transmit/receive pair utilizes 0° linear polarization and the other utilizes 90° linear polarization (p. 18148, col. 1), but does not expressly designate one of these as the "P" direction.
Linearly polarized light admits of only two orthogonal states relative to a given plane of incidence, conventionally designated P and S. The selection of one of two known, art-recognized alternatives, absent a showing of unexpected results, is a matter of obvious design choice. It would have been obvious to one of ordinary skill in the art before the effective filing date to select the P direction for the emitted beam.
Applicant's specification at paragraphs [0023]–[0024] states a rationale for preferring P, namely that sunlight reflected from a horizontal surface at the Brewster angle is polarized in the S direction.
Claim 7 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of one of the references.
Ahmed discloses the system of claim 6 as set forth above. Ahmed discloses on-off keying, variable pulse position modulation, color shift keying, pulse amplitude modulation and OFDM (p. 18148, col. 2), but does not expressly disclose generating a pulse width modulated control signal, modulating that control signal from the received data sequence, and controlling emission of the light beam from the modulated control signal.
Primary: US 9,814,115 B2 discloses a dimming controller that performs PWM dimming on a light emitter such that the emitter's duty cycle is the product of the duty cycle the emitter would have if modulation were performed and the duty cycle it would have if PWM dimming were performed without modulation. This discloses a PWM control signal that is itself modulated by the data.
Alternative: US 9,979,475 B2 discloses that LEDs may use pulse width modulation and that dimming control may be effected by varying duty cycle timing, and addresses apparatus and methods for power-efficient joint dimming and visible light communication.
It would have been obvious to one of ordinary skill in the art before the effective filing date to generate the drive signal for Ahmed's transmitter as a PWM control signal modulated by the data sequence, as taught by the secondary reference. PWM is the conventional means of controlling LED luminous intensity, and where a light source must simultaneously perform an illumination function and convey data, the art teaches combining the dimming waveform with the data modulation in a single drive signal. The motivation would have been to permit the emitter to satisfy its illumination requirement while conveying data on the same beam.
Claim 8 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of Plant et al., US 6,765,495 B1, issued 20 July 2004 (hereinafter "Plant '495").
Ahmed discloses the system of claim 6 as set forth above. Ahmed does not expressly disclose a computation unit arranged to detect, in the extracted data sequence, the presence of the data sequence that modulated the emitted beam, and to determine a time-of-flight separating emission from reception.
Plant '495 discloses an inter-vehicle communication system in which information is encoded onto vehicle headlights and taillights and the modulated light is sensed and decoded on board the vehicle. Plant '495 further discloses that modulation of the emitted light from the headlights allows forward light sensors to detect and distinguish reflections of this light from a leading vehicle, and that the time of flight for a message transmitted and reflected back from another vehicle can be used to determine distance, the message being an optical pulse transmitted from a first vehicle, reflected back by the second vehicle, with the first vehicle calculating the time required for the pulse to travel out and back to determine the separation.
It would have been obvious to one of ordinary skill in the art before the effective filing date to configure Ahmed's receiver, together with a computation unit, to identify the vehicle's own transmitted sequence in the received signal and to compute a time-of-flight from that identification, as taught by Plant '495. Ahmed already provides both an emitter and a co-located receiver on the vehicle and already recovers a data sequence at the receiver; Plant '495 teaches that the same modulated beam can serve a ranging function by detecting its reflection and timing the round trip. The motivation would have been to obtain obstacle detection and inter-vehicle distance measurement from hardware already present for communication, without adding a separate ranging sensor. Ahmed itself contemplates VLC transceivers integrating in a complementary manner with ultrasound sensors, depth cameras, Lidar and Radar (p. 18145, col. 2), confirming that a person of skill would look to combine ranging and communication functions.
Claim 9 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed.
Ahmed discloses the system of claim 1 as set forth above. Ahmed discloses that today's automobiles come pre-fitted with daytime running lamps and parking cameras which may readily be utilized for VLC communication to provide a complementary technology of communication among vehicles or between vehicles and traffic infrastructure (p. 18145, col. 2).
A daytime running lamp is a photometric function required by regulation on vehicles in the relevant markets. Ahmed thus teaches using a lamp that performs a mandated photometric function as the VLC transmitter, such that the emitted beam participates in the completion of that function while simultaneously conveying data.
It would have been obvious to one of ordinary skill in the art before the effective filing date to arrange Ahmed's emission module such that the emitted light beam fully or partially participates in the completion of a predetermined statutory photometric function. The motivation is the one Ahmed supplies: automobiles are already fitted with such lamps, so using them as VLC transmitters avoids adding dedicated emitters and provides the communication function at no additional hardware cost.
Claim 10 is rejected under 35 U.S.C. § 103 as being unpatentable over Ahmed in view of one of the references.
Ahmed discloses the system of claim 1 as set forth above, and discloses vehicle head LEDs and cameras and tail LEDs and cameras in a V2V and V2I setting (Fig. 1). Ahmed does not expressly disclose that the emission module and the reception module are arranged in a front headlamp of the automotive vehicle.
Primary: US 9,802,527 B2 discloses a vehicle headlight comprising a housing and modulatable light or IR radiation sources arranged within the housing on a movable module support, wherein an image sensor for determining depth information from the backscatter radiation of those sources is arranged within the housing, and a processor connected to the image sensor is connected via a modulator to at least some of the modulatable light sources arranged within the housing. Both the modulated emitter and the receiving sensor are thus housed in a single front headlight.
Alternative: US 11,245,469 B2 discloses a vehicle external lamp module including a transceiver circuit comprising an integrated driver circuit and receiver circuit used both to drive the light source and to receive a signal from the light source indicative of received light, permitting both sending and receiving of messages using optical communication from a single LED.
It would have been obvious to one of ordinary skill in the art before the effective filing date to arrange both the emission module and the reception module of Ahmed's system within a front headlamp of the vehicle, as taught by the secondary reference. Co-locating the emitter and the receiver in the existing headlamp housing provides a protected, sealed, optically transmissive enclosure already positioned with a forward field of view, and avoids the cost and styling penalty of a separate sensor aperture. Where, as in Ahmed's own contemplation and in claim 8, the received beam is a reflection of the emitted beam, co-location in a single housing further simplifies the optical geometry.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MONICA C KING whose telephone number is (571)270-3429. The examiner can normally be reached Mon-Fri.
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, Alexander H. Taningco can be reached at (571) 272-8048. 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.
/MONICA C KING/Primary Examiner, Art Unit 2844
9/5/2026
