DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11 February 2026 has been entered.
Response to Arguments
Applicant’s arguments, see “Remarks”, filed 26 January 2026, with respect to claims 1-21 have been fully considered and are persuasive. The Final Rejection of 24 October 2025 has been withdrawn.
Note: the amendment has not overcome the interpretation under 35 USC 112(f) because the claimed first and second optical sensing devices have only been amended to delete some of the functional limitations, without adding any structure to the claimed first and second optical sensing devices. Sensing devices invokes 112(f) in a similar manner to ink delivery means. MPEP 2181 recites: “"ink delivery means positioned on …" invokes 35 U.S.C. 112, sixth paragraph since the phrase "ink delivery means" is equivalent to "means for ink delivery"); Seal-Flex, Inc. v. Athletic Track and Court Construction, 172 F.3d 836, 850, 50 USPQ2d 1225, 1234 (Fed. Cir. 1999) (Rader, J., concurring”
In the instant case, the claim requires optical sensing devices, wherein devices is a generic placeholder for means, optical sensing devices is equivalent to devices for optical sensing, thus modified by functional language and not modified by structure to perform the act of sensing.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are:
“a first optical sensing device” in claims 1 and 17-19. (corresponding structure disclosed in paragraph [0007] as a photoreceiver (e.g., a quadrant-cell photoreceiver (quad-cell)) configured to generate first sensing data at a first rate (e.g., 50 kHz))
“a second optical sensing device” in claims 1 and 17-19 (corresponding structure an imaging device (e.g., a photodetector, photodiode, camera, or other suitable device) configured to generate second sensing data at a second rate (e.g., 5 Hz) disclosed in paragraph [0007]).
“a first illumination device configured to illuminate a fuel target” in claim 4. (corresponding structure is disclosed to be [0055], backlight laser modules)
“a second illumination device configured to illuminate a fuel target” in claim 4 (corresponding structure is disclosed to be backlight laser modules ([0055])).
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1-21 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 fails to meet the written description requirement for reciting “a controller configured to…generate fuel target data based on first sensing data and the second sensing data; and generate, at a third rate and based on the fuel target data, a steering control configured to steer the laser beam or the fuel target.”
Specifically, the first and second sensing devices are disclosed to be cameras, photodetectors, photodiodes or equivalents thereof (see for instance paragraph [0007]), as claimed each sensing device obtains data at a first and second rate. As disclosed in paragraph [0054]:
“The inputs can include, for example, (a) quad-cell data (e.g., updated at a faster rate such as 50 kHz), (b) image data (e.g., updated at a lower rate such as 5 Hz), and (c) steering data (e.g., updated a faster rate such as at 50 kHz). The outputs can include, for example, (d) a control signal that steers the laser beam, a control signal that steers the fuel targets, or one or more control signals that steer both the laser beam and the fuel targets”
That is, the inputs to the controller include faster and slower rate data (obtained from sensing devices) and the output includes a signal to steer the laser beam or fuel targets. However, the specification is devoid of any algorithm, process, prose, equations, flow chart to suggest as to how the claimed first and second sensing data is used to generate fuel target data and generate at a third rate a steering of the laser beam or fuel target based on the fuel target data.
Further discussion with respect to the alignment system starts at paragraph [0112]. At paragraph [0121] the instant disclosure recites:“computing system 1000 shown in FIG. 10, any other suitable controller or computing system, or any combination thereof. In some aspects, the L2D alignment controller 510 can be configured to receive (e.g., directly or indirectly; raw, pre-processed, or processed) the first sensing data from the first optical sensing device 502A at a first rate. In some aspects, the L2D alignment controller 510 can be further configured to receive the second sensing data from the second optical sensing device 502B at a second rate. In some aspects, the L2D alignment controller 510 can be further configured to generate, at a third rate, stereoscopic sensing data based on the first sensing data and the second sensing data. In some aspects (e.g., in a configuration that includes a photoreceiver having a faster refresh rate and an imaging device having a slower refresh rate), the second rate can be different from the first rate, and the third rate can be about equal to the first rate. In other aspects (e.g., in a configuration that includes two imaging devices having about the same refresh rate), the first rate and the second rate can be about equal to the third rate.”
That is, again the specification suggests generating a third rate stereoscopic sensing data based on first and second sensing data, however is devoid of any disclosure as to how that stereoscopic sensing data is generated.
Paragraph [0122] again reiterates the fuel data is generated based on first and second sensing data and includes a set of properties for example:
“one or more values or other data indicative of the difference (e.g., magnitude, direction) between the fuel target and a center of mass of the pre-pulse laser beam. For example, the L2D data can include: L2D_X data indicative of the difference (e.g., magnitude, direction) between the fuel target and the center of mass of the pre-pulse laser beam along the X-axis; L2D_Y data indicative of the difference (e.g., magnitude, direction) between the fuel target and the center of mass of the pre-pulse laser beam along the Y-axis; L2D_Z data indicative of the difference (e.g., magnitude, direction) between the fuel target and the center of mass of the pre-pulse laser beam along the Z-axis; any other suitable value or data; and any combination thereof”
That is, the controller takes image data from two different sensors operating a different rates and performs some operation based on the data from the two sensing devices to obtain new data indicative of the relationship between laser and droplet. However, again the specification is devoid of any disclosure as to how that data is generated using the first and second sensing data or how it is used to steer the laser or fuel target.
Paragraph [0123] further suggests the result of steering the laser beam or the fuel target, however again it is silent with respect to how the data is uses to steer the laser or target.
Paragraph [0124]-[0126] suggests estimations, however is devoid as to how the estimation is performed.
Figure 7 and associated text merely reiterate that the results are achieved without disclosure as to how the claimed results are achieved.
Figure 8, shows measured fuel target data using the process of figure 7, however does not provide how that fuel target data is generated based on first and second sensing data as required by claim 1. Indeed paragraph [0140] merely recites at block 704 in figure 7
“a controller (e.g., controller 411, L2D alignment controller 510; example computing system 1000) receives the first sensing data and the second sensing data along communications path 703 and generates stereoscopic sensing data based on the first sensing data and the second sensing data. The controller then generates measured fuel target data indicative of set of measured fuel target properties based on the stereoscopic sensing data”.
That is, the specification is silent with respect to how this stereoscopic sensing data is generated and used to generate measured fuel target data. Then estimates are made by some manner not disclosed in paragraph [0141]-[0143], but again there is no disclosure as to how the estimates are made.
Figure 9 shows an example of the claimed process performed as a flow chart, however the specification is silent with respect to any steps, process, flow chart, equations, algorithm, etc… as to how the fuel target data is generated (step 906) based on first and second sensing data and how the steering control signal is generated based on the fuel target data.
Figure 10 shows the computer which is disclosed to carry out the claimed processing steps, making clear that these steps are computer implemented functional limitations.
MPEP 2161 (I) recites:
“original claims may lack written description when the claims define the invention in functional language specifying a desired result but the specification does not sufficiently describe how the function is performed or the result is achieved. For software, this can occur when the algorithm or steps/procedure for performing the computer function are not explained at all or are not explained in sufficient detail (simply restating the function recited in the claim is not necessarily sufficient). In other words, the algorithm or steps/procedure taken to perform the function must be described with sufficient detail so that one of ordinary skill in the art would understand how the inventor intended the function to be performed. ”
In the instant case, claim 1 recites the computer/controller function of “a controller configured to…generate fuel target data based on first sensing data and the second sensing data; and generate, at a third rate and based on the fuel target data, a steering control configured to steer the laser beam or the fuel target.” However, the specification is silent with respect to how the fuel target data is generated based on the first and second sensing data, except to suggest that stereoscopic data is generated. However, again how the stereoscopic data is generated or manipulated into the fuel target data is absent from the instant specification. Therefore, claim 1 fails to meet the written description requirement under 35 USC 112(a)
It is noted here that the entire purpose of the claimed invention is for “estimating L2D that is inexpensive (e.g., low cost of hardware and repair) and not prone to the aforementioned thermal drifts [[and]]… for a model-based estimation of L2D alignment using two cameras for stereoscopic vision” ([0053]).
That is, the claimed computer functional limitations are the disclosed inventive concept of the instant disclosure, however the specification is silent with respect to any algorithm, steps, prose, flow chart as to how the computer implemented functional limitations are achieved. These steps are imperative to demonstrate possession of the claimed invention and are only disclosed as achieved without any disclosure of the steps to generate the fuel target data and the steering data based on claimed particulars.
Further MPEP 2161 recites “It is not enough that one skilled in the art could write a program to achieve the claimed function because the specification must explain how the inventor intends to achieve the claimed function to satisfy the written description requirement. See, e.g., Vasudevan Software, Inc. v. MicroStrategy, Inc., 782 F.3d 671, 681-683, 114 USPQ2d 1349, 1356, 1357 (Fed. Cir. 2015) “
Here, as discussed above, the specification merely indicates the results are achieved, however fails to disclose how those results are achieved.
Therefore, claim 1 fails to meet the written description requirement under 35 USC §112(a).
Independent claim 4 requires the same limitations as above in claim 1 and therefore fails to meet the written description requirement for the same reasons above.
Claim 7 fails to meet the written description requirement for reciting “controller is further configured to: generate stereoscopic sensing data based on the first sensing data and the second sensing data; and generate the fuel target data based on the stereoscopic sensing data.”
As discussed above, the specification is devoid of any teaching as to how the stereoscopic data is generated, only that it is based on first and second sensing data. Therefore, this amounts to a claimed result with no disclosure demonstrating possession of the claimed invention.
Claim 8 fails to meet the written description requirement for requiring “generate first estimated fuel target data; generate a comparison of the fuel target data and the first estimated fuel target data; generate fuel target estimation error data based on the comparison; and generate second estimated fuel target data based on the fuel target data, the first estimated fuel target data, and the fuel target estimation error data.”
As discussed above, the specification is devoid of any equation, flow chart prose that suggests how these estimates are generated. Indeed paragraph [0053] teaches the estimations resolve issues in the prior art. However, the specification is notably silent as to how the estimations are made, raising the question of possession under 35 USC 112(a). As demonstrated above, the specification throughout only recites that the estimations are made, but provides no guidance as to how they are made. This amounts to a claimed result, where no algorithm is disclosed to suggest how the result is achieved. Therefore, claim 8 fails to meet the written description requirement.
Claim 10 lacks written description for the same reasons above in claim 8 as it is directed towards additional estimations.
Claims 16 and 19 require commensurate limitations that lack written description recited in claims 1 and 8 and therefore lacks written description for the same reasons as discussed above.
Moreover, claims 16 and 19 require a “mathematical model” that maps values of fuel target data into geometric properties of the fuel target, however the specification is devoid of any discussion as to what this mathematical model is, raising the issues of possession under 35 USC 112(a).
Claim Rejections - 35 USC § 112
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.
Claim 3 is 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.
Claim 3 is vague and indefinite for requiring both the first and second optical sensing devices comprise a camera. Specification, optical sensing device invokes 112(f), wherein the specification teaches that the first sensing device is a photoreceiver and the second sensing device is an imaging device such as a camera. It is not clear how the photoreceiver could also be a camera.
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)(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.
Claim(s) 1, 4, 5, 7 and 21 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Riggs (US pgPub 2023/0018949).
Regarding claim 1, Riggs teaches a radiation source (fig. 17) comprising:
an enclosing structure (1751) in which a plasma formation region that receives a laser beam and a fuel target is defined ([0194] teaches the enclosing structure is that of fig. 8 having a plasma formation region that receives a laser beam and fuel target );
a first optical sensing device (1731/620 in figures 17 and 6) facing the plasma formation region and mounted outside the enclosing structure and away from a propagation path of the laser beam; a second optical sensing device (1732 (622)) facing the plasma formation region and mounted outside the enclosing structure and away from the propagation path of the laser beam (dual droplet formation system 1732/1731 mounted outside of 1751, see paragraph [0143] which teaches two cameras 1732 and 1731 or a quadrant sensor ([0101]), [0146] teaches detection of overlap. Note, 1713 is the laser steering system, thus requiring a laser, therefore the dual DFC is outside of the laser propagation path, see for instance figure 12);
a controller (discussed with respect to figures 4 and 6, controller 408) configured to:
receive first sensing data, generated at a first rate from the first optical sensing device, the first sensing data being indicative of a first overlap between a fuel target and the laser beam in the plasma formation region (620, see discussion above with respect to overlap (paragraph [0146]) and paragraph [0100] for acquisition rate of 620, see also figure 12 for overlap); receive second sensing data, generated at a second rate from the second optical sensing device, the second sensing data being indicative of a second overlap between the fuel target and the laser beam in the plasma formation region (622, see paragraph [0100] for acquisition rate and paragraph [0146] for overlap);
generate fuel target data based on the first sensing data and the second sensing data ([0099] teaches sensors 620/622 provide information about physical effects that occur on different time scales (i.e. fuel target data)); and
generate, at a third rate and based on the fuel target data, a steering control signal configured to steer the laser beam or the fuel target ([0145] teaches “the dual DFC system disclosed herein can be implemented as an incremental change to the hardware of the metrology system, and the calibration technique for unification of the different metrology systems in the laser steerer 1713, the fuel target steerer 1763, and the plasma generator 1764 (FIG. 17) can be implemented”. That is, the incremental change, must inherently occur at the controller is interpreted as the third rate steering control based on fuel target data (i.e. physical effects that occur [0099])).
Regarding claim 4, Riggs et al. teach the commensurate limitations as discussed above, further Riggs teaches a first illumination device configured to illuminate a fuel target from a first illumination angle at about the time that a laser beam is generated in the plasma formation region; a second illumination device configured to illuminate the fuel target from a second illumination angle different from the first illumination angle at about the time that the laser beam is generated in the plasma formation region (fig. 12, 1233A and 1233B, see angles in figure 12 and paragraph [0137]). Cameras taught in paragraph ([0143]).
Regarding claim 5, Riggs teaches wherein the laser beam comprises a pre-pulse laser beam ([0144]).
Regarding claim 7, Riggs teaches generate stereoscopic sensing data based on the first sensing data and the second sensing data; and generate the fuel target data based on the stereoscopic sensing data ([0147]).
Regarding claim 21, Riggs teaches wherein: the first optical sensing device comprises a first droplet formation camera; the second optical sensing device comprises a second droplet formation camera (see figure 12 and paragraph [0143]); and the controller being configured to generate fuel target data comprises generating a three- dimensional perception of the fuel target ([0143]).
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.
Claim(s) 1, 3-4, 6 and 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Graham (US pgPub 2013/0043401) in view of Gambino et al. (US pgPub 2015/0179401).
Regarding claim 1, Graham teaches a radiation source (figs. 1-2) comprising:
an enclosing structure (fig. 1, 130) in which a plasma formation region that receives a laser beam and a fuel target is defined (as seen in figure 2, laser 210 irradiates target region to produce plasma discussed in paragraphs [0054]-[0055]);
a first optical sensing device (fig. 2, 271 facing the plasma formation region enclosing structure and away from a propagation path of the laser beam (as seen in figure 2, note the sensing devices may be a photodiode or a photomultiplier ([0056]));
a second optical sensing device (272) facing the plasma formation region and away from the propagation path of the laser beam (as seen in figures 1-2, note the sensing devices may be a photodiode or a photomultiplier ([0056]));
a controller (155) configured to:
receive first sensing data, generated at a first rate from the first optical sensing device, the first sensing data being indicative of a first overlap between a fuel target and the laser beam in the plasma formation region ([0067]-[0068] and [0059] sensed signals from 271-274 used to determine offset between drive axis 211 of beam 210 and target region 205 sent to master controller, paragraph [0023] teaches sampling rate of sensors);
receive second sensing data, generated at a second rate from the second optical sensing device, the second sensing data being indicative of a second overlap between the fuel target and the laser beam in the plasma formation region ([0067]-[0068] and [0059] sensed signals from sensors 271-274 used to determine offset between drive axis 211 of beam 210 and target region 205 sent to master controller, paragraph [0023] teaches sampling rate of sensors);
generate fuel target data based on the first sensing data and the second sensing data ([0069] determine how to adjust the position of one or more elements based on the energy sensors [0066]-[0067]); and
generate, at a third rate and based on the fuel target data, a steering control signal configured to steer the laser beam or the fuel target ([0069] adjusts the one or more elements, the rate of adjustment is interpreted as the third rate. Moreover, [0076] teaches the rate of one sample (in which the relative radial alignment RA is determined in a sample) per droplet of target mixture). That is, the determination occurs once per droplet, which is imaged, thus the rate of alignment is about the same as the sampling rate of the sensors ([0023])).
Graham fails to disclose the sensors located outside of the enclosure.
However, Gambino et al. teaches sensors located outside of the enclosure ([0094]).
Gambino modifies Graham by suggesting locating the sensors outside of the vacuum chamber of Graham.
Since both inventions are directed towards detecting the position of droplets, it would have been obvious to one of ordinary skill in the art to move the sensors outside of the vacuum chamber because it avoids any type of damage to the sensors and increases flexibility for the alignment between different tracking components ([0094]).
Regarding claim 3, the Graham teaches wherein: the first optical sensing device comprises a first droplet formation camera; the second optical sensing device comprises a second droplet formation camera configured to be synchronized to the first droplet formation camera ([0023] teaches sampling rates of sensor of order of the laser and paragraph [0076] teaches the rate of one sample per droplet, thus both sensors are synchronized to each droplet. Photodiode taught in paragraph [0056]); the second rate is about equal to the first rate; and the third rate is about equal to the first rate (all rates are about the same as the alignment is also determined once per sample as discussed in paragraph [0076]).
Regarding claim 4, Graham in view of Gambino teaches the commensurate limitations as discussed above.
Moreover, Graham fails to disclose a first illumination device configured to illuminate a fuel target from a first illumination angle at about the time that a laser beam is generated in the plasma formation region; a second illumination device configured to illuminate the fuel target from a second illumination angle different from the first illumination angle at about the time that the laser beam is generated in the plasma formation region
However, Gambino teaches a first illumination device (fig. 1, 5) configured to illuminate a fuel target from a first illumination angle (as seen in figure 1) at about the time that a laser beam is generated in the plasma formation region ( capable of performing at the time that a laser beam is generated, see MPEP 2114);
a second illumination device (9) configured to illuminate the fuel target from a second illumination angle different from the first illumination angle (perpendicular as seen in figure 1) at about the time that the laser beam is generated in the plasma formation region (capable of performing at the time that a laser beam is generated, see MPEP 2114).
Gambino modifies Graham by suggesting the use of laser to irradiate the droplets detected by respective detectors.
Since both inventions are directed towards detection of droplets, it would have been obvious to one of ordinary skill in the art to modify Graham to include lasers opposite each sensor because the laser beams are created with two different wavelengths to allow better discriminating the different laser current signals at the different photosensitive detectors. That is, by backlighting the imaging area the image quality of the droplets would be improved.
Regarding claim 6, Graham teaches wherein the fuel target data comprises laser-to-droplet data ([0059]).
Regarding claim 11, Graham teaches a laser steering system (158), wherein: the steering control signal comprises a laser steering control signal indicative of an electronic instruction to steer the laser beam towards a plasma generation region (inherent to a beam control system, see paragraph [0048]); and the controller is further configured to transmit the laser steering control signal to the laser steering system ([0069]).
Regarding claim 12, Graham teaches wherein the laser steering system comprises a laser steering actuator configured to: receive the laser steering control signal; and steer the laser beam towards the plasma generation region based on the laser steering control signal ([0069]).
Regarding claim 13, Graham in view of Gambino teaches a fuel target steering system (Gambino, paragraph [0006] teaches adjustment of the droplet position), wherein: the steering control signal comprises a fuel target steering control signal indicative of an electronic instruction to steer the fuel target towards a plasma generation region; and the controller is configured to transmit the fuel target steering control signal to the fuel target steering system ([0067] teaches adjustment of droplet position by moving dispenser via motors, which are controlled via a motor controller 17b, part of the controller 20) (note it would have been obvious to additionally adjust droplet position as suggested in Gambino in the device of Graham because it would provide additional means of adjusting the droplet relative to the laser so as to improve speed or precision of adjustment).
Regarding claim 14, Graham in view of Gambino teaches wherein the fuel target steering system comprises a fuel target steering actuator configured to: receive the fuel target steering control signal; and steer the fuel target towards the plasma generation region based on the fuel target steering control signal ([0067] of Gambino).
Claim 15 is taught as discussed in the citations above in claims 11-12
Claim(s) 2 is rejected under 35 U.S.C. 103 as being unpatentable over Graham in view of Gambino et al. (US pgPub 2015/0179401) and further in view of Fleuov et al. (US pgPub 2014/0264091).
Regarding claim 2, Graham teaches the first optical sensing device comprises a photoreceiver (photodiode) and the third rate is about equal to the first rate ([0076] teaches the rate of one sample (in which the relative radial alignment RA is determined in a sample) per droplet of target mixture). That is, the determination occurs once per droplet, which is imaged, thus the rate of alignment is about the same as the sampling rate of the sensors ([0023]) ).
However, the combined device fails to disclose the second optical sensing device comprises an imaging device; the second rate is different from the first rate.
However, Flueov teaches he second optical sensing device comprises an imaging device; the second rate is different from the first rate ([0052] teaches different data acquisition rates from separate sensors and [0087] teaches the first sensor (420) has a high acquisition rate than the second (421) and paragraph [0088] teaches the second sensor may be a camera).
Flueov modifies the combined device by suggesting different acquisition rates of the different sensors and a second sensor being a camera.
Since both devices are directed towards measuring alignment in an EUV system, it would have been obvious to one of ordinary skill in the art to have the lower imaging rate of the second sensor of the combined device be lower and from a camera as suggested by Fluov because using “ sensors with different data acquisition rates can provide additional information because the time scales of the physical effects that cause the irradiating amplified light beam to move relative to the target location vary.” ([0052]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL J LOGIE whose telephone number is (571)270-1616. The examiner can normally be reached M-F: 7:00AM-3:00PM.
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/MICHAEL J LOGIE/Primary Examiner, Art Unit 2881
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