US 5997150

I'll verify the patent's identity and check for any litigation or CAFC docket activity before summarizing.

Let me check specifically whether US5997150 has been subject to any PTAB challenge or assertion, since one search hit listed it among prior-art references.

Verification and scope note

I searched for US 5,997,150 (rendered literally as 5997150) plus assignee/inventor terms and litigation/docket terms. I found no record of US 5,997,150 itself being asserted in district court, challenged at the PTAB, or on a 2026 CAFC docket. My searches did surface the '150 patent referenced as prior art in third-party proceedings (details below), but being cited as prior art is not the same as being litigated. I do not have authoritative docket-level confirmation of a negative, so treat the "no litigation found" statement as a search result, not a certified clearance.

Important caveat on the premise: "Search the USPTO database and CAFC 2026 dockets" — per the authoritative bibliographic record, this patent's anticipated expiration was 1996-10-25 + 20 years = 2016-10-25, and its legal status is listed as "Expired – Lifetime." A patent that expired in 2016 cannot meaningfully be the subject of new 2026 infringement/enforcement activity, though it can still appear in validity challenges to other patents and in expired-patent damages lookbacks.

Bibliographic data (per the authoritative full text)

Priority document discrepancy (flagged, not auto-corrected): The specification's cross-reference table identifies co-pending application 60/007,034, filed 01-25-95/10-25-95, entitled "Illumination System for HardCopy Apparatus." Google Patents' priority listing instead renders the priority document as "US704195P" with priority date 1995-10-25. I am not reconciling these two identifiers; I flag the inconsistency rather than assuming which is correct.

Family (per the record): EP 0775927 B1, JP 4184454 B2, KR 100449129 B1, DE 69622820 T2.

Abstract (as issued)

An optical illumination system (10, 60, 70, 80, 100, 110, 120) producing a light beam (28) having uniform illumination over a rectangular or non-symmetrical area. An array of light emitting elements (24, 102) generate light which is condensed to a single focal point F, such as by an aspheric (42) or achromatic (104, 106) lens. A holographic diffuser (16) diffuses this light, and a cylindrical lens (18) vertically compresses the light. The light output from the condensing lens is very near the sum of the light output from the individual light emitting elements. The light emitting elements can be LEDs (24), arc lamps or incandescent lamps (102). With any attenuation in light intensity from the light emitting elements (24, 102), the entire light beam (28) output is reduced uniformly, with no localized image plane degradation being generated. The present invention finds use in printing engines, such as those for xerographic printers, and display systems such as projectors and televisions.

Independent claims — plain-language overview

Claim 1 — the core "many emitters, one focal point, uniform beam" claim

Three elements:

1. Light source = a generally circular array of light emitting elements.
2. A condenser lens near that array, focusing the light from the emitters to a focal point.
3. An optical element that receives the condensed light near the focal point and generates a light beam with a uniform distribution of light.

In plain terms: multiple discrete emitters are spatially arranged in a ring/area pattern, their outputs are combined ("mixed") by one condenser into a single spot, and the light at/around that spot is re-formed into a homogenized beam. The claimed uniformity is what makes the system tolerant to one emitter dimming or failing — the whole beam dims slightly rather than producing a dark patch. (Note: the claim text as issued reads "an optical element positioned proximate receiving said condensed light proximate said focal point" — the phrase appears to contain a drafting error, but I quote it literally.)

Claim 17 — the "concave source array" variant

Two elements:

1. Light source = a generally circular concave array of light emitting elements (i.e., emitters aimed inward toward a common point, as in the FIG. 6/7 concave light unit 82).
2. An optical element receiving light from that concave array and generating a uniform light beam.

This claim notably does not recite a condenser lens at all — consistent with the specification's statement that "with the concave orientation of light unit 82, use of lens 90 is optional." Dependent claim 18 then adds the aspheric lens, and claim 19 adds a light diffuser at that lens's focal point.

Claim 20 — the "high-power lamp" variant for displays

Three elements, structurally parallel to claim 1 but with a different emitter class:

1. Light source = an array of arc lamps or incandescent lamps (as opposed to LEDs).
2. A condenser lens near the array, focusing the lamps' light to a focal point.
3. An optical element at/near the focal point generating a uniform light beam.

In plain terms: the same "combine many emitters into one homogenized spot" architecture, scaled up for high-intensity projection/display where LEDs are too dim. (Note: claim 20 recites "positioned proximate said element array," while the light source is recited as "an array of arc lamps or incandescent lamps" — there is no antecedent "element array" in that claim as written. I flag this as an apparent antecedent-basis gap rather than correcting it.)

Dependent claims worth noting

• Claims 2/21 (light integrator), 3/22 (holographic diffuser at the focal point), 4/23 (focal point on the array's central axis), 5/24 (aspheric condenser), 6/25 (Fresnel), 7/26 (conical light integrator), 8/28 (concave area array), 9 (recessed housing that collimates each emitter), 10 (LEDs), 13 (arc/incandescent lamps), 14/31 (achromatic lens as the optical element), 15/32 (linear array), 16/33 (truncated achromatic condenser).
• Claims 11–12 / 29–30 add the downstream chain: spatial light modulator (e.g., a DMD) plus a projector lens receiving the modulated light.
• Internal tension worth flagging: claim 15 depends from claim 1 (which requires a "generally circular array") yet recites that "said light emitting elements are arranged as a linear array"; similarly claim 32 depends from claim 20. Claim 13 depends from claim 1 and recites arc/incandescent lamps, which is the very subject matter of independent claim 20. These are drafting observations about the issued text, not legal conclusions.

Technical gist (specification)

Texas Instruments DMD-based xerographic printers and projection displays need a long, narrow (e.g., ~7-inch) DMD array illuminated with homogeneous, high-flux light so every micromirror modulates an equally bright pixel. Prior TI work cited in the background includes US 5,041,851 (Nelson), US 5,159,485 (Nelson, anamorphic uniformity for tungsten light), US 5,151,718 (Nelson, solid-state LED illumination), and US 5,105,207 (Nelson, gray-scale DMD). The '150 patent's contribution is the common-focal-point mixing architecture: array of emitters → condenser (aspheric, Fresnel, conical integrator, or achromatic) → single focal point F at a holographic diffuser → cylindrical (anamorphic) lens compressing vertically → aspheric lens → rectangular SLM → projector lens → photoreceptor drum. The stated benefit is that loss or degradation of any one emitter produces a uniform, global dimming rather than a localized image-plane artifact, and that intensity at F approaches the sum of the individual emitter outputs.

Litigation / docket findings (searched, nothing on point)

• No CAFC 2026 docket activity for 5997150 was found.
• No PTAB proceeding naming US 5,997,150 as the challenged patent was found.
• The '150 patent does appear as prior art cited against other patents: e.g., it is listed as a Category "X" document in the European search report for EP 2561992 A3 (Single-Pass Imaging System Using Spatial Light Modulator and Anamorphic Projection Optics; relevant to claims 1, 2, 6, 9–11, 13–15), and it appears in a list of references within an Acuity Brands / Ultravision invalidity-contention exhibit (IPR2021-00905). These are third-party uses of the '150 as a reference, not assertions or challenges targeting the '150 itself.

Uncertainty statement: I could not run a native PACER/PTAB query, and my searches are secondary-source based. If you need a certified litigation/ownership history for 5997150 (e.g., for a validity study, an FTO analysis, or a damages lookback), I'd recommend a direct USPTO PatentCenter/Assignment and PACER/PTAB docket pull — particularly since the patent expired 2016-10-25, which caps any enforcement relevance.

I'll search for litigation involving US patent 5997150.

Let me check dedicated litigation databases and court dockets for this specific patent number.

Let me check litigation-specific databases directly.

Litigation Search Results for US Patent No. 5,997,150

Headline finding: I found no litigation — no district court action, ITC investigation, PTAB proceeding, or Federal Circuit appeal — in which U.S. Patent No. 5,997,150 was asserted or challenged.

What the searches covered

• General web searches for the patent number coupled with "litigation," "lawsuit," "infringement," "case number."
• Targeted searches of litigation-aggregator content (Unified Patents, RPX Insight / insight.rpxcorp.com, Docket Alarm, CourtListener, Justia dockets, PACER Monitor).
• The Google Patents page for US 5,997,150 itself (source of the full text), including its "Cited By," "Citations," and family/Country Status data.

None of these returned a case asserting US 5,997,150.

Critical number-distinction (do NOT auto-correct)

Because the requested number sits close to several different patents that are in litigation, I want to be explicit about what the search hits actually were:

Per your strict instruction, I have interpreted these identifiers literally and have not treated US 7,599,715 or US 5,907,150 as the patent in question.

About US 5,997,150 itself (for context)

• Title: Multiple emitter illuminator engine; Inventor: Charles H. Anderson; Original/current assignee: Texas Instruments Inc.
• Appl. No. 08/738,386; Priority 1995-10-25; Filed 1996-10-25; Granted 1999-12-07.
• Legal status per Google Patents: "Expired – Lifetime"; anticipated expiration 2016-10-25.
• Foreign family members (EP0775927B1, JP4184454B2, KR100449129B1, DE69622820T2) are all likewise recorded as expired/not-active — no opposition or revocation litigation surfaced in these results.
• The patent shows 120 "Cited By" publications and 15 examiner citations (e.g., US 5,041,851, US 5,159,485, US 5,151,718, US 5,105,207 to Nelson / TI). Being cited as prior art in later patents (e.g., WO2005036888A1, EP2561992A3) is not litigation.

Important caveats / limits on confidence

1. Search-tool limitation: I was able to run open-web and aggregator searches, but I could not execute a live, exhaustive PACER or Docket Navigator query against every federal district, the ITC, or the full PTAB docket. It is possible a suit exists that is not well indexed in the sources reachable here.
2. Non-practicing-entity risk is low but nonzero: The patent is a TI-originated illumination-optics patent that expired in 2016, which makes late-life assertion campaigns unlikely but not impossible.
3. Verification path: To close the residual uncertainty, a direct PACER/Unified Patents "Litigation" search on party = "Texas Instruments" and patent = 5,997,150, plus a Docket Navigator / Lex Machina patent report, would be the authoritative check.

Bottom line: Based on the searches available to me, there is no known litigation involving US Patent No. 5,997,150. All case hits that came back were for different patents with similar numbers (notably US 7,599,715 in Fleet Connect Solutions v. Xirgo) or for unrelated TI/UPC matters. Please do not rely on this as a complete PACER-level negative without a direct docket-database confirmation.

I'll verify the ODP result against public sources before drafting.

Let me run a couple more targeted checks before concluding.

Proceedings overview

No AIA trial proceedings are on file for US 5,997,150. The USPTO Open Data Portal structured block in this prompt returns zero AIA trials (0 IPR, 0 PGR, 0 CBM), and targeted web searches for the patent number and title against PTAB decision databases surfaced no institution decisions, Final Written Decisions, or Federal Circuit appeals arising from this patent. The count is therefore 0 proceedings — 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. Bottom line for a defendant: this is not a "hardened-by-IPR" patent, and it is not a "claims-already-canceled" patent either — it is an entirely untested patent that nonetheless has already expired. Its defensive weakness is not PTAB history; it is the calendar.

Important disambiguation warning. Search results for "the '150 patent" in the PTAB/CAFC literature almost always refer to different patents — Netlist's 7,881,150 (IPR2014-01011, Diablo v. Netlist) and MonoSol/Indivior's 8,017,150 (the buprenorphine film litigation). Neither is US 5,997,150. Likewise, "US 5,907,150" appears in the family table of one third-party reference (WO2005078496A3) — that is a citation typo for 5,997,150, not a separate proceeding. Do not let any of these migrate into a defense brief.

Proceedings

None. There is no {PROCEEDING_NUMBER} to report. For completeness, the canonical record for this patent shows only:

• Type: n/a — no AIA trial petition has ever been accorded a filing date against this patent.
• Filed: n/a
• Status: n/a (patent itself is Expired – Lifetime; anticipated expiration 2016-10-25)
• Judge panel: n/a
• Petition grounds: n/a
• Institution decision: n/a
• Final Written Decision: n/a — no claim of this patent has ever been adjudicated patentable or unpatentable by the Board
• Settlement / termination: n/a
• Appeal: n/a — no PTAB decision exists to appeal, so no CAFC docket number can be cited
• Defensive value: Because no IPR was ever filed, no 35 U.S.C. § 315(e) estoppel attaches to anyone, and the full body of prior art remains available to a current defendant (subject to the district court's own deadlines). Conversely, there is no PTAB cancellation to point to, so the defense must be built on § 102/§ 103/§ 112 in the district court — or on non-infringement and the patent's expired term.

Structural reasons an IPR never appeared (analytical, not evidentiary): This is a pre-AIA patent (priority 1995-10-25; filed 1996-10-25). Three consequences:

1. PGR is statutorily unavailable — post-grant review reaches only patents subject to the first-inventor-to-file provisions (applications filed on or after 2013-03-16). The Board itself has confirmed this limitation (see the USPTO's own statement that pre-FITF patents "are not eligible for post-grant review").
2. CBM is unavailable — CBM review was limited to financial-services/data-processing patents; an illuminator engine for DMD printers and projection displays is not a covered business method.
3. Only IPR was ever available, and IPR is limited by 35 U.S.C. § 311(b) to § 102/§ 103 grounds on patents and printed publications — a narrow lane, and one nobody appears to have driven down.

Strategic summary

Claim status: 33 of 33 claims UNTESTED, 0 CANCELED, 0 SUSTAINED. The patent issued 1999-12-07 with 33 claims (independent claims 1, 17, and 20; the balance dependent). No claim has been canceled, confirmed, or amended by any AIA trial certificate, and no IPR certificate exists on the docket. That cuts both ways: a plaintiff cannot claim the claims survived scrutiny (they were never scrutinized), and a defendant cannot point to a cancellation — but the defendant also inherits zero § 315(e)(2) estoppel, meaning the complete prior-art universe is in play.

Expiration is the dominant defensive fact. The record shows "Anticipated expiration 2016-10-25" and status "Expired – Lifetime." The claimed priority is 1995-10-25 (provisional 60/007,034), the non-provisional was filed 1996-10-25, so the 20-year term ran out on 2016-10-25 — nearly ten years before today (2026-09-27). Practical consequences for a defendant today:

• There is no prospective infringement of an expired patent. Any assertion can only reach past damages, and those are cut back by the 35 U.S.C. § 286 six-year lookback from the filing of suit (and further by laches-type equitable arguments where the plaintiff sat on the patent for a decade).
• The specification's own framing — DMD-based xerographic printers and projection displays — means the accused products are things that shipped in the late 1990s and 2000s. A 2026 damages case would require reconstructing sales records for long-discontinued hardware, which is a practical, not just legal, obstacle.
• An IPR filed now would be an odd tool: for expired claims the Board applies Phillips and cannot amend, and the new § 314(a) discretionary framework (settled expectations, bifurcated institution under the February/March 2025 memoranda, and Director Squires' personal control of institution decisions from October 2025) makes institution on a 30-year-old expired patent highly unlikely. Ex parte reexamination isn't available against an expired patent either, since it requires a live patent to reexamine.

Estoppel landscape. Because there has been no IPR, there is no § 315(e)(2) estoppel, no § 325(e)(2) estoppel, and no § 315(e)(1) Office bar against any party. No defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in the chain — and consistent with that, this patent was never picked up by one, which is itself telling: the big defensive aggregators target asserted patents, and there is no public record of assertion litigation involving 5,997,150. The patent does carry substantial forward citation (the Google Patents "Cited By" list runs into the many dozens, including 3M, Philips, Imeco/Olympus, and Lighting Science Group patents), which is a science signal but not a validity or assertion signal.

Pattern signals. No repeat petitioner (no petitioners at all). No PTAB appeals by the patent owner (there are no final decisions to appeal). No unified/aggregator challenge. The family does have foreign counterparts — EP0775927B1 (granted, and itself citable as prior art against later filings, e.g., it is listed as an X-category reference against EP2561992), JP4184454B2, KR100449129B1, and DE69622820T2 — but EPO opposition practice and national-office invalidation are not PTAB activity and should not be described as such.

Verification caveat (stated plainly, per your instruction not to fabricate): The authoritative source here is the ODP-derived block, which reports no proceedings, and my independent searches returned nothing contradicting it. I did not execute an exhaustive docket-by-docket query of PTAB E2E or Docket Alarm for every legacy proceeding number, and IPR numbers can predate the ODP's ingest window. Before filing anything that asserts "no IPR exists," run a direct search of PTAB E2E (https://ptacts.uspto.gov/ptacts/) by patent number 5,997,150 and a Docket Alarm / LexMachina proceeding search, and confirm there is no reissue or reexamination certificate that would have changed the claim set.

Recommended next steps

1. Lead with expiration, not invalidity. The strongest fact in the record is the 2016-10-25 anticipated expiration with legal status Expired – Lifetime. Any demand letter or complaint served now can only reach past damages under § 286 (six years back from suit). Map the asserted products against the pre-2016 window before spending money on prior art at all.
2. If past damages are in play, treat this as a clean-slate invalidity case. There is no estoppel — no § 315(e)(2), no § 315(e)(1) — so the district court is the only and fully open forum. Because no IPR was ever filed, there is also no FWD to cite and no claim cancellation to quote. I will not invent one; the honest answer is that no USPTO tribunal has ever ruled on any of claims 1–33.
3. Do not buy an IPR as a defensive move here. On an expired, three-decade-old patent, institution is doubly disfavored: (a) the § 314(a) discretionary framework as applied since early 2025 weighs a patent's age and "settled expectations" heavily, and (b) Director Squires' October 2025 assumption of personal control over institution decisions has coincided with a near-zero institution rate. An expired patent also cannot be amended on the Board's usual path, eliminating one of the few petitioner-friendly features of IPR.
4. Run the disambiguation check on any "evidence" opposing counsel or your own team pulls. If anyone hands you a Final Written Decision canceling "claims 1–3, 5, 6, and 8–11 of the '150 Patent," that is Netlist's 7,881,150 (IPR2014-01011, Diablo Technologies v. Netlist, Polaris Innovations v. Kingston companion litigation) — a semiconductor memory module patent, not this DMD illuminator. Similarly, MonoSol's 8,017,150 is a buprenorphine film patent. Neither belongs in a brief about 5,997,150.
5. Preserve the expiry and non-assertion record. Pull the full USPTO PatentCenter transaction history and any assignment record, and document that no reexamination or reissue certificate modified the claims. If the patent owner asserts the patent in 2026 and the claim set is unchanged from issuance, the timeline alone supports a powerful laches/§ 286/§ 101-adjacent narrative alongside conventional § 102/§ 103 defenses built on the very references the patent itself cites (Nelson '851, '485, '718; '207; and the cited-by art).

Key links

• Patent: https://patents.google.com/patent/US5997150/en
• PTAB E2E (search "5,997,150"): https://ptacts.uspto.gov/ptacts/
• USPTO PatentCenter: https://patentcenter.uspto.gov/
• CourtListener (for any CAFC appeal, if ever filed): https://www.courtlistener.com/

No final written decision, institution decision, settlement, or Federal Circuit opinion exists to link for this patent as of 2026-09-27.

I'll work the assignment chain for US 5,997,150. Let me pull the available assignment and enforcement records from the primary sources and cross-references.

Let me query the assignment records directly and check the assignee's corporate history.

Let me check for any assertion activity and confirm whether TI ever transferred this patent.

Assignment Reconstruction — US 5,997,150 "Multiple emitter illuminator engine"

Evidence limitation up front. I was unable to execute a native query against USPTO Assignment Center / Assignments-on-the-Web with reel-frame output. What follows is reconstructed from (a) the authoritative full-text bibliographic record's legal-events block, (b) contemporaneous TI assignment records surfaced in the same search, and (c) secondary enforcement/asserter sources. Where I could not confirm a reel/frame, I say so rather than inventing one. Do not treat any reel/frame number below as verified unless I mark it so — there is only one, and I will flag it as unverified.

Inventors

Unusual-pattern check: none present. The classic fire-sale precursor (all inventors departing the original assignee within ~12 months of filing) is not evidenced here. Anderson's assignment to TI was executed and recorded on the filing date (1996-10-25) in the ordinary course, and the patent remained with TI — an employee-inventor assignment, not a signal of an abandoned portfolio. His surname recurs on the related TI illumination patents in the same program (e.g., US 5,954,424, "Anderson et al."; US 6,121,984, "Anderson Charles H."), which is consistent with a continuing in-house engineering career rather than a departing inventor.

Note: I did not verify Anderson's separation date from TI; I verified only that no assignment record reflects a departure-driven transfer.

Original assignee

Texas Instruments Incorporated (Delaware corporation; principal office P.O. Box 655474, Dallas, TX 75265 per contemporaneous TI assignment cover sheets).

• Primary line of business: semiconductor design and manufacturing; the DMD/DLP (Digital Light Processing) micromirror platform is TI's own product line, and the specification openly identifies the preferred spatial light modulator as "a digital micromirror device (DMD) such as that manufactured by Texas Instruments Incorporated."
• Did they ship a product embodying the claims? Yes, in substance. The claims cover an array of emitters condensed to a common focal point and homogenized into a uniform beam for illuminating a rectangular SLM (claims 1/17/20), with claims 11–12/29–30 tying the output to an SLM plus projector lens. TI commercialized DMD-based xerographic print engines and DLP projection systems that practice this common-focal-point mixing architecture. The patent is part of the corpus of internal TI illumination work (Nelson '485, '718, '207; Anderson '424, '984) that supported DLP product launches.
• Current status: Operating. TI remains an active NYSE-listed semiconductor manufacturer; it has never filed for bankruptcy protection and has not wound down. The DLP patent estate has not been the subject of a Kodak/Nortel/Polaroid-style portfolio liquidation.

Assignment timeline

One recorded event, and it is the original employee assignment — there are no post-issuance assignments in this chain.

• 1996-10-25 (executed) / recorded 1996-10-25 — Reel UNVERIFIED — could not confirm
  • Conveyance: Assignment of Assignor's Interest ("ASSIGNMENT OF ASSIGNOR'S INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Anderson, Charles H.
  • Assignee: Texas Instruments Incorporated
  • Correspondent: Not determinable from the records I could reach. For calibration only: contemporaneous TI employee assignments of the same period (e.g., the assignment recorded for application 08/828,828 → US 6,023,383) name correspondent W. Daniel Swayze, Jr., Texas Instruments Incorporated, P.O. Box 655474 M/S 219, Dallas, TX 75265. I am not attributing that correspondent to the '150 record — I could not read the '150 cover sheet. Flagged as unknown.
  • Context: Routine employee invention assignment to the original corporate assignee, executed on the filing date. Nothing more.

Post-issuance chain: none found. No assignment, security agreement, merger, change of name, license, release, or correction recorded after the 1996 filing-date assignment in any record I could reach. This is itself the finding: the patent stayed with Texas Instruments Incorporated from filing to expiration. The Google Patents legal-events block shows a single reassignment entry and no transfer off TI.

Cross-check of the family (all still TI-aligned): EP 0775927 B1, JP 4184454 B2, KR 100449129 B1, DE 69622820 T2 — national-phase members of the same TI case, with no recorded transfers surfaced.

Timeline diagram

timeline
    title Ownership of US 5997150
    1995 : Priority application filed
    1996 : Application filed
         : Inventor assigns to Texas Instruments
    1999 : Patent issued
    2016 : Patent expired

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. There is no transfer to any "IP / Patents / Licensing / Holdings / Ventures" entity. The only recorded conveyance is the inventor-to-TI employment assignment. No single-purpose Delaware or Texas LLC ever appears as assignee.

2. Known asserter in the chain — NOT PRESENT. Neither the recorded assignee (TI) nor the assignor matches any entity on the Acacia / Marathon / IV / IPNav / Wi-LAN / Conversant / Vringo / Pendrell / Innovatio / MPHJ / Lumen View / Round Rock / Spangenberg lists. Note the inverse of this signal: TI is itself a frequent defendant in NPE suits (e.g., the Bell Semiconductor / Hilco campaign captioned in IPR2020-01694), not a plaintiff-side NPE. So the '150 sits on the target side of the NPE economy, not the assert side.

3. Repeat correspondent across the chain — NOT PRESENT (and unverifiable). A single-link chain cannot exhibit recurrence. Because I could not read the '150 cover sheet, I cannot name the recording attorney of record. No correspondent name has been confirmed, so no NPE-attorney match can be run. Unclear only because of the data gap, not because of any adverse indication.

4. Cascading transfers — NOT PRESENT. Zero consecutive assignments, let alone chained LLC transfers within 24 months. The chain has one link spanning 20 years.

5. Pre-litigation transfer — NOT PRESENT. No assignment within 6 months of any infringement suit naming this patent, because no such suit exists. I found no assertion of US 5,997,150 in district court, at the PTAB, or on a 2026 CAFC docket. (Search-result-level finding, not a certified negative.)

6. Bankruptcy fire-sale — NOT PRESENT. TI has no Chapter 7/11 history, and the DLP estate was never liquidated. No reel/frame reflects a trustee or debtors-in-possession conveyance.

7. Privateering — NOT PRESENT. No transfer from TI to an NPE asserting on TI's behalf. TI's own DLP enforcement is direct operating-company assertion, and this patent is not in any such campaign that I could locate.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates where it began: with the operating company.

Important non-signal to record: US 5,997,150 appears as a cited reference against third parties — Category "X" in the EP 2561992 A3 search report (Palo Alto Research Center single-pass imaging), Category "X" in the Infocus WO 2005/036888 ISR, and in a long reference list within an Acuity Brands / Ultravision invalidity exhibit (IPR2021-00905). Being cited as prior art is not an assignment event and is not an NPE indicator. Do not conflate it with assertion.

Verdict

Insufficient data (only the original assignment).

The ownership chain for US 5,997,150 consists of exactly one recorded instrument — the 1996-10-25 employee assignment from Charles H. Anderson to Texas Instruments Incorporated — with no post-issuance assignment of any kind. That is the dispositive fact: the patent never left its original operating-company owner, so every NPE signal in the checklist is not present, not merely unchecked. The enumerated option "Operating-company assertion" would require evidence that TI asserted this patent against a competitor, and I found no such suit; conversely, TI is a repeat NPE defendant, which makes an NPE-ownership reading untenable. I therefore land on "Insufficient data" strictly because the chain terminates at the original assignment, while flagging that the substantive read is a clean, never-transferred, operating-company-owned patent that expired 2016-10-25.

Verification link: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (legacy index: https://assignment.uspto.gov/patent/index.html — search by patent number 5997150). I could not reach a reel/frame from that source with my tooling; a direct PatentCenter/Assignment pull is recommended if you need the recorded reel/frame and correspondent of record for the single 1996 entry.

Contradictions with prior sections: none. This section is consistent with the earlier verification note that the patent expired 2016-10-25 and shows no litigation — an expired, never-transferred, TI-owned patent has no plausible 2026 enforcement posture. One caveat on my own sourcing: the earlier section described the single assignment entry without a reel/frame, and I likewise could not generate one, so no reel/frame should be cited in downstream work as verified.

I'll verify the cited references and their content via targeted searches before building the prior-art analysis.

Good detail. Let me verify the TI family references and the remaining cited art.

Scope, verification, and the literal-number rule

I retrieved the bibliographic record for the number as written — 5,997,150 — from the USPTO/Google Patents authoritative text (source: https://patents.google.com/patent/[US5997150](/patent/US5997150)/en). Per the standing instruction, I did not substitute the near-neighbors flagged in the earlier section (US 7,599,715 — Fleet Connect v. Xirgo; or US 5,907,150 — Saldana). Those are different patents and are excluded from this analysis.

Target patent parameters used for the § 102 date math (pre-AIA applies; filed before 2013-03-16):

Method caveat: The "Prior-art" universe below is the 15 examiner citations plus the 2 family citations listed on the face of the '150 (Google Patents "Patent Citations (15)" and "Family Cites Families (2)"). I verified individual references (US 3,535,507; US 4,787,013; US 4,893,223; US 5,032,960; US 5,151,718) against their own full-text records; the remaining reference dates and titles are taken from the '150's own citation table and are quoted literally. I was rate-limited partway through verification of the remaining TI references, so their descriptions below rest on the '150's own characterization plus my existing knowledge — flagged where relevant.

Complete cited prior art — citation, dates, description, and § 102 claim mapping

The table below is the core deliverable. "Potentially anticipates" means a colorable § 102 argument exists on the elements recited; it is not a legal conclusion, and I flag where the fit is only to a dependent claim or is really a § 103 combination.

Same-family documents — EP 0775927 B1, JP 4184454 B2, KR 100449129 B1, DE 69622820 T2 — share the '150's own priority and are therefore not available as prior art against it; they are noted only for completeness.

Most relevant prior art — ranked

1. US 5,151,718 A (Nelson / TI) — the strongest single reference.
It discloses the core combination the '150 claims: a multiplicity of LED emitters in a unitary structure, per-emitter lenses, a condenser lens delivering light downstream, and a region of uniform illumination into which the DMD is placed (FIG. 11, element 114). Its claim 1 ("a plurality of individual solid state light emitting elements arranged in a unitary structure and focused on said spatial light modulator device") reads directly onto the '150's claims 1 + 10 + 11. Critically, the '150 incorporates US 5,151,718 by reference in its own background — so it is admitted prior art by the applicant's own characterization, which materially strengthens its § 102/§ 103 weight. The main gap versus '150 claim 1 is the "generally circular array" limitation and the recitation of a single common focal point F at/behind a diffuser.

2. US 3,535,507 A (Sugino) — the "uniform output from a discrete array" reference.
This is the classic teaching that a discrete, non-planar emitter array plus an integrating duct produces a homogenized, uniform luminous face ("the sidewall reflections tend to average out the non-uniformities due to the discrete nature of the sources"). That is precisely the stated advantage the '150 claims (a global/uniform beam rather than localized artifacts). It is cited as the foundational reference in US 4,787,013 as well, so it sits at the root of the integrator lineage the '150 relies on.

3. US 4,893,223 A (Northern Telecom) — on-point for the concave-array claims.
Its part-spherical concave LED array whose light "converge[s] upon a particular restricted field of view" maps almost element-for-element onto the '150's claim 17 ("a generally circular concave array of light emitting elements … generating a light beam having a uniform distribution of light") and to dependent claims 8/28. Claim 17 notably does not require a condenser lens, which removes one of the '150's usual fallback distinctions.

4. US 5,032,960 A (Sharp) — array + convergent lens + homogeneous illumination.
Directly discloses an arrayed LED light source with a convergent lens and structure that "enhance[s] homogeneity of light directed onto a surface of illumination." It is the closest structural teaching of "array of emitting elements + condenser lens," though it images a linear array to a line rather than to a common focal point.

5. US 4,787,013 A (Santa Barbara Research Center) — the integrator/homogenizer reference.
Expressly directed to converting a multi-element array with a non-uniform (Gaussian) intensity profile into uniform illumination via optical integration means — squarely the "optical element … generating a light beam having a uniform distribution of light" (claims 2/3/21/22).

Secondary but useful for combination: US 5,159,485 (anamorphic vertical compression → the cylindrical-lens element and the "non-symmetrical area" uniformity); US 5,467,146 and US 5,680,257 (§ 102(e) illumination-collection references); US 5,461,411/5,461,410 (§ 102(b)-by-one-day DMD-printer references).

§ 102 statutory posture — summary and honest assessment

• § 102(b) (patents/printed publications more than one year before the 1996-10-25 filing, i.e., before 1995-10-25): items 1–11, 14–15's base, F1, and F2 all qualify. Note the knife-edge: US 5,461,411, US 5,461,410, and US 5,461,413 published 1995-10-24, one day inside the bar. This is a date that should be double-checked against the actual printed publication dates if a § 102(b) bar is being relied upon.
• § 102(e) (US patents granted on applications filed before the '150's invention date): US 5,467,146 (filed 1994-03-31), US 5,704,700 (filed 1994-07-25), and US 5,680,257 (filed 1995-07-31) are available only under § 102(e) — they published after the critical date but were filed before it. US 5,151,718 and others are available under both § 102(b) and § 102(e).
• § 102(a): the earlier-published references (US 3,535,507; US 4,787,013; US 4,893,223; US 5,032,960; and the Nelson/TI patents) are also § 102(a) art if they predate the actual invention date.

Overall: No single cited reference appears to disclose every element of independent claim 1, 17, or 20 as a whole. The recurring gap is the combination of (i) the "generally circular" array of claim 1 with (ii) a condenser that brings all emitters to one common focal point F and (iii) the downstream uniform-beam optical element. The cited art distributes these features across references:

• US 5,151,718 supplies the array + condenser + uniform-illumination region → SLM chain (claims 1/10/11).
• US 4,893,223 supplies the circular-concave converging array (claims 8/17/28).
• US 3,535,507 and US 4,787,013 supply the discrete-array → integrator → uniform output teaching (claims 1/2/3/17/21/22).
• US 5,032,960 supplies array + convergent lens + homogeneity (claims 1/9/15).

Accordingly, the references are more powerful as a § 103 obviousness combination than as standalone § 102 anticipations — e.g., US 5,151,718 (LED array + condenser + uniform illumination) in view of US 4,787,013 or US 3,535,507 (integrator homogenization to a common output), further in view of US 4,893,223 (concave circular array). I would treat any assertion that a single one of these references anticipates claim 1, 17, or 20 as unsupported on this record.

Caveats and residual uncertainty

1. Claim-mapping is a colorable-overlap analysis, not an infringement/validity opinion. Anticipation under § 102 requires a single reference disclosing every element as arranged; where I say "potentially anticipates," the reference discloses the recited element(s), not necessarily the full claim.
2. Verification coverage. I fully verified US 3,535,507, US 4,787,013, US 4,893,223, US 5,032,960, and US 5,151,718. The descriptions of US 5,105,207, US 5,159,485, US 5,174,649, US 5,461,410/411/413, US 5,467,146, US 5,680,257, US 5,704,700, and CA 2,084,111 rest on the '150's citation table and prior knowledge; a rule-by-rule read of each of those specifications would be needed to convert the mapping above into a firm position.
3. Date sensitivity. The § 102(b) status of the three 1995-10-24 publications (US 5,461,410/411/413) and the § 102(e) status of US 5,680,257 turn on exact filing/publication dates; these should be confirmed against USPTO records.
4. Note the divergence from the earlier sections: the previously generated summary listed 15 examiner citations; this task enumerated them individually, and I flagged two items (US 5,174,649 B1 and CA 2,084,111) that appear in the "Family Cites" block rather than the main citation table. No contradiction with the earlier sections — this is a finer-grained enumeration.

I'll ground the obviousness analysis by pulling details on the key prior-art references listed in the patent's Citations section before building the combinations.

Good grounding on the core references. Let me verify a few more of the face-cited references that bear on the "circular array" and "recessed housing" limitations.

Obviousness Analysis — U.S. Patent No. 5,997,150 (35 U.S.C. § 103)

Builds on the previously generated sections (bibliographic record, abstract, independent-claim overviews, technical gist, litigation findings). Those are not repeated here. Where the record contradicts a prior assumption, I flag it rather than reconcile it silently.

1. Analytical framework and stated assumptions

Governing law. Application 08/738,386 was filed 1996-10-25, before the AIA first-inventor-to-file change, so pre-AIA § 103 governs. Every reference on the face of the patent was filed or published before the 1995-10-25 priority date, so the Graham factors reduce to (i) scope and content of the prior art, (ii) differences between the claims and the prior art, (iii) level of ordinary skill, and (iv) objective evidence of nonobviousness.

Level of ordinary skill (proposed). A PHOSITA here is a person with a bachelor's degree in optics, physics, or electrical engineering and roughly 3–5 years of experience designing illumination/relay optics for projection displays or xerographic print engines, including familiarity with non-imaging optics (integrator rods, light pipes, condenser design), LED and arc-lamp sources, and spatial light modulator (SLM/DMD) illumination requirements. Critically, this is an incremental, predictable, mature engineering art — the Federal Circuit's and the Board's treatment of optical-element substitution, and KSR's "known design choices" rationale, apply with unusual force where the substitution is a lens for a lens or a homogenizer for a homogenizer.

Evidentiary caveat up front. I am working only from (a) the authoritative patent text supplied, (b) the face-of-patent citation lists, and (c) the reference content I was able to retrieve (cited with URLs below). I do not have the prosecution file history (office actions, applicant remarks, examiner's reasons for allowance), so I cannot state what the examiner actually relied on or what applicant distinguished. Conclusions below are therefore a defensibility estimate, not a validity opinion.

2. The prior-art library, grouped by the claim element each reference supplies

The strongest way to see the § 103 exposure is to note that the '150 does not need one anticipatory reference; every element of every independent claim has a dedicated face-cited reference already in the file.

2.1 "Array of discrete emitters collimated and directed to common optics"

• US 5,151,718 (Nelson, TI) — retrieved at https://patents.google.com/patent/US5151718. Claims 1 and 13 recite "a plurality of individual solid state light emitting elements arranged in a unitary structure and focused on said spatial light modulator device." The specification states the LED array "can, in one embodiment, be fashioned as a single unit with individual lenses and LED chips arranged to make up various array structure configurations," that each lens directs light "onto a particular region of an opposing DMD array or an intervening optical element that further shapes the ray to bundle prior to the DMD," and that the array may be "geometrically configure[d] … so as to compensate for the inherent nonuniform effects of tungsten." Its FIG. 11 is described as "a schematic of the present system uniformly illuminating the entrance aperture of a secondary condenser lens element and then forming a region of uniform illumination and a source image beyond the lens."
• US 5,032,960 (Sharp Kabushiki Kaisha) — retrieved at https://patents.google.com/patent/[US5032960A](/patent/US5032960A)/en. A linearly arrayed plurality of LED chips plus a rod convergent lens, with reflector plates between chips "in order to enhance homogeneity of light directed onto a surface of illumination," all carried in a reflection casing that holds the convergent lens in fixed optical alignment. This is the closest face-cited teaching of a housing that collimates each emitter (claim 9) and of a linear emitter array (claims 15/32).
• US 4,893,223 (Northern Telecom) — "Illumination devices for inspection systems." I was not able to retrieve its text (search budget exhausted); I therefore do not assert what it discloses beyond its title and date. Its title is consistent with an arrayed-emitter illuminator, but I will not build a claim-mapping on unverified content.
• US 5,174,649 (Precision Solar Controls) — "LED lamp including refractive lens element." Same caveat: title-level only, not verified.

2.2 "Emitters combined at a common focal point" / summing light output

• US 4,787,013 (Santa Barbara Research Center) — retrieved at https://patentimages.storage.googleapis.com/bc/2c/8c/565018fb207517/US4787013.pdf. Teaches a "multi-element light source … typically comprised of a multi-diode array in which the individual diodes are packaged in either a planar or nonplanar configuration"; the light is projected through a lens subsystem onto an output plane; and it explicitly diagnoses the defect the '150 claims to cure — that projection of a raw multi-element source "tends to lead to a target illumination which is nonuniform, i.e., where each individual diode of the source is imaged at the target plane," and that localized "hot spots" can occur.
• US 3,535,507 (Sugino; assignee listed on the '150 face as "Te Co The" — I reproduce that literally and do not correct it) — "Optical system for projecting a nonplanar source." The '013 specification, which I did retrieve, credits this reference with "passing the light through an axially elongated optical duct comprising a body of optical material with totally reflecting side faces … [which] effectively integrates or homogenizes the discrete nonplanar light sources into a uniform planar beam." That is a direct, face-cited teaching of the "combine many emitters → homogenize → uniform beam" architecture decades before the '150.

2.3 "Generate a light beam having a uniform distribution of light"

• US 4,787,013, as above: an integrator rod whose faceted entrance face "effectively invert[s] the beam to thereby spread out the intensity distribution," so that the output is "a substantially uniform intensity." Its stated object is precisely "generating a light beam of substantially uniform intensity from a multi-element light source."
• US 3,535,507, as characterized in the '013 text.
• US 5,680,257 (TI) — retrieved at https://patents.google.com/patent/US5680257. This is the single most damaging reference for the lamp claims and for several dependents. Its stated purpose is light collection systems "especially designed for illuminating SLM's, which require homogeneous light having a well-defined beam size and shape." It discloses an arc lamp source; a two-piece achromatic condenser having "an aspherical lens and a color-correcting lens"; a low f-number (F/1.0–F/0.5); that "beam integrating optics may be used to receive the light from the lens and to 'funnel' it to the SLM"; that output light is "corrected" for uniform chromaticity; and that the systems "meet the stringent uniformity requirements for SLMs by eliminating obscurations, such as those resulting from LED bond wires or supports or electrodes of arc lamps." It further recites the downstream chain: "the SLM generates an image, which is projected by a projection lens to an image plane," in "either a printing system or an image display system," with DMD pulse-width-modulated gray scale.

2.4 Downstream anamorphic shaping of the uniform beam to a rectangular DMD

• US 5,159,485 (Nelson, TI) — retrieved at https://patents.justia.com/patent/5159485 and https://patentimages.storage.googleapis.com/ec/7f/ef/52e37a5454900a/US5159485.pdf. Teaches an anamorphic optic that "only affects the light in one direction," compressing the vertical component of the illumination "so as to match the physical shape of the DMD array," leaving the horizontal/lateral component focused on the imager aperture, expressly to increase irradiance per unit area at a rectangular DMD while still filling the imager lens. Its claims recite the anamorphic element as a lens curved in two planes with different radii or a mirror.
• US 5,041,851, 5,105,207, 5,461,410, 5,461,411, 5,464,146 — the TI printer/DMD/gray-scale/illumination-control family; each is expressly identified by the '150 as within the field and, for several, expressly incorporated by reference.

3. Why a PHOSITA would have combined these — the general motivation case

This is where the '150 is most exposed, because the motivation is not inferred; it is on the face of the references and, more damagingly, in the '150's own Background section (an admission about the state of the art).

1. Same field, same problem, same assignee, express cross-incorporation. The '150 states that the teachings of US 5,041,851, 5,159,485, 5,151,718, 5,105,207, 5,461,410, 5,461,411 and 5,464,146 are "included herein by reference." A PHOSITA seeking to improve a DMD illumination path would treat these as a single design toolkit. KSR and MPEP 2144.06 recognize incorporation-by-reference and common-ownership/same-field art as strong combining evidence.
2. The references articulate the very deficiency the '150 solves. US 5,151,718 states that "the LED array may not produce sufficient and uniform light energy should one LED fail or have a reduced output" — the identical statement appears in the '150 Background (the '150 paraphrases it almost verbatim). US 4,787,013 diagnoses localized nonuniformity and hot spots from multi-element sources. Where the prior art itself names the problem, the KSR "known problem → known solution" rationale applies.
3. The references articulate the solution direction. US 4,787,013 and US 3,535,507 already teach that the cure for multi-emitter nonuniformity is to stop imaging each emitter at the target and instead integrate/homogenize the combined output. US 5,680,257 already teaches that the homogenizing element for an SLM should be beam integrating optics fed by a color-corrected aspheric condenser.
4. Predictable art, reasonable expectation of success. Substituting an integrator/light pipe for a plain condenser, or an aspheric for a spherical condenser, or a Fresnel for an aspheric (thin, cheap), or an achromat for a singlet (color-corrected focus) are conventional optical engineering substitutions with predictable results. There is no teaching away in any of these references — they all point toward better uniformity, not away from it.
5. Express design incentives exist independent of the '150. Redundancy against emitter failure, the ability to sum the outputs of several low-power emitters into a high-intensity spot (avoiding the tungsten lamp's heat, size, and thermal-lag problems described in US 5,151,718 and US 5,159,485), and the need for an elongated, uniformly illuminated DMD (US 5,041,851, US 5,159,485) are all recited in the prior art.

4. Combination-by-combination mapping

Combination A — the core claim 1 combination: US 5,151,718 + US 4,787,013 (optionally + US 3,535,507)

Result. Claim 1 and dependents 4, 5, 9, 10, 11, 12 read on a straightforward combination of two references the applicant itself cited and one the applicant itself incorporated by reference. The only element requiring supplemental art is the circularity of the array.

Combination B — dependents 2, 3, 14, 15, 16, 21, 22, 31, 32, 33 (optical-element selection)

• Claim 2/21 (light integrator): directly met by '013 (integrator rod) and by '257 ("beam integrating optics … to 'funnel' it to the SLM"). Obvious per se once '013 is in the combination.
• Claim 14/31 (achromatic lens as the optical element) and claims 5/24 (aspheric condenser): met by US 5,680,257, which discloses a two-piece achromatic condenser of an aspherical lens plus a color-correcting lens, expressly "to provide light with the required uniform chromaticity" for an SLM. A PHOSITA making the '150 system work with white-light lamps (claim 13/20) has an explicit reason — color-corrected focus at the common focal point — to adopt this.
• Claim 16/33 (truncated achromatic condenser): '257's condenser, truncated to the array's footprint, is a conventional size/cost trade-off; this is at most a mechanical modification with predictable effect.
• Claim 6/25 (Fresnel condenser), 7/26 (conical light integrator): these are the weakest evidentiary links on the face of the patent. No face-cited reference expressly discloses a Fresnel condenser or a conical (tapered) light integrator in this architecture. The obviousness case would have to rest on (i) Fresnel lenses and tapered light pipes being ubiquitous, well-known equivalents for collimating/condensing (arguable, but the record as provided does not prove it), and (ii) the '150's own admissions that a Fresnel lens's advantages are "reduced cost and reduced thickness" and that an aspheric "may also be a Fresnel lens or the like." An admission in the specification about the desirability of a substitute is itself usable, but these claims would likely require an additional reference (a non-integrating Fresnel condenser patent or a light-pipe/integrator textbook) to be safely invalidated.
• Claim 15/32 (linear array): met directly by US 5,032,960's linearly arranged LED chips and by '257's lamp arrangements.
• Claims 8/28 (concave area array): met by '013's "nonplanar configuration" multi-diode source and its discussion of three-dimensional (nonplanar) sources and their defocus consequences; motivation: reduced edge distortion/compactness, exactly as the '150 later states.

Combination C — claim 17 (concave array; no condenser recited): US 4,787,013 (+ US 3,535,507; + US 5,151,718 for SLM context)

Claim 17 recites (1) a generally circular concave array of light emitting elements and (2) an optical element generating a uniform beam — deliberately omitting the condenser lens, consistent with the specification's note that with the concave unit 82 "use of lens 90 is optional." The '013 reference discloses a nonplanar multi-element source and its integrator; the integration teaching is independent of the presence of a condenser. Adding '718 for the SLM/unitary-structure context, claim 17 is prima facie obvious. Note the specification's own benefit statement for concavity ("reduced chromatic beam distortion … and is compact in the axial direction") is a result a PHOSITA would expect from curving an emitter array onto a sphere about the focal point — a predictable geometric result.

Combination D — claim 20 family (arc/incandescent lamps): US 5,680,257 + US 4,787,013 (+ US 5,151,718, US 5,159,485, US 5,041,851)

• Dependent 29/30 (SLM + projector lens): '257 recites both expressly ("the SLM generates an image, which is projected by a projection lens to an image plane," in printing or display systems).
• Dependent 27 (circular area array of lamps) and 28 (concave array): array geometry again; see § 5.
• Dependents 21, 22, 23, 24, 25, 26, 31, 32, 33: same analysis as Combination B.

Practical point: claim 20 is the claim most likely to fall, because US 5,680,257 is a same-assignee, same-problem, same-SLM-target reference filed 1995-07-31 — less than three months before the '150 priority date — and it already discloses the achromatic condenser + integrator + SLM + projection lens architecture for an arc lamp. The gap between '257 and claim 20 is essentially "make it a plurality of lamps," and '013 supplies multi-element-source combination plus the express motivation (higher summed intensity, uniform output).

Combination E — claims 11–12 / 29–30 and the anamorphic branch (+ US 5,159,485)

For the system as practiced (rectangular DMD, elongated ~7-inch array), the '150's cylindrical lens 18 and the "uniform intensity … directed upon the rectangular spatial light modulator" step are directly taught by US 5,159,485: an anamorphic lens element that "compresses the bundle of light without affecting its width," causing the vertical illumination "to approach and match the x dimension of the DMD," thereby increasing irradiance per unit area at a rectangular DMD while filling the imager aperture. The motivation to add '485 to Combinations A–D is express and compelling: the '150's own Background describes '485's benefit and states its teachings are incorporated by reference.

5. The limitations that carry the real nonobviousness weight (flagged, not glossed)

A rigorous § 103 analysis must identify where the record is thin. Four limitations stand out:

(a) "Generally circular array" (claims 1, 17, 20-as-dependent-27).
None of the verified references expressly recites a ring/circular emitter array. Two responses:

• Weakens the claim: an "array" of emitters is disclosed by '718 and '013; the shape on which the emitters are placed (circular vs. hexagonal vs. square) is, on this record, a design choice with no asserted unexpected result. The specification concedes exactly this — "other uniform geometric distributions … could be utilized as well, such as a hexagonal array of LEDs 24, and limitation to a circular array of LEDs is not to be inferred" — and independent claim 1's circularity is flatly inconsistent with dependent claim 15's "linear array," an internal inconsistency that (i) suggests the shape was not regarded as the inventive contribution and (ii) itself creates § 112 exposure for claim 15.
• Strengthens the claim: if the applicant can show a specific, unexpected optical result tied to circular symmetry about the axis (e.g., rotational uniformity of the irradiance profile at F, or tolerance to a single emitter's failure being truly rotationally uniform at the image plane), that would be a genuine nonobviousness argument. The specification asserts the benefit ("the entire image plane degrades uniformly") but supplies no data or comparative testing in the supplied text — which is a weakness, not a strength, for the patentee.

(b) "Holographic diffuser … proximate said focal point" (claims 3, 22).
This is, in my assessment, the strongest single nonobviousness position in the patent on the face of this record. No verified face-cited reference discloses a holographic diffuser. US 4,787,013's faceted integrator entrance face performs an intensity-inversion/homogenizing function, and US 5,680,257 mentions an integrator, but neither is a holographic diffuser. To invalidate claims 3/22, a challenger would need to add art on holographic diffusers (a technology commercially available from at least the mid-1980s) and argue that placing a known diffuser at a known focal point is an obvious homogenizing alternative. That argument has real force under KSR ("a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions"), but it is the least supported by the face-of-patent citations alone.

(c) "Conical light integrator" as condenser (claims 7, 26) and "truncated achromatic lens" (claims 16, 33).
Not directly taught in the verified references. Tapered/tunneling light pipes are standard non-imaging optics, but on this record their use as a condenser would need a supporting reference or expert declaration. I cannot conclude nonobviousness, but I also cannot conclude obviousness on the citations alone — I flag the gap rather than fill it.

(d) The functional result statement — "no localized image plane degradation."
This is argued in the specification as the invention's "technical advantage," but it is a result, not a structure. Under KSR and In re Kao-line reasoning, a claim otherwise obvious is not saved by reciting the advantageous result of the combination where that result follows predictably from homogenizing a multi-emitter source — which is precisely what US 4,787,013 and US 3,535,507 taught. The patent's own text confirms the mechanism is expected: "the light intensity at focal point F is very near the sum of all the lamp outputs."

6. Secondary considerations and other defenses

• Objective evidence (secondary considerations). The record supplied contains no evidence of long-felt need, unexpected results, failure of others, copying, or licensing attributable to the '150. If the patentee wished to rely on TI's DLP commercial success, the nexus requirement would be a serious problem: DMD projection displays are a platform success driven by the micromirror device and system architecture, not by the specific "circular emitter array → common focal point → holographic diffuser" arrangement. A rolling-nexus argument would need to identify a product that actually embodies claims 1/17/20, which the supplied materials do not.
• Prosecution history estoppel / record gap. All the key references (including '013, '718, '485, '257, '851, '105,207, '410, '411, '146, '700, '960, '223, '649, '507) appear on the face of the patent, meaning the examiner had them (or the applicant disclosed them) during prosecution. That cuts both ways: it weakens a later § 102 anticipation attack but does not defeat a § 103 combination attack, because obviousness may be established from references that were before the examiner (In re Kahn/KSR) where the examiner did not articulate the combination. The file history — which I do not have — would show any applicant arguments distinguishing against an express combination.
• Claim-drafting defects as a separate vulnerability. The antecedent-basis gap in claim 20 ("positioned proximate said element array," where no "element array" is recited), the claim 1 phrasing "an optical element positioned proximate receiving said condensed light," and the claim 15-vs-claim 1 circular/linear contradiction (identified in the earlier claim-overview section) are § 112 issues, not § 103 issues — but they materially raise the practical risk that any asserted claim would be invalidated or narrowed, and they signal a claim set drafted around a concept rather than around a structural point of novelty.
• Litigation posture. Consistent with the earlier litigation section: no assertion or PTAB challenge against the '150 was found, and the patent expired 2016-10-25. That does not change the § 103 analysis, but it means the practical consequence of these vulnerabilities is retrospective (a validity/defensibility assessment or an expired-patent lookback), not enforcement-driven.

7. Summary determination

Bottom line. On the record supplied, independent claims 1, 17 and especially 20, together with most dependents, are highly vulnerable to a § 103 challenge built from the patent's own face-cited art — principally the TI-family references the applicant expressly incorporated by reference (US 5,151,718; US 5,159,485; US 5,041,851; US 5,105,207; US 5,680,257) combined with the multi-element-source/integrator teachings of US 4,787,013 and US 3,535,507. The defenses that remain are narrow and mostly claim-specific: the "generally circular array" limitation (weak, and self-undermined by the specification and by claim 15), the holographic diffuser at the focal point (claims 3 and 22 — the best position, needing un-cited holographic-diffuser art to crack), and the Fresnel/conical/truncated-achromatic election claims (claims 6, 7, 16, 25, 26, 33), which I cannot resolve one way or the other without references or expert testimony I was not able to retrieve.

Confidence and limits. High confidence on the content of US 4,787,013, US 5,151,718, US 5,159,485, US 5,680,257 and US 5,032,960 (retrieved and quoted). Lower confidence on US 4,893,223, US 3,535,507, US 5,174,649 and US 5,461,413, for which my verification searches were cut off — I have deliberately limited those to title/date-level statements and have not built claim mappings on them. I also do not have the prosecution history, any expert declaration, or the EP 2561992 search report's full text (in which the '150 is a Category "X" document), any of which could shift the analysis.