US 8537357

I'll search for authoritative information on this specific patent number and any related docket activity.

Let me check for any Federal Circuit (CAFC) 2026 activity and confirm the claims.

Let me pull the actual claim text for US 8,537,357 specifically.

US 8,537,357 — Analyst Summary

Source hierarchy used. The authoritative text is the Google Patents record at https://patents.google.com/patent/US8537357/en (page metadata timestamp 2026‑09‑27), supplemented by Web results including PTAB/PTACTS filings, the sibling patent PDF US 8,917,394 B2, and docket reporting. Note: I did not query USPTO PatentCenter/Patent Public Search or PACER/CourtListener directly in this session; Google Patents mirrors USPTO bibliographic data, and the litigation data shown there is sourced from third parties (Unified Patents, Darts‑ip) as the page itself discloses. Also note a date discrepancy: your frame says April 26, 2026, while the authoritative page I was given was fetched 2026‑09‑27. I treated the fetched page as controlling.

1. Bibliographic summary (verified against the fetched record)

Lineage note (from US 8,917,394 B2's own front page): application 12/660,937 (now US 8,537,357) is itself recited as a division of an earlier application, i.e., the '357 sits mid‑chain in a long continuation/division family claiming priority to 1997‑08‑25. The PTAB record for the related Albert Docket ML‑0376C5 application 11/452,879 (filed 2006‑06‑14) carries the same title and is part of this family's prosecution history. I could not verify in this session the exact immediate parent of 12/660,937 beyond what the sibling front page states.

2. Abstract

Caveat on sourcing: the fetched Google Patents text for US 8,537,357 did not include the formal "(57) Abstract" block verbatim. The following is the abstract text appearing in the same-family sibling US 8,917,394 B2 (a patent with the same title, same inventor, same specification family, and the same 29‑claim/54‑sheet format), which is very likely textually identical or near‑identical. Treat it as a faithful family abstract, not as a character-exact quotation of the '357:

"In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the sample to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non‑contact measurements of color samples rendered on a display or a sheet, and are self‑calibrating by the use of calibration references."

The specification's own "Definitions" opening (as fetched) is consistent: the invention "relates to a system (method and apparatus) for distributing and controlling color reproduction at multiple sites… to provide a uniform appearance of color within the output colors attainable at each rendering device," using a color measurement instrument (CMI) per rendering device, node computers, and a data structure called a Virtual Proof (VP) for storing/distributing color transformation information.

3. Independent claims — plain-language overview

Explicit uncertainty flag. I was not able to retrieve the verbatim claim text of US 8,537,357 (claims 1–29) in this session; the searches surfaced claim text for related patents in the family (e.g., the large claim sets quoted in IPR2019‑00628 and related filings, and the separated-claim language of the siblings), and I will not represent those as the '357's claims. What follows is therefore an inference from the specification's stated objects and summary, not a verified claim chart. Anyone relying on this should read the claims directly at https://patents.google.com/patent/US8537357/en or https://www.freepatentsonline.com/[8537357](/patent/8537357).html.

Based on the specification's stated objects and the five disclosure clusters in the fetched text, the 29 claims most plausibly include independent claims of these kinds:

1. System / network claim (color reproduction across sites). A computer at a site plus a network interface; memory storing tonal transfer curves for multiple color channels, one or more color transformations between coordinate sets, and gamut data; the information is communicated to another site over a network protocol so colors at each rendering device appear substantially the same within each device's attainable output colors. (The "Virtual Proof" data structure — shared components vs. local components — is the conceptual centerpiece.)
2. Rendering-device + color-measurement-instrument system claim (printer/press path). A rendering device whose rendered sheet is measured by a sensor coupled to a transport mechanism that moves sensor and sheet relative to one another, the sensor feeding light to a spectrograph, with calibration references enabling self‑calibration and non‑contact measurement.
3. Display-path system claim. A display with a member/cowel surrounding the screen periphery supporting a color measuring instrument positioned off‑axis (non‑contact, ambient‑shielded) to receive light from an area of the screen, feeding a computer that calibrates the display and enables soft proofing.
4. Method claim for maintaining calibration of a color display. Adjusting screen output when dark to account for ambient light; neutral‑balancing the display; measuring gamma in each color channel; adjusting displayed color per measured channel gammas.
5. Apparatus claim(s) for a self‑calibrating measuring instrument. Either (a) a dual‑beam spectrograph with first/second inputs and a light source, with fiber optics routing source light to a first input, sample light to a second input, and one or more sensors monitoring calibration; or (b) an instrument using a one‑dimensional array of fiber optics whose first/second/third fibers carry, respectively, source light, a dark reference, and one or more known wavelengths, with the remaining fibers imaging the sample — the spectrograph's spectrum for those fibers providing automatic calibration references. A computer‑readable‑medium claim mirroring one of the above is also plausible given the family's style.

What I can say with confidence: the claims total 29 and the patent has 54 sheets; the patent is in the Holub/RAH color‑management family claiming 1997‑08‑25 priority; and the '357 was asserted in litigation (below). What I cannot confirm: claim numbering, which of the above are truly independent, exact claim language, and the precise independent‑claim count.

4. Litigation and docket posture (including the CAFC question)

CAFC / 2026: I found no Federal Circuit docket, appeal, or 2026 proceedings involving US 8,537,357. My searches of 2026 Federal Circuit materials (including 2026 Federal Circuit opinion roundups from law‑firm trackers) turned up nothing naming this patent or RAH Color Technologies. This is consistent with the record: the '357 is listed Expired – Fee Related with adjusted expiration 2019‑04‑26, i.e., it lapsed on maintenance fees years before your stated date, removing the practical predicate for a 2026 appeal. I state this as a negative search result, not as proof of absence — I could not query PACER/CourtListener directly, so a dormant or sealed 2026 docket cannot be ruled out with certainty.

What the record does show (per Google Patents / Unified Patents / Darts‑ip, N.D. Ill.; W.D.N.Y.; W.D. Mich.; E.D. Mich. or E.D. Wis.; S.D. Ill.):

• RAH Color Techs. v. R.R. Donnelley & Sons, N.D. Ill. 1:17‑cv‑00894 (filed 2017‑02‑02) — asserted '357 among seven patents.
• RAH Color Techs. v. Xerox, N.D. Ill. 1:17‑cv‑06813 (amended complaint) — '357 among eight asserted patents; Xerox separately in W.D.N.Y. 6:18‑cv‑06746.
• RAH Color Techs. v. Quad Graphics, 2:18‑cv‑00087 — asserted '357 among six patents (per Darts‑ip/ip‑navi and the MDL schedule, E.D. Wis.; the Google Patents page lists a Michigan Eastern case with the same 2:18‑cv‑00087 number — this is an unresolved discrepancy I am flagging rather than reconciling).
• X‑Rite, Inc. — '357 among ten asserted patents (W.D. Mich. docketing shown on the Google Patents page as 1:14‑cv‑00638).
• S.D. Ill. 1:17‑cv‑04931 — listed for the family; defendant not verified in this session.
• Consolidation: the Adobe, Xerox, EFI, Kodak, Dalim, and Heidelberger cases were centralized by the JPML as In re: RAH Color Technologies LLC Patent Litigation, MDL No. 2874, N.D. Cal. 3:18‑md‑02874‑SI (Judge Susan Illston). The MDL docket shows a final judgment on 2021‑09‑27 and dismissal of the Adobe and Dalim actions; the MDL is closed.
• PTAB: Adobe filed IPRs on related patents — IPR2019‑00627 (US 7,729,008), IPR2019‑00628 (US 8,416,444), IPR2019‑00629, IPR2019‑00646 (US 7,791,761) — with final written decisions in 2020. I did not find an IPR naming US 8,537,357 itself.

5. Bottom line for your request

• Title, inventor, assignee, filing date, issue date, application number, and expiration status above are grounded in the authoritative record and can be relied on.
• The abstract is reproduced from the same‑family sibling because the fetched '357 page omitted it — high confidence, but not a character-exact quotation of the '357.
• The independent‑claim overview is an inference and is flagged as such; verbatim claim text for claims 1–29 was not obtained. Please verify against the Google Patents or FPO claim listing before using it in any analysis.
• No CAFC 2026 docket exists in my search results for this number; if your task requires a definitive docket check, it should be run against PACER/CourtListener and the Federal Circuit's own docket system, which I could not reach here.

Sources: https://patents.google.com/patent/US8537357/en (primary, fetched 2026‑09‑27); https://patentimages.storage.googleapis.com/7c/77/74/18cc9876f58995/US8917394.pdf (sibling front page/abstract); https://www.freepatentsonline.com/8537357.html; https://www.docketalarm.com/cases/PTAB/IPR2019-00628/ (RAH complaints); https://unicourt.com/case/pc-jpml-casejrfdd9b8a5c1c9-[480002](/patent/480002) (MDL 2874); https://portal.unifiedpatents.com/litigation/… (as cited on the Google Patents page).

I'll search for litigation involving US patent 8,537,357 across patent litigation databases.

Let me dig deeper into the specific cases.

Litigation Involving U.S. Patent No. 8,537,357

Patent identified: U.S. 8,537,357 B2 — "System for Distributing and Controlling Color Reproduction at Multiple Sites" — inventors Richard A. Holub and Daniel R. Mongeau; original assignee RAH Color Technologies LLC; filed 2010-03-08 (App. No. 12/660,937); granted 2013-09-17; priority 1997-08-25; status Expired – Fee Related (adjusted expiration 2019-04-26).

Important scope note: I have not auto-corrected or substituted any numbers. In particular, U.S. 8,540,347 (asserted in the recent ITC ink-cartridge dispute, 337-TA-1451) is a different patent from 8,537,357 and is excluded. Only cases in which 8,537,357 itself appears as a patent-in-suit are listed as "confirmed."

A. Confirmed assertions of the '357 patent

1. RAH Color Technologies LLC v. X-Rite, Inc.

• Plaintiff: RAH Color Technologies LLC
• Defendant: X-Rite, Inc. (Michigan corporation, Grand Rapids, MI)
• Jurisdiction: U.S. District Court, Western District of Michigan (Judge Robert Holmes Bell)
• Case No.: 1:14-cv-00638
• Filed: June 16, 2014
• '357 status: Named in the complaint among ten Patents-in-Suit (the complaint lists the '897, '433, '560, '052, '008, '761, '175, '236, '444 and '357 patents).
• Outcome/status: Disposed. Docket shows a joint motion to stay granted in part (Dkt. 26/27, 90-day stay), followed by a stipulation of dismissal (Dkt. 28) and an order granting the stipulation to dismiss (Dkt. 29); the case is recorded as "Disposed – Other Disposed." This is consistent with a settlement/license.
• Sources: https://unicourt.com/case/rc-db1-rah-color-technologies-llc-v-x-rite-inc-[512978](/patent/512978) ; complaint text at https://www.docketalarm.com/cases/[PTAB](/ptab)/IPR2019-00628/Adobe_Inc._v._RAH_Color_Technologies_LLC/docs/12-13-2019-Patent_Owner/Exhibit-2222-Exhibit_2222__Complaint__X_Rite.pdf

2. RAH Color Technologies LLC v. R.R. Donnelley & Sons Company

• Plaintiff: RAH Color Technologies LLC
• Defendant: R.R. Donnelley & Sons Company
• Jurisdiction: U.S. District Court, Northern District of Illinois
• Case No.: 1:17-cv-00894
• Filed: February 2, 2017 (Document #1)
• '357 status: Named among seven Patents-in-Suit: '870, '897, '008, '704, '546, '314, and '357.
• Outcome/status: Not confirmed from the sources retrieved. (Available documents confirm the filing and the patents asserted; the terminal disposition was not captured.)
• Source: complaint in IPR2019-00628 Exhibit 2227 ("Complaint__RR_Donnelley.pdf"), header "Case: 1:17-cv-00894 Document #: 1 Filed: 02/02/17," at https://www.docketalarm.com/cases/PTAB/IPR2019-00628/Adobe_Inc._v._RAH_Color_Technologies_LLC/docs/12-13-2019-Patent_Owner/Exhibit-2227-Exhibit_2227__Complaint__RR_Donnelley.pdf ; also flagged as "Illinois Northern District Court case 1:17-cv-00894" on the Google Patents family-litigation tab.

3. RAH Color Technologies LLC v. Quad/Graphics, Inc.

• Plaintiff: RAH Color Technologies LLC
• Defendant: Quad/Graphics, Inc. (Wisconsin corporation, Sussex, WI)
• Jurisdiction: Originally filed in the U.S. District Court, Northern District of Illinois; transferred to the U.S. District Court, Eastern District of Wisconsin
• Case No.: 2:18-cv-00087-JPS (E.D. Wis.). Note: the Google Patents "family litigation" tab labels the 2:18-cv-00087 case as "Michigan Eastern District Court," which conflicts with the complaint caption ("Civil Action No. 2:18-cv-00087-JPS," E.D. Wis.). I am flagging rather than correcting the discrepancy.
• Filed / First Amended Complaint: Original N.D. Ill. complaint filed 2017; First Amended Complaint filed March 15, 2018 in E.D. Wis. (Dkt. 89).
• '357 status: Named among the Patents-in-Suit. Original N.D. Ill. complaint named seven patents including '357; the First Amended Complaint named five ('870, '897, '008, '704, and '357). Accused products included the "QG Accused Printer Servers" and color-managed systems (e.g., EFI Fiery print servers with Command Workstation/Color Profiler Suite).
• Outcome/status: Not confirmed; the case is referenced in later PTAB proceedings (Adobe IPRs) as a related district-court action. Quad was adjudged not a real party in interest in the Adobe IPRs.
• Sources: https://www.docketalarm.com/cases/PTAB/IPR2019-00628/Inter_Partes_Review_of_U.S._Pat._8416444/docs/12-13-2019-Patent_Owner/Exhibit-2225-97-Exhibit_2225__Complaint__Quad.pdf ; Exhibit 2226 (Amended Complaint, Quad) ; IP NAVI dispute record (identifies court as E.D. Wisconsin, case 2:18-cv-00087, patents including US8537357) at https://www.ip-navi.or.kr/disputenews/disputenewsIpDetail.navi?news_seq=[177171](/patent/177171)

4. RAH Color Technologies LLC v. Xerox Corporation

• Plaintiff: RAH Color Technologies LLC
• Defendant: Xerox Corporation
• Jurisdiction: U.S. District Court, Western District of New York (Judge Charles J. Siragusa)
• Case No.: 6:18-cv-06746
• Filed: 2018 (RPX lists 10/17/2018; other sources cite a September 2018 date), Closed 12/06/2018
• '357 status: Named among eight Patents-in-Suit in the amended complaint, including the '357 Patent. Accused products included Xerox digital presses (iGen, Versant series) and software suites (MatchAssure, IntegratedPLUS, FreeFlow Core, CX Print Server, and EFI Fiery-based print servers).
• Outcome/status: Case closed in W.D.N.Y.; the Adobe/Xerox/EFI cases were centralized for coordinated pretrial proceedings in the Northern District of California by the Judicial Panel on Multidistrict Litigation (MDL No. 2874; Case No. 3:18-md-02874). This is the "New York Western District Court case 6:18-cv-06746" flagged on the Google Patents family-litigation tab.
• Sources: https://insight.rpxcorp.com/litigation/nywdce-[119998](/patent/119998)-rah-color-technologies-v-xerox ; https://dockets.justia.com/docket/new-york/nywdce/6:2018cv06746/119998 ; PTAB final written decision in IPR2019-00646 (describing the MDL).

B. Case listed in the patent's litigation record that I could not fully identify

5. "Illinois Southern District Court case 1:17-cv-04931" (per the Google Patents family-litigation data for US 8,537,357)

• Court: U.S. District Court, Southern District of Illinois
• Case No.: 1:17-cv-04931
• Plaintiff / Defendant / filing date / outcome: Not confirmed. The Google Patents page for US 8,537,357 lists this case under "Family has litigation," but my searches at the time of this response did not surface the complaint or docket details identifying the defendant or disposition. Treat as an unresolved lead requiring a PACER/docket check.

C. Related RAH Color Technologies cases where '357 was not confirmed as asserted

These involve the same patent family/portfolio but the retrieved complaints did not list the '357 patent, so they are not counted as '357 litigation:

Caveat: for Heidelberg, Dalim, Kodak and EFI I did not locate a complete patents-in-suit list; it is possible (but not established) that '357 was asserted in one or more of them.

D. PTAB / IPR proceedings

The Adobe Inc. petitions against RAH — IPR2019-00627, IPR2019-00628, IPR2019-00629 and IPR2019-00646 — challenged RAH patents including U.S. 7,312,897 and U.S. 7,791,761 (and the '008/'444/'870 family). In final written decisions, the Board held claims of the '897 patent (claims 32, 33, 37) and of the '761 patent (claims 7, 8, 10, 11, 13) unpatentable (the '761 decision issued October 8, 2020). I found no IPR that specifically challenged U.S. 8,537,357. If an IPR against the '357 patent exists, I did not locate it.

Summary

• Four (4) confirmed lawsuits naming U.S. 8,537,357 as a patent-in-suit, all brought by RAH Color Technologies LLC: X-Rite (W.D. Mich. 1:14-cv-00638, disposed by stipulated dismissal), R.R. Donnelley (N.D. Ill. 1:17-cv-00894), Quad/Graphics (E.D. Wis. 2:18-cv-00087-JPS, originally N.D. Ill.), and Xerox (W.D.N.Y. 6:18-cv-06746, closed and drawn into MDL No. 2874 in N.D. Cal.).
• One (1) additional listed case I could not identify: S.D. Ill. 1:17-cv-04931 (defendant/outcome unconfirmed).
• The patent is expired (adjusted expiration 2019-04-26, fee-related), and no IPR specifically targeting the '357 patent was found.

Confidence note: Case numbers, courts, parties and patent lists above are grounded in the complaint documents and docket-aggregator pages cited. The filing dates/dispositions I could not verify from a primary docket (particularly the R.R. Donnelley and Quad/Graphics terminations, and the S.D. Ill. case) are expressly flagged as unconfirmed. For litigation-grade certainty, these should be re-verified against PACER for each district and against the PTAB docket.

Proceedings overview

Total AIA trial proceedings on US 8,537,357: 0. No IPR, PGR, or CBM petition has ever been instituted against this patent — the USPTO Open Data Portal returns no AIA trial proceedings for it (0 active / 0 invalidated / 0 sustained / 0 settled / 0 institution-denied). The bottom line for a defendant: there is no PTAB work product to lean on — no claim of the '357 patent has been canceled, narrowed, or even construed by the Board, so you cannot borrow an IPR record. What you do have is a much softer fact: the patent is expired (adjusted expiration 2019-04-26, "Expired – Fee Related"), so exposure is limited to past damages, and the patent was not among the RAH Color patents that Adobe successfully attacked at the PTAB.

No proceedings to report

The canonical structured list in this prompt ("PTAB proceedings on file") is empty. Independent web searching found no third-party AIA challenge — IPR, PGR, or CBM — naming U.S. Patent No. 8,537,357. The "357" hits in search results are unrelated (e.g., ITC ink-cartridge patents 8,540,347/11,535,037 in Inv. No. 337-TA-1451; a Korean patent sequence listing). I could not confirm the existence of any petition, institution decision, FWD, or settlement for this patent. Searches are not exhaustive, and a recently filed petition may not yet be indexed, but the default conclusion is: no PTAB activity on file.

Adjacent proceedings — these are NOT on the '357 patent (context only)

Four Adobe Inc. IPRs were filed on sibling RAH Color patents sharing the same specification and title, and the same assertion campaign. Do not cite these as decisions about the '357 patent:

Sources: Adobe's petition in IPR2019-00629, https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1523317](/patent/1523317)/download-documents (listing the four concurrent petitions); institution decision in IPR2019-00646, https://www.docketalarm.com/cases/PTAB/IPR2019-00646/Inter_Partes_Review_of_U.S._Pat._7791761/docs/02-27-2020-Board/Order-75-Decision_Granting_Institution_of_Inter_Partes_Review.pdf; IPR2019-00627 FWD, https://bannerwitcoff.com/wp-content/uploads/2020/09/PTAB-IPR2019-00627-124.pdf. Adobe's petitions expressly enumerated the related patents as the '008, '761, '444, and '897 — not the '357.

Litigation context (why the absence is notable): the '357 patent was heavily asserted — RAH Color Technologies sued X-Rite (W.D. Mich. 1:14-cv-00638, per docket block; complaint lists the '357 among ten Patents-in-Suit), R.R. Donnelley (N.D. Ill. 1:17-cv-00894, filed 2017-02-02), Quad/Graphics (E.D. Mich. 2:18-cv-00087), and Xerox (W.D.N.Y. 6:18-cv-06746), and it appears in the MDL In re RAH Color Technologies LLC Patent Litigation (N.D. Cal. M18-md-02874-SI). So the patent was in the line of fire for years and still drew no AIA petition — while its siblings did.

Strategic summary

Claim status. Because no AIA trial ever reached a Final Written Decision on the '357 patent, the claim picture is: untested at the PTAB — no claim canceled, none sustained, none construed by the Board. I cannot give you a claim-by-claim "canceled vs. sustained" list because no PTAB record exists; the patent text supplied contains no claim listing, and I will not infer one. Any IPR-style argument against the '357 must therefore be built from scratch on the '357's own claims and specification.

Estoppel landscape. There is no § 315(e)(2) estoppel attributable to this patent — no petitioner has been through an IPR on it, so no prior-art ground is foreclosed by PTAB estoppel for a defendant being asserted against today. Conversely, there is no free "borrowed" invalidity record either. Your invalidity case is a district-court / ex parte reexamination case, not an IPR-follow-on. Note the practical constraints on the routes: (a) PGR is unavailable — it applies only to patents with an effective filing date on or after 2013-03-16, and the '357's priority date is 1997-08-25; (b) CBM review is entirely unavailable — the transitional program sunset on 2020-09-16 and, in any event, a color-imaging/color-management patent is not a "covered business method"; (c) IPR remains the only AIA route, subject to the § 315(b) one-year bar running from service of an infringement complaint on you; and (d) the patent's expired status (adjusted expiration 2019-04-26) materially undercuts the incentive to file at all.

Pattern signals. The campaign was run by RAH Color Technologies LLC (Dr. Richard A. Holub, sole member) through Global IP Law Group, with 30+ patents and dozens of licensees; Adobe was the only sophisticated challenger to go to the PTAB, and it targeted the four patents actually asserted against Adobe — the '357 was not among them. No defensive aggregator (Unified Patents, RPX, etc.) appears as a petitioner on this patent. The Unified Patents "Family has litigation" link in the docket block is a litigation-data portal, not evidence of a Unified Patents IPR filing. And while RAH has defended Board proceedings, I found no Federal Circuit appeal concerning the '357 patent.

Recommended next steps

• Do not rely on any PTAB outcome. Because no AIA proceeding exists on the '357 patent, an accusation citing it cannot be answered with "the claims are already canceled." Treat the patent as live-but-expired: verify that the 2019-04-26 adjusted expiration and the "Expired – Fee Related" status bar prospective (post-expiration) relief, and confine the damages analysis to the pre-expiration period (plus the six-year § 286 look-back).
• If you are newly served, diary the § 315(b) date. You have one year from service of a complaint alleging infringement to file an IPR. Given the expiry, weigh whether an IPR is worth the cost versus an invalidity case in court or an ex parte reexamination (no § 315(b) bar, lower cost, and no estoppel).
• Mine the siblings' record as prior-art intelligence, not as estoppel or as a decision about this patent. The Adobe IPRs on the '897, '008, '761, and '444 patents share the specification; their petition art (e.g., the Tajika, Stone, Giorgianni, Poynton-based combinations discussed in the consolidated Adobe proceedings, and the ICC v.3.0/Poynton grounds) may be adaptable to the '357's claims. Nothing in that record estops you, and nothing in it adjudicates the '357.
• Confirm independently before relying on the negative. Re-run the PTAB E2E / Patent Trial and Appeal Board Decisions search and the USPTO Open Data Portal closer to your filing or response deadline; a very recent petition (post-ingest) would not appear in the structured block above, and I did not find one.

Caveat: the "no proceedings" conclusion rests on the ODP structured block plus my web searches; I found no contrary evidence. If you need a litigation-grade determination, pull the Patent Trial and Appeal Board E2E docket for US 8,537,357 and the complete MDL (N.D. Cal. 3:18-md-02874) docket directly, since the litigation block in Google Patents shows five district-court cases that this analysis does not fully reconstruct.

I'll research the assignment chain for US 8537357 using multiple sources.

Let me dig into the assignment records and litigation history directly.

Ownership & Assignment Analysis — US 8,537,357

Data-quality note up front (important): I could not open the USPTO Assignment Center record itself in this session, so I do not have verified reel/frame numbers or the recorded correspondent of record for any link in this chain. Google Patents' legal-events feed and the litigation record do show that an assignment event exists (details below), so I am not saying "no records exist." But I am declining to invent reel/frame or correspondent data. Every reel/frame cell below is therefore marked [NOT RETRIEVED]. Treat the timeline as complete only as to events, not as to recording metadata.

Inventors

Unusual pattern (present): the commercialization vehicle died. Imagicolor Corporation was formed 1998 and "eventually dissolved" (per RAHCT's own complaints, e.g. W.D.N.Y. 6:19-cv-06112 ¶15). No product embodying the claims ever shipped — Holub's own prototype is described in the complaints as a demonstration prototype, and the Epson/Kodak complaints allege a licensing program rather than a product business. The patents were held personally and then moved into a licensing LLC, which is the classic "inventor → shell licensing entity" sequence (see Signal 1).

Original assignee

RAH Color Technologies LLC — Google Patents lists the same entity as Original Assignee and Current Assignee ("RAH Color Tech LLC"), Alexandria, VA.

• Product embodying the claims? No. RAH Color Technologies LLC was formed in 2005, expressly "as a vehicle for an on-going licensing program for companies whose products depend on Dr. Holub's innovations" (W.D.N.Y. 6:19-cv-06112 ¶16; N.D. Ill. complaint ¶20). Holub is its sole member (IPR2019-00646, Ex. 2121 ¶1: "I am the sole member of RAH Color Technologies LLC").
• Primary line of business: patent licensing / assertion. RAHCT's complaints claim licenses to "12 of the largest manufacturers of color imaging and printing products" plus end-user licenses.
• Address of record: 7012 Colgate Drive, Alexandria, Virginia 22307 — a residential street address, not a commercial campus.
• Current status: Operating as a licensing/assertion entity; the patent itself is "Expired – Fee Related" (adjusted expiration 2019-04-26) per Google Patents. The earlier operating entity, Imagicolor Corporation, is dissolved.

Assignment timeline

⚠️ The USPTO Assignment Center's recorded metadata (reel/frame + correspondent) was not retrievable in this session. What follows is what the Google Patents legal-events feed and the public litigation record establish. The feed is incomplete: it does not show the original inventor→LLC assignment that must exist for the '357 to have issued to RAHCT (the '357 was filed 2010-03-08 with RAHCT already as applicant of record).

• ~2005 (date not recorded in retrievable sources) / recorded [NOT RETRIEVED] — Reel [NOT RETRIEVED]

  • Conveyance: Assignment (inferred, unverified)
  • Assignor: Richard A. Holub (and possibly Daniel R. Mongeau)
  • Assignee: RAH Color Technologies LLC
  • Correspondent: [NOT RETRIEVED]
  • Context: inventor moves personally-held family patents into a purpose-formed licensing LLC.

• 2013-05-14 (recorded; execution date not shown) — Reel [NOT RETRIEVED]

  • Conveyance: Merger ("MERGER (SEE DOCUMENT FOR DETAILS)", per Google Patents legal events)
  • Assignor: RAH Color Technologies LLC
  • Assignee: RAH COLOR TECHNOLOGIES LLC
  • Correspondent: [NOT RETRIEVED]
  • Context: internal reorg / change-of-entity, not an arm's-length sale. Note that the earlier RAHCT filings list the LLC as Rochester, NY (e.g., US 8,279,236, assignee "Rah Color Technologies LLC, Rochester, NY"), while post-2013 litigation identifies it as a Virginia LLC (7012 Colgate Drive, Alexandria, VA). A 2013 merger recording is consistent with a domicile/entity change from New York to Virginia — that is an inference from the two addresses, not a recorded fact.

No other post-issuance assignments are visible. There is no sale to Acacia, Marathon, IV, or any other aggregator, no securitization, no bankruptcy sale, and no chain of sequentially-named LLCs.

Timeline diagram

timeline
    title Ownership of US 8537357
    1996 : Parent application filed
         : Holub and Mongeau named inventors
    1997 : Family priority date Aug 25
    1998 : Imagicolor Corporation formed
         : Commercialization attempt
    2005 : RAH Color Technologies LLC formed
         : Licensing vehicle launched
    2010 : Continuation filed March 8
         : First suit vs Seiko Epson Dec 21
    2013 : Merger recorded May 14
         : Patent issues Sep 17
    2017 : Asserted vs RR Donnelley
    2018 : Asserted vs Quad Graphics
    2019 : Patent expires fee related

NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT (with caveat).
   The patent sits in a single-member licensing LLC with no products and no commercial address (RAHCT, formed 2005 "as a vehicle for an on-going licensing program"; Holub sole member per IPR2019-00646 Ex. 2121 ¶1; address 7012 Colgate Drive, Alexandria VA per the complaints). The operating entity Imagicolor Corporation is dissolved. Caveat: this is an inventor-owned licensing vehicle, not a carve-out from a going concern — there was never a healthy operating assignee to strip the patent out of.

2. Known asserter in the chain — PRESENT (not on the enumerated lists).
   RAHCT does not match the named lists (Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Spangenberg, etc.). However it is a high-frequency assertion vehicle tracked in the same directories: RPX Insight hosts its complaints (e.g. insight.rpxcorp.com litigation_documents/13228848, /12841124), Unified Patents indexes the family (portal.unifiedpatents.com/patents/patent/US-8537357-B2, /US-6043909-A), and its suits were consolidated as In re RAH Color Technologies LLC Patent Litigation, N.D. Cal. MDL No. 2874. Opposition defendants include Adobe, Xerox, EFI, Kodak, Quad/Graphics, RR Donnelley, Heidelberger, Dalim, Seiko Epson, Ricoh.

3. Repeat correspondent across the chain — UNCLEAR / NOT DETERMINABLE.
   I could not retrieve the assignment correspondents of record, so I cannot call recurrence. Distinct from assignment correspondence (and therefore not a finding under this test, but worth recording): PTAB filings identify Irwin Park (USPTO Reg. No. 68,865) as lead counsel for RAHCT, and later-family patents name Lukacher Law Group / Kenneth J. Lukacher as attorney of record (US 10,560,676), while the 2002 licensing overtures came from Niro, Scavone, Haller & Niro. Keeping these distinct from the recording correspondent is deliberate — conflating them would be exactly the error the brief warns about.

4. Cascading transfers — NOT PRESENT.
   Only one recorded transfer event is visible (2013-05-14 merger), and it is an internal entity/domicile change within the same owner. There is no <24-month chain of unrelated LLCs sharing an address or attorney.

5. Pre-litigation transfer — NOT PRESENT.
   RAHCT's first assertion predates the only recorded assignment: the Seiko Epson suit was filed 2010-12-21 (W.D.N.Y. 6:10-cv-06710), i.e. ~2.5 years before the 2013-05-14 merger recording. The '357 was first asserted in RR Donnelley (N.D. Ill. 1:17-cv-00894, filed 2017-02-02) and Quad/Graphics (E.D. Wis. 2:18-cv-00087, filed 2018-01-17) — both years after the merger. No transfer was arranged on the courthouse steps.

6. Bankruptcy fire-sale — NOT PRESENT.
   Imagicolor's wind-down was a voluntary dissolution, not a Chapter 7/11; the patents were held personally by Holub and transferred to his own LLC. No bankruptcy docket, no estate sale, no trustee conveyance.

7. Privateering — NOT PRESENT.
   There is no operating-company benefactor behind RAHCT. The asserter is the inventor; the suits are direct enforcement, not a proxy campaign funded by a competitor.

8. Defensive aggregator (anti-NPE) — NOT PRESENT.
   The chain terminates at RAHCT, an assertion vehicle — the inverse of neutralization. No RPX / AST / LOT / Unified / OIN assignment appears.

Verdict

NPE — high confidence.

Justification: Two independently sufficient signals are present and evidenced outside of naming: (a) the patent is held by a single-member, product-less licensing LLC formed in 2005 specifically as an assertion/licensing vehicle (IPR2019-00646 Ex. 2121 ¶1; W.D.N.Y. 6:19-cv-06112 ¶16), with the attempted commercializer Imagicolor Corporation dissolved; and (b) that LLC is a high-frequency plaintiff whose cases were consolidated into MDL No. 2874, asserting the '357 against RR Donnelley (1:17-cv-00894, filed 2017-02-02) and Quad/Graphics (2:18-cv-00087, filed 2018-01-17). The single recorded transfer — a 2013-05-14 merger of RAH Color Technologies LLC — is an internal reorganization, not a cascading shell chain, pre-litigation transfer, bankruptcy sale, or privateering arrangement, all of which I mark as not present.

Two honest caveats to the verdict: (i) it rests on docket and declaration evidence, not on reel/frame entries, which I could not retrieve — I am flagging that gap rather than papering it; and (ii) this is the inventor-owner variety of NPE (failed commercialization → self-licensing), which is materially different from a buy-and-sue aggregator, even though the same verdict category applies under the rubric given.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent number 8537357); mirrored at https://assignment.uspto.gov/patent/index.html. Google Patents legal events for the same patent: https://patents.google.com/patent/US8537357/en.

I'll search for the specific patent and its citations.

Let me get the actual cited references from the patent's front page.

Identification of the Patent (interpreted literally)

Sources: Google Patents (https://patents.google.com/patent/US8537357/en), FreePatentsOnline (https://www.freepatentsonline.com/[8537357](/patent/8537357).html), Justia, Unified Patents litigation portal.

Important caveats before the §102 analysis

1. What I could and could not verify. The live search returned the patent's bibliographic data, family data, litigation data, and the sibling front pages (US 8,760,704 and US 8,917,394 — same specification, same lineage). I was not able to open the literal front-page "References Cited" box of US 8,537,357 itself in these searches. The reference list below is assembled from (a) the sibling front pages of the same family, (b) the applicant's IDS materials for related applications (e.g., Ser. No. 11/452,869), and (c) the references the patent's own specification discusses by name. Treat the set as reliable but the exact per-patent box membership as requiring confirmation against the printed front page.
2. A citation is not anticipation. A reference listed in a patent is not thereby §102 prior art. Under §102, a reference must (i) predate the effective filing/priority date and (ii) disclose every element of a given claim, arranged as in the claim.
3. Two possible priority dates. The family claims benefit of prov. 60/056,947 (1997-08-25) and is "related to" Ser. No. 08/606,883 (1996-02-26). For subject matter carried over from the 1996 application, the effective date may be 1996-02-26; for new matter, 1997-08-25. This matters: several cited NPL items from 1995–1997 straddle that line.
4. Self-citations. Many "references" are the inventor's own family members (US 6,043,909; 6,157,735; 6,459,425; 6,750,992; 6,995,870; 7,075,643; 7,280,251; 7,312,897; 7,710,560; 7,715,052; 7,728,845; 7,729,008; 7,791,761). These share priority and inventorship and therefore cannot be §102 prior art against US 8,537,357. They are family, not prior art.
5. Claim numbering. The authoritative claim set was not in the material available to me. I therefore map references to claim groupings/concepts rather than asserting specific claim numbers.

A. Third-party U.S. patent references (the substantive §102 candidates)

These are the cited third-party U.S. patents that predate the 1996/1997 priority dates and are therefore the only cited patents capable of supporting §102 anticipation.

B. Third-party U.S. patents/applications that post-date the priority date

The following appear in family citations but were published after 1996/1997, so they cannot be §102 prior art against the '357 claims:

• US 5,937,087 (Sasanuma, 8/1999); US 6,222,639 (Suzuki, 4/2001); US 6,404,509 (Kuwata, 6/2002); US 6,430,311 (Kumada, 8/2002); US 6,330,368/6,320,668 (Kim, 11/2001); US 6,373,580 (Walker, 4/2002); US 6,176,007 (Harrington, 1/2001); US 6,204,919 (Barshad, "Double beam spectrometer," 3/2001); US 6,232,954 (Rozzi, 5/2001); US 6,256,638 (Dougherty, 7/2001); US 6,076,988 (Schwartz, 6/2000); US 6,072,546 (Nakayabu, 6/2000); US 6,155,735 / 6,043,909 (Holub — family); US 6,219,155 / 6,271,937 / 6,636,326 (Zuber, 2001–2003); US 6,606,165 / 6,633,396 / 6,657,741 (Barry et al., 2003); US 6,634,091 (Hidaka, 2003); US 7,161,558 (Eidem, 2007); US 7,057,639 (Spoonhower, 2006); US 6,753,990 (Payne, 2004); US 7,280,251 (Holub, 2007 — family).

The Zuber and Barry patents are directed to multiple-print-engine page routing/contone and halftone color correction — relevant only if later-filed claims (or the patent's later continuations) are at issue, not the original 1996/1997-priority claims.

C. Cited non-patent literature (NPL) and its §102 relevance

Print publications can be §102(a)/102(b) prior art. Those dated before the 1996-02-26 / 1997-08-25 priority dates:

NPL dated after the priority date (Wallace 2005; GretagMacbeth Eye-One Beamer 2004; Koldenhof 2003; Marszalec 1997 SPIE) cannot be §102 prior art against the original claims.

D. Bottom line

• The most relevant §102 prior art among the cited patents is: US 5,272,518 (Vincent) for the network-wide spectral calibration concept; US 5,107,332 (Chan) and US 5,185,673 (Sobol) for closed-loop printer calibration via a printed/scanned calibration form; US 5,182,721 (Kipphan et al.) for on-press spectral colorimetry and ink-key correction; and US 5,231,481 (Eouzan et al.) for camera-based display control. Each is expressly distinguished in the '357 specification, and each is directed at one node/one device — none discloses the combination that the claims emphasize: a network of nodes, a self-calibrating/auto-verifying color measurement instrument at each rendering device, a portable data structure (the "Virtual Proof") carrying shared color-transformation information separately from image data, and gamut-relationship management across devices.
• US 5,272,518 (Vincent) is the single most dangerous reference because it is a spectral colorimeter expressly mentioned for "consistent color across a network." Its express deficiencies per the specification (no teaching of how distributed calibration is done, no self-checking, no verification) are the classic grounds on which the '357 claims survived — and are the natural attack vectors in a validity challenge.
• Most non-patent literature (ICC Profile Format 3.01, MCT, Neugebauer, Gordon/Holub/Poe on gamut operators, ANSI IT8.7/2, Södergård, Vanhala teleproofing) discloses individual claim elements but not the claimed distributed architecture.
• All of the Holub-family self-citations (US 6,043,909; 6,157,735; 6,459,425; 6,750,992; 6,995,870; 7,075,643; 7,280,251; 7,312,897; 7,710,560; 7,715,052; 7,728,845; 7,729,008; 7,791,761; plus the closely related US 8,917,394, 9,057,645, 9,404,802, 9,894,338) are the same family and the same invention — they cannot be §102 prior art against US 8,537,357.

Confidence note: I am confident in the bibliographic data for US 8,537,357, in the family/priority structure, and in the specification's own characterizations of Chan, Sobol, Kipphan, Vincent, Eouzan, Sodergård, and the ICC/MCT documents (those characterizations are quoted/paraphrased from the patent text I was given). I am not able to certify that every reference in Section A appears verbatim in the "References Cited" box of US 8,537,357 specifically, versus a sibling's box — that box should be confirmed against the printed front page or the PatentCenter "References Cited" listing before being relied on.

I'll ground this analysis in the actual record. Let me pull the claim text and verify the prior-art references cited in the patent's background.

Let me pull the actual issued claims of US 8,537,357 and check its litigation/IPR record.

Let me get the '357 claim set itself and the outcomes of the related IPRs.

Obviousness Analysis — U.S. Patent 8,537,357 B2

"System for Distributing and Controlling Color Reproduction at Multiple Sites"
35 U.S.C. § 103 — using the prior art identified in the patent's own "Prior Art" section

0. Record and caveats (read first)

Before the analysis, three limitations on what follows. Per the operating rules, I state these rather than paper over them.

1. I do not have the verbatim issued claim set of US 8,537,357. The Google Patents text supplied in the prompt terminates mid‑description ("Newton‑Raphson") before the claims appear, and my searches returned the claim sets of related family members rather than the '357 claims themselves. Accordingly, I analyze against (a) the claim categories that the '357 specification and drawings are directed to, (b) the claims of parent US 6,043,909 as published at uspto.report, and (c) claim language that appears in USPTO records for sibling RAH patents. Where I attribute claim language to the '357, I flag it as unverified.
2. Priority date is ambiguous in the public records and I am not resolving it. Google Patents lists the '357 priority/prior‑art date as 1997‑08‑25; Unified Patents lists 1997‑08‑24 for the family; other family members (e.g., US 7,715,052; US 7,830,546) are listed at 1996‑02‑25. The '357 (App. 12/660,937, filed 2010‑03‑08) is a division of a chain, and US 8,917,394 is in turn a division of 12/660,937. The effective filing date therefore falls somewhere in 1996–1997, which matters for whether the 1995–1997 references are §102(a) or §102(b) art. I treat the 1996/1997 window as the operative range.
3. The patent is expired. Google Patents records legal status "Expired – Fee Related, expires 2019‑04‑26" (adjusted expiration). The §103 question today is therefore retrospective — relevant to the damages window in the pending/decided district court matters (e.g., N.D. Ill. 1:17‑cv‑00894; W.D.N.Y. 6:18‑cv‑06746; W.D. Mich. 1:14‑cv‑00638; E.D. Mich. 2:18‑cv‑00087; S.D. Ill. 1:17‑cv‑04931) rather than to injunctive relief.

1. Governing framework

• Graham v. John Deere Co., 383 U.S. 1 (1966): scope/content of claims; differences over prior art; level of ordinary skill; secondary considerations.
• KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): a combination is obvious if it flows from "ordinary creativity," from a "finite number of identified, predictable solutions," or from "known work [that] is ready for improvement." Motivation need not be found in the references themselves.
• In re Keller, 642 F.2d 413 (CCPA 1981): the test is what the combination teaches, not whether each reference's own purpose is preserved.
• In re Nomiya, 509 F.2d 566 (CCPA 1975); MPEP §2144.03: statements in the applicant's own specification about the state of the art are admissions usable as prior art and as evidence of motivation. This is unusually important here, because the '357's "Prior Art" section is a densely written, self‑critical survey of the field.
• In re O'Farrell, 853 F.2d 894 (Fed. Cir. 1988): reasonable expectation of success is required for each combination.

Level of ordinary skill in the art (proposed): a person with a bachelor's or master's degree in color science, imaging science, electrical engineering, or the graphic arts, plus 2–5 years of experience in color management / color reproduction for print and display. Note that the named inventor's own 1988–1995 publications (below) are themselves evidence of what that person was expected to know; several are co‑authored and are the standard references in the field.

2. The prior art of record (grouped by function)

Taken from the "Prior Art" section of the '357 specification.

Two record facts materially strengthen any §103 case:

• The patentee conceded the ICC Profile Format is prior art. In the Adobe IPRs, Petitioner argued from the patentee's own identification of ICC v.3.0/v.3.01 in the grandparent application (filed with the PTO May 28, 1996) and from the specification's references to the "prior art ICC profile specification" that the concession binds. (Hearing transcript excerpts, https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1523317](/patent/1523317)/...)
• The '357 specification repeatedly frames the invention as curing defects it identifies in the cited art — a textbook motivation record.

3. The claimed subject matter, and the gaps the art must fill

From the '357 specification and the family, the claims fall into five families. The "gaps" column is what a combination must supply beyond any single reference.

For the record, the presented '909 claims (uspto.report, https://uspto.report/patent/grant/[6043909](/patent/6043909)) contain verbatim limitations very close to Family A: "means for providing color calibration data at each said node characterizing output colors of the rendering device of the node"; "said data structure comprises components shared by the nodes and other components present only at each said node, and said color preferences define one of said shared components"; and "means for verifying at each said node that said information … properly transformed the input color image data." I use these as a proxy, not as the '357's claims.

Additionally, claims appearing in USPTO records for sibling RAH patents recite "data representing tonal transfer curves for a plurality of color channels; one or more color transformations … and a data structure expressing colors that are in or out of gamut"; "a chromatic adaptation transform useable to compensate for change in viewing conditions"; and "annotations … separable from said image data." If the '357 contains claims of this style (unverified), those limitations need the art discussed in §5.

4. The combinations, with motivation

Combination 1 — The broad network claim (Family A)

Primary: Vincent, US 5,272,518 — portable spectral colorimeter, expressly "mention[ing] applicability to insuring consistent color across a network," but (per the patent) "does not discuss how distributed calibration would be implemented."
Secondary 1: Neugebauer, US 2,790,844 — colorimetric (device‑independent) representation plus soft proof projected onto the actual printing stock.
Secondary 2: Schreiber, US 4,500,919 — matching a hard copy to a monitor display (i.e., calibrating one device against another).
Secondary 3: Södergård et al., "A general teleproofing system," TAGA 1991 — digitized image of one device transmitted over ISDN to a remote display; the patent states this "lacks any provision for calibration or verification of the devices at either end of a link and also lacks the data structures needed to support remote proofing and negotiation of color approval."
Secondary 4: Bonino, US 5,309,257 — harmonizing the output of multiple color devices by measuring each and adjusting V/L functions to a commonly achievable maximum (i.e., a network‑wide calibration target).
Secondary 5: ICC Profile Format v3.01 — a device‑independent connection space plus device profiles that are themselves shareable data tables.

Motivation (KSR factors (a)–(f)):

• The patent's own background admits the problem: a magazine printed at "5 regional plants scattered across the nation," with "no feedback from production to earlier functions," and printed color varying "from site to site."
• Södergård's teleproofing system supplies the system and its own deficiency supplies the problem to be solved — combination of the network link (Södergård) with calibration instrumentation (Vincent, Bonino) and a profile format (ICC) is the natural, finite set of solutions.
• Bonino (multiple networked displays) + Vincent (networkable spectral colorimeter) + ICC (shareable transform data) yields the claimed system with predictability: all three are directed to the same result, and the result ("substantially the same appearance within attainable colors") is the stated aim of each.

What this combination does not squarely supply: the shared/local partition of the data structure and the verification‑then‑revision loop with statistical comparison of verification‑form measurements. Those are addressed next.

Combination 2 — Verification / revision (Family B)

Primary: Kipphan et al., US 5,182,721 — printed sheets scanned by a spectral colorimeter; readings compared in CIELAB to aim values; color errors converted to corrections and fed to the ink preset control panel.
Secondary 1: Chan, US 5,107,332 — closed‑loop printer calibration in which a standardized calibration form produced by the printing system is scanned, deviations from expected color values are quantified, and correction coefficients are generated to improve subsequent renderings.
Secondary 2: Sobol, US 5,185,673 — same closed‑loop geometry.
Secondary 3: ANSI IT8.7/2‑1993, Annex B — a standard calibration‑target methodology.
Secondary 4: Van Aken, US 5,319,437 — dual‑beam spectrophotometry (measuring the sample against a known reference, which is the instrument‑level analogue of "comparing measured colors with reference data").

Motivation: The patent's own "Prior Art" critique identifies the motivation verbatim — Kipphan's system "is not capable of calibration self‑check," "operator override is possible and is necessary when the colorimeter goes out of calibration," and "the operator must be pro‑active in sampling the press run." An artisan seeking to remove operator dependence would combine Kipphan's error‑to‑correction loop with Chan/Sobol's automated form‑based calibration and Van Aken's self‑referencing measurement. Chan and Sobol even recite the statistical‑deviation element ("distortions or deviations from the expected color values are used to generate correction coefficients").

Counterweight (real): The patent distinguishes Chan/Sobol: desktop devices, scanner‑rather‑than‑colorimeter based, and — citing Gordon & Holub (1993) and Holub (1995) — "No requirements are placed upon the spectral sensitivities of the scanner's RGB channel sensitivities. This has ramifications for the viability of the method for sets of rendering colorants other than those used in the closed printing system." If a court credits that, Chan/Sobol are usable for the verification‑and‑correction element but not as primary references for a colorimetric, cross‑device, multi‑colorant system.

Combination 3 — The transform pipeline (Family C)

This is where the §103 case is, in my assessment, strongest, because every step is a named, published numerical method.

Motivation for combining: the motivation is internal to the problem — each element is a known technique applied to the immediately preceding element, and the predictability is high (a least‑squares polynomial with SVD, a barycentric linear interpolator, a Newton search with gradient descent, and a percentile‑based GCR curve are all standard). This is the paradigm KSR case of "a finite number of identified, predictable solutions."

Combination 4 — Instrumentation (Family D)

Primary: Vincent, US 5,272,518 — linearly variable interference filter + linear photodiode array; portable, low‑cost spectral colorimeter.
Secondary 1: Van Aken, US 5,319,437 — dual‑beam spectrophotometer (the '357 expressly says "the preferred embodiment of the unitary device SOM 13 approximates a dual‑beam device, such as spectrophotometer of Van Aken et al.").
Secondary 2: Greivenkamp, US 4,987,496 (anti‑aliasing optics) — the '357 claims an imaging colorimeter "having an anti‑aliasing filter."
Secondary 3: Garini (SpectraCube™) — per‑pixel spectral imaging; the '357 names it outright for the imagical.
Secondary 4: Hoyt (1995) and Shnitser (1995) — tunable filters for illuminant substitution.
Secondary 5: Eouzan, US 5,231,481 — camera measuring display image area (the '357 states Eouzan's procedures "are suited to the environment in which the displays are manufactured and not to where they are used" and that "concepts of colorimetric calibration … are not disclosed" — an admitted gap that Vincent/Van Aken fill).

Motivation: automation and non‑contactness. The '357's own admissions supply it: many prior devices "require manual measurements … conducive to operator error"; others "require physical contact with the copy and consequent scuffing"; others still rely on white plaques and black traps that "are not usually performed." Vincent + Van Aken supply a self‑referencing, non‑contact spectral head.

Weakest element in this combination: the specific display‑surround cowel with the sensor at an oblique angle to avoid specular reflection and the in‑instrument reference/dark/known‑wavelength fiber channels for automatic calibration. Vincent, on the record I retrieved, expressly teaches dark‑current compensation and spectrum adjustment against a reference light source (claims 6 and 10), and Van Aken teaches reference comparison. Those are close, but a limitation‑by‑limitation mapping of the "cowel reflecting off the screen onto a blackened inner surface" geometry should be verified against the actual '357 claims before asserting per se obviousness.

Combination 5 — Data structure / file format (the shared‑local partition)

Primary: ICC Profile Format v.3.01 (prior‑art‑admitted by the patentee) — profiles as data tables for conversion, exchangeable among devices.
Secondary: MCT™ Metric Color Tag Specification, Rev. 1.1d (1993) — tags defining the data required in data files for color management.
Secondary: TIFF Rev. 6.0 (1992) — the patent itself says "the structure of the VP is similar to that of the Tagged Image File Format."

Motivation: The specification supplies the motivation as a criticism of the art — "The ICC Profile Format provides for embedding profiles with image data. This generates large data transfers over a network whenever profiles are updated." Separating the transform data from the bulk image data and giving it a shared/local partition is the direct, predictable solution to a problem the patent itself articulates — precisely the "known work ready for improvement" rationale of KSR. The MCT/TIFF tag structure supplies the mechanism.

Residual gap: the particular shared‑vs‑local allocation (e.g., calibration data local, color preferences shared) is a design choice of the kind KSR treats as obvious in the absence of unexpected results — but it is where a claim of the '909 claim 2 style is narrowest.

5. Where the challenge is weaker, and what a challenger must do

1. Teaching away by the applicant's own field. Gordon & Holub (1993) and Holub (1995) establish that unless a sensor's channel sensitivities are linear combinations of the human color‑matching functions, "the gamut of an artificial sensor will not be identical to that of a normal human." A patent owner can argue that this teaches away from the Chan/Sobol scanner‑based closed loops as the primary architecture for a multi‑vendor, multi‑colorant network. The counter is that it merely identifies why a colorimeter (Vincent, Van Aken) must be substituted for a scanner — a substitution of one known measurement device for another with a predictable improvement.

2. PTAB outcomes on sibling claims cut against a broad attack. In IPR2019‑00627 (Adobe v. RAH Color, U.S. 7,729,008), the Board's Final Written Decision found that Petitioner "has not demonstrated by a preponderance of the evidence that claims 28–33 and 36–38 … are unpatentable." (https://bannerwitcoff.com/wp-content/uploads/2020/09/PTAB-IPR2019-00627-124.pdf) IPR2019‑00646 (U.S. 7,791,761) was instituted on Feb. 27, 2020 (https://www.docketalarm.com/cases/PTAB/IPR2019-00646/.../Order-75-Decision_Granting_Institution...). Institution is not outcome, but the '008 result is affirmative evidence that at least some sibling claims survived a real §103 record — because those claims carried limitations (chromatic adaptation transforms, tonal transfer curves, separable annotations, in/out‑of‑gamut data structures) that the cited art did not reach.

3. Claim‑form risk. If the '357 claims are of the "tonal transfer curves for a plurality of color channels … one or more color transformations … a data structure expressing colors that are in or out of gamut … chromatic adaptation transform useable to compensate for change in viewing conditions … network interface … using a network protocol" style (family‑member language; unverified for the '357), then the obviousness case requires art mapping each of those limitations, and the MCT/ICC references — which the patentee has already conceded are prior art — become the load‑bearing references rather than the rendering‑pipeline art. Concededly prior art references are the least vulnerable to authenticity and date attacks; that is a meaningful advantage for a challenger.

4. Secondary considerations. The objective‑indicia record is mixed to weak:

   • Long‑felt need is arguable from the patent's own account (static calibration "proved inadequate"; remote proofing "not really useful" without verification).
   • Licensing is evidenced by the multi‑district litigation campaign, but a licensing program alone, without nexus and without commercial success, carries little weight.
   • Commercial success is affirmatively undermined: per Dr. Holub's own declaration, Imagicolor Corporation was formed in 1998 and "investment did not materialize and Imagicolor was eventually dissolved" (https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1523296](/patent/1523296)/...). A patent owner would have difficulty establishing a nexus‑bearing commercial success case.
   • Copying evidence is not apparent in the record I reviewed.

5. Priority‑date exposure. Much of the "Prior Art" section is the inventor's own work (Holub et al. 1988; Holub & Kearsley 1989; Holub 1995; Holub, TAGA 1988; Schwartz et al. 1985), and the 1995 items (Hoyt, Shnitser, Garini, Komori World News, Blessing) sit within a year of a 1996 filing. This creates §102(a)/102(b) timing questions that a challenger must brief carefully; the safest references are the pre‑1995 ones: Neugebauer '844; Schreiber '919; Chan '332; Sobol '673; Kipphan '721; Vincent '518; Eouzan '481; Bonino '257; Greivenkamp '496; Rose '816; Van Aken '437; MCT 1993; Hardy & Wurzburg 1948; Pobboravsky 1962; Gordon et al. 1987; Holub et al. 1988; Holub & Kearsley 1989; Södergård TAGA 1991; ANSI IT8.7/2‑1993; CIE 15.2.

6. Bottom line

Most vulnerable: the transform‑pipeline and calibration‑methodology claims (Family C and the model‑building steps of the '909 claim‑8 type), and the broad network claims to the extent they are not limited by the shared/local split or the chromatic‑adaptation/separable‑annotation limitations. A combination of Pobboravsky + Schwartz et al. + Gordon et al. + Holub & Kearsley + Gallagher/Press et al. + Rose + ICC/MCT is a well‑motivated, high‑expectation‑of‑success combination that renders those steps obvious under KSR; the strongest single motivation statement is the patent's own admission that the ICC format's profile‑embedding "generates large data transfers over a network whenever profiles are updated."

Moderately vulnerable: the network/system claims (Family A). The combination of Vincent + Neugebauer '844 + Schreiber '919 + Södergård teleproofing 1991 + Bonino '257 + ICC supplies every element at the level of generality the specification describes, with the motivation supplied by Södergård's admitted deficiencies and by Bonino's network‑wide harmonization goal. The residual gap — a data structure partitioned into shared and local components, revised in response to measured color error — is bridged by MCT/TIFF tagging + Chan/Sobol + Kipphan, subject to the Gordon & Holub sensor‑linearity teaching‑away argument.

Least vulnerable: the instrument‑specific claims directed to the display‑surround geometry, the transport‑coupled spectrograph for printed sheets, and the automatic in‑instrument reference/dark/known‑wavelength self‑calibration. Vincent and Van Aken get close, but the challenger needs a precise limitation‑by‑limitation mapping against the actual issued claims, which I was unable to retrieve in this session. I would not assert per se obviousness of those claims without that claim text.

Practical caution: any real §103 challenge must be run against the verbatim claim set of US 8,537,357 — which this analysis could not obtain — and must address the priority‑date ambiguity (1996‑02‑25/26 vs. 1997‑08‑24/25) that governs whether the 1995 items are §102(a) or §102(b) art. Treat the above as a reasoned framework keyed to the patent's own prior‑art record, not as a substitute for a claim chart.