US 5953546

I'll search for authoritative information on US 5953546, including any CAFC/litigation activity.

Let me look for the actual claim text and any litigation/docket records.

US 5,953,546 — "Camera"

Bottom line: I confirmed the patent's bibliographic record from two independent sources, but I could not retrieve the verbatim claim set, and I found no CAFC 2026 docket (or any litigation) involving this patent. Details and explicit uncertainty flags below.

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Bibliographic data

Note the legitimate one-day discrepancies between the two databases (filing, grant, priority, expiry). These are the classic JST-vs-UTC rendering artifacts; I am reporting them literally rather than harmonizing them. Per your rule, I did not auto-correct either.

Abstract (verbatim, per Unified Patents US-5953546-A)

"A camera divides a light beam having passed through a taking lens unit into two light beams. One light beam forms an image on a silver salt film. Another light beam forms an image on a CCD. A light path for said another light beam is provided with an aperture diaphragm. The taking lens unit has an aperture diaphragm. Said two aperture diaphragms are correlatively controlled by a controller incorporated in the camera."

Plain-language overview of the disclosed invention

This is a hybrid SLR that simultaneously exposes silver-halide film and an image-pickup device (CCD) from a single taking lens, using a beam-splitting main mirror. The disclosure's "summary of the invention" passages (which typically track the independent claims) describe the invention in terms of at least two principal aspects:

• Aspect A — dual-diaphragm correlation. A camera takes a photograph on silver-salt film (first imaging) and picks up an image on an image pickup device (second imaging) by dividing the light beam from a taking lens that has a first aperture diaphragm. A second aperture diaphragm is placed in the light path of one of the divided beams (the beam traveling to the image pickup device). The controller correlatively controls the two diaphragms. Worked examples in the specification tie the relay/imaging diaphragm value to the taking-lens value scaled by the relay magnification (the "a/γ" and "c·γ" relationships discussed in the film-shooting flow charts), and use a variable-density ND filter plus shutter-time/gain compensation when the taking lens is set wider than the relay diaphragm can track.
• Aspect B — preview without darkening. A camera that does both photosensitive-medium imaging and image-pickup-device imaging, with the picked-up image viewable in an electronic viewfinder, is provided with a setting device for setting the aperture value of the first aperture diaphragm. During periods when imaging on the photosensitive recording medium is not being performed, the second aperture diaphragm is actuated according to the same user setting, the image pickup device images the scene, and the electronic viewfinder displays that image. Practically, this lets the photographer preview depth-of-field (or shake/shutter-speed) effects electronically at full viewfinder brightness, rather than through a darkened stopped-down optical finder, and without the stopped-down aperture obstructing the focus-detection light beam used by the AF module.

Supporting disclosure includes multiple shooting modes (film-only PH, video-only MV, simultaneous PM, still-video SV, playback V, edit E), a rotatable/pop-out electronic viewfinder, film-cartridge recording of aspect-ratio/print information, and a large number of further embodiments (second through forty-ninth) covering optical layouts, focus plates/diffusion plates, photometry/AF mirror shading, grips, and EVF accessories.

⚠️ What I could not verify

1. Literal claim text / claim count. The authoritative full-text dump supplied did not include the claims section, and my searches did not surface a verbatim claims listing. I therefore cannot quote claim 1, nor state how many independent claims exist, nor enumerate their exact limitations. The two "aspects" above are drawn from the specification's summary passages; they are indicative of the independent-claim subject matter but are not verified claim language. If exact claim text matters for your analysis, pull it directly from the USPTO Patent Public Search / PatentCenter record for 08/834,107 or the granted-PDF claims, which is the authoritative source.
2. USPTO database & CAFC 2026 dockets — patent 5,953,546. I found no litigation, no IPR/PGR, and no CAFC 2026 docket naming 5,953,546. My search surfaced CAFC activity referencing "the '595 patent" in MRI, Inc. v. Samsung (Fed. Cir. No. 24-2228, opinion Mar. 31, 2026) — but that is a display-cooling/"constricted convection plate" patent, a different patent entirely. I am explicitly declining to conflate it with 5,953,546. Treat "no CAFC 2026 docket for 5,953,546" as a search-based negative, not a certified clean record.
3. Forward citations / third-party use. Unified Patents lists 76 "Referenced By" entries, and 5,953,546 is cited as background art in, e.g., EP 2 752 710 A4 (lens device / exposure control) — evidence of it being treated as relevant prior art in later camera exposure-control filings, but not evidence of assertion.

Sources

• Google Patents full text: https://patents.google.com/patent/[US5953546A](/patent/US5953546A)/en
• Unified Patents portal record: https://portal.unifiedpatents.com/patents/patent/US-5953546-A
• CAFC opinion (unrelated '595 patent, checked and excluded): https://cafc.uscourts.gov//opinions-orders/24-2228.OPINION.3-31-2026_2668801.pdf

I'll search for litigation involving US patent 5953546.

Let me search more specifically for litigation databases and case records.

Let me try more targeted searches on litigation-specific databases.

Findings: Litigation involving U.S. Patent No. 5,953,546

Short answer: I found no evidence of any litigation — no district court case, no Federal Circuit appeal, and no PTAB proceeding — involving U.S. Patent No. 5,953,546.

I want to be precise about what I did and did not verify, because the honest answer here is a negative result with meaningful caveats rather than a confirmed "clean bill of health."

What I searched and what came back

Patent identity (for the record, since the instruction is to interpret the number literally)

Per the Google Patents and Unified Patents records, US 5,953,546:

• Title: "Camera"
• Inventors: Takashi Okada, Shigeto Ohmori, Hideki Nagata
• Original assignee: Minolta Co., Ltd. (current parent: Konica Minolta, Inc.)
• Application: US 08/834,107, filed 1997-04-14
• Priority date: 1995-06-08 (JP 14204995A)
• Grant date: 1999-09-14
• Status: Expired – Lifetime; anticipated expiration 2016-06-06
• Subject matter: a camera that splits an incident light beam for simultaneous silver-halide film exposure and CCD image pickup, with correlative control of two aperture diaphragms.

Why the negative result is plausible

The patent is a 1999-issued Minolta camera patent that expired in June 2016. Its claims cover internal camera opto-mechanics (beam-splitting prism/mirror arrangements, relay aperture diaphragms). This kind of patent is not the profile typically asserted in infringement suits, and both the expiration date and the absence of any assertion flag on the aggregator sites are consistent with it never having been litigated.

Important caveats — what I could NOT confirm

1. I was unable to directly query PACER, the CAFC docket, or the Docket Alarm / CourtListener full-text litigation databases within the scope of this search. The Unified Patents litigation caselist page you pointed me to did not return case-level results for this patent, and my queries for it were cut short. A "no results in web search" outcome is weaker evidence than a confirmed empty docket query.
2. Older, pre-2010 suits (which is when this patent would realistically have been asserted, as a then-live Minolta patent) are the least well covered by free web sources. It is possible — though I found no indication — that a short-lived or settled suit exists in a paper-era docket not indexed publicly.
3. Litigation under family members (e.g., US 7,133,608, which claims priority to the same application line) is a separate question and would not count as litigation on 5,953,546 itself. To my knowledge and searches, nothing surfaced there either, but I did not fully investigate the family.

Bottom line

No litigation is known to me involving U.S. Patent No. 5,953,546. There is no plaintiff, defendant, jurisdiction, case number, filing date, or outcome to report, because no case was found. If you need a definitive clearance on this point, the reliable next step is a paid-docket search (Lex Machina, Docket Navigator, or Docket Alarm's patent-litigation module) keyed to patent number 5,953,546, which would cover settled suits and older paper dockets that free web sources miss.

If you'd like, I can pursue that deeper docket-level check, or run the same analysis on the related family member US 7,133,608.

I'll verify the structured-data default with targeted searches before writing anything up.

The two direct searches came back with unrelated patents. Let me run a few more angles — the continuation, and any Minolta-family litigation — to be confident the null result isn't a query artifact.

Let me do a final confirmation pass from the docket-aggregator side.

Proceedings overview

The USPTO Open Data Portal returns zero AIA trial proceedings for US 5,953,546 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, and 0 institution denials — which leaves a defendant facing no PTAB record at all, and, more decisively, no live patent to defend against: the '546 patent expired 2016-06-06, so there is nothing an IPR could invalidate, nothing to enjoin, and no recoverable damages within 35 U.S.C. § 286's six-year lookback.

Because the structured feed is empty, there is no per-proceeding section to write. Instead, this report (a) documents the negative search, (b) explains why the absence is expected here rather than suspicious, and (c) sets out the posture that actually matters to a defendant — which is a patent-term problem, not a PTAB problem.

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Verification of the null result (no proceedings to enumerate)

I ran the following checks against the structured data and open-web sources:

One apparent false positive worth flagging: the Unified Patents patent page for US-5953546-A (portal.unifiedpatents.com/patents/patent/US-5953546-A) renders an "Opposition Documents" heading. That is a generic template field on the Unified portal, not evidence of an opposition or a PTAB filing — no proceeding number, petitioner, or document is attached to it. I would not treat it as a signal of a defensive aggregator in the chain.

Caveats I want to be explicit about: web search is a weak instrument for a patent that expired a decade ago, and it is not a substitute for PTAB E2E / the former PTAB Trial Statistics database. I could not run an exhaustive E2E docket query in this session. Given (i) the ODP feed is the designated canonical source and is empty, (ii) two independent query formulations returned nothing, and (iii) the patent's term expired in 2016, a missed active proceeding is very unlikely — but I am characterizing this as "no PTAB activity on file," not as a certified negative.

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Why there is no PTAB history — and why that is not the usual "well-asserted patent" signal

The prompt's default heuristic — "well-asserted patents eventually attract IPRs" — does not apply cleanly here, and a defendant should not read the empty docket as "this patent is untested and therefore fragile." The real explanation is structural:

• The patent is expired. Google Patents records the '546 (App. No. 08/834,107, filed 1997-04-14, granted 1999-09-14) as "Expired – Lifetime," with anticipated expiration 2016-06-06. That is consistent with the front page's related-application data: the '546 is a continuation of application 08/659,690, filed 1996-06-06, so the 20-year term ran from 1996-06-06. Unified's record shows a 2016-06-05 expiration date — a one-day bookkeeping variance, immaterial to the analysis.
• The IPR window against it was short and closed. IPR became available 2012-09-16. The '546 was in force for roughly the first four years of the IPR era, then expired. Nobody filed in that window.
• The other AIA vehicles were never available. PGR applies only to patents with an effective filing date on or after 2013-03-16 — the '546 is a 1995/1996-priority, pre-AIA patent, so PGR was categorically unavailable. CBM likewise: a camera with an optical beam-splitter and correlatively controlled aperture diaphragms (G03B 19/04, G03B 17/48, H04N 23/xx) is not a covered business method, and would likely qualify as a "technological invention" anyway. IPR was the only route in, and it went unused.
• Owner and status. Original assignee Minolta Co., Ltd.; currently associated with Konica Minolta per Unified. Google Patents lists legal status as Expired – Lifetime. The continuation US 7,133,608 B1 is listed as "Expired – Fee Related" — i.e., lapsed for failure to pay maintenance fees, a separate and equally terminal event for the family.

So: no petitioner ever had a reason to spend money on this family, because the family's commercial and legal life ended in 2016.

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Strategic summary

Claim status of US 5,953,546. There is no PTAB record, so no claim of the '546 has been canceled by the Board and no claim has been sustained by the Board. Read literally, that means every claim is UNTESTED in an AIA trial — the abstract (a light beam from the taking lens split into a film path and a CCD path, with an aperture diaphragm in the image-pickup path and the two diaphragms correlatively controlled by a controller) stands as issued and unreviewed. I want to be precise here rather than useful: I cannot tell you which claims are canceled, because none are. Anyone who tells a defendant "claims 1-5 were canceled in an IPR" about this patent is wrong, and I found no support for any such statement. Conversely, I also cannot tell you the claims are strong — the Board never passed on them, and there is no FWD to point to. The claim set is simply untouched by the AIA trial regime.

Estoppel landscape. Because no IPR, PGR, or CBM was ever instituted against the '546, § 315(e)(2) estoppel does not exist against anyone. There is no petitioner, no privy, and no ground that was "raised or reasonably could have been raised." Practically, that means no prior-art ground is foreclosed — a defendant would have the full universe of § 102/§ 103 art available. But this is a purely academic advantage. Estoppel is only meaningful when it constrains a party; with zero proceedings there is nothing to constrain and, correspondingly, no FWD holding, no Board claim construction, and no instituted-ground record to leverage in a district court or ITC invalidity case. A defendant here gets no free gift from the PTAB — it arrives at a blank slate with a dead patent.

Pattern signals. No repeated-petitioner pattern (there is no petitioner). No aggressive patent-owner PTAB appeal practice — there is no Board decision to appeal to the Federal Circuit, and I found no CAFC docket activity on this patent via CourtListener or the Federal Circuit's docket in my searches. No defensive aggregator (Unified Patents, RPX, etc.) appears in the chain as an IPR filer; the only Unified touchpoint is a passive, template-driven patent profile page. The litigation history that does exist for Minolta as a patent defendant — the 1992 Honeywell autofocus verdict, ~$96.35M in the District of New Jersey (Deseret News, 1992-02-08; Chicago Tribune, 1992-02-07) — is a Minolta-loses-as-infringer story from a different era and a different patent set. It is legally irrelevant to the '546 but worth knowing as context for how the brand's IP story developed.

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Recommended next steps

If you are a defendant and a demand letter or complaint cites US 5,953,546, the PTAB is the wrong tool — and you likely do not need a tool at all. The dispositive facts are the patent term and the damages statute, not invalidity:

1. Check the expiration date first. Google Patents lists anticipated expiration 2016-06-06 (see the US5953546A record and the Anticipated expiration 2016-06-06 entry in the ODP timeline). An expired patent cannot be infringed going forward, cannot support an injunction, and cannot support a reasonable royalty for post-expiration conduct.
2. Run the § 286 arithmetic before anything else. 35 U.S.C. § 286 bars recovery of damages for any infringement occurring more than six years before the complaint is filed. For a complaint filed on 2026-09-30, the recoverable window opens 2020-09-30. All possible infringement of the '546 necessarily ceased at expiration on 2016-06-06 — over ten years ago and roughly four years before the window even opens. The recoverable damages are zero. Note also that under SCA Hygiene Prods. v. First Quality Baby Prods. (2017), laches is no longer a defense — but you do not need it; § 286 does the work on its own terms.
3. Do not expect a PTAB-based response to be available or useful. An expired patent is a poor IPR target (no amendment, no practical estoppel value, and the Board's discretionary-denial practice increasingly disfavors trials with no live controversy), and PGR/CBM were never available for this pre-AIA, non-financial camera patent. If you nonetheless want to confirm the absence of proceedings directly, query PTAB E2E by patent number 5,953,546 and by application 08/834,107, and check CourtListener for any Federal Circuit appeal naming the '546 — my searches returned nothing on either front, but those are the authoritative endpoints I could not fully exhaust in this session.
4. Look at the family. If the assertion cites the Minolta camera family rather than the '546 alone, check US 7,133,608 B1 (App. No. 10/680,340, filed 2003-10-08, claiming priority back to this line). It is listed as "Expired – Fee Related" — lapsed for non-payment of maintenance fees — and likewise shows no PTAB activity in my searches. That is a second independent reason the family has no assertion value.

Bottom line for the defense: the "is this patent hardened by surviving IPRs?" framing does not fit. There are no IPRs, no cancellations, and no sustaining decisions — the claim set is simply unreviewed. The controlling facts are that the '546 expired on 2016-06-06 and its continuation lapsed for failure to pay maintenance fees. If your demand letter cites this patent, the response is not an invalidity case — it is a one-paragraph § 286 and expiration letter. Document that and preserve it; the absence of any PTAB record means there is no Board proceeding to wait on, no trial-stage milestone to track, and no FWD deadline to calendar.

I'll research the assignment record for US 5953546 before drafting.

I hit the tool-call limit before I could complete direct queries, so this report is built from the authoritative patent text you supplied plus the secondary sources I did reach (Google Patents legal events, the Unified Patents portal entry, and Konica Minolta / Minolta corporate records). Read the data-limitation note in the Assignment timeline section before relying on any of it.

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Inventors

Employer attribution is inferential: the authoritative patent text names Minolta Co Ltd as both original and current assignee, which indicates the inventors were under an obligation to assign to Minolta at filing. I found no inventor-specific assignment documents (i.e., no separately recorded "Assignment of Assignors Interest" naming these three individuals on this application) in the sources I reached.

Unusual patterns: none determinable. I could not verify departure dates for any inventor, so the "all inventors left within 12 months of filing" fire-sale precursor you asked me to screen for is unclear / not assessable on this record. I will not assert it.

One conflation risk worth flagging: several search hits discussing "the '546 patent" in NAND-flash litigation (Lifetime Patents, WDTX, PTAB SLC/MLC obviousness petitions) are a different patent. US 5,953,546 is a camera patent and has no connection to those proceedings.

Original assignee

• Minolta Co., Ltd. (Osaka, Japan) — named on the issued patent as assignee, and still shown by Google Patents as both original assignee and current assignee.
• Line of business: Japanese photographic/optical manufacturer (35 mm SLR bodies and lenses — Maxxum/Dynax/Alpha — plus compact cameras, film, and office imaging equipment).
• Did they ship a product embodying the claims? Not verified. US 5,953,546 claims a camera that splits the incident beam between a silver-halide film and an image pickup device, with two correlated aperture diaphragms (taking-lens diaphragm and relay/CCD-path diaphragm) and electronic-viewfinder preview. Minolta demonstrably sold film SLRs and, later, digital cameras, but I found no evidence tying any specific shipping product to these claims. Treat as unproven either way.
• Current status: Minolta Co., Ltd. no longer exists as an independent entity. It was integrated with Konica Corporation via share exchange on 2003-08-05, creating Konica Minolta Holdings, Inc.; the group's camera business was terminated as of 2006-03-31 and customer service for Konica Minolta cameras ended 2010-12-31. The successor operating entity is Konica Minolta, Inc. (Chiyoda-ku, Tokyo), following the 2013-04-01 reorganization. No bankruptcy.

Assignment timeline

Data-limitation disclosure (read first). I was not able to execute the USPTO Assignment Center query against US 5,953,546 during this session. Therefore I cannot confirm the presence or absence of reel/frame records for this patent, and I will not invent reel/frame numbers. What the sources I did reach show:

• The Google Patents legal-events list you supplied contains no assignment events at all — only the 1995-06-08 JP priority claims, the 1997-04-14 filing by Minolta, the 1999-09-14 grant/publication, the 2003-10-08 priority link to US 10/680,340 (which issued as US 7,133,608 B1, a continuation in this family), and the 2016-06-06 anticipated expiration. Google Patents does index recorded assignments in that field, so its silence is weak evidence of no post-issuance record — but it is not proof.

• Google Patents lists current assignee = "Minolta Co Ltd" (not a Konica Minolta entity, not an LLC). This is consistent with no recorded post-issuance transfer of this specific patent. It may simply reflect an un-updated field.

• Unified Patents' portal entry for US-5953546-A lists Original Assignee = Minolta Co Ltd and Parent Company = Konica Minolta Inc, with no "current assignee" value captured. Again consistent with the patent sitting in the Konica Minolta lineage, but not dispositive.

• The only ownership-relevant recorded document I can surface is portfolio-level, not patent-specific:

• 2013-04-01 (executed) / recorded 2015-09-10 — Reel 36585/0946

  • Conveyance: Merger and Change of Name (document states "see document for details")
  • Assignor: Konica Minolta Business Technologies, Inc.; and Konica Minolta Holdings, Inc.
  • Assignee: Konica Minolta, Inc., 2-7-2 Marunouchi, Chiyoda-ku, Tokyo, Japan
  • Correspondent: not captured in the source I could read — no correspondent name or firm to report, and therefore nothing to flag as recurring.
  • Context: internal corporate reorganization / change of name only.
  • Caveat: I could not verify that US 5,953,546 is among the properties listed in this record. It is a bulk portfolio record for the Konica Minolta group and is presented here only as the successor-entity chain, not as a confirmed assignment of this patent.

No other assignment, security agreement, license, release, or correction record touching this patent appeared in any source I reached. If Assignment Center in fact holds records for 5,953,546, my report has a gap and you should re-run the query.

Timeline diagram

Corporate events below are the Konica Minolta successor chain; the only recorded item is 2013 (reel 36585/0946), and it is not confirmed to list this patent.

timeline
    title Ownership of US 5953546
    1995 : Japanese priority filings
    1997 : US application filed by Minolta
    1999 : Patent issued to Minolta Co Ltd
    2003 : Minolta integrated into Konica Minolta Holdings
         : Camera business later terminated in 2006
    2013 : Holdings merger recorded at reel 36585 0946
    2016 : Patent expired

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No LLC, no "IP/Holdings/Ventures" assignee, no registered-agent address appears anywhere in the record I could reach. The only assignee names in the chain are Japanese operating corporations (Minolta Co., Ltd.; Konica Minolta Holdings, Inc.; Konica Minolta, Inc.). Absence of any transfer at all is the correct characterization, not a hidden shell.

2. Known asserter in the chain — not present. No Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or Spangenberg-linked entity appears in the assignee names I could retrieve. Note that the search hits tying "Taction Technology / Burford Capital" and "Lifetime Patents / WDTX NAND" to patents numbered ~'546 concern other patents.

3. Repeat correspondent across the chain — not present (unclear). I could not capture a correspondent of record for any link, so I have nothing to test for recurrence. Do not read this as a negative finding; it is a data gap. (For context only, an unrelated 2020 Konica Minolta assignment, reel 52037/366, shows a correspondent address in Alexandria, VA 22314 — that is a different record and different patent and I am not attributing it here.)

4. Cascading transfers — not present. Zero post-issuance transfers were identified, so no chain of LLC-to-LLC hops exists to evaluate.

5. Pre-litigation transfer — not present. I found no infringement suit naming US 5,953,546, and no assignment within six months preceding any litigation. The patent's term expired 2016-06-06 and Google Patents records its status as "Expired – Lifetime," so assertion value is spent regardless.

6. Bankruptcy fire-sale — not present. Minolta's end was a merger (Konica, 2003-08-05), not a Chapter 7/11. Konica Minolta restructured and exited cameras in 2006 but never filed bankruptcy, and I found no evidence this patent was sold in any proceeding. Notably, the 2006 camera-business transfer to Sony does not appear to have carried this patent, since Minolta/Konica Minolta remains the assignee of record.

7. Privateering — not present. No operating company → NPE transfer exists to characterize.

8. Defensive aggregator (anti-NPE) — not present. The patent appears on Unified Patents' database portal, which is an informational index, not an acquisition. Unified Patents, RPX, AST, LOT, and OIN do not appear as assignees. No neutralization event, but also no acquisition.

Verdict

Insufficient data (no records, or only the original assignment).

Justification: the only assignee appearing in every source I could reach — the Google Patents current-assignee field and the Unified Patents portal, both reading Minolta Co Ltd, with successor parent Konica Minolta Inc — is the original assignee, and the one recorded corporate document I can cite (reel 36585/0946, executed 2013-04-01, recorded 2015-09-10, "Merger and Change of Name" to Konica Minolta, Inc.) is a group-level record I could not confirm covers this patent. There is no shell transfer, no known asserter, no litigation, and no post-issuance assignment of any kind tied to US 5,953,546; the patent expired 2016-06-06. That is a clean "no NPE activity" result, but because I could not execute the Assignment Center query directly, the honest call is insufficient data rather than a no-signal finding.

Verification links: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ · Assignments on the Web — https://assignment.uspto.gov/patent/index.html (search patent number 5953546) · Google Patents legal events — https://patents.google.com/patent/US5953546/en · Unified Patents portal — https://portal.unifiedpatents.com/patents/patent/US-5953546-A

Action item for you: re-run the Assignment Center query against 5953546 to close the gap. If it returns the Minolta → Konica Minolta change-of-name/merger entry, this becomes a confirmed no-NPE / original-assignee-retains file and the verdict should be upgraded to Defensive / non-asserting (inert, expired); if it returns any LLC assignee or any attorney correspondent, my signal analysis above is stale and must be re-run.

I'll search for the cited prior art on the face of US 5,953,546 and cross-check the USPTO record.

Let me dig for the actual "Patent Citations" table on US5953546 and the JP reference named in the specification.

Let me try to pull the exact "Patent Citations" table from Justia/FPO and the USPTO record.

Prior-Art Analysis — US 5,953,546 ("Camera," Minolta Co., Ltd.)

⚠️ Scope/verification caveat (read first)

I was able to confirm the existence and count of the references cited on the face of this patent but not the full enumerated list. Specifically:

• The authoritative full‑text dump you supplied (and the Google Patents page it was fetched from) does not include the front‑page "References Cited" block.
• The Unified Patents portal record for US‑5953546‑A reports "Patent Art (4)" and "Non‑Patent Literature (0)" — i.e., this patent carries an unusually small examiner/field citation set (4 patent documents). [source: https://portal.unifiedpatents.com/patents/patent/US-5953546-A]
• My searches did not surface the verbatim contents of that 4‑item list. I ran out of search steps before retrieving the table from Justia / FPO / PatentCenter.

I am therefore not going to fabricate citations. Below I give (a) what is verified, and (b) how to complete the enumeration from the authoritative source. I did not auto‑correct any patent number or identifier; everything is reported literally.

Also flagging a new bibliographic discrepancy surfaced in this round vs. the prior section: Unified Patents now renders the Priority Date as 1995‑06‑07 (the prior section recorded 1995‑06‑08 from Google Patents) and Expiration Date 2016‑06‑05. These one‑day/one‑year rendering artifacts are reported as found, not harmonized.

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1. Prior art expressly named in the '546 specification (verified from the patent's own text)

These are the only two references the applicant itself identifies in the background/summary, and they are the substantive starting point for the §102 analysis.

Discrepancy to flag: The '546 specification relies on reference B as its closest printed‑publication art, yet Unified Patents reports "Non‑Patent Literature (0)" for this patent — meaning the article appears to have been discussed in the background but not entered as a formally cited reference on the face of the patent. Treat B as specification‑acknowledged prior art, not necessarily a PTO‑cited reference.

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2. The four "Patent Art" references — not enumerated

Unified Patents' "Patent Art (4)" indicates four patent documents were cited. I could not retrieve the four Document Numbers/Countries/Dates in this session. I decline to guess them.

To complete this rigorously, pull the authoritative list directly:

• USPTO Patent Public Search / PatentCenter, application 08/834,107 (patent 5,953,546) → the printed "References Cited" column of the granted front page.
• Or the granted‑PDF front page (page 1) of US 5,953,546 at patentimages.

(Note: I did see a Google Patents snippet listing US5953546A among 13 "Patent Citations" of US 7,400,827 — that is a forward citation (later patent citing '546), the opposite direction from what you asked, and I have not treated it as prior art.)

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3. One item to explicitly disregard

The Google Patents dump for US5953546A contains a "Links" block with entries such as "sodium;9,10‑dioxoanthracene‑2‑sulfonic acid … abstract description 175" and "silver halide … description 2." This is Google Patents chemical/entity‑extraction noise on an optics/camera patent and is not a citation or a claim of the '546 patent. Disregard it.

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4. §102 anticipation assessment — and why it is only a provisional call

Critical constraint: Consistent with the prior section, the verbatim claim set of US 5,953,546 was not retrieved. Anticipation under 35 U.S.C. §102 is limitation‑by‑limitation, element‑by‑element; without the literal claims I cannot state that any reference anticipates any specific claim. What I can responsibly say:

• JP S63‑284527 (ref. A) — does not appear to anticipate. On its face it teaches a film camera + electronic preview viewfinder. The '546 summary passages require, at minimum, (i) a second aperture diaphragm in the image‑pickup beam path and (ii) correlative control of the two diaphragms (specification's "a/γ" and "c·γ" relationships). Reference A does not appear to disclose either. At most it is §103 background against a claim directed to film+EVF preview.
• "Photographic Industries" June 1994 article (ref. B) — does not appear to anticipate. It is characterized by the applicant as showing beam‑splitting for simultaneous photographing/observation — i.e., an SLR‑type split‑beam camera. Beamsplitter‑to‑film + CCD alone is not the claimed novelty; the claimed point of novelty is the correlated dual‑diaphragm control (and the preview‑without‑darkening operation). B appears to be §103/SWOT art, not §102 art.
• Because claim 1 (and any independent claim) cannot be quoted, I flag explicitly: "potentially anticipates" cannot be responsibly assigned to any claim number here. If anticipation is material to your analysis, obtain the claim text from PatentCenter and re‑run the mapping.

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5. Bottom line

Sources

• Google Patents (full text): https://patents.google.com/patent/US5953546A/en
• Unified Patents portal: https://portal.unifiedpatents.com/patents/patent/US-5953546-A
• JPS63284527A (JP S63‑284527) Google Patents: https://patents.google.com/patent/JPS63284527A/
• '546 granted PDF (spec text naming both references): https://patentimages.storage.googleapis.com/c2/28/d5/f3b48c541b126d/US5953546.pdf

I'll try to retrieve the patent's front-page citation list and any verbatim claim text, since the supplied full-text dump omits both.

Obviousness Analysis — U.S. Patent No. 5,953,546 ("Camera") under 35 U.S.C. § 103

Analysis date: 2026-04-26 (see the date-contradiction flag in Caveats below)

Builds on the prior two sections. I do not repeat the bibliographic table, the plain-language overview of Aspects A/B, or the negative litigation finding. Where I rely on them I cross-reference by name.

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0. Threshold caveat, restated because it governs everything below

The authoritative full-text dump supplied for this task still does not contain the claims section, and my searches this round again failed to surface verbatim claim language (the best result, portal.unifiedpatents.com/patents/patent/US-5953546-A, returns the abstract and a "Patent Art (4) / Non-Patent Literature (0) / Referenced By (76)" count — but the four patent-art entries themselves were not rendered in the fetched content).

Consequence, stated plainly:

• A §103 analysis is inherently claim-by-claim and limitation-by-limitation. I cannot complete that mapping.
• Everything below is therefore keyed to the two disclosed subject-matter aspects (A and B) that the specification's own summary passages describe — not to verified claim language. This is a working hypothesis, not a finding about the claims.
• I also could not enumerate the front-page "Patent Art (4)" list. The references I can ground are the ones the patent discusses in its own text, plus one document that surfaced incidentally in search (flagged as probably post-priority and therefore probably not art).

If you need a defensible invalidity opinion, retrieve (i) the granted-PDF claims and (ii) the front-page reference list from USPTO Patent Public Search for application 08/834,107.

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1. Governing legal framework

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2. Scope and content of the prior art of record

2.1 References the patent itself identifies

PA-3 is the analytically most valuable reference in the whole file, because (i) it is an admission, so no priority/authenticity fight exists, and (ii) the applicant's own statement of its deficiencies supplies the motivation to combine and the problem the alleged invention solves. An admission of a problem in the prior art is ordinarily the strongest possible KSR "known problem → known solution" predicate.

2.2 Field-level knowledge imputed to the PHOSITA (the "ordinary creativity" reserve)

None of the following is a document I can cite, so I present it as art-recognized capability categories, not as references. If you need them cited, they must be located and verified:

1. Auto-exposure SLRs with a user-settable aperture value (Av/aperture-priority, program, manual) and electronically driven diaphragm motors under microprocessor control — the patent's own C01/L01/L12 architecture is a conventional implementation.
2. Relay/re-imaging optical systems with their own internal stop feeding a secondary detector. The patent itself describes "a relay aperture diaphragm C18 ... provided inside the relay optical system C14" as an ordinary structural component, introduced without any assertion of novelty.
3. Variable-density ND filters for light attenuation without color shift; the patent treats the ND filter C13 and its motorized position control as an implementation detail.
4. CCD electronic-shutter (charge-accumulation-time) and voltage-controlled-amplifier gain control as the standard second/third lever of exposure after aperture and ND.
5. Beam-splitting main mirrors (semi-transparent, fixed 45°) in SLRs, with an auxiliary mirror feeding an AF module — the patent's C04/C05/C02 arrangement is depicted as conventional SLR furniture.
6. Through-the-lens metering, AF phase-difference detection, and the general SLR light-path discipline (the AF beam is taken from behind the main mirror; obstructing the return path breaks AF).

2.3 One search-surfaced document, flagged

Search surfaced JP H08-6135 A ("Imaging device"), describing a film/image-sensor hybrid camera in which aperture control changes the illuminance on the sensor's image-forming surface and the sensor's gain is adjusted accordingly to keep film-plane exposure correct. This is germane to the field, but the "H08" numbering indicates a 1996 publication — after the 1995-06-08 priority date — so it would be post-priority and likely unavailable as prior art (subject to §102(e)-type considerations only if it has a qualifying U.S. counterpart, which I did not check). Do not rely on it. Flagged so it isn't silently imported into an office action.

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3. Level of ordinary skill in the art

A PHOSITA at the June 1995 priority date: a bachelor's degree in electrical engineering, applied physics, or optical engineering (or equivalent), with roughly 3–5 years designing camera exposure-control and/or optical systems; familiarity with SLR light paths, autoexposure algorithms, motorized diaphragm control, CCD driving/gain, and relay optics. This is a mature, crowded, heavily-engineered art — which cuts against non-obviousness, because in a mature art the ordinary artisan's toolkit is deep and the KSR "predictable variations" rationales bite harder.

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4. Graham factor 2 — the differences

4.1 Aspect A (dual diaphragm with correlative control)

4.2 Aspect B (preview without darkening, using the second diaphragm)

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5. Proposed obviousness combinations

Combination I — PA-1 + PA-2 + PHOSITA knowledge (ordinary skill) → Aspect A

References combined: the 1994 Photographic Industries beam-splitting film+CCD camera (PA-1) as the base; PA-2 for the electronic viewfinder observation channel; the relay-stop and diaphragm-control design knowledge of §2.2.

Motivation to combine (articulable, all grounded):

1. PA-1 already frames the problem the invention solves. Because PA-1 splits one lens's beam between film and a 1/2-inch CCD, it necessarily throws away light and necessarily presents two detectors with different sensitivity and different acceptable exposure — which the patent itself confirms when it reads film sensitivity and sets ND density "based on the sensitivity difference between the image pickup device C21 and the film." A PHOSITA starting from PA-1 has a standing design incentive to make each branch independently trimmable.
2. The solution PA-1 lacks is the standard tool for the job. When a secondary conjugate path needs its own exposure control, the conventional answer is a stop inside the relay/re-imaging system — precisely the "relay aperture diaphragm C18 ... provided inside the relay optical system C14" the patent introduces as unremarkable hardware. Supplying a second diaphragm in the CCD branch is therefore the combination of known elements according to known methods yielding a predictable result (KSR rationale 1) and the use of a known technique to improve a similar device in the same way (KSR rationale 3).
3. Correlation of the two stops is dictated by the geometry, not by insight. If the first stop sits in the taking lens and the second sits in a relay of magnification γ forming a secondary image from the aerial primary image, then the two stops are conjugate. The patent's own worked relationships — the taking-lens value c corresponds to a relay value c·γ, and the relay's open value a corresponds to a taking-lens-equivalent a/γ — are the arithmetic of that conjugation. Expressing a controlled second aperture as a scaled function of a first aperture is a predictable design choice / mere expression of a known optical relationship (KSR rationale 4). Nothing here is an unpredictable result; it is a magnification factor.
4. The correlation has a concrete, stated engineering payoff. The point of a simultaneous film+video camera is that the video frame matches the film frame. If the CCD branch ran its own independent autoexposure it would drift away from the photographer's chosen taking-lens aperture, and hence from the intended depth of field and the film frame's appearance — defeating the product's stated purpose. Correlating the stops is the only way to make the two records agree. Where the art discloses a finite number of identified, predictable solutions to the exposure-consistency problem (correlate the stops; or correlate plus compensate), KSR makes that an "obvious to try" situation.
5. The acknowledged limit is handled by routine compensation. Because the CCD branch cannot receive light wider than a/γ, the patent's compensation is to slow the CCD's charge-accumulation time, reduce ND density, or raise the voltage-controlled amplifier gain — every one of which is individually conventional (§2.2 items 3–4). The patent's own flow charts (#A11–#A13, #A25–#A27, #P25–#P29, #S2016–#S2020) read as a catalogue of standard exposure levers rather than as inventive subject matter. A PHOSITA would expect success in implementing them.

Reasonable expectation of success: high. Both elements exist; the interfaces (microcomputer setting a diaphragm motor; CCD accumulation time; ND density) are all mature; the only "new" behaviour is a mapping formula.

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Combination II — PA-3 + PA-2 (+ PA-1) + PHOSITA knowledge → Aspect B

References combined: the conventional stopped-down optical preview mechanism (PA-3, AAPA) as the thing to be improved; PA-2 (and PA-1) for the film+image-pickup camera with an electronic observation channel; PA-1 for the beam-split CCD branch that makes the electronic observation channel available at full aperture.

Motivation to combine (the strongest ground in this file):

1. PA-3 supplies the problem in the applicant's own words. Two admitted defects — the previewed image "is dark," and "it is impossible to detect focus during previewing, because a light beam to be used for focus detection is obstructed when the aperture is extremely stopped down." These are express, admitted long-felt problems, and §103 motivation analysis rarely gets cleaner.
2. PA-2 supplies the known alternative channel. PA-2 already teaches that the image taken by the image pickup device "can be reproduced and observed through a viewfinder," and even calls it a preview of the film frame. So the idea of previewing via the electronic channel rather than the optical channel is squarely in the art — it is not the invention.
3. Substitution yields precisely the two admitted benefits. Route the preview through the image-pickup branch and set the second diaphragm to the value corresponding to the user-set taking-lens value (scaled by γ). The electronic viewfinder then shows the depth-of-field condition of the set aperture, while the display is kept bright by the standard accumulation-time/gain compensation — curing defect (a). And because the film-path taking-lens aperture remains open during preview, the AF return beam behind the main mirror is never obstructed — curing defect (b). This is the textbook KSR case of simple substitution of one known element for another to obtain the predictable advantage of the substitute, and of a known problem solved by a known, finite set of solutions.
4. No structural change is required. The preview is an operating mode of hardware the PHOSITA already must build (a beam-splitting body, two diaphragm actuators, a microprocessor, an EVF). Implementing "actuate the second stop per the set value while not exposing film, and display the picked-up image" is control logic on existing hardware — a change of software/mode configuration, which weighs toward obviousness.
5. Cross-support from the patent's own disclosure. The patent implements preview simply by retaining a frame in an existing frame memory and re-displaying it still, and by having the dual-purpose button select the preview behaviour per mode. Nothing in the preview path is bespoke.

Reasonable expectation of success: high — the applicant himself frames the invention as achieving what the conventional mechanism could not, using components (EVF, CCD branch, frame memory, diaphragm motors) all present in the art.

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6. KSR rationale ledger (for use in a rejection narrative)

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7. Anticipated applicant rebuttals, and how they fare

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8. Bottom line

• Prima facie obviousness under pre-AIA §103(a) is strong for both hypothesized aspects.
  • Aspect A — Photographic Industries (June 1994) already discloses the whole system architecture (one lens, split beam, film on one branch, 1/2-inch CCD on the other); adding a relay-path stop and correlating it to the taking-lens stop is a combination of known elements producing a predictable result, with the scaling relationship being the geometry of relay magnification.
  • Aspect B — the conventional SLR preview mechanism is admitted prior art whose admitted defects (dark viewfinder, obstructed AF beam) cry out for the electronic-preview substitution that JP S63-284527 already supplies; the result is the predictable advantage of the substitute.
• The single material gap is the claim text. Without it, all of this is a §103 theory about the disclosed subject matter, not a limitation-by-limitation rejection. Retrieve the claims before relying on this.
• Defensively, an applicant could plausibly salvage a narrow dependent claim to specific numeric aperture relationships or to a specific compensation hierarchy (ND-first vs. gain-first vs. accumulation-time-first). I cannot assess that without the claims.

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9. Caveats and contradictions (explicit, per operating rules)

1. Claim text remains unretrieved. Consistent with the two prior sections; this is not a new finding, but it is a hard ceiling on the analysis. No contradiction between sections on this point.
2. Front-page "Patent Art (4)" list unretrieved. The Unified Patents record shows the count (4 patent-art references, 0 NPL, 76 referenced-by) but the fetched content did not render the four entries. My analysis relies on the references named in the patent's own description, which is a narrower set.
3. PA-1's and PA-2's contents are characterized only as the patent characterizes them. I did not locate the June 1994 Photographic Industries article itself, nor a translation of S63-284527. Treat their teachings above as grounded in the patent's own admissions/discussion.
4. S63 = 1988 is my literal reading of the Showa-era designation. Flagged as an inference, not a verified publication date.
5. JP H08-6135 A is likely post-priority (1996) and likely not prior art. Included only to show what the search surfaced; explicitly excluded from the combinations.
6. Date contradiction between instructions. The system framing states "Today's date is 2026-09-30"; the current task states "Current Date: April 26, 2026." I have used 2026-04-26 as the analysis date per the task instruction, but flag the discrepancy rather than resolving it.
7. Earlier-section data discrepancies persist and are unchanged: Google Patents vs. Unified Patents differ by one day on priority (1995-06-08 vs. 1995-06-07 per the portal snippet in this round), filing (1997-04-14 vs. 1997-04-13), grant (1999-09-14 vs. 1999-09-13), and expiry (2016-06-06 vs. 2016-06-05). Reporting literally; not harmonizing. None of these one-day shifts changes any conclusion above (all prior-art dates clear the one-year bar by years).
8. Pre-AIA foreign-priority/§102(b) question deliberately side-stepped, as explained in §1, because the reference dates make it unnecessary to resolve.

Recommended next steps if this is to become an opinion of counsel: (a) pull granted claims and front-page references from USPTO PatentCenter for 08/834,107; (b) obtain the June 1994 Photographic Industries article and a translation of JP S63-284527 and confirm their actual disclosures against each limitation; (c) confirm whether any of the four "Patent Art" references is the closest art (my PA-2 estimate is a hypothesis, not a verified front-page listing).