Claim chartsEvidenceWorked examples

Claim chart examples with real evidence rows

By Ipiry TeamPublished August 25, 20267 min read

Short answer

A claim chart maps each element of a claim to corresponding evidence in two columns. A usable chart has one row per limitation, a specific cited source with a page or figure reference, and an honest grade including unverified where the evidence does not exist. The examples below show a clean infringement chart, one with a gap handled properly, and an invalidity chart, which reads the same way against prior art instead of a product.

A claim chart example is more useful than a description of one, because the format is simple and the discipline is where charts succeed or fail.

Two columns. Claim language on the left, evidence on the right.

One row per limitation, a cited source in every row, and an honest grade including "unverified" where the evidence does not exist.

Three worked examples below — a clean infringement chart, one with a gap, and an invalidity chart.

The columns

Column	Contains
Element	The exact claim words, one limitation per row
Accused feature / prior art	The specific corresponding thing
Evidence	Source with page, figure or paragraph
Grade	Present / absent / arguable / unverified
Notes	Construction applied, source date

A two-column chart is the minimum. The grade and notes columns are what make it usable months later by someone who was not there.

Example 1: a clean infringement chart

Claim 1: A fluid separator comprising: a housing defining a flow path having an inlet and an outlet; a baffle disposed within the flow path, the baffle defining an aperture; and a biasing element coupled to the baffle and configured to vary an area of the aperture in response to a flow velocity within the flow path.

#	Element	Accused feature	Evidence	Grade
1a	A housing	Cast aluminium body	Service Manual SM-400 rev 3, fig. 2	Present
1b	defining a flow path	Internal bore, inlet to outlet	SM-400, fig. 2, items 4–7	Present
1c	having an inlet and an outlet	Ports A and B	Spec sheet DS-400, p.1	Present
2a	A baffle	Deflector plate	SM-400 §4.2	Present
2b	disposed within the flow path	Mounted in the bore	SM-400, fig. 3	Present
2c	the baffle defining an aperture	Central 12 mm opening	SM-400, fig. 3, item 11	Present
3a	A biasing element	Compression spring	SM-400 §4.3	Present
3b	coupled to the baffle	Direct mechanical coupling	SM-400, fig. 3, item 14	Present
3c	configured to vary aperture area	Aperture opens with flow	Their US 11,XXX,XXX, para. 41	Present
3d	in response to a flow velocity	Velocity-driven	Their US 11,XXX,XXX, para. 44	Present

Ten rows from three claim elements. Splitting at every limitation is what makes the chart checkable.

Rows 3c and 3d cite the target's own patent application. Companies describe their approach accurately in their filings, and those documents are public and dated.

The product also has a heater and a digital display. Irrelevant — the transition is "comprising", so extra features never avoid the claim.

Example 2: a chart with a gap handled properly

Same claim, a different product.

#	Element	Accused feature	Evidence	Grade
1a–1c	Housing, flow path, ports	Moulded body	User Manual UM-22, p.4	Present
2a–2c	Baffle with aperture	Internal disc	Teardown photos, 12 Mar 2026	Present
3a	A biasing element	Not observable externally	—	Unverified
3b	coupled to the baffle	Assumed from operation	—	Unverified
3c	varies aperture area	Aperture visibly changes in operation	Test video, 12 Mar 2026	Arguable
3d	in response to flow velocity	Correlates with flow rate	Test data, 12 Mar 2026	Arguable

What the chart says about itself

Finding	Note
Elements 3a–3b unverified	Internal mechanism not observable
What would settle it	Full teardown, service manual, or discovery
Elements 3c–3d arguable	Behaviour observed, mechanism inferred
Conclusion	Not established on public evidence

This chart is more useful than one asserting the mechanism exists. It tells the reader exactly what is missing and what would close it.

Grading honestly protects the chart. One assumption presented as fact makes every other row suspect.

Example 3: an invalidity chart

Same claim, mapped against prior art instead of a product.

#	Element	Prior art disclosure	Evidence	Grade
1a–1c	Housing, flow path, ports	Disclosed	US 6,XXX,XXX (Hallberg), col. 3:12–28	Present
2a–2c	Baffle with aperture	Disclosed	Hallberg, fig. 4, col. 4:5–19	Present
3a	A biasing element	Fixed baffle — no biasing	Hallberg, col. 4:22	Absent
3b–3d	Variable aperture	Not disclosed	—	Absent

The obviousness combination

Reference	Supplies
Hallberg	Elements 1a–2c
JP-XXXXXX (Tanaka), fig. 2	Spring-biased variable aperture
Motivation to combine	Must be shown, not assumed

Anticipation fails here. Hallberg lacks the biasing element, and a single reference must disclose every element for §102.

Obviousness needs the combination argued, not just charted. A two-reference chart showing all elements between them does not by itself establish that a skilled person would have combined them. See patent invalidity search.

What separates usable from unusable

Usable	Unusable
One row per limitation	Elements combined
Specific page or figure cited	"See product literature"
Honest grades including unverified	Everything marked present
Source dates recorded	Undated
Every element addressed	Elements skipped
Construction stated where disputed	Silent
The full claim charted	Partial

"See the website" is not evidence. A source citation must let someone else find the same thing.

Date every source. A 2022 manual may not describe the 2026 product, and that gap gets found by the other side if not by you.

Method claims need a performer column

#	Step	Performed by	Evidence
1	Directing the fluid stream	The customer	UM-22, p.9
2	Varying the aperture area	The device	SM-400 §4.3
3	Reporting the result	The vendor's service	Portal docs, p.2

Steps split across parties raise divided infringement. Where no single party performs every step, attribution requires direction or control, and an ordinary vendor-customer relationship generally does not meet that.

Add the column whenever the claim is a method. It surfaces the issue rather than hiding it.

What the chart does not decide

Question	Where it lives
What the claim terms mean	Construction, before the chart
Whether a gap is bridged by equivalents	Separate analysis
Whether estoppel bars equivalents	Prosecution history
Whether the patent is valid	A different chart
Whether pursuit is worthwhile	Commercial judgement

Construe before charting. A mapping built on an unstated reading of a term changes when a court reads it differently.

Check estoppel before relying on equivalents. It is free to establish from a public file wrapper and frequently disposes of the argument. See prosecution history estoppel.

Before charting anything

Check	Why	Time
Is the patent in force?	58.6% are abandoned before term	3 min
Who owns it?	The front page is out of date	5 min
Which claims survived challenge?	Narrowed claims chart differently	10 min

Ipiry Patent Survival Curve v1.0	Rate
Survive the 3.5-year fee (2022 cohort)	85.8%
Survive the 7.5-year fee (2018 cohort)	64.6%
Reach full term (2014 cohort)	41.4%

Computed from 27,273,654 USPTO maintenance fee records covering 8,262,336 US utility patents — see the patent survival curve.

Where automation helps

Task	Automation
Finding candidate products	Substantial
Retrieving documentation	Substantial
First-draft mapping	Substantial
Verifying every citation	Human
Grading honestly	Human
Deciding what to do	Human

Verify every cited source. A fabricated or misread citation is worse than an empty row, because it makes the whole chart untrustworthy at exactly the moment it matters.

Claim chart example: the checklist

Two columns minimum, four if the chart will be read later.
One row per limitation, splitting at every requirement.
Cite a specific page, figure or paragraph in every row.
Search the target's own patent filings. Best available evidence.
Grade honestly. "Unverified" is more useful than an assumption.
State what evidence would close each gap.
Chart the full claim. Skipping an element makes it useless.
Add a performer column for method claims.
Construe disputed terms before charting, and record the construction.
Check the patent is in force before doing any of it.

Common questions

What does a claim chart look like?

Two main columns — the claim language on the left, broken into elements, and the corresponding evidence on the right. Working charts add a grade column and a source reference, since a chart without citations cannot be checked by anyone.

How many rows should a chart have?

One per limitation, not one per claim clause. A phrase containing two requirements produces two rows, because each must be independently satisfied and combining them hides which one is weak.

What counts as good evidence?

A specific, locatable source — a manual page, a figure number, a specification line, a paragraph of the target's own patent application. Assertions without a source carry no weight and undermine the rest of the chart.

What do I put when I cannot verify an element?

Grade it unverified and state what evidence would settle it. An honest gap is more useful than a guess, and a chart containing one assumption presented as fact becomes untrustworthy in its entirety.

Are invalidity charts different?

Structurally identical, but mapped against prior art rather than a product. The chart shows where each claim element appears in a reference, and for obviousness combinations it must also address why a skilled person would combine them.

Should the chart include the whole claim?

Yes, every element of the claim being charted. Omitting an element makes the chart useless, because infringement requires all of them and a chart that skips one has not addressed the question.

Which claims should I chart?

Independent claims first. If a product falls outside every independent claim it cannot infringe any dependent claim, so charting dependents before that is wasted work.

How long does a chart take?

A screening chart on one claim can be done in a day where public documentation exists. A litigation-quality chart with verified sources and construction reasoning takes considerably longer and is usually done with counsel.

Can charts be generated automatically?

First drafts, yes, and the time saving is real. Every cited source still needs verification, because a fabricated or misread citation is worse than an empty row and makes the entire chart unreliable.

What is the most common mistake?

Comparing overall similarity instead of element by element. The second most common is treating extra features in the accused product as avoiding the claim, which almost never works because nearly every claim uses comprising.

Does a chart prove infringement?

No. It documents a mapping. Whether infringement follows depends on claim construction, the doctrine of equivalents where an element is absent, and prosecution history estoppel, none of which fits inside the chart itself.

Why does a chart matter for selling a patent?

Because evidence that a patent reads on products in the market is the largest single factor in what a buyer will pay. A patent with a documented chart against a shipping product is a different asset from one without.

Patent claim chart: how to build one

A claim chart maps every element of a patent claim to a feature of an accused product or a prior art reference. How to build one, what makes it credible, and where they are used.

Product mapping methodology for patent infringement

A repeatable method for mapping a product against patent claims — parsing the claim, gathering evidence, building the chart, grading each element, and knowing when the mapping is finished.

Patent invalidity search

How an invalidity search differs from a patentability search, why the priority date governs everything, where the best references hide, what it costs, and how to brief one.

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