Gideon Korrell Lists 5 Reasons PTAB Findings Don’t Bind Courts
                     Gideon Korrell 
Lists 5 Reasons 
PTAB Findings 
Don’t Bind 
Courts
On October 15, 2025, the Federal 
Circuit sent back a district court 
ruling in Inland Diamond Products 
v. Cherry Optical. The court said 
the district court made a key 
mistake—it relied too heavily on 
earlier PTAB decisions to 
invalidate patent claims.
The message was clear: PTAB 
findings cannot automatically 
decide validity in district court. 
Here are the five main reasons 
why.
1. PTAB and Courts 
Use Different Proof 
SAt tthae nPTdABa, ar pdatsent can be found 
unpatentable using a lower standard of 
proof (preponderance of the evidence). 
In district court, invalidity must be 
proven by clear and convincing 
evidence, which is much harder.
Because of this difference, facts found 
by the PTAB do not settle the issue in 
court. The Federal Circuit relied on 
ParkerVision, Inc. v. Qualcomm Inc. to 
confirm this rule.
2. Courts Must 
Decide Validity on 
Their Own Record
The district court treated PTAB findings as 
if they already proved invalidity. That was 
wrong. Courts must review the evidence 
presented in court, not copy conclusions 
from the PTAB.
Using PTAB findings as shortcuts shifts the 
burden away from the accused infringer, 
which the law does not allow.
3. Similar Claims Still 
Need Fresh Analysis
Cherry argued that the asserted 
claims were almost the same as 
claims the PTAB already rejected. 
The Federal Circuit disagreed.
Even if claims are very similar, 
courts still must independently 
decide validity. This point comes 
directly from Kroy IP Holdings, LLC 
v. Groupon, Inc.
4. Claim 
Construction Was 
DTheirffe wears eannothter problem: the 
PTAB and the district court used 
different claim interpretation rules.
The PTAB applied the “broadest 
reasonable interpretation,” while 
the district court had to apply the 
Phillips standard. Different 
standards mean issue preclusion 
does not apply especially in older 
IPRs like this one.
5. Surviving an IPR 
Does Not End the 
Question
The district court also relied on the fact 
that the claims survived the IPRs. The 
Federal Circuit said that does not matter.
Unless claims are finally ruled invalid 
and affirmed on appeal, they remain 
valid. This case was not like XY, LLC v. 
Trans Ova Genetics, where claims had 
already been invalidated on appeal.
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