<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-03-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000099106</issuerCik>
        <issuerName>TRANS LUX Corp</issuerName>
        <issuerTradingSymbol>TNLX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001784269</rptOwnerCik>
            <rptOwnerName>Fazio Nicholas J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TRANS-LUX CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>135 EAST 57TH STREET, 14TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>I</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2061856</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.97</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3377645</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Director and Executive Officer of the owner of the shares, Unilumin North America</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-04-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>I</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3608247</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.97</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6985892</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Director and Executive Officer of Unilumin North America (the holder of these shares)</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrant</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.97</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-03-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>I</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2061856</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.97</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2018-11-02</value>
            </exerciseDate>
            <expirationDate>
                <value>2020-11-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20161856</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3608247</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Director and Executive Officer of Unilumin North America (the holder of these warrants)</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrant</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.97</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-04-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>I</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3608247</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.97</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2018-11-02</value>
            </exerciseDate>
            <expirationDate>
                <value>2020-11-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3608247</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Director and Executive Officer of Unilumin North America (the holder of these warrants)</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As Director and Executive Officer of Unilumin North America (the holder of these shares), Mr. Fazio has voting and dispositive power over the shares, but does not have a pecuniary interest in these
shares.</footnote>
        <footnote id="F2">As Director and Executive Officer of Unilumin North America (the holder of these warrants), Mr. Fazio has voting and dispositive power over the warrants, but does not have a pecuniary interest in these warrants.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Nicholas Fazio</signatureName>
        <signatureDate>2019-10-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2019-03-04
0
0000099106
TRANS LUX Corp
TNLX
0001784269
Fazio Nicholas J
C/O TRANS-LUX CORPORATION
135 EAST 57TH STREET, 14TH FLOOR
NEW YORK
NY
10022
1
0
1
0
Common Stock
2019-03-04
4
I
1
2061856
0.97
A
3377645
I
Director and Executive Officer of the owner of the shares, Unilumin North America
Common Stock
2019-04-05
4
I
1
3608247
0.97
A
6985892
I
Director and Executive Officer of Unilumin North America (the holder of these shares)
Warrant
0.97
2019-03-04
4
I
1
2061856
0.97
D
2018-11-02
2020-11-02
Common Stock
20161856
3608247
I
Director and Executive Officer of Unilumin North America (the holder of these warrants)
Warrant
0.97
2019-04-05
4
I
1
3608247
0.97
D
2018-11-02
2020-11-02
Common Stock
3608247
0
I
Director and Executive Officer of Unilumin North America (the holder of these warrants)
As Director and Executive Officer of Unilumin North America (the holder of these shares), Mr. Fazio has voting and dispositive power over the shares, but does not have a pecuniary interest in these
shares.
As Director and Executive Officer of Unilumin North America (the holder of these warrants), Mr. Fazio has voting and dispositive power over the warrants, but does not have a pecuniary interest in these warrants.
Nicholas Fazio
2019-10-18