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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000099106</issuerCik>
        <issuerName>TRANS LUX CORP</issuerName>
        <issuerTradingSymbol>TLX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001258601</rptOwnerCik>
            <rptOwnerName>BRANDT RICHARD PAUL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 839</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TESUQUE</rptOwnerCity>
            <rptOwnerState>NM</rptOwnerState>
            <rptOwnerZipCode>87571</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.45</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-12-13</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-12-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>Richard Brandt</signatureName>
        <signatureDate>2007-12-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2007-12-13
0
0000099106
TRANS LUX CORP
TLX
0001258601
BRANDT RICHARD PAUL
PO BOX 839
TESUQUE
NM
87571
1
0
1
0
Director Stock Option
5.45
2007-12-13
4
A
0
2500
0
A
2008-12-13
2013-12-12
Common Stock
2500
2500
D
Richard Brandt
2007-12-17