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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-06-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001321913</rptOwnerCik>
            <rptOwnerName>ELSER MARCO M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>VIA SISTINA 121</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROME</rptOwnerCity>
            <rptOwnerState>L6</rptOwnerState>
            <rptOwnerZipCode>00187</rptOwnerZipCode>
            <rptOwnerStateDescription>ITALY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-06-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>166666</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>197011</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Manager of accounts for indirectly owned shares</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">2,145 shares are directly owned by me.  12,100 shares are owned by Elser &amp; Co., over which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  180,366 shares are owned by Carlisle Investments Inc., over which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  2,400 shares are owned by AdviCorp plc, over which I exercise voting and dispositive rights as the account manager, and I also own 50% of the equity of AdviCorp plc.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Marco Elser</signatureName>
        <signatureDate>2014-06-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2014-06-20
0
0000099106
TRANS LUX CORP
TNLX
0001321913
ELSER MARCO M
VIA SISTINA 121
ROME
L6
00187
ITALY
1
0
0
0
Common Stock
2014-06-20
4
A
0
166666
6
A
197011
I
Manager of accounts for indirectly owned shares
2,145 shares are directly owned by me.  12,100 shares are owned by Elser & Co., over which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  180,366 shares are owned by Carlisle Investments Inc., over which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  2,400 shares are owned by AdviCorp plc, over which I exercise voting and dispositive rights as the account manager, and I also own 50% of the equity of AdviCorp plc.
Marco Elser
2014-06-23