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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-08-14</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>2013-08-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>90000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.2</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>705000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Manager of the accounts.</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>A Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.2</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-08-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>90000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.2</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2011-11-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-09-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>90000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Manager of the accounts.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>B Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-08-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>90000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2013-08-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-11-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>90000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>90000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Manager of the accounts.</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">302,500 of which are owned by Elser &amp; Co., of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  342,500 of which are owned by Carlisle Investments, of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  60,000 of which are owned by AdviCorp plc, of which I exercise voting and dispositive rights as the account manager, and own 50% of the equity of AdviCorp plc.  No change in ownership on behalf of AdviCorp plc is being reported in this Form 4.</footnote>
        <footnote id="F2">40,000 of which are owned by Elser &amp; Co., of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  50,000 of which are owned by Carlisle Investments, of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.</footnote>
        <footnote id="F3">Each B Warrant entitles the holder to purchase one share of Common Stock, at an exercise price of $0.50 per share.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Marco Elser</signatureName>
        <signatureDate>2013-08-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2013-08-14
0
0000099106
TRANS LUX CORP
TNLX
0001321913
ELSER MARCO M
VIA SISTINA 121
ROME
L6
00187
ITALY
1
0
0
0
Common Stock
2013-08-14
4
C
0
90000
0.2
A
705000
I
Manager of the accounts.
A Warrants
0.2
2013-08-14
4
C
0
90000
0.2
D
2011-11-14
2013-09-13
Common Stock
90000
0
I
Manager of the accounts.
B Warrants
0.5
2013-08-14
4
C
0
90000
0.5
A
2013-08-14
2014-11-14
Common Stock
90000
90000
I
Manager of the accounts.
302,500 of which are owned by Elser & Co., of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  342,500 of which are owned by Carlisle Investments, of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  60,000 of which are owned by AdviCorp plc, of which I exercise voting and dispositive rights as the account manager, and own 50% of the equity of AdviCorp plc.  No change in ownership on behalf of AdviCorp plc is being reported in this Form 4.
40,000 of which are owned by Elser & Co., of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.  50,000 of which are owned by Carlisle Investments, of which I exercise voting and dispositive rights as the account manager, but disclaim any beneficial ownership.
Each B Warrant entitles the holder to purchase one share of Common Stock, at an exercise price of $0.50 per share.
/s/ Marco Elser
2013-08-16