<SEC-DOCUMENT>0001739237-18-000001.txt : 20180503
<SEC-HEADER>0001739237-18-000001.hdr.sgml : 20180503
<ACCEPTANCE-DATETIME>20180503104320
ACCESSION NUMBER:		0001739237-18-000001
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180502
FILED AS OF DATE:		20180503
DATE AS OF CHANGE:		20180503

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PARROTTE DIANNE M
		CENTRAL INDEX KEY:			0001739237

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34218
		FILM NUMBER:		18802270

	MAIL ADDRESS:	
		STREET 1:		1 VISION DRIVE
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COGNEX CORP
		CENTRAL INDEX KEY:			0000851205
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		IRS NUMBER:				042713778
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE VISION DR
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760
		BUSINESS PHONE:		5086503000

	MAIL ADDRESS:	
		STREET 1:		ONE VISION DRIVE
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2018-05-02</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000851205</issuerCik>
        <issuerName>COGNEX CORP</issuerName>
        <issuerTradingSymbol>CGNX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001739237</rptOwnerCik>
            <rptOwnerName>PARROTTE DIANNE M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE VISION DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NATICK</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01760</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Dianne M. Parrotte</signatureName>
        <signatureDate>2018-05-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
