Document And Entity Information (USD $)	12 Months Ended
	Sep. 30, 2011	Dec. 29, 2011	Mar. 31, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	LOGIC DEVICES INC
Entity Central Index Key	0000802851
Trading Symbol	logc
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--09-30
Entity Filer Category	Smaller Reporting Company
Entity Well-Known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		8,918,166
Entity Public Float			$ 2,520,711
Document Type	10-K
Document Period End Date	Sep. 30, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY