Warranty reserves (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Movement in warranty reserves [Roll Forward]
Warranty reserves at beginning of period	$ 88	$ 70	$ 89	$ 96
Decrease in beginning balance for warranty obligations settled during the period	(8)	(11)	(16)	(37)
Other changes to pre-existing warranties	0	0	(8)	(25)
Foreign currency translation adjustment	(1)	0	(1)	2
Net increase in warranty reserves for products sold during the period	0	28	15	51
Warranty reserves at end of period	$ 79	$ 87	$ 79	$ 87