Condensed Consolidated Statements of Operations (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011
Net sales	$ 193,284	$ 200,880	$ 384,051	$ 383,991
Cost of sales	115,636	112,111	226,044	212,828
Gross profit	77,648	88,769	158,007	171,163
Operating expenses:
Research and development	20,323	21,246	39,102	39,776
Selling, general and administrative	35,377	38,979	70,008	75,057
Amortization of intangible assets	1,611	2,257	3,247	4,352
Total operating expenses	57,311	62,482	112,357	119,185
Income from operations	20,337	26,287	45,650	51,978
Other income (expense):
Interest and dividend income	29	161	231	344
Interest expense	(5)	(17)	(7)	(32)
Other—net	1,888	9,181	2,206	10,767
Total other income (expense), net	1,912	9,325	2,430	11,079
Income before income taxes	22,249	35,612	48,080	63,057
Provision for income taxes	6,094	11,889	14,874	20,221
Net income	$ 16,155	$ 23,723	$ 33,206	$ 42,836
Net income per share:
Basic	$ 0.69	$ 0.94	$ 1.41	$ 1.72
Diluted	$ 0.67	$ 0.92	$ 1.38	$ 1.68
Shares used in computation:
Basic	23,521	25,246	23,491	24,967
Diluted	23,996	25,832	23,979	25,550