Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Oct. 02, 2011	Oct. 03, 2010	Oct. 02, 2011	Oct. 03, 2010
Revenue
Product	$ 74,165	$ 69,288	$ 220,608	$ 190,968
Service	5,920	5,705	17,264	14,803
Total revenue	80,085	74,993	237,872	205,771
Cost of revenue
Product	15,705	15,537	47,258	44,362
Service	3,248	3,376	9,457	9,209
Total cost of revenue	18,953	18,913	56,715	53,571
Gross margin
Product	58,460	53,751	173,350	146,606
Service	2,672	2,329	7,807	5,594
Total gross margin	61,132	56,080	181,157	152,200
Research, development, and engineering expenses	10,608	7,961	30,596	24,140
Selling, general, and administrative expenses	28,135	25,857	86,762	75,217
Restructuring charges		(13)		75
Operating income	22,389	22,275	63,799	52,768
Foreign currency gain (loss)	(231)	102	(80)	(71)
Investment income	917	384	2,219	949
Other expense	(156)	(129)	(509)	(531)
Income before income tax expense	22,919	22,632	65,429	53,115
Income tax expense	4,882	4,487	14,659	11,498
Net income	$ 18,037	$ 18,145	$ 50,770	$ 41,617
Earnings per weighted-average common and common-equivalent share:
Basic	$ 0.43	$ 0.46	$ 1.22	$ 1.05
Diluted	$ 0.42	$ 0.45	$ 1.19	$ 1.05
Weighted-average common and common-equivalent shares outstanding:
Basic	42,128	39,729	41,765	39,693
Diluted	42,976	39,917	42,682	39,792
Cash dividends per common share	$ 0.09	$ 0.06	$ 0.26	$ 0.17