Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Net sales:
Products	$ 56,242	$ 49,283	$ 154,870	$ 140,736
Services	3,652	5,361	13,061	14,786
Licenses	653	300	1,303	750
Total net sales	60,547	54,944	169,234	156,272
Cost of sales:
Cost of products sold	22,844	21,935	64,825	64,013
Cost of services	3,534	3,614	9,801	11,671
Total cost of sales	26,378	25,549	74,626	75,684
Gross profit	34,169	29,395	94,608	80,588
Operating expenses:
Research, development, and engineering	7,745	6,349	22,280	17,832
Selling, general, and administrative	11,469	11,484	32,938	32,301
Operating income	14,955	11,562	39,390	30,455
Interest expense	(1)	(4)	(6)	(16)
Interest and other income, net	126	(74)	208	40
Income before income tax	15,080	11,484	39,592	30,479
Provision for income taxes	2,638	1,020	5,779	2,420
Net income	$ 12,442	$ 10,464	$ 33,813	$ 28,059
Net income per share - basic (in dollars per share)	$ 0.46	$ 0.40	$ 1.27	$ 1.09
Number of shares used in per share computations - basic (in shares)	27,047	25,977	26,635	25,678
Net income per share - diluted (in dollars per share)	$ 0.45	$ 0.39	$ 1.23	$ 1.05
Number of shares used in per share computations - diluted (in shares)	27,777	26,647	27,481	26,620