Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Apr. 01, 2012	Apr. 03, 2011
Revenue
Product	$ 71,407	$ 68,877
Service	6,302	5,517
Total revenue	77,709	74,394
Cost of revenue
Product	15,556	15,099
Service	3,502	3,284
Total cost of revenue	19,058	18,383
Gross margin
Product	55,851	53,778
Service	2,800	2,233
Total gross margin	58,651	56,011
Research, development, and engineering expenses	10,361	9,482
Selling, general, and administrative expenses	30,549	29,161
Operating income	17,741	17,368
Foreign currency loss	(638)	(59)
Investment income	972	605
Other income (expense)	3	(205)
Income before income tax expense	18,078	17,709
Income tax expense	3,796	4,073
Net income	$ 14,282	$ 13,636
Earning per weighted-average common and common-equivalent share:
Basic	$ 0.34	$ 0.33
Diluted	$ 0.33	$ 0.32
Weighted-average common and common-equivalent shares outstanding:
Basic	42,570	41,336
Diluted	43,590	42,286
Cash dividends per common share	$ 0.1	$ 0.08