Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Net sales:
Products	$ 42,159	$ 33,403	$ 80,180	$ 60,969
Services	3,562	3,434	7,327	7,377
Licenses	200	0	300	100
Total net sales	45,921	36,837	87,807	68,446
Cost of sales:
Cost of products sold	21,546	17,383	41,151	32,831
Cost of services	2,904	2,944	6,153	6,113
Total cost of sales	24,450	20,327	47,304	38,944
Gross profit	21,471	16,510	40,503	29,502
Operating expenses:
Research, development, and engineering	7,993	8,175	16,417	16,389
Selling, general, and administrative	12,015	12,418	24,058	24,384
Operating income (loss)	1,463	(4,083)	28	(11,271)
Interest expense	(20)	0	(51)	(2)
Interest and other income (expense), net	48	105	187	422
Income (loss) before income tax	1,491	(3,978)	164	(10,851)
Provision for (benefit from) income taxes	(48)	(88)	312	10
Net income (loss)	$ 1,539	$ (3,890)	$ (148)	$ (10,861)
Net income per share - basic (in dollars per share)	$ 0.06	$ (0.14)	$ (0.01)	$ (0.38)
Number of shares used in per share computations - basic (in shares)	27,780	28,320	27,799	28,265
Net income per share - diluted (in dollars per share)	$ 0.06	$ (0.14)	$ (0.01)	$ (0.38)
Number of shares used in per share computations - diluted (in shares)	27,980	28,320	27,799	28,265