CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Net sales	$ 80,152	$ 81,884	$ 139,121	$ 158,930
Cost of sales	46,632	45,943	81,948	89,229
Gross profit	33,520	35,941	57,173	69,701
Operating expenses:
Selling, service and administration	15,114	14,884	30,777	31,380
Research, development and engineering	10,527	10,742	20,061	21,976
Legal settlement costs				550
Net operating expenses	25,641	25,626	50,838	53,906
Operating income	7,879	10,315	6,335	15,795
Non-operating income (expense):
Gain on sale of previously impaired auction rate securities				2,729
Interest and other income (expense), net	91	(406)	(59)	(543)
Total non-operating income (expense)	91	(406)	(59)	2,186
Income before income taxes	7,970	9,909	6,276	17,981
Provision for income taxes	2,759	1,372	2,009	3,531
Net income	$ 5,211	$ 8,537	$ 4,267	$ 14,450
Net income per share - basic	$ 0.18	$ 0.30	$ 0.15	$ 0.51
Net income per share - diluted	$ 0.17	$ 0.29	$ 0.14	$ 0.49
Weighted average number of shares - basic	29,339	28,747	29,228	28,609
Weighted average number of shares - diluted	29,961	29,426	29,912	29,326
Cash dividends paid per common share	$ 0.08		$ 0.16