Stock Based Compensation Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 28, 2012	Dec. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 46,000	$ 235,000	$ 124,000	$ 480,000
Cost of Products Sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	3,000	23,000	10,000	52,000
Research, development & engineering expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	12,000	69,000	35,000	155,000
General and Administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	28,000	133,000	69,000	249,000
Sales and Marketing Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 3,000	$ 10,000	$ 10,000	$ 24,000