Stock Incentive and Purchase Plans (Tables)

9 Months Ended

Jan. 25, 2013

Stock Incentive and Purchase Plans [Abstract]

Allocation Of Share Based Compensation Costs

Amounts of stock-based compensation recognized in the condensed consolidated statement of income by expense category are as follows:

	For the Thirteen Weeks Ended				For the Thirty-Nine Weeks Ended
	January 25,		January 27,		January 25,		January 27,
	2013		2012		2013		2012
Cost of goods sold	$	95,940	$	134,953	$	402,450	$	459,493
Selling, general and administrative		1,635,373		1,927,393		6,096,914		6,302,349
Research and development		531,921		778,998		2,610,058		1,669,097
Total stock-based compensation expense	$	2,263,234	$	2,841,344	$	9,109,422	$	8,430,939

Amounts of stock-based compensation expense recognized in the condensed consolidated statement of income by type of arrangement are as follows:

	For the Thirteen Weeks Ended				For the Thirty-Nine Weeks Ended
	January 25,		January 27,		January 25,		January 27,
	2013		2012		2013		2012
Stock option awards	$	681,541	$	673,875	$	2,245,928	$	2,000,847
Service-based restricted share and restricted share unit awards		970,664		1,053,475		3,974,127		4,194,361
Performance-based restricted share and restricted share unit awards		611,029		1,113,994		2,889,367		2,235,731
Total stock-based compensation expense	$	2,263,234	$	2,841,344	$	9,109,422	$	8,430,939

Summary Of Stock Option Activity

	For the Thirty-Nine Weeks Ended January 25, 2013
Options	Number of Shares	Wtd. Avg. Exercise Price		Wtd. Avg. Remaining Contractual Term (years)	Aggregate Intrinsic Value (1)
Outstanding — at April 27, 2012	1,441,057	$	23.75
Granted	216,802		43.34
Exercised	(466,232)		24.07
Forfeited	(14,131)		27.41
Expired	(1,267)		36.87
Outstanding — at January 25, 2013	1,176,229		27.18	6.35	$	18,975,803
Fully vested and exercisable — end of period	608,752		23.35	4.43		12,260,480
Fully vested and expected to vest — end of period (2)	1,142,951		26.98	6.29		18,666,528

Schedule Of Activity For Restricted Stock And Restricted Stock Unit Awards

Restricted Stock and Restricted Stock Unit Awards

The following table details the activity for service-based restricted stock and restricted stock unit awards:

	For the Thirty-Nine Weeks Ended January 25, 2013
	Number of Shares	Wtd. Avg. Grant Date Fair Value
Non-vested shares at April 27, 2012	639,033	$	20.75
Granted	107,636		44.11
Vested	(356,044)		16.43
Forfeited	(6,292)		27.01
Non-vested shares at January 25, 2013	384,333	$	31.18

Performance-based and Market-Based Restricted Stock and Restricted Stock Unit Awards

The following table details the activity for performance-based restricted stock and restricted stock unit awards and restricted stock market-based awards:

	For the Thirty-Nine Weeks Ended January 25, 2013
	Number of Shares	Wtd. Avg. Grant Date Fair Value
Non-vested shares at April 27, 2012	464,125	$	25.36
Granted	8,982		50.10
Vested	(76,946)		27.34
Forfeited	-		-
Non-vested shares at January 25, 2013	396,161	$	25.54