Consolidated Statements of Income (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010
Net sales	$ 90,344	$ 73,174	$ 191,885	$ 158,204
Cost of sales	62,214	52,785	130,819	110,644
Gross profit	28,130	20,389	61,066	47,560
Research and development expenses	2,374	1,956	4,617	4,082
Selling, general and administrative expenses	7,082	5,810	14,242	11,350
Operating income	18,674	12,623	42,207	32,128
Other income (expense), net	(76)	(94)	(89)	(42)
Income before income taxes	18,598	12,529	42,118	32,086
Income taxes	6,137	4,176	13,941	10,788
Net income	$ 12,461	$ 8,353	$ 28,177	$ 21,298
Net income per common share:
Basic	$ 0.69	$ 0.46	$ 1.56	$ 1.18
Diluted	$ 0.68	$ 0.46	$ 1.55	$ 1.18
Cash dividends paid per common share	$ 0.18	$ 0.16	$ 0.36	$ 0.32