Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Revenues	$ 68,932	$ 63,595
Cost of revenues	43,822	38,977
Gross margin	25,110	24,618
Selling and administrative expenses	14,704	14,055
Research and development expenses	5,727	3,860
Operating profit	4,679	6,703
Other income (expense):
Investment income	671	646
Gain on investment in affiliate	0	730
Equity loss	0	(650)
Impairment of investment in affiliate	0	(350)
Interest expense	(195)	(121)
Other expense, net	(69)	(144)
Income before provision (benefit) for income taxes	5,086	6,814
Provision (Benefit) for income taxes	1,400	(560)
Net income	3,686	7,374
Net income per common share:
Basic (in Dollars per share)	$ 0.44	$ 0.89
Diluted (in Dollars per share)	$ 0.43	$ 0.86
Average shares outstanding:
Basic (in Shares)	8,412,633	8,329,081
Diluted (in Shares)	8,604,651	8,540,955
Statements of Comprehensive Income
Net Income	3,686	7,374
Other comprehensive income (loss):
Foreign currency translation adjustment	(782)	(1,070)
Change in market value of marketable securities	821	74
Deferred tax effect of change in marketable securities	(296)	(26)
Total other comprehensive income (loss)	(257)	(1,022)
Comprehensive income	$ 3,429	$ 6,352