CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 22,465	$ 21,943
Cost of sales	14,522	14,757
Gross profit	7,943	7,186
Operating (income) expenses:
Selling expenses	358	585
General and administrative expenses	2,287	2,529
Asset impairment charges	1,029	113
Gain on disposal of equipment	(16)	(3)
Research and development costs	1,893	1,225
Total operating expenses	5,551	4,449
Operating income	2,392	2,737
Other income (expense):
Interest and dividend income	225	27
Interest expense	(7)	(12)
Total other income	218	15
Income from continuing operations before income taxes	2,610	2,752
Income tax expense (benefit)	989	(2,089)
Net income from continuing operations	1,621	4,841
Income from discontinued operations, net of income taxes		243
Net income	1,621	5,084
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) from marketable equity investments, net of income taxes	(186)	33
Comprehensive income	$ 1,435	$ 5,117
Basic income per share:
Net income from continuing operations	$ 0.38	$ 1.20
Income from discontinued operations		0.06
Net income	0.38	1.26
Diluted income per share:
Net income from continuing operations	0.37	1.19
Income from discontinued operations		0.06
Net income	$ 0.37	$ 1.25
Weighted average common shares outstanding:
Basic	4,304,602	4,040,308
Diluted	4,344,765	4,077,575