CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 6,854	$ 5,494	$ 20,168	$ 16,217
Cost of sales	4,591	3,518	12,930	10,663
Gross profit	2,263	1,976	7,238	5,554
Operating (income) expenses:
Selling expenses	122	83	252	257
General and administrative expenses	641	701	1,838	1,781
Impairment of goodwill and long-lived assets				230
Gain from disposal of equipment			(7)	(16)
Research and development costs	603	560	1,337	1,445
Total operating expenses	1,366	1,344	3,420	3,697
Operating income	897	632	3,818	1,857
Interest expense	(67)	(2)	(156)	(6)
Gain on sale of investments			356
Interest and other income	93	73	261	166
Income before income taxes	923	703	4,279	2,017
Income tax expense	(191)	(223)	(1,019)	(564)
Net income	732	480	3,260	1,453
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) from marketable equity investments, net of income taxes	33	60	(163)	(64)
Comprehensive income	$ 765	$ 540	$ 3,097	$ 1,389
Basic net income per share:
Net income	$ 0.18	$ 0.11	$ 0.77	$ 0.34
Diluted net income per share:
Net income	$ 0.17	$ 0.11	$ 0.75	$ 0.34
Weighted average common shares outstanding:
Basic	4,143	4,363	4,224	4,290
Diluted	4,257	4,403	4,338	4,330
Common shares outstanding	4,136	4,361	4,136	4,361