Nature of Business and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Significant Accounting Policies [Line Items]
Short-term time deposits	$ 460,000		$ 460,000
Intangible assets amortization expense	66,000	$ 78,000
Estimated amortization expense- 2020	264,000
Estimated amortization expense - 2021	223,000
Estimated amortization expense - 2022	188,000
Estimated amortization expense - 2023	159,000
Estimated amortization expense- 2024	$ 134,000
Remaining weighted average amortization period for acquired intangible assets	8 years 10 months 24 days	9 years 10 months 24 days
Research and development costs	$ 1,749,000	$ 1,745,000
Antidilutive options outstanding excluded from diluted EPS computations	0	0
Stock-based compensation costs	$ 17,000	$ 5,000
Foreign Currency Transaction Gain (Loss), before Tax	$ 0	$ 0
Stock-based compensation costs, effect on EPS	$ 0.00	$ 0.00
Number of Operating Segments	1
Cost of Goods and Services Sold	$ 14,767,000	$ 13,817,000
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising and promotion costs	514,000	650,000
Sales revenue, net [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	260,000	282,000
Cost of sales [Member]
Significant Accounting Policies [Line Items]
Research and development costs	1,749,000	1,745,000
Cost of sales [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	112,000	$ 101,000
Allowance for doubtful accounts current [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	$ 88,000			$ 88,000