Nature of Business and Summary of Significant Accounting Policies - Income Statement location (Details) - USD ($)	12 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Research and development	$ 7,620,000	$ 7,257,000	$ 7,212,000
Cost of sales	63,884,000	57,767,000	59,042,000
Selling, General and Administrative
Advertising and promotion costs	1,306,000	1,722,000	2,047,000
Operating Expenses.
Research and development	7,620,000	7,257,000	7,212,000
Cost of sales \| Shipping and Handling
Cost of sales	395,000	452,000	430,000
Sales revenue, net \| Shipping and Handling
Cost of sales	$ 1,058,000	$ 1,034,000	$ 1,115,000

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
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The total expense recognized in the period for promotion, public relations, and brand or product advertising.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
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-Name Accounting Standards Codification
-Topic 730
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