Nature of Business and Summary of Significant Accounting Policies - Income Statement location (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Research and development	$ 9,328,000	$ 8,024,000	$ 7,620,000
Net sales	169,997,000	143,593,000	114,035,000
Cost of sales	96,764,000	84,437,000	63,287,000
Selling, General and Administrative Expenses
Advertising and promotion costs	2,931,000	2,889,000	1,306,000
Operating Expenses.
Research and development	9,328,000	8,024,000	7,620,000
Cost of sales | Shipping and Handling
Cost of sales	1,697,000	1,425,000	1,058,000
Sales revenue, net | Shipping and Handling
Net sales	$ 450,000	$ 428,000	$ 395,000