Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jul. 01, 2019	Jul. 01, 2018	Jun. 30, 2018
Cash, Uninsured Amount	$ 3,700,000	$ 1,500,000
Depreciation, Total	6,000,000	7,500,000
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	$ 0
Standard Warranty Extended Term for Exceptions (Year)	10 years
Defined Contribution Plan, Cost	$ 1,300,000	1,300,000
Research and Development Expense, Total	$ 3,600,000	$ 5,300,000
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares (in shares)	368,000	324,000
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance	$ 109,000	$ (16,000)
Retained Earnings (Accumulated Deficit), Ending Balance	(1,920,000)	(5,808,000)		$ 15,715,000	$ 15,124,000
Operating Lease, Right-of-Use Asset	8,663,000
Operating Lease, Liability, Total	9,397,000
Accounting Standards Update 2014-09 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Retained Earnings (Accumulated Deficit), Ending Balance				$ 591,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			$ 10,400,000
Operating Lease, Liability, Total			10,800,000
Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Retained Earnings (Accumulated Deficit), Ending Balance			$ 400,000
Other Expense [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ 500,000	$ 100,000
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	20 years
Standard Warranty Term (Year)	5 years
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	8 years
Standard Warranty Term (Year)	1 year
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		15 years