Stockholders' Equity - Stock options outstanding and exercisable (Details)	12 Months Ended
	Jun. 30, 2022 $ / shares shares
Options Outstanding	3,182,872
Options Exercisable	2,999,974
Range One
Option Exercise Price | $ / shares	$ 0.70
Options Outstanding	225,000
Remaining Contractual Life (in years)	3 years 5 months 4 days
Options Exercisable	225,000
Range Two
Option Exercise Price | $ / shares	$ 0.77
Options Outstanding	25,000
Remaining Contractual Life (in years)	2 years 1 month 20 days
Options Exercisable	25,000
Range Three
Option Exercise Price | $ / shares	$ 0.80
Options Outstanding	16,000
Remaining Contractual Life (in years)	3 years 1 month 20 days
Options Exercisable	16,000
Range Four
Option Exercise Price | $ / shares	$ 0.90
Options Outstanding	15,000
Remaining Contractual Life (in years)	3 years 1 month 6 days
Options Exercisable	15,000
Range Five
Option Exercise Price | $ / shares	$ 1.00
Options Outstanding	15,000
Remaining Contractual Life (in years)	2 years 8 months 12 days
Options Exercisable	15,000
Range Six
Option Exercise Price | $ / shares	$ 1.05
Options Outstanding	305,000
Remaining Contractual Life (in years)	4 years 1 month 24 days
Options Exercisable	305,000
Range Seven
Option Exercise Price | $ / shares	$ 1.07
Options Outstanding	33,898
Remaining Contractual Life (in years)	3 months 14 days
Options Exercisable	33,898
Range Eight
Option Exercise Price | $ / shares	$ 1.09
Options Outstanding	60,000
Remaining Contractual Life (in years)	3 years 10 months 24 days
Options Exercisable	60,000
Range Nine
Option Exercise Price | $ / shares	$ 1.10
Options Outstanding	105,000
Remaining Contractual Life (in years)	3 years
Options Exercisable	105,000
Range Ten
Option Exercise Price | $ / shares	$ 1.15
Options Outstanding	104,400
Remaining Contractual Life (in years)	7 months 9 days
Options Exercisable	104,400
Range Eleven
Option Exercise Price | $ / shares	$ 1.20
Options Outstanding	274,000
Remaining Contractual Life (in years)	5 years 18 days
Options Exercisable	274,000
Range Twelve
Option Exercise Price | $ / shares	$ 1.25
Options Outstanding	32,000
Remaining Contractual Life (in years)	7 months 13 days
Options Exercisable	32,000
Range Thirteen
Option Exercise Price | $ / shares	$ 1.50
Options Outstanding	185,000
Remaining Contractual Life (in years)	5 months 23 days
Options Exercisable	185,000
Range Fourteen
Option Exercise Price | $ / shares	$ 1.59
Options Outstanding	25,000
Remaining Contractual Life (in years)	5 years 10 months 13 days
Options Exercisable	25,000
Range Fifteen
Option Exercise Price | $ / shares	$ 1.80
Options Outstanding	86,550
Remaining Contractual Life (in years)	1 year 2 months 23 days
Options Exercisable	86,550
Range Sixteen
Option Exercise Price | $ / shares	$ 1.85
Options Outstanding	16,000
Remaining Contractual Life (in years)	10 months 20 days
Options Exercisable	16,000
Range Seventeen
Option Exercise Price | $ / shares	$ 1.95
Options Outstanding	200,000
Remaining Contractual Life (in years)	6 years 3 days
Options Exercisable	200,000
Range Nineteen
Option Exercise Price | $ / shares	$ 2.13
Options Outstanding	216,708
Remaining Contractual Life (in years)	8 years 4 months 20 days
Options Exercisable	209,746
Range Twenty
Option Exercise Price | $ / shares	$ 2.17
Options Outstanding	35,955
Remaining Contractual Life (in years)	8 years 10 months 13 days
Options Exercisable	14,981
Range Twenty Two
Option Exercise Price | $ / shares	$ 2.40
Options Outstanding	332,833
Remaining Contractual Life (in years)	6 years 4 months 17 days
Options Exercisable	332,833
Range Twenty Three
Option Exercise Price | $ / shares	$ 2.43
Options Outstanding	61,250
Remaining Contractual Life (in years)	8 years 11 months 4 days
Options Exercisable	43,750
Range Twenty Four
Option Exercise Price | $ / shares	$ 2.45
Options Outstanding	173,000
Remaining Contractual Life (in years)	8 years 1 month 6 days
Options Exercisable	115,332
Range Twenty Five
Option Exercise Price | $ / shares	$ 2.49
Options Outstanding	88,435
Remaining Contractual Life (in years)	7 years 10 months 2 days
Options Exercisable	81,717
Range Twenty Six
Option Exercise Price | $ / shares	$ 2.50
Options Outstanding	20,000
Remaining Contractual Life (in years)	6 years 10 months 17 days
Options Exercisable	20,000
Range Twenty Seven
Option Exercise Price | $ / shares	$ 2.64
Options Outstanding	30,882
Remaining Contractual Life (in years)	9 years 1 month 6 days
Options Exercisable	0
Range Twenty Eight
Option Exercise Price | $ / shares	$ 2.67
Options Outstanding	33,194
Remaining Contractual Life (in years)	9 years 2 months 19 days
Options Exercisable	0
Range Twenty Nine
Option Exercise Price | $ / shares	$ 2.99
Options Outstanding	8,000
Remaining Contractual Life (in years)	7 years 10 months 13 days
Options Exercisable	6,000
Range Thirty
Option Exercise Price | $ / shares	$ 3.13
Options Outstanding	208,000
Remaining Contractual Life (in years)	7 years 4 months 17 days
Options Exercisable	207,333
Range Thirty One
Option Exercise Price | $ / shares	$ 3.50
Options Outstanding	8,000
Remaining Contractual Life (in years)	7 years 7 months 13 days
Options Exercisable	6,667