Annual report pursuant to Section 13 and 15(d)

PATENTS (Details)

v3.21.1
PATENTS (Details) - USD ($)
Dec. 31, 2020
Dec. 31, 2019
Patents, net $ 1,578,000 $ 1,819,000
Patents [Member]    
Gross carrying amount 7,848,000 7,797,000
Accumulated amortization (6,270,000) (5,978,000)
Patents, net $ 1,578,000 $ 1,819,000