CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues	$ 17,732,000	$ 16,429,000
Cost of revenues	9,353,000	9,146,000
Gross margin	8,379,000	7,283,000
Research and development expenses	2,761,000	2,395,000
Selling, general and administrative expenses	3,888,000	4,159,000
Income (loss) from operations	1,730,000	729,000
Interest income and other	22,000	264,000
Income (loss) before income taxes	1,752,000	993,000
Income tax expense (benefit)	311,000	149,000
Net income (loss)	$ 1,441,000	$ 844,000
Net income (loss) per share – Basic	$ 0.20	$ 0.12
Net income (loss) per share – Diluted	$ 0.19	$ 0.11
Weighted average shares outstanding – Basic	7,293	7,157
Weighted average shares outstanding – Diluted	7,463	7,367