CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenues	$ 15,044,000	$ 15,854,000	$ 30,020,000	$ 29,974,000
Cost of revenues	8,455,000	8,590,000	16,405,000	16,491,000
Gross margin	6,589,000	7,264,000	13,615,000	13,483,000
Research and development expenses	2,249,000	2,243,000	4,542,000	4,423,000
Selling, general and administrative expenses	3,761,000	4,146,000	7,924,000	8,503,000
Income from operations	579,000	875,000	1,149,000	557,000
Interest income and other	77,000	95,000	136,000	157,000
Income before income taxes	656,000	970,000	1,285,000	714,000
Income tax expense	192,000	230,000	326,000	147,000
Net income	$ 464,000	$ 740,000	$ 959,000	$ 567,000
Net income per share – Basic	$ 0.07	$ 0.11	$ 0.14	$ 0.08
Net income per share – Diluted	$ 0.06	$ 0.10	$ 0.13	$ 0.08
Weighted average shares outstanding – Basic	7,106	7,010	7,103	6,998
Weighted average shares outstanding – Diluted	7,296	7,242	7,309	7,114