Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Net sales	$ 69,259	$ 67,512	$ 211,390	$ 206,170
Cost and expenses:
Cost of sales	46,038	44,718	142,044	137,529
Research and development	8,634	8,605	24,742	24,901
Selling, general and administrative	13,591	11,923	41,976	38,006
Cost and expenses	68,263	65,246	208,762	200,436
Income from operations	996	2,266	2,628	5,734
Interest and other, net	71	9	173	19
Income from continuing operations before taxes	1,067	2,275	2,801	5,753
Income tax provision	849	940	1,832	2,251
Income from continuing operations	218	1,335	969	3,502
Income (loss) from discontinued operations	51	(222)	(4)	(5,201)
Net income (loss)	$ 269	$ 1,113	$ 965	$ (1,699)
Basic:
Income from continuing operations (in dollars per share)	$ 0.01	$ 0.05	$ 0.04	$ 0.13
Loss from discontinued operations (in dollars per share)	0	(0.01)	0	(0.20)
Net income (loss) (in dollars per share)	0.01	0.04	0.04	(0.07)
Diluted:
Income from continuing operations (in dollars per share)	0.01	0.05	0.04	0.13
Loss from discontinued operations (in dollars per share)	0	(0.01)	0	(0.20)
Net income (loss) (in dollars per share)	$ 0.01	$ 0.04	$ 0.04	$ (0.06)
Weighted average shares used in computing loss per share:
Basic (in shares)	26,761	26,175	26,596	25,995
Diluted (in shares)	27,367	26,796	27,356	26,679
Cash dividends declared per share (in dollars per share)	$ 0.06	$ 0.06	$ 0.18	$ 0.18