Geographic and Product Data (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 04, 2014	Mar. 29, 2013
Geographic and Product Data [Line Items]
Net sales	$ 20,178	$ 18,001
Japan [Member]
Geographic and Product Data [Line Items]
Net sales	5,008	4,739
United States [Member]
Geographic and Product Data [Line Items]
Net sales	2,874	3,240
China [Member]
Geographic and Product Data [Line Items]
Net sales	2,225	2,071
Korea [Member]
Geographic and Product Data [Line Items]
Net sales	2,621	2,035
Spain [Member]
Geographic and Product Data [Line Items]
Net sales	1,618	1,291
Other [Member]
Geographic and Product Data [Line Items]
Net sales	$ 5,832	$ 4,625