CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 29, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Accumulated depreciation on property and equipment	$ 19,994,000	$ 19,445,000
Accumulated amortization on patents, licenses and purchased technology	$ 2,400,000	$ 2,367,000
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	536,520	564,642
Preferred stock, shares outstanding	536,520	564,642
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	4,751,284	4,193,690
Common stock, shares outstanding	4,751,284	4,193,690