Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013
Current assets:
Cash and cash equivalents	$ 37,987	$ 44,765
Marketable securities	49,374	48,097
Accounts receivable, net of allowances of $295 and $293, respectively	33,458	31,436
Inventories	37,753	34,520
Inventories-delivered systems	358	6,901
Prepaid expenses and other	9,911	10,519
Deferred income tax assets	14,054	14,516
Total current assets	182,895	190,754
Property, plant and equipment, net	47,244	47,439
Goodwill	11,677	11,743
Intangible assets, net	6,280	7,864
Deferred income tax assets	4,344	4,338
Other assets	679	696
Total assets	253,119	262,834
Current liabilities:
Accounts payable	6,982	10,604
Accrued payroll and related expenses	8,059	7,853
Deferred revenue	7,870	21,749
Other current liabilities	8,348	7,993
Income taxes payable	121	758
Total current liabilities	31,380	48,957
Deferred revenue	2,626	3,718
Income taxes payable	615	1,171
Other long-term liabilities	1,603	1,615
Total liabilities	36,224	55,461
Commitments and contingencies (Note 16)
Stockholders’ equity:
Preferred stock, $0.001 par value; 3,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.001 par value, 47,000,000 shares authorized; 24,029,033 shares and 23,537,275 shares, respectively, issued and outstanding	24	24
Additional paid-in capital	251,679	244,733
Accumulated deficit	(35,813)	(37,996)
Accumulated other comprehensive income	1,005	612
Total stockholders’ equity	216,895	207,373
Total liabilities and stockholders’ equity	$ 253,119	$ 262,834