Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 25, 2016	Dec. 26, 2015
Current assets:
Cash and cash equivalents	$ 60,032	$ 38,154
Marketable securities	35,952	44,931
Accounts receivable, net of allowances of $136 and $150, respectively	54,099	37,832
Inventories	41,111	47,749
Inventories-delivered systems	9,594	2,856
Prepaid expenses and other	6,793	6,592
Total current assets	207,581	178,114
Property, plant and equipment, net	43,484	44,493
Goodwill	9,680	9,415
Intangible assets, net	989	1,867
Deferred income tax assets	1,272	1,118
Other assets	549	533
Total assets	263,555	235,540
Current liabilities:
Accounts payable	11,004	11,675
Accrued payroll and related expenses	10,565	10,097
Deferred revenue	25,603	12,790
Other current liabilities	9,333	8,878
Income taxes payable	608	1,771
Total current liabilities	57,113	45,211
Deferred revenue	95	827
Income taxes payable	824	775
Deferred tax liability	645	521
Other long-term liabilities	878	878
Total liabilities	59,555	48,212
Commitments and contingencies (Note 11)
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: 24,691,585 and 24,224,286, respectively, issued and outstanding	25	24
Additional paid-in capital	264,317	258,715
Accumulated deficit	(56,711)	(66,209)
Accumulated other comprehensive income	(3,631)	(5,202)
Total stockholders’ equity	204,000	187,328
Total liabilities and stockholders’ equity	$ 263,555	$ 235,540