Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Current assets:
Cash and cash equivalents	$ 26,421	$ 34,676
Marketable securities	48,368	49,286
Accounts receivable, net of allowances of $214 and $253, respectively	44,441	26,121
Inventories	41,539	35,105
Inventories-delivered systems	1,574	1,912
Prepaid expenses and other	6,842	9,289
Deferred income tax assets	1,427	1,457
Total current assets	170,612	157,846
Property, plant and equipment, net	47,541	49,633
Goodwill	9,590	10,494
Intangible assets, net	2,886	4,294
Deferred income tax assets	387	410
Other assets	541	559
Total assets	231,557	223,236
Current liabilities:
Accounts payable	13,358	10,199
Accrued payroll and related expenses	9,457	8,700
Deferred revenue	10,555	10,021
Other current liabilities	8,221	8,265
Income taxes payable	1,039	1,017
Total current liabilities	42,630	38,202
Deferred revenue	1,479	2,591
Income taxes payable	751	701
Deferred tax liabilities	1,007	926
Other long-term liabilities	1,226	1,279
Total liabilities	$ 47,093	$ 43,699
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: 24,059,033 and 23,813,729, respectively, issued and outstanding	24	24
Additional paid-in capital	254,143	251,396
Accumulated deficit	(65,214)	(69,114)
Accumulated other comprehensive income (loss)	(4,489)	(2,769)
Total stockholders’ equity	184,464	179,537
Total liabilities and stockholders’ equity	$ 231,557	$ 223,236