Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 29, 2018
Current assets:
Cash and cash equivalents	$ 51,009	$ 110,951
Marketable securities	93,101	40,841
Accounts receivable, net of allowances of $200 and $170, respectively	56,969	50,854
Inventories	69,691	61,915
Inventories-delivered systems	117	180
Prepaid expenses and other	7,398	6,140
Total current assets	278,285	270,881
Property, plant and equipment, net	52,449	47,900
Operating lease - right of use assets, net	9,996
Goodwill	26,310	26,372
Intangible assets, net	25,078	27,326
Deferred income tax assets	3,664	2,569
Other assets	441	582
Total assets	396,223	375,630
Current liabilities:
Accounts payable	17,541	16,540
Accrued payroll and related expenses	12,283	21,658
Deferred revenue	7,370	8,990
Operating lease liabilities	2,773
Other current liabilities	8,702	9,421
Income taxes payable	1,162	3,164
Total current liabilities	49,831	59,773
Deferred revenue	1,432	1,753
Income taxes payable	1,620	871
Deferred tax liabilities	158	162
Operating lease liabilities	7,193
Other long-term liabilities	217	219
Total liabilities	60,451	62,778
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: 24,842,959 and 24,372,193, respectively, issued and outstanding	25	24
Additional paid-in capital	259,744	247,983
Retained earnings	78,516	67,402
Accumulated other comprehensive loss	(2,513)	(2,557)
Total stockholders’ equity	335,772	312,852
Total liabilities and stockholders’ equity	$ 396,223	$ 375,630