CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 27, 2014		Sep. 28, 2013
Cash flows from operating activities:
Net income (loss)	$ 8,334		$ (26,968)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Gain on disposal of video camera segment	(4,133)
Operating cash flows of discontinued operations	(694)		1,958
Depreciation and amortization	10,229		9,968
Share-based compensation expense	4,790		3,872
Deferred income taxes	(1,306)		(1,090)
Other accrued liabilities	(356)		431
Changes in current assets and liabilities, excluding effects from acquisitions and divestitures:
Accounts receivable	(28,383)		780
Inventories	(6,008)		10,225
Other current assets	774		1,525
Accounts payable	8,782		(806)
Deferred profit	5,174		3,249
Income taxes payable, including excess stock option exercise benefit	1,352		5
Accrued compensation, warranty and other liabilities	6,464		(1,271)
Net cash provided by operating activities	5,019		1,878
Cash flows from investing activities, excluding effects from acquisitions and divestitures:
Cash received from sale of video camera segment	9,886
Payment for purchase of Ismeca, net of cash received			(53,463)
Sales and maturities of short-term investments	45		812
Purchases of property, plant and equipment	(1,241)		(2,479)
Other assets	(62)		(151)
Investing cash flows of discontinued operations	(6)		(34)
Net cash provided by (used in) investing activities	8,622		(55,315)
Cash flows from financing activities:
Cash dividends paid	(4,535)		(2,972)
Issuance of stock, net of repurchases	1,222		900
Net cash used in financing activities	(3,313)		(2,072)
Effect of exchange rate changes on cash and cash equivalents	(1,418)		(1,051)
Net increase (decrease) in cash and cash equivalents	8,910		(56,560)
Cash and cash equivalents at beginning of period	51,668	[1]	102,808
Cash and cash equivalents at end of period	60,578		46,248
Supplemental disclosure of cash flow information:
Cash paid (refunded) for income taxes	976		(1,135)
Inventory capitalized as property, plant and equipment	1,059		572
Dividends declared but not yet paid	$ 1,532		$ 1,496

[1] Derived from December 28, 2013 audited financial statements