Entity Central Index Key Document and entity information. Document And Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Trading Symbol Trading Symbol Entity Well-known Seasoned Issuer Entity Well Known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Shell Company Entity Shell Company Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Accounts receivable, net of allowance for doubtful accounts of $213 as of December 29, 2018 and $226 as of December 30, 2017 Accounts Receivable Net Current Inventories Inventory Net Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Property and equipment, net Property Plant And Equipment Net Intangible assets, net Finite Lived Intangible Assets Net Goodwill Goodwill Other long-term assets Other Assets Noncurrent Total assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued compensation Employee Related Liabilities Current Accrued expenses Accrued Liabilities Current Accrued warranty Product Warranty Accrual Classified Current Deferred revenue Contract With Customer Liability Current Total current liabilities Liabilities Current Long-term liabilities: Liabilities Noncurrent [Abstract] Accrued warranty Product Warranty Accrual Noncurrent Other long-term liabilities Other Liabilities Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 9) Commitments And Contingencies Stockholders’ equity: Stockholders Equity [Abstract] Preferred stock, $0.01 par value, 2,000,000 shares authorized, no shares issued and outstanding Preferred Stock Value Common stock, $0.01 par value: Authorized: 30,000,000 shares; Issued and outstanding 11,596,274 and 11,304,736 shares as of December 30, 2017 and December 31, 2016, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated other comprehensive income Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders’ equity Liabilities And Stockholders Equity Accounts receivable, allowance for doubtful accounts Allowance For Doubtful Accounts Receivable Current Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares issued Preferred Stock Shares Issued Preferred stock, shares outstanding Preferred Stock Shares Outstanding Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Income Statement [Abstract] Total revenues Revenue From Contract With Customer Excluding Assessed Tax Cost of revenues Cost Of Revenue Gross profit Gross Profit Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense Sales and marketing Selling And Marketing Expense General and administrative General And Administrative Expense Gain on sale of intellectual property Gain Loss On Disposition Of Intangible Assets Impairment of long-lived assets Impairment Of Intangible Assets Indefinitelived Excluding Goodwill Total operating expenses Operating Expenses Loss from operations Operating Income Loss Other income (expense), net Nonoperating Income Expense Loss from operations before provision for (benefit from) income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Provision for (benefit from) income taxes Income Tax Expense Benefit Net loss Net Income Loss Net loss per share: Earnings Per Share [Abstract] Basic Earnings Per Share Basic Diluted Earnings Per Share Diluted Weighted average shares used in computing net loss per common share: Weighted Average Number Of Shares Outstanding [Abstract] Basic Weighted Average Number Of Shares Outstanding Basic Diluted Weighted Average Number Of Diluted Shares Outstanding Statement Of Income And Comprehensive Income [Abstract] Net loss Change in foreign currency translation adjustments Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent Comprehensive loss Comprehensive Income Net Of Tax Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid In Capital [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income [Member] Accumulated Deficit Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Beginning Balance, value Beginning Balance, shares Proceeds from issuance of common stock, net of issuance costs, value Stock Issued During Period Value New Issues Proceeds from issuance of common stock, net of issuance costs, shares Stock Issued During Period Shares New Issues Issuance of common stock under stock option plan Stock Issued During Period Value Stock Options Exercised Issuance of common stock under stock option plan, shares Stock Issued During Period Shares Stock Options Exercised Employee stock-based compensation expense Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Release of restricted stock, value Adjustments Related To Tax Withholding For Share Based Compensation Release of restricted stock, shares Stock Issued During Period Shares Restricted Stock Award Gross Other comprehensive income Other Comprehensive Income Loss Net Of Tax Ending Balance, value Ending Balance, shares Increase decrease in prepaid deferred expense and other current assets. The increase (decrease) during the reporting period in warranty expenses incurred but not yet paid. Transfer of inventory to property and equipment. Cash paid during the period. Statement Of Cash Flows [Abstract] Operating activities: Net Cash Provided By Used In Operating Activities [Abstract] Net loss Profit Loss Adjustments to reconcile net loss to net cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Loss on disposal of property and equipment Gain Loss On Sale Of Property Plant Equipment Depreciation and amortization Depreciation And Amortization Change in fair value of earn-out liability Business Combination Contingent Consideration Arrangements Change In Amount Of Contingent Consideration Liability1 Stock-based compensation Allocated Share Based Compensation Expense Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts receivable Increase Decrease In Accounts Receivable Inventories Increase Decrease In Inventories Prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Current Assets Other long-term assets Increase Decrease In Other Noncurrent Assets Accounts payable Increase Decrease In Accounts Payable Accrued compensation Increase Decrease In Employee Related Liabilities Accrued expenses Increase Decrease In Accrued Liabilities Accrued warranty Increase Decrease In Accrued Warranty Liabilities Deferred revenue Increase Decrease In Contract With Customer Liability Other long-term liabilities Increase Decrease In Other Noncurrent Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Investing activities: Net Cash Provided By Used In Investing Activities [Abstract] Acquisition of property and equipment Payments To Acquire Property Plant And Equipment Proceeds from sale of intellectual property Proceeds From Sale Of Intangible Assets Payment on earn-out liability Payments For Previous Acquisition Net cash used in investing activities Net Cash Provided By Used In Investing Activities Financing activities: Net Cash Provided By Used In Financing Activities [Abstract] Proceeds from issuance of common stock, net of issuance costs Proceeds From Issuance Of Common Stock Proceeds from stock option exercises Proceeds From Stock Options Exercised Taxes paid related to net share settlements of equity awards Payments Related To Tax Withholding For Share Based Compensation Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Effect of foreign exchange rate changes Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Net decrease in cash and cash equivalents Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents, beginning of year Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash and cash equivalents, end of year Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid during the year for: Cash Paid During Period [Abstract] Income taxes Income Taxes Paid Net Supplemental disclosure of non-cash activities: Noncash Investing And Financing Items [Abstract] Transfer of inventory to property and equipment Transfer Of Inventory To Property And Equipment Organization Consolidation And Presentation Of Financial Statements [Abstract] Organization Business Description And Basis Of Presentation [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurement Fair Value Disclosures [Text Block] Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Property Plant And Equipment [Abstract] Property and Equipment Property Plant And Equipment Disclosure [Text Block] Goodwill And Intangible Assets Disclosure [Abstract] Goodwill Goodwill Disclosure [Text Block] Intangible Assets Intangible Assets Disclosure [Text Block] Payables And Accruals [Abstract] Accrued Expenses Other Liabilities Disclosure [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Equity [Abstract] Stockholders' Equity Stockholders Equity Note Disclosure [Text Block] Compensation And Retirement Disclosure [Abstract] Employee Benefit Plan Pension And Other Postretirement Benefits Disclosure [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Debt Disclosure [Abstract] Loan and Security Agreement Debt Disclosure [Text Block] Segment Reporting [Abstract] Business Segments and Geographical Information Segment Reporting Disclosure [Text Block] Computation of Basic and Diluted Net Loss Per Common Share Earnings Per Share [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Financial Statement Presentation Basis Of Accounting Policy Policy [Text Block] Use of Estimates Use Of Estimates Cash and Cash Equivalents Cash And Cash Equivalents Policy [Text Block] Sales returns allowance and allowance for doubtful accounts. Sales Returns Allowance and Allowance for Doubtful Accounts Sales Returns Allowance And Allowance For Doubtful Accounts Policy [Text Block] Inventories Inventory Policy [Text Block] Property and Equipment Property Plant And Equipment Policy [Text Block] Valuation of Goodwill and Intangible Assets Goodwill And Intangible Assets Policy [Text Block] Revenue Recognition Revenue From Contract With Customer Policy [Text Block] Taxes Collected from Customers and Remitted to Governmental Authorities Utility Revenue And Expense Recognition Policy Contract with customer liability. Deferred Revenue Contract With Customer Liability Policy [Text Block] Warranty Standard Product Warranty Policy Contract with customer, shipping and handling costs. Shipping and Handling Costs Contract With Customer Shipping And Handling Costs Policy [Text Block] Research and Development Research And Development Expense Policy Advertising Advertising Costs Policy [Text Block] Income Taxes Income Tax Policy [Text Block] Accounting for Uncertainty in Income Taxes Income Tax Uncertainties Policy Accounting for Stock-Based Compensation Compensation Related Costs Policy [Text Block] Concentration of credit risk and other risks and uncertainties. Concentration of Credit Risk and Other Risks and Uncertainties Concentration Of Credit Risk And Other Risks And Uncertainties Policy [Text Block] Concentrations of supplier risk. Reliance on Certain Suppliers Concentrations Of Supplier Risk Policy [Text Block] Net Income per Share Earnings Per Share Policy [Text Block] Reclassifications Prior Period Reclassification Adjustment Description Recently Adopted Accounting Standards and Recent Accounting Standards Not Yet Adopted New Accounting Pronouncements Policy Policy [Text Block] Schedule of reconciliation of changes in allowance for doubtful accounts. Reconciliation of Changes in Allowance for Doubtful Accounts Schedule Of Reconciliation Of Changes In Allowance For Doubtful Accounts