Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 28, 2019 USD ($) Customer	Dec. 29, 2018 USD ($) Customer
Disclosure Summary Of Significant Accounting Policies [Line Items]
Provision for sales returns	$ 264,000	$ 277,000
Gross value of demos and loaners	2,800,000	3,100,000
Accumulated amortization on inventory demos and loaners	$ 1,400,000	1,400,000
Estimated useful life of demos and loaners	4 years
Estimated useful lives of the assets	3 years
Extended product warranty period	1 year
Extended warranty, period to determine nature of sale	60 days
Products warranty period	2 years
Advertising and promotion costs	$ 300,000	500,000
Accrued interest and penalty incurred	0	$ 0
Right-of-use assets	2,764,000
Lease liabilities	3,209,000
ASU 2016-02
Disclosure Summary Of Significant Accounting Policies [Line Items]
Right-of-use assets	4,000,000
Lease liabilities	4,500,000
Deferred rent related to operating lease	$ 500,000
Revenue, Total | Customer Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	0	0
Accounts Receivable | Customer Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Customer and supplier accounted percentage of total revenues, accounts receivable and purchases	10.00%
Accounts Receivable | Credit Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	1	0
Revenue Benchmark | Customer Concentration Risk
Disclosure Summary Of Significant Accounting Policies [Line Items]
Customer and supplier accounted percentage of total revenues, accounts receivable and purchases	10.00%	10.00%
Percentage of revenues accounted	11.00%
Shipping and Handling
Disclosure Summary Of Significant Accounting Policies [Line Items]
Shipping and handling costs	$ 200,000	$ 300,000
Royalty Agreements
Disclosure Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	2