UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): November 16, 2012

PLANAR SYSTEMS, INC.

(Exact name of registrant as specified in its charter)

1195 NW Compton Drive

Beaverton, Oregon 97006

(503) 748-1100

(Address, including zip code, and telephone number, including

area code, of registrant’s principal executive offices)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Effective as of November 16, 2012, Planar Systems, Inc. (the “Company”) and Bank of America, N.A. (the “Bank”) entered into a Fourth Amendment to Amended and Restated Credit Agreement (the “Amendment”). The Amendment amends the Amended and Restated Credit Agreement between the Company and the Bank dated as of December 1, 2009, as amended. The Amendment reduces the amount required to satisfy the tangible net worth covenant and increases the amount of the commitment fee. The foregoing description of the Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the Amendment, which is attached hereto as Exhibit 10.1, and is incorporated herein by reference.

On November 20, 2012, the Company issued a press release announcing its financial results for the fourth quarter and year ended September 28, 2012, and its expectations regarding certain financial results for the first quarter of fiscal 2013 (the “Earnings Release”). The Earnings Release contains forward-looking statements regarding the Company, and includes cautionary statements identifying important factors that could cause actual results to differ materially from those anticipated. The Earnings Release is furnished herewith as Exhibit 99.1 to this Report, and shall not be deemed filed for purposes of Section 18 of the Exchange Act.

In addition to disclosing financial results calculated in accordance with U.S. generally accepted accounting principles (“GAAP”), the Earnings Release contains non-GAAP financial measures that exclude share-based compensation and the requirements of Topic 718 of the FASB Accounting Standards Codification, “Compensation-Stock Compensation.” The non-GAAP financial measures also exclude impairment and restructuring charges, the amortization of intangible assets related to previous acquisitions, various tax charges including the valuation allowance against deferred tax assets, the gain or loss on foreign currency due to the non-cash nature of the charge, and various other adjustments. The non-GAAP financial measures disclosed by the Company should not be considered a substitute for, or superior to, financial measures calculated in accordance with GAAP, and the financial results calculated in accordance with GAAP and reconciliations to those financial results should be carefully evaluated. The non-GAAP financial measures used by the Company may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies. The Company has provided reconciliations of the non-GAAP financial measures to the most directly comparable GAAP financial measures.

Management uses the non-GAAP financial measures for internal managerial purposes, including as a means to compare period-to-period results on a consolidated basis and as a means to evaluate the Company’s results on a consolidated basis compared to those of other companies. In addition, management uses certain of these measures when publicly providing forward-looking statements on expectations regarding future consolidated basis financial results. The Company discloses this information to the public to enable investors who wish to more easily assess the Company’s performance on the same basis applied by management.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized on November 20, 2012.

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