LogEtronics Inc., the Springfield photographic and optical equipment firm, has signed an agreement to acquire Dunn Systems Inc. of San Francisco for approximately $7 million.

The announcement came at the company's annual shareholders meeting yesterday, which was attended by Lionel Simon, chairman and chief executive officer of Dunn, a major supplier and manufacturer of cathode-ray tube imaging equipment used in the computer graphics and medical imaging fields.

Under the agreement, in which Dunn would become a wholly owned subsidiary of LogEtronics, Dunn shareholders will receive 260,000 shares of LogEtronics common stock upon completion of the acquisition and could receive an additional 90,000 shares based on the company's future performance.

The agreement to purchase Dunn is part of LogEtronics' plan to expand into the business of computer graphic imaging. The company has completed one acquisition and has another one in progress.

In January, LogEtronics purchased Interpretation Systems Inc. of Overland Park, Kan., and recently filed documents with the Securities and Exchange Commission for the acquisition of Spatial Data Systems Inc. of Goleta, Calif.

"For LogEtronics, which has been very strong in photograpic systems, this now puts us very strongly into digital electronic imaging," said Chairman Gordon Johnson in an interview.

The addition of Dunn will increase LogEtronics' annual sales by 25 percent, Johnson said. Dunn had sales of $8 million last year, and LogEtronics revenues topped $30 million. According to Johnson, 40 percent of those sales came from overseas customers.