Efforts to increase exports of U.S. products got a boost yesterday when one of Japan's largest electronics producers, Sanyo Electric Co., said it will export annually to Japan 5,000 to 6,000 luxury television sets made at its Arkansas factory.

A Sanyo spokesman in Tokyo said the company wanted to introduce the sets' high-quality wood cabinets to the Japanese market. However, analysts saw it as another effect of the fall in the dollar, which has made production in the United States cheaper than in Japan in many cases.

A growing number of foreign companies are sending back home a small portion of the output of their U.S. plants opened here years ago to supply the U.S. market. Big names that are involved, or plan to be involved, include: Honda (with U.S.-produced cars), Mazda (cars), Hitachi (computer disk drives), Sony (TV tubes) and Yamaha (golf carts).

In relative terms, the volume is small. A recent survey by the Japan External Trade Organization found 21 Japanese companies engaged in the practice. But in view of the $60 billion U.S. trade deficit with Japan in 1986, it represents an intriguing flow against the general tide of trans-Pacific commerce.

With worldwide annual sales of $7.5 billion, Sanyo is one of Japan's main producers of electronic equipment for the office and home.

It has been manufacturing in the United States for a decade at a Forest City, Ark., plant it operates as a joint venture with Sears, Roebuck & Co. and other investors.

Sanyo's choice of goods for the Japanese market is 37-inch color television sets made at the plant. They will be sold in Japan for about 600,000 yen (currently equivalent to about $4,800), the same price charged for similar Japanese-made sets, which have imitation wood cabinets. Because of lower production costs in Arkansas, profits are expected to be higher on the U.S.-made TVs.

The large sets will be made especially for the Japanese market because TV channels there are on different points in the broadcast spectrum than in the United States.

It was unclear what strategy Sanyo intends to use for marketing. Japanese consumers often view U.S. products as inferior to their own in quality and workmanship. If they are aware of the sets' origin, they may be reluctant to buy them.

The U.S. dollar has fallen more than 50 percent against the yen since 1985, a decline started by a joint effort of major industrial countries that year. This was intended to decrease the U.S. trade deficit by raising the price of Japanese-made goods on the world market.

In response, Japanese companies have shifted portions of their production out of the home market to foreign countries, notably to its newly industrializing neighbors of South Korea, Taiwan, Hong Kong and Singapore.

They are also increasingly eying the United States; a flood of Japanese scouts are shopping around for production sites here.