COMING ATTRACTIONS

Japanese conglomerates Sony and Nippon Telegraph & Telephone have developed a tiny picture-telephone at a price they think would-be tube-talkers can afford. Expected to go on sale in July with a price tag under $350, the gadget combines a four-inch black-and-white television tube and a camera using a sophisticated computer microchip, a Sony spokesman said. It can be linked to conventional telephone sets and will transmit the picture over existing communications circuits. Current picturephones cost about $70,000 and are used almost exclusively by companies for televised phone conferences.