TOKYO (dpa) - Japan is best known in modern times for having brought the Walkman and karaoke to the world. Now a new craze is on its way from Japan: "food on the conveyor belt".Dispense with the waitresses and waiters? Well not quite. But sushi on the conveyor belt is here already and becoming more popular. And it is a big hit in Japan.At a kaiten sushi - as the conveyor-belt sushi restaurant is called - customers pick up the delicacies they want from an assortment running past on a machine-driven conveyor belt.Japan's kaiten sushi market was worth 246 billion yen (about 2 billion dollars) last year, according to a Tokyo-based research firm Fuji Keizai, and the number of such restaurants in Japan totals 2,700.Japan's third kaiten sushi boom has just come and gone and some kaiten sushi chains as well as conveyor-belt makers are seeking opportunities overseas because of the severe economic recession in Japan and the increasing competition at home."Kaiten sushi has been getting popular overseas. We exported about five per cent of the total sushi conveyor belt machines we produced last year to other countries, including Europe, the United States and other Asian countries," said Ippei Sugita, a spokesman at Japan's major conveyor belt maker, Kitanihon Kakoh Co.Mitsuko Mori, head of public relations at an Osaka-based kaiten sushi chain, Kura Corp., said the company has a desire to expand its business overseas with its newest machine.Kura's new computer-graphics touch-panel system, which the sushi chain spent about 25 million yen (200,000 dollars) to develop jointly with Tokyo-based game maker Sega Corp., was installed at its Senboku outlet in Osaka.The system is a modified version of a virtual aquarium.Instead of waiting to see what sushi comes along the conveyor belt, a customer can touch one of 16 different fish that swim on the 16-inch liquid crystal display. The order shows up on a monitor in the kitchen; for example: "Table 5; one order of tuna."The ordered sushi is then delivered to the customer's table via the conveyor belt.In case the customer is not sure what the fish looks like once it has been prepared as sushi, he or she can switch the screen over to display a total of 35 kinds of ready-to-eat sushi."We feel we can succeed even better overseas with this new system because people outside of Japan love going to a kaiten sushi restaurant for high-tech entertainment experience," said Kura's Mori.Mori said since the company installed the system in its Senboku outlet in February, the number of customers rose by 30 per cent."What is good about installing this system is that it helps reducing waste by precisely tracking orders. We used to throw out about 300 pieces of sushi, or 7 per cent of the total, every day but now waste has fallen to 2 per cent, or about 85 pieces," said Mori.Kura's official said the current tables were invented by the company's president Kunihiko Tanaka in 1987.Seats at kaiten sushi restaurants, which date back to 1958, used to be set around the conveyor belt facing the centre. And that's okay if a diner wants to sit alone. But what about groups of people?Kura's president Tanaka took out the chairs and installed each table at right angles to the conveyor belt, allowing people to face each other and be more sociable. At a table of four though it might be wise to get the two people with the biggest appetite to sit nearest the conveyor belt so they can pass the food on.Kaiten sushi literally means turnover sushi and its story begins in the big mercantile city of Osaka.Yoshiaki Shiraishi, chairman of Genroku Sushi, invented the mass- selling system and opened the nation's first kaiten sushi restaurant in April 1958 in Osaka. It was called "Mawaru Genroku Sushi".Shiraishi used to be the owner of a small sushi bar which he had opened in 1947. His restaurant was very popular but he was suffering from a chronic staff shortage, according to Genroku Sushi's spokesman Tomohisa Ueyama."It was hard for him to manage his popular sushi bar alone. One day, a light lit up in his head when he saw a conveyor belt, as he was taking a study tour at an Asahi Beer Co. factory," said Ueyama.Ueyama said Shiraishi spent about five years developing the sushi conveyor belt. Determining the ideal speed for of the conveyor belt was the problem."The speed of the conveyor was determined through many tests. The speed, which is used now at most kaiten sushi restaurants, is about eight centimetres per second. If it is faster than that, the sushi dries out and customers have trouble grabbing the plates," said Ueyama.Japan's first kaiten sushi boom came in the 1970s after the concept became known nationwide during the Osaka Expo of 1970, when a kaiten sushi stall was set up by Shiraishi's Genroku Sushi at the Expo site.The second boom came in the mid-1980s, when more and more Japanese households bought their own cars and an increasing number of people started eating out. Chain outlets with huge parking lost mushroomed along surburban highways during that time.Its third golden age came in the late 1990s after Japan's bubble economic burst. Many people who wanted to eat sushi but had limited budgets, so they started going to kaiten sushi restaurants.