The northern Japanese prefecture of Ibaraki has one foot firmly in the 17th century, the other in the 21st. In tiny villages, craftsmen (some designated ''national cultural treasures'') spend up to six months weaving rich silk kimonos, or lovingly produce unique styles of Japanese paper, stoneware, and ceramics by the centuries-proven methods of their forefathers.
But in the midst of this, scientists and academics work on an intense and costly program to give Japan international preeminence in 21st-century high technology.
Since World War II, Japan's extraordinary economic success has depended heavily on borrowed technology, from steel to miniature televisions. But the future prosperity of Japanese industry, tied as it is to trade competition with advanced nations, is dependent on the success of its research and development efforts.
Japan, whose cultural and educational systems have traditionally sanctioned consensus and collective rather than individual efforts, has therefore invested heavily in the past several years in technological innovation.
Sprouting up out of ancient rice paddies some 40 miles northeast of Tokyo, ''Tsukuba science city'' spearheads this drive by government and private industry.
The Tokyo government decided in 1963 to set up Tsukuba and construction began eight years later. Today, 50 state laboratories, private and public research institutions, and universities have been relocated to the city. More are scheduled to follow in the years ahead, probably doubling Tsukuba's present 100, 000 population by the end of this decade.
A brochure prepared for visitors proclaims the first priority is ''research to improve the nation's quality of life,'' conforming with Tsukuba's dream of being a model ''ideal city'' free from contemporary urban blight.
One way it is promoting this aim is by playing host to an international exposition in 1985 under the theme ''dwellings and surroundings - science and technology for man at home.''
According to exposition chairman Toshio Doko: ''It will search for a new image of man's dwellings and surroundings which are a common foundation for all existence. Each country has its own science and technology conditioned by historical and cultural diversity, and by bringing these together we hope to discover new values and a new road to development.''
Among the current features of Tsukuba are frequent interdisciplinary meetings for a free exchange of ideas among scholars. The city eventually plans to build facilities to expand this concept into international research cooperation.
The science city is a visible sign of the government's firm commitment to expand its promotion of technological development.
Three years ago it adopted a basic policy that set targets for 1990 of increasing the proportion of the gross national product that is spent on high-technology research and development. The goal is 3 percent compared to an existing level of less than 2 percent. Government's share of this spending would be boosted from the present 30 percent to the 40 or 50 percent prevalent in the West.
''There has been a significant change in the technological field here in recent years,'' says Toru Namiki, a senior director of the Science and Technology Agency.
''Until the late 1970s average product life in Japan was 3.5 years compared to the five to seven years prevalent in the United States and Europe. This short commercial life showed the emphasis of Japanese R&D on products ensuring market viability, with technical improvements being made in small increments.''
That, however, is changing and is being reflected in the growing number of Japanese international patent applications and gradual rectification of the Japanese technology trade imbalance, in significant areas like semiconductors, optical fibers, industrial robots, and office automation, he adds.
The new longer-range commitment is typified at Tsukuba by the delightfully named ''Sunshine'' and ''Moonlight'' projects. Those working on Sunshine are trying to find new ways to utilize energy from such sources as the sun and sea. The Moonlight men are concerned with energy conservation.
Tsukuba researchers are also playing the main role in a government-backed program to beat the United States to development of a so-called ''fifth generation'' computer which would function like the human brain rather than just having learning and deduction functions as now.
Several hundred staff members at the Electrotechnical Laboratory (ETL) have been given a good part of its $40 million annual budget to develop a ''pattern information processing system'' capable of processing information in characters, diagrams, and voice. Present computers can't handle any of these.
And Dr. Shigeru Maekawa, head of ETL's research planning office, warns: ''We are already looking beyond to the sixth-generation computer.''
Another Tsukuba star (with a $100 million budget) is the National Laboratory for High Energy Physics, which has scored a number of international scientific firsts.
It has developed a ''photon factory'' (claimed to be superior to anything in the US or Europe) creating a powerful new light force with many valuable applications in physics, biology, and medicine. For example, it is superior to lasers, making possible the ultra-minute lithography necessary for the tiny ''chips'' containing millions of circuits needed in new computers. Also under development here are superconductive magnets for a proposed high-speed, nonpolluting linear car.
The National Space Development Agency (NASDA) is also at Tsukuba. Having developed the capacity to launch and orbit advanced scientific and communications satellites, NASDA has begun work on Japan's answer to the US space shuttle.
Tsukuba is virtually the midwife of the government's ''technopolis'' project to create regional high-technology research and development centers forming ''the backbone of the Japanese economy in the 21st century.''
Nineteen provincial sites have been selected so far for a marriage of high-technology industries, both domestic and foreign, and academic and scientific research organizations into an ''integrated life sphere'' as an existing ''mother city'' at the core.
Hoping that this will trigger a ''grass-roots technological revolution,'' government planners have proposed concentration on 14 industrial sectors: aircraft, space, optics, biotechnology, medicine and medical supplies, medical electronics, industrial robots, integrated circuits, computers, word processors, metal-based new materials, fine ceramics, industrial machinery, and computer software.