The copier business today is a multibillion-dollar industry, replete with huge corporations, slick promotions, and all the other trappings of big business. Yet the process that started it all, xerography, was the product of one man's often lonely struggle against huge financial odds and a business community convinced that his idea was worthless.

Chester Carlson made the discoveries fundamental to xerography in his spare time, working in his kitchen in Jackson Heights, N.Y. A barber's son, he grew up in Seattle, Wash., worked his way through a junior college and then through the California Institute of Technology. He graduated with a physics degree and started searching for jobs just as the Depression began. He applied to 82 companies, but received just two replies. One was from the Bell Telephone Laboratories in New York, which he joined as a research engineer at a salary of $35 a week. As the Depression worsened, he was laid off, but managed to find another job with an electronics company. He studied for his law degree at night and eventually became head of that company's patent department.

In the course of his work with patents, Carlson noticed that there never seemed to be enough carbon copies of specifications and that there was no quick or inexpensive way of making more. He began after-hours reading and research in the obscure field of photoconductivity, staying away from offshoots of the conventional photographic process, because he knew the research and development departments of a number of major corporations were working in that area. Finally, in October 1937, he was able to file his first patent application. Shortly thereafter, in a small rented room over a bar in Astoria, N.Y., he made the process he called xerography work for the first time.

The struggle was far from over. Carlson was apparently alone in his belief that xerography was of use to anybody. From 1939 to 1944 he was turned down by more than 20 companies, including IBM, as he sought to commercialize his invention. Even the National Inventors Council dismissed his work as useless. Finally, a nonprofit research organization signed a royalty-sharing contract with him and began to invest funds to develop the process. In 1947, the Haloid Co., a small manufacturer of photo paper, entered the partnership, and nine years later, Carlson was able to persuade a skeptical Englishman named Joseph Rank to join forces with him for full-scale commercialization. The first Xerox machine, the 914, was introduced in 1959.

Carlson died in 1968, at the age of 62. By then he was a wealthy man. But his 21-year saga of entrepreneurial persistence is proof that not every important technological innovation takes root overnight.