US offices reaching out to fax someone - anyone

``Do you have a fax number?'' The question crops up with increasing frequency as businesses turn to facsimile machines to speed communications.

``I'll tell you what amazes me - people are lined up all day long to use them,'' says Charles Eaton, an investment strategist with Nikko Securities in New York. Nikko, with about 350 employees, sports seven or eight machines, he adds. ``It's mind boggling.''

The technology became popular in the last few years in the United States because of its speed, efficiency, and accuracy. The fax machine, a sort of telephone and photocopier combined, can transmit and receive pages of information to other such machines anywhere in the world, using telephone lines as a link. Many copy a page in less than 30 seconds.

Faxes ``used to be the realm of large corporations,'' says Judy Pirani, a senior market analyst at CAP International Inc., a market research company in Marshfield, Mass. But, she adds, because they are so easy to use, they are increasingly becoming standard office equipment, like the typewriter, the personal computer, and the copy machine.

About 1 million facsimile machines have been installed in the US. Most are made in Japan. Leading companies include Sharp, Canon, Brother, Toshiba, Panasonic, and Ricoh.

In Japan, faxes are as ordinary as typewriters are in the US, says Don Orrick, director of marketing communications in Ricoh Corporation's fax division, adding, ``We're rapidly approaching that here.''

Faxes originated in Japan, he says, because businessmen needed a fast way to transmit a picture - specifically, their language, which is graphic in character.

The fax's ability to convey artwork is one reason for its popularity. Some machines reproduce a halftone or a gray scale of 8, 16, or even 64 shades, says Eric Arnum, editor of a fax newsletter at International Resource Development Inc. in New Canaan, Conn. With a good enough gray scale, this capability could allow a photo to be sent to a publisher ready for paste-up, he adds.

Basic fax machines retail for less than $1,000. CAP International calculates that the average price of a machine, including both the high and low end of the market, has dropped from $2,700 in 1986 to $2,400 in 1987 and could reach $2,000 by the end of this year.

``Like anything else, they will come down and down in prices,'' says Mr. Orrick, though he adds that major price differences will continue between basic machines and those offering high-performance options (such as the ability to send a text to 100 locations at the same time).

The expense of sending a fax is primarily that of making a phone call. Although the speed and cost of faxes compares favorably with more-traditional communications systems, such as telexes, the post office, and Federal Express, Mr. Arnum does not expect the machines to make serious inroads on these businesses.

Still, it takes very little document traffic to justify spending $2,000 on a fax machine, Orrick notes. A couple of pages a day would represent a saving on couriers, he says.

Although portable machines and car machines are coming on the market, industry observers say their sales are small.