RIFAX 600S: The World's First High-speed Digital Facsimile for Offices, Capable of Connecting to Public-line Networks

In 1973 when the RIFAX 600S was released, analog connection with a telephone line indirectly through acoustic couplers was the standard at the time; facsimile at that time required as long as six minutes to transmit a single A4-page. The RIFAX 600S was an epoch-making high-speed facsimile that could directly connect to the public-line network, where all of the system controls for page reading, data processing, transmission and output are digitally processed. It could transmit an A4 standard page in one minute, six times faster than the analog facsimile.

The communication experiment conducted between Japan and the U.S. in advance of the release, and the resulting presentation in 1973, demonstrated the high-speed performance and innovative spirit of the RIFAX 600S to the world. It was simultaneously released in Japan as the RIFAX 600S and in the USA as the Rapifax 100 the following year in 1974. It was the forerunner of digitized facsimile machines. Taking advantage of this opportunity, facsimile applications expanded from specific business use, such as newscasts and railroad systems over dedicated lines, to general office work using the public-line network.

RIFAX 600S

[Historical transition]
Revision of Public Telecommunications Act enforced in November 1972 opened the public-line network in Japan, making it possible for general companies to use it for data transmission and facsimile communications other than audio communication. The RIFAX 600S was commercialized taking advantage of this opportunity. The fact that it was used for a demonstration with the USA at the launch event for this product in 1973 and its use for communication by NASA (beyond use in general offices) demonstrated the epoch-making nature of this product.
The core of facsimile communication is data compression and digital communication technology. A facsimile communication procedure based on the communication technology used in this product was proposed at the international convention of CCITT (current ITU-T) ^(*1), the international standard, and was formally advised in 1980 as a facsimile-transmission procedure (T. 30 protocol standard) in the public-line network. With this procedure, mutual communication between facsimiles, regardless of manufacturer or model, became possible, contributing greatly to the expansion of facsimile service.

*1ITU-T (International Telecommunication Union Telecommunication Standardization Sector) is a division of International Telecommunication Union, which is charged with standardizing telecommunication. The old CCITT (Comite Consultatif International Telegraphique et Telephonique) was the abbreviated name for International Telegraph and Telephone Consultative Committee; it was split up in 1993 and renamed ITU-T.

[The technical features of RIFAX 600S]
Communication by facsimile is achieved by four major processes of “conversion of document image to digital signals,” “compression and transmission of digital signals,” “decompression of the transmitted digital signals,” “creation of images from decompressed digital signals,” and the system control for aligning them to act in concert. Digitizing all processes from scanning of the image to output achieved high-speed processing with the RIFAX 600S.

◆Flatbed page scanning technology
The method used to scan image information for facsimiles in those days was the rotating drum, in which the page is wrapped around the drum. But for the RIFAX 600S, Ricoh developed and mounted a new scanning technology called the pinhole rotary system. This technology increased transmission efficiency on the order of two or more pages. This flatbed scanning type became the standard in facsimiles for offices after that. It was the unique forerunner technology before the widespread use of CCD (Charge Coupled Device), currently the page scanning element.

◆Data compression technology and high-speed-transmission technology
The key technologies for one minute facsimile were a data compression technology by the two line collective-encoding method, and transmission technology using a fast modem. The modem operated at 1,200 baud, yielding a transmission speed of 4,800 bps, which achieved high speed transmission of 4,800-bps over telephone subscriber lines by automatically equalizing line characteristics at the receiving side.

◆LSI (Large Scale Integration) technology
LSI technology is also important in the RIFAX 600S. It made it possible to achieve both a modem and a data-compression device with a single PC board each. By reducing hardware to these two PC boards, the transceiver integral type facsimile was completed with the complicated controller built in.

◆Multi-stylus recording technology
Wet electrostatic recording using multi-stylus heads (multi-stylus electrode) with less odor, dust, and electric noise was adopted for the image recording system to write digital image signals on a page. We also commercialized electrostatic recording paper to achieve this recording method concurrently.

Today, the basic functions of facsimiles, such as “scanning,” “recording,” and “copying” are included in multifunction printers. We can say that the RIFAX 600S was a forerunner of high-speed digital facsimiles for offices, having contributed greatly to the telecommunications sector in our country. At the same time, it signified the first step in building a foundation for developing the advanced digital technologies of today.