Word Processing for the Japanese Language

This article was initially written as part of the IEEE STARS program.

Citation

Toshiba introduced the JW-10 word processor for the Japanese language in 1978. Based on a 1967 proposal by Toshihiko Kurihara, it provided methods for converting kana to kanji, and the Roman alphabet to kana and kanji. These word-processing technologies were rapidly adopted throughout Japan. People preferred kana input initially, but Roman alphabet input gained in popularity as personal computers replaced word processors. Japanese-language word processing was subsequently applied to the Internet and cell phones, where it revolutionized communications and the availability of information. It contributed to economic growth, cultural change, and enhanced living standards throughout Japan.

Introduction

In the English language, any text of any length can be written using only 26 different letters of the alphabet, because any English word can be spelled by some combination of those letters. In practice users want to have each of the 26 letters in two forms, capitals and lower case, and also want to have the Arabic numerals of 0 to 9, as well as punctuation marks and various special symbols. Thus a typical keyboard for the English language has 44 keys, which can produce 88 characters by means of a shift function that permits each key to produce two characters. This many characters are sufficient for most applications.

Challenges of the Japanese Language

By contrast, the written Japanese language uses three character sets combined: a large number of kanji, or Chinese characters, plus two sets of native symbols collectively called kana. Today both sets of kana and thousands of different kanji are used in daily life.

The Japanese began adopting the Chinese characters to record their native language in the 5th century CE. They used the Chinese ideographic characters as symbols to represent objects and concepts, though pronouncing them with Japanese sounds for words. They added new kanji and new meanings. The Japanese also used characters purely to represent native sounds, including those having grammatical significance in a manner similar to word endings in English such as -ed, -ing, and -ly. This latter group of characters was developed into the two sets of kana, called hiragana and katakana, and comprised of 48 basic symbols each. This development has been attributed to the Buddhist priest, Kukai, in the 9th century. Katakana are traditionally used to spell foreign words. The present sets of kana were codified by the 1900 Elementary School Order and their orthography standardized in 1946 by the Cabinet announcement on Gendai Kanazukai, or Modern Kana Usage.