Translation guide
Hitachi is a major Japanese multinational conglomerate. In Japanese, it is written as 日立 and pronounced ひたち. It can refer to the company, the city in Ibaraki Prefecture, or other entities bearing the name.
Referring to Hitachi, Ltd. or the Hitachi Group
The standard way to refer to the company in Japanese. Often used with 製作所 (せいさくしょ) for the full corporate name.
Referring to Hitachi City in Ibaraki Prefecture
The city name. Use 市 (し) to specify the city, as 日立 alone could be ambiguous.
Referring to other things named Hitachi (e.g., train line, period, person's name)
Used in various proper nouns. Context determines the meaning.
日立は日本の大手電機メーカーです。
Hitachi is a major Japanese electronics manufacturer.
The full official name, Hitachi, Ltd. Used in formal or official contexts.
Hitachi, Ltd.'s stock price went up.
Hitachi City is in Ibaraki Prefecture.
Can be used without 市 when context makes it clear you mean the city, but adding 市 is safer.
I was born in Hitachi.
Please get off at Hitachi Station.