The Hojo family had a symbol that looked exactly like the Hylian triforce symbol of Zelda. Since they were a very powerful and influential family of the era, their symbols would not be too uncommon. So it is probably not a reference to Zelda, but a historical reference.
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After looking it up, a member of the Hojo family did appear in Inu Yasha. Hojo Akitoki, early in the series. So the triforce crest had to be the symbol for his family. http://inuyasha.wikia.com/wiki/Hojo_Akitoki
It's called the mitsu-uroko. I've seen it all over the place. The Legend of Zelda was not the first to use it.
Djinn beat me to it, but anyway... Question answered, thread closed.