Did Toyota invent the hybrid car in 1997?

Nope. Not by a long-shot! In fact, they were 100 years behind the curve.

This Wired article erroneously places the first gasoline/electric hybrid car in 1972. The car they mention is the converted 1972 Buick Skylark which was the work of electrical engineer Victor Wouk. Although much earlier than the Totota Prius of the Honda Insight, Victor Wouk's work was a full 75 years later than the first hybrid car.

From 1897 to 1907, the Compagnie Parisienne des Voitures Electriques in France built a series of electric and hybrid vehicles, including the 1903 Krieger (which additionally featured front-wheel drive and power steering).

At about the same time, Ferdinand Porsche (you might recognize the surname) found a way to integrate electric motors into the weel-hubs of his gasoline/electric hybrid, delivering power directly to the wheels. Using a gasoline engine to drive a generator, these hybrids where known as Lohner-Porsches

In 1900 General Motors built a gasoline/electric hybrid with a 4-cylinder gasoline engine. Their tremendously late re-entry into hybrid vehicles suggests they forgot how to do this in 105 years.

Perhaps most impressive, though, was the Woods Dual Power made in Chicago from 1917 to 1918. This gasoline/electric hybrid worked much like modern hybrids. There are three of these cars known to remain -- one is housed in the Peterson Auto Museum in Los Angeles.

This excellent article from Modern Racer has an excellent article on they history of hybrids.