Patent ID: 7070282

Claim:
A projection type display apparatus comprising: a color separation optical system that executes color separation to separate light emitted from a light source into first color light, second color light and third color light; reflection type light valves provided each in correspondence to one of the first color light through the third color light; polarization beam splitters provided each in correspondence to one of the first color light through the third color light, which execute polarization separation of the first color light, the second color light and the third color light resulting from the color separation, cause the first color light, the second color light and the third color light to enter the reflection type light valves and analyze light exiting the reflection type light valves after being modulated at the reflection type light valves; a color composition optical system having a first prism, a second prism and a third prism having shapes of substantially triangular columns with the first prism and the second prism bonded via a first dichroic film achieving characteristics whereby the first color light is transmitted and the second color light is reflected and the second prism and the third prism bonded via a second dichroic film achieving characteristics whereby the third color light is reflected and the first color light and the second color light are transmitted, in which the analyzed first color light having entered through the first prism and the analyzed second color light having entered through the second prism undergo color composition at the first dichroic film and composite light constituted of the analyzed first color light and the analyzed second color light and the analyzed third color light having entered through the third prism undergo color composition at the second dichroic film; and a projection lens that projects light resulting from the color composition, wherein: lengths of optical paths through which the first color light through the third color light travel from the light source to the reflection type light valves are equal to one another.