Patent ID: 7175283

Claim:
An optical device, comprising: a light source; an optical modulation element to modulate a luminous flux emitted from the light source in response to image information to form an optical image; an optical modulation element holder that is formed with cooling chambers having cooling fluid sealed in an interior, and that holds the optical modulation element so as to be able to transfer heat to the cooling fluid within the cooling chambers; a plurality of fluid circulation members that are connected in communication to the cooling chambers of the optical modulation element holder and that guide the cooling fluid to an exterior of the cooling chambers and lead the cooling fluid again into the interior of the cooling chambers; and a cooling fluid relay section that is disposed at a predetermined position relative to an optical axis of the luminous flux emitted from the light source and that relays, via the plurality of fluid circulation members, at least one of cooling fluid moving from the exterior to the interior of the cooling chambers of the optical modulation element holder, and cooling fluid moving from the interior to the exterior of the cooling chambers of the optical modulation element holder; the optical modulation element holder defining an inflow port to allow the cooling fluid to flow into the interior of the cooling chambers and an outflow port to allow the cooling fluid inside the cooling chambers to the exterior of the cooling chambers; the plurality of fluid circulation members including fluid circulation members that each have one-side end connected in communication to the inflow port and outflow port so that another-side end thereof protrudes in the optical axis direction of the luminous flux emitted from the light source; and the cooling fluid relay section defining insertion holes that extend inwardly through the cooling fluid relay section and that are capable of receiving therethrough the another-side end of the fluid circulation members connected in communication to the inflow port and outflow port.