Optical device and projector

An optical device comprising:

• an optical element disposed on an optical axis of incident light;
• and
• a holding section configured to hold the optical element,
• wherein the holding section includes
• an inflow part to which a liquid supplied from an outside of the holding section inflows,
• a flow channel forming part disposed along a circumferential edge of the optical element so as to have an annular shape, and having a flow channel through which the liquid flowed from the inflow part circulates, and
• an outflow part from which the liquid having flowed through the flow channel outflows to the outside of the holding section,
• wherein at least one of an inside of the inflow part and an inside of the flow channel is provided with at least one projection,
• wherein the flow channel forming part is formed so as to surround the optical axis of incident light, and the at least one projection protrudes along the optical axis of incident light,
• wherein the flow channel includes
• a first flow channel part and a fourth flow channel part disposed so as to be opposed to each other, the first flow channel extending in a first direction, the fourth flow channel extending in a third direction opposite to the first direction, and
• a second flow channel part and a third flow channel part disposed so as to be opposed to each other and extending in a second direction crossing the first direction,
• wherein the first flow channel part, the second flow channel part, the third flow channel part, and the fourth flow channel part are connected so as to form an annular shape, and
• wherein the at least one projection is disposed inside the flow channel.

An optical device comprising:

• an optical element disposed on an optical axis of incident light;
• and
• a holding section configured to hold the optical element,
• wherein the holding section includes
• an inflow part to which a liquid supplied from an outside of the holding section inflows,
• a flow channel forming part disposed along a circumferential edge of the optical element so as to have an annular shape, and having a flow channel through which the liquid flowed from the inflow part circulates, and
• an outflow part from which the liquid having flowed through the flow channel outflows to the outside of the holding section,
• wherein the inflow part and the outflow part are disposed on a same side with respect to the flow channel forming part,
• wherein an entirety of the liquid flowed through the flow channel is substantially perpendicular to the optical axis,
• wherein the flow channel includes
• a first flow channel part configured to circulate, in a first direction, a part of the liquid flowed from the inflow part,
• a second flow channel part configured to circulate, in a second direction crossing the first direction, a rest of the liquid flowed from the inflow part,
• a third flow channel part configured to circulate, in the second direction, a liquid flowed through the first flow channel part, and
• a fourth flow channel part configured to circulate, in a third direction opposite to the first direction, a liquid flowed through the third flow channel part, and
• wherein the outflow part outflows a liquid obtained by combining a liquid circulated through the second flow channel part and a liquid circulated through the fourth flow channel part.