Abstract: A flow path diagnosis method includes: acquiring the number of rotations of a pump configured to send a refrigerant for cooling a cooling target to a flow path through which the refrigerant circulates; acquiring an environmental temperature; setting a first threshold value as a threshold value of the number of rotations when the environmental temperature is lower than a first temperature; setting a second threshold value higher than the first threshold value as the threshold value when the environmental temperature is equal to or higher than the first temperature; determining that the flow path is normal when the number of rotations is less than the threshold value; and determining that the flow path is abnormal when the number of rotations is equal to or more than the threshold value.

Abstract: A light source apparatus includes a light source, a light source enclosure that accommodates the light source and has a plurality of openings formed therein in a circumferential direction around an optical axis of the light source, a channel having an introduction port through which air is introduced from outside of the light source enclosure, the channel allowed to communicate with the plurality of openings, and an opening/closing mechanism that rotates around the optical axis to selectively open and close the plurality of openings, and the opening/closing mechanism has an opening/closing section that opens and closes the plurality of openings in a first posture in which the optical axis extends along a horizontal plane in such a way that upper openings located on a vertically upper side are open and at least part of lower openings located on a vertically lower side is closed.

Abstract: A light source apparatus includes a light source, a light source enclosure that accommodates the light source and has a plurality of openings formed therein in a circumferential direction around an optical axis of the light source, a channel having an introduction port through which air is introduced from outside of the light source enclosure, the channel allowed to communicate with the plurality of openings, and an opening/closing mechanism that rotates around the optical axis to selectively open and close the plurality of openings, and the opening/closing mechanism has an opening/closing section that opens and closes the plurality of openings in a first posture in which the optical axis extends along a horizontal plane in such a way that upper openings located on a vertically upper side are open and at least part of lower openings located on a vertically lower side is closed.

Abstract: A reflective polarizing plate apparatus includes a reflective polarizing plate that transmits first linearly polarized light and reflects second linearly polarized light polarized in a direction substantially perpendicular to the direction in which the first linearly polarized light is polarized, a holding member that accommodates and holds the reflective polarizing plate, and a first biasing member that biases a glass surface of the reflective polarizing plate accommodated in the holding member.

Abstract: A light source device includes: an arc tube having a bulb portion and a sealing portion; a reflector which fixes the arc tube; and a holding portion which holds the reflector, wherein the holding portion includes an inlet port, a partition provided between the inlet port and the arc tube, a pair of passages to which diverges in the partition and can circulate the cooling air to the arc tube, a first opening provided in the partition, and a shutter which is provided on that side of the partition where the inlet port is located, rotates about a rotation axis, and blocks a lower passage of the pair of passages, and on that side of the shutter where the rotation axis is located, a second opening is provided so as to overlap the first opening as seen from the inlet port.

Abstract: A reflective polarizing plate apparatus includes a reflective polarizing plate that transmits first linearly polarized light and reflects second linearly polarized light polarized in a direction substantially perpendicular to the direction in which the first linearly polarized light is polarized, a holding member that accommodates and holds the reflective polarizing plate, and a first biasing member that biases a glass surface of the reflective polarizing plate accommodated in the holding member.

Abstract: In a projection optical system comprising: two lens groups, and a curved plane mirror, wherein the projection optical system including two story structure, and having bend means for bending at least two times the light incident from an electro-optic modulator.

Abstract: In a projection optical system comprising: two lens groups, and a curved plane mirror, wherein the projection optical system including two story structure, and having bend means for bending at least two times the light incident from an electro-optic modulator.

Abstract: A light source device includes: an arc tube having a bulb portion and a sealing portion; a reflector which fixes the arc tube; and a holding portion which holds the reflector, wherein the holding portion includes an inlet port, a partition provided between the inlet port and the arc tube, a pair of passages to which diverges in the partition and can circulate the cooling air to the arc tube, a first opening provided in the partition, and a shutter which is provided on that side of the partition where the inlet port is located, rotates about a rotation axis, and blocks a lower passage of the pair of passages, and on that side of the shutter where the rotation axis is located, a second opening is provided so as to overlap the first opening as seen from the inlet port.

Abstract: In a projection optical system comprising: two lens groups, and a curved plane mirror, wherein the projection optical system including two story structure, and having bend means for bending at least two times the light incident from an electro-optic modulator.

Abstract: In a projection optical system comprising: two lens groups, and a curved plane mirror, wherein the projection optical system including two story structure, and having bend means for bending at least two times the light incident from an electro-optic modulator.

Abstract: An illuminating device includes: a lamp device that includes a lamp body, which is a light source, and a concave reflector for reflecting light emitted from the lamp body; and a lens member that has a planar optical surface and a nonplanar optical surface opposite to the planar optical surface and is provided on an emission side of the lamp device. In the illuminating device, the lens member is arranged such that a normal line of the planar optical surface is slightly inclined at a predetermined angle with respect to an optical axis of the lamp device. The lens member is arranged such that light beams substantially parallel to the optical axis are incident on the planar optical surface, and a filter that reflects at least one of an ultraviolet ray and an infrared ray is provided on the planar optical surface.

Abstract: An illuminating device includes: a lamp device that includes a lamp body, which is a light source, and a concave reflector for reflecting light emitted from the lamp body; and a lens member that has a planar optical surface and a nonplanar optical surface opposite to the planar optical surface and is provided on an emission side of the lamp device. In the illuminating device, the lens member is arranged such that a normal line of the planar optical surface is slightly inclined at a predetermined angle with respect to an optical axis of the lamp device. The lens member is arranged such that light beams substantially parallel to the optical axis are incident on the planar optical surface, and a filter that reflects at least one of an ultraviolet ray and an infrared ray is provided on the planar optical surface.