Abstract: A projection lens system projects an image of a reduction side into a magnification side in an image projection device, a back glass being disposed on the reduction side. In the projection lens system, all of one or more negative lenses that satisfy, in a surface on the reduction side or a surface on the magnification side, condition |h/H|<2.0 defined by height h of a most off-axis principal ray and height H of an axial ray passing through a highest pupil position satisfy conditions Tn?98.5% and Dn/Db?0.05 defined by transmittance Tn, thickness Dn of the negative lens on an optical axis, and total thickness Db of the back glass.

Abstract: A projection lens system that projects an image of a reduction side into a magnification side includes a diaphragm, a plurality of positive lenses, and a plurality of negative lenses. The plurality of positive lenses include a first positive lens closer to the magnification side than the diaphragm is and closest to the diaphragm, a second positive lens second closest to the diaphragm after the first positive lens on the magnification side, a third positive lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The plurality of negative lenses include a first negative lens closer to the magnification side than the diaphragm is and closest to the diaphragm, and a second negative lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The lenses have transmittances larger than threshold values, respectively.

Abstract: A phosphor wheel (13) includes: a first surface having a disk shape; a second surface opposite the first surface; a phosphor layer (13b) having an annular shape and being provided on the first surface; a plurality of openings (13c); and a plurality of first blade parts (33a). The plurality of openings (13c) are disposed radially inward of the annular-shaped phosphor layer (13b) and arrayed along a circumferential direction. The plurality of first blade parts (33a) are located respectively adjacent to the plurality of openings (13c) in the first surface and configured to blow air to a surface of the phosphor layer (13b).

Abstract: A projection lens system that projects an image of a reduction side into a magnification side includes a diaphragm, a plurality of positive lenses, and a plurality of negative lenses. The plurality of positive lenses include a first positive lens closer to the magnification side than the diaphragm is and closest to the diaphragm, a second positive lens second closest to the diaphragm after the first positive lens on the magnification side, a third positive lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The plurality of negative lenses include a first negative lens closer to the magnification side than the diaphragm is and closest to the diaphragm, and a second negative lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The lenses have transmittances larger than the respective lower limit values.

Abstract: A projection lens system projects an image of a reduction side into a magnification side in an image projection device, a back glass being disposed on the reduction side. In the projection lens system, all of one or more negative lenses that satisfy, in a surface on the reduction side or a surface on the magnification side, condition |h/H|<2.0 defined by height h of a most off-axis principal ray and height H of an axial ray passing through a highest pupil position satisfy conditions Tn?98.5% and Dn/Db?0.05 defined by transmittance Tn, thickness Dn of the negative lens on an optical axis, and total thickness Db of the back glass.

Abstract: Lens barrel includes first group lens frame unit, second group lens frame unit, lens frame, insertion hole, and depressions. First group lens frame unit holds lenses. Second group lens frame unit holds lens. Lens frame is disposed between first group lens frame unit and second group lens frame unit on an inner circumference side of first group lens frame unit through radial clearance. Insertion hole is provided on an outer peripheral surface of first group lens frame unit, and a jig of lens frame is inserted into insertion hole. Depressions are provided at a position accessible from an outside in a state where first group, second group lens frame units and lens frame are assembled, and fix lens frame to first group lens frame unit.

Abstract: A phosphor wheel includes a first face that has a phosphor layer, a second face located on an opposite side to the first face, a first blade provided to project from one of the first face and the second face, and a passage that sends air to the second face from the first face. The first blade is provided to send air on a side of the first face to a side of the second face through the passage during rotation of the phosphor wheel.

Abstract: A phosphor wheel (13) includes: a first surface having a disk shape; a second surface opposite the first surface; a phosphor layer (13b) having an annular shape and being provided on the first surface; a plurality of openings (13c); and a plurality of first blade parts (33a). The plurality of openings (13c) are disposed radially inward of the annular-shaped phosphor layer (13b) and arrayed along a circumferential direction. The plurality of first blade parts (33a) are located respectively adjacent to the plurality of openings (13c) in the first surface and configured to blow air to a surface of the phosphor layer (13b).

Abstract: A phosphor wheel includes a first face that has a phosphor layer, a second face located on an opposite side to the first face, a first blade provided to project from one of the first face and the second face, and a passage that sends air to the second face from the first face. The first blade is provided to send air on a side of the first face to a side of the second face through the passage during rotation of the phosphor wheel.

Abstract: A cooling device is adapted to cool a DMD including a reflection surface and a support frame for supporting the outer edge of the reflection surface, and includes first and second contact portions and a water cooling pump. The first and second contact portions each have a contact surface that is brought into contact with a side surface in a direction transverse the reflection surface at the support frame. The water cooling pump is connected to the first and second contact portions so as to cool the first and second contact portions.

Abstract: A lens barrel: an optical system; a focusing manipulation unit capable of changing a focal position of the optical system in a normal photographing area and in a macro photographing area where the focal position can be changed for an object located at a position shorter than a shortest distance position of the normal photographing area; a photographing mode switching unit for switching between a normal photographing mode and a macro photographing mode; and an index ring having a normal scale and a macro scale, the normal scale indicating an object distance in the normal photographing mode, and the macro scale indicating the object distance in the macro photographing mode. Then, the photographing mode switching unit switches a display position of the index ring between the normal scale and the macro scale, and the focusing manipulation unit changes the focal position displayed on the index ring by rotation manipulation.

Abstract: Lens barrel includes first group lens frame unit, second group lens frame unit, lens frame, insertion hole, and depressions. First group lens frame unit holds lenses. Second group lens frame unit holds lens. Lens frame is disposed between first group lens frame unit and second group lens frame unit on an inner circumference side of first group lens frame unit through radial clearance. Insertion hole is provided on an outer peripheral surface of first group lens frame unit, and a jig of lens frame is inserted into insertion hole. Depressions are provided at a position accessible from an outside in a state where first group, second group lens frame units and lens frame are assembled, and fix lens frame to first group lens frame unit.

Abstract: A cooling device is adapted to cool a DMD including a reflection surface and a support frame for supporting the outer edge of the reflection surface, and includes first and second contact portions and a water cooling pump. The first and second contact portions each have a contact surface that is brought into contact with a side surface in a direction transverse the reflection surface at the support frame. The water cooling pump is connected to the first and second contact portions so as to cool the first and second contact portions.

Abstract: An imaging device comprises an imaging optical system with a plurality of lenses, a focusing manipulation component, an imaging state switching manipulation component, and first, second, third, and fourth restrictors. The focusing manipulation component can be turned to change the focal position formed by the imaging optical system. The imaging state switching manipulation component can be turned to move lenses and switch between the first imaging state and the second imaging state. When the imaging state switching manipulation component is turned, the range over which the focusing manipulation component can be turned is switched from a first range that is restricted by first and second restrictors, to a second range that is restricted by third and fourth restrictors and that is at least partly shifted from the first range.

Abstract: Embodiments of a lens barrel may comprise an imaging optical system with a plurality of lenses, a cylindrical focusing manipulation component, a stationary frame, and a restrictor. The focusing manipulation component changes the focal position of the imaging optical system by turning operation around the optical axis of the imaging optical system and to set the distance up to a second imaging region that is at least partially different from a first imaging region, and to move at least some of the lenses of the imaging optical system to switch between first and second imaging states. The restrictor restricts the rotatable range of the focusing manipulation component. When the focusing manipulation component is turned, its rotatable range is switched from a first rotatable range to a second rotatable range.

Abstract: A lens barrel: an optical system; a focusing manipulation unit capable of changing a focal position of the optical system in a normal photographing area and in a macro photographing area where the focal position can be changed for an object located at a position shorter than a shortest distance position of the normal photographing area; a photographing mode switching unit for switching between a normal photographing mode and a macro photographing mode; and an index ring having a normal scale and a macro scale, the normal scale indicating an object distance in the normal photographing mode, and the macro scale indicating the object distance in the macro photographing mode. Then, the photographing mode switching unit switches a display position of the index ring between the normal scale and the macro scale, and the focusing manipulation unit changes the focal position displayed on the index ring by rotation manipulation.

Abstract: Embodiments of a lens barrel may comprise an imaging optical system with a plurality of lenses, a cylindrical focusing manipulation component, a stationary frame, and a restrictor. The focusing manipulation component changes the focal position of the imaging optical system by turning operation around the optical axis of the imaging optical system and to set the distance up to a second imaging region that is at least partially different from a first imaging region, and to move at least some of the lenses of the imaging optical system to switch between first and second imaging states. The restrictor restricts the rotatable range of the focusing manipulation component. When the focusing manipulation component is turned, its rotatable range is switched from a first rotatable range to a second rotatable range.

Abstract: An imaging device comprises an imaging optical system with a plurality of lenses, a focusing manipulation component, an imaging state switching manipulation component, and first, second, third, and fourth restrictors. The focusing manipulation component can be turned to change the focal position formed by the imaging optical system. The imaging state switching manipulation component can be turned to move lenses and switch between the first imaging state and the second imaging state. When the imaging state switching manipulation component is turned, the range over which the focusing manipulation component can be turned is switched from a first range that is restricted by first and second restrictors, to a second range that is restricted by third and fourth restrictors and that is at least partly shifted from the first range.

Abstract: There is provided a lens barrel with a high degree of design latitude, with which an index display portion can be driven regardless of the amount of drive of the lens. This lens barrel comprises a first driver first driver that moves a lens frame in a rectilinear direction, a position sensor that senses the position of the lens frame, a computer that computes an optical characteristic on the basis of the position of the lens frame sensed by the position sensor, a display portion that displays the optical characteristic, and a second driver that drives the display portion on the basis of the computation result of the computer.