US Pat. No. 9,798,068

ILLUMINATION MODULE

KEIO UNIVERSITY, (JP) NI...

1. An illumination module, comprising:
a light guiding plate having an end surface and a first light exit surface;
a light source aligned along the end surface, the light source being configured to emit light that enters the end surface;
and

a diffusion plate that is configured by a monolithic body, the light diffusion plate including:
a main member having a light incident surface and a second light exit surface opposite to each other, the light incident surface
directly facing the first light exit surface; and

a protrusion that is provided at a peripheral edge of the diffusion plate, the protrusion having a protrusion top surface
and a protrusion side surface, the protrusion top surface directly facing the first light exit surface,

wherein the protrusion top surface, the protrusion side surface and the light incident surface continuously extend,
wherein the light, which is exited from the first light exit surface of the light guiding plate, enters into the diffusion
plate via the protrusion top surface, the protrusion side surface and the light incident surface.

US Pat. No. 9,910,251

LENS SYSTEM AND IMAGING APPARATUS HAVING A LENS AT EACH SIDE OF AN INTERMEDIATE IMAGE WHICH MOVE IN SYNCHRONIZATION DURING FOCUSING

NITTOH INC., Nagano (JP)...

1. A lens system that comprises a first optical system and forms an intermediate image that is formed inside the first optical
system by light from an input side, into a final image on an output side,
wherein the first optical system includes a combination of lenses as follows:
a first lens with positive refractive power that is disposed at a position closest to the intermediate image, on the input
side of the intermediate image, compared to any other lens in the lens system, wherein the first lens moves during a focusing;

a second lens with negative refractive power that is disposed at a position closest to the intermediate image, on the output
side of the intermediate image, compared to any other lens in the lens system, wherein the second lens moves in synchronization
with the first lens during the focusing; and

a third lens with positive refractive power that is disposed at a position closest to the second lens, on the output side
of the second lens, compared to any other lens in the lens system, wherein the third lens does not move in synchronization
with the first lens during focusing.

US Pat. No. 9,785,043

PROJECTION OPTICAL SYSTEM AND PROJECTOR APPARATUS

NITTOH INC., Nagano (JP)...

1. A projection optical system that projects from a first image plane on a reducing side onto a second image plane on an enlargement
side, comprising: a first refractive optical system that forms a first intermediate image on the enlargement side using the
light incident from the reducing side; a second refractive optical system that forms the first intermediate image on the reducing
side into a second intermediate image on the enlargement side; and a first reflective optical system including a first reflective
surface with positive refractive power that is positioned on the enlargement side of the second intermediate image, wherein
the second refractive optical system includes a first focus lens group that moves when focusing is carried out, and the first
refractive optical system includes a second focus lens group that moves when focusing is carried out, and wherein a curvature
of field FC1 of the first intermediate image and a curvature of field FC2 of the second intermediate image satisfy the following conditions:
0
0.03<|FC1|.

US Pat. No. 10,139,589

ZOOM LENS UNIT AND INDICATOR MEMBER

Nittoh Inc., (JE)

1. A zoom lens unit comprising:a zoom ring that has a scale indicating a focal length of the zoom lens unit, the zoom ring having a zoom ring inner surface and a zoom ring outer surface opposite to each other, the zoom ring inner surface being located closer to an optical axis of the zoom lens unit than the zoom ring outer surface, the zoom ring having a cut-out that is concave from the zoom ring outer surface toward the zoom ring inner surface;
an indicator ring that is disposed in the cut-out of the zoom ring, the indicator ring having an indicator ring inner surface and an indicator ring outer surface opposite to each other, the indicator ring having an indicator that is configured to point a desired value on the scale; and
a spring that is disposed in the cut-out between first part of the zoom ring and the indicator ring inner surface,
wherein when a spring force is applied between the first part of the zoom ring and the indicator ring inner surface, a relative location between the zoom ring and the indicator ring is fixed so that the indicator ring and the zoom ring are configured to rotate together, and
when the zoom ring maintains at a current location so as to prevent the zoom ring from rotating with respect to the zoom lens unit, the indicator ring is configured to rotate relative to the zoom ring.

US Pat. No. 9,995,903

LENS DEVICE

Nittoh Inc., (JP)

1. A lens device, comprising:a lens barrel;
a control unit mounted to the lens barrel; and
a cable having one end connected to the control unit, wherein
a cable housing groove circumferentially extends about the lens barrel, the cable housing groove opening radially outwardly relative to the lens barrel, the cable housing groove housing a part of the cable therein such that the part of the cable is wound within the cable housing groove from a radially outer side of the lens barrel so as to be exposed.

US Pat. No. 10,310,366

PROJECTION OPTICAL ASSEMBLY AND PROJECTOR DEVICE

NITTOH INC., Suwa-Shi, N...

1. A projection optical system that projects from a first image plane on a reducing side to a second image plane on an enlargement side, comprising:a zoom optical system that includes a plurality of lenses and forms light incident from the reducing side via a first intermediate image formed inside the zoom optical system into a second intermediate image on the enlargement side, the zoom optical system including multiple lenses arranged on the reducing side of the first intermediate image and being configured to correct aberrations including curvature of filed, astigmatism and comatic aberration and multiple lenses arranged on the enlargement side of the first intermediate image and being configured to correct distortion including keystone distortion;
a reflective optical system that includes a first reflective surface with positive reflective power that is positioned closer to the enlargement side than the second intermediate image,
wherein the zoom optical system includes, in order from the reducing side, a former group, a middle group, and a latter group, the latter group including a first lens and a second lens and the first intermediate image being formed therebetween, and
when zooming from a wide angle end to a telephoto end, the former group moves from the reducing side to the enlargement side, the middle group moves so as to compensate for movement of the former group, and the latter group is fixed,
wherein the zoom optical system consists of the former group, the middle group and the latter group, distances between lenses included in the former group are fixed during zooming, and distances between lenses included in the middle group are fixed during zooming.

US Pat. No. 10,133,022

OPTICAL DEVICE

Nittoh Inc., (JP)

1. An optical device comprising:a fixed tube that has a straight groove extending in a first direction parallel to an optical axis of the optical device;
a cam ring that has a cam groove extending in a second direction intersecting to the first direction;
a cam follower that is engaged with the straight groove and the cam groove;
a lens unit that moves in conjunction with the cam follower in the first direction; and
an auxiliary cam follower that is engaged with the straight groove and that is not engaged with the cam groove,
wherein when the fixed tube and the cam ring relatively rotate, the lens unit moves in the first direction, and
the lens unit is fixed to the cam follower and the auxiliary cam follower.

US Pat. No. 10,063,819

PROJECTION OPTICAL SYSTEM AND PROJECTOR

NITTOH INC., Nagano (JP)...

1. A projection optical system that projects from a first image plane on a reducing side to a second image plane on an enlargement side, comprising:a first optical system that includes a plurality of lenses and forms a first intermediate image formed inside the first optical system by light incident from the reducing side into a second intermediate image on the enlargement side of the first optical system;
a second optical system that includes a first reflective surface with positive refractive power which is positioned further to the enlargement side than the second intermediate image; and
a glass block that is disposed between the first optical system and the first reflective surface, the glass block passing rays from the first optical system to the second intermediate image;
wherein an image height Ih of the first image plane and a diameter MR of the first reflective surface satisfy a following condition
2.0

US Pat. No. 10,503,051

OPTICAL DIAPHRAGM DEVICE, LENS BARREL, AND IMAGING DEVICE OR PROJECTION DEVICE

NITTOH INC., Nagano (JP)...

1. An optical diaphragm device capable of changing an aperture diameter of a diaphragm aperture by advancing and retracting a plurality of blades with respect to an optical axis, the optical diaphragm device comprising:a plurality of diaphragm blades each including: a first blade portion which is formed of a first planar plate and shields light incident on the diaphragm aperture of the optical diaphragm device; a first fixing boss which protrudes from one surface of the first planar plate toward a side in a first direction along the optical axis; and a moving boss which protrudes from the other surface of the first planar plate toward a side in a second direction opposite to the first direction;
a plurality of light leakage prevention blades each including: a second blade portion which is formed of a second planar plate and shields light incident on the diaphragm aperture of the optical diaphragm device; and a second fixing boss which protrudes from one surface of the second planar plate toward the side in the first direction, the light leakage prevention blade forming a pair with the diaphragm blade;
a drive ring having a plurality of first cam grooves into each of which the moving boss is inserted, wherein a distance between the first cam groove and the optical axis differs corresponding to a position of the first cam groove, and the first cam groove is movable in a circumferential direction about the optical axis due to rotation of the drive ring about the optical axis; and
a housing body capable of accommodating the diaphragm blades, the light leakage prevention blades, and the drive ring, wherein
the optical diaphragm device includes a plurality of pairs each consisting of the diaphragm blade and the light leakage prevention blade, and a plurality of the first cam grooves each of which corresponds to each of the moving bosses are formed in the drive ring,
a plurality of pairs each consisting of a first hole and a second hole are formed in the housing body corresponding to the plurality of pairs each consisting of the diaphragm blade and the light leakage prevention blade, the number of pairs each consisting of the first hole and the second hole being equal to the number of pairs each consisting of the diaphragm blade and the light leakage prevention blade, the first fixing boss and the second fixing boss being inserted into the pair of the first hole and the second hole respectively,
a second cam groove is formed in the light leakage prevention blade, and
the moving boss of the diaphragm blade is inserted into the second cam groove of the light leakage prevention blade, and is inserted into the first cam groove of the drive ring.

US Pat. No. 10,422,981

LENS SYSTEM AND IMAGING APPARATUS HAVING ADJACENT STOP AND FIXED LENS SYSTEM AT AN OUTPUT SIDE

NITTOH INC., Suwa, Nagan...

1. A lens system that comprises:an input side;
an output side; and
wherein the lens system includes:
a first optical system and a second optical system that is disposed on the output side of the first optical system, the second optical system including a zooming optical system;
wherein the lens system forms an intermediate image that is formed inside the first optical system by light from the input side, into a final image on the output side through the second optical system,
wherein the second optical system includes the zooming optical system disposed on the input side, a fixed lens system disposed closer to the output side than any other lens in the lens system and a stop disposed on the input side of the fixed lens system without any other lens of the lens system disposed between the stop and the fixed lens system, wherein the fixed lens system and the stop do not move in response to zooming performed by the zooming optical system, and
wherein the first optical system does not move in response to zooming performed by the second optical system, wherein the first optical system includes a first subsystem that is configured to move for focusing, the first subsystem including:
a first lens that is disposed at a position closest to the intermediate image on the input side of the intermediate image, compared to any other lens in the lens system; and
a second lens that is disposed at a position closest to the intermediate image on the output side of the intermediate image, compared to any other lens in the lens system.

US Pat. No. 10,557,975

REFLECTING MIRROR AND MIRROR HOLDING MECHANISM

Nittoh Inc., (JP)

1. A reflection mirror having a concave curved reflection surface, whereinwhen a surface on which the reflection surface is formed is a front surface, a surface opposite to the front surface is a rear surface, a direction parallel to an optical axis of the reflection mirror from the rear surface toward the front surface is a first direction, and a direction parallel to the optical axis from the front surface toward the rear surface is a second direction,
the rear surface has a recessed flat surface orthogonal to the first direction and a wall surface that rises from at least a part of a periphery of the flat surface toward the second direction,
the flat surface has three or more protruding portions that protrude in the second direction, the three or more protruding portions being located inboard of the wall surface, and
when viewed from the first direction, the three or more protruding portions are disposed so as to surround a center of the flat surface.

US Pat. No. 10,466,439

MIRROR HOLDING MECHANISM

Nittoh Inc., (JP)

1. A mirror holding mechanism, comprising:a reflection mirror having a curved reflection surface;
a mirror holding member holding the reflection mirror; and
a cam member rotatably held by the mirror holding member, wherein
when a direction parallel to an optical axis of the reflection mirror is a first direction, a direction orthogonal to the first direction is a second direction, and a direction orthogonal to the first direction and the second direction is a third direction,
the mirror holding member has two side surface portions disposed so as to sandwich the reflection mirror in the second direction,
at least one of the two side surface portions has a guide hole through which a shaft portion protruding from the reflection mirror to an outer side in the second direction is inserted, the guide hole being formed so as to pass through the side surface portion,
the guide hole is formed into a long hole a longitudinal direction of which is an orthogonal direction orthogonal to the second direction,
the cam member is disposed on an outer side of the side surface portion in the second direction and rotatably held by the side surface portion,
the cam member has a cam surface with which a distal end part of the shaft portion comes into contact, and
when the cam member rotates, the shaft portion moves in the orthogonal direction.

US Pat. No. 10,375,363

PROJECTION OPTICAL SYSTEM AND PROJECTOR

NITTOH INC., Suwa-Shi, N...

1. A projection optical system that projects from a first image plane on a reducing side to a second image plane on an enlargement side, comprising:a first optical system that includes a plurality of lenses and forms a first intermediate image formed inside the first optical system by light incident from the reducing side into a second intermediate image on the enlargement side of the first optical system;
a second optical system that includes a first reflective surface with positive refractive power which is positioned further to the enlargement side than the second intermediate image; and
a first glass block that is disposed between the first optical system and the first reflective surface, wherein the first glass block is located on an output side of the first optical system and passes rays from the first optical system to the second intermediate image.

US Pat. No. 10,481,362

CIRCUMFERENTIAL ANGLE ADJUSTMENT DEVICE FOR GENERATRIX OF CYLINDRICAL LENS, AND LENS BARREL EQUIPPED WITH CIRCUMFERENTIAL ANGLE ADJUSTMENT DEVICE FOR GENERATRIX OF CYLINDRICAL LENS

Nittoh Inc., (JP)

1. A circumferential angle adjustment device for a generatrix of a cylindrical lens, comprising:a lens holding tube which holds the cylindrical lens, the lens holding tube having an optical axis;
an outer tube in which the lens holding tube is arranged at an inner periphery of the outer tube, the outer tube having a longitudinal through-hole, the longitudinal through-hole extending parallel to the optical axis; and
a cam member which is provided at an outer periphery of the lens holding tube and has a cam surface eccentric with respect to a cam axis intersecting with the optical axis, the cam surface slidably engaging with an inner surface of the longitudinal through-hole so that the cam member moves in a direction parallel to the optical axis,
wherein the lens holding tube is rotatably supported with respect to the outer tube in a circumferential direction of the optical axis.

US Pat. No. 10,663,702

ZOOM LENS SYSTEM AND IMAGING APPARATUS

NITTOH INC., Suwa-Shi, N...

1. A zoom lens system that forms light from an object side into a final image via an intermediate image formed inside the zoom lens system, comprising in order from the object side:a plurality of fixed lens groups that includes a positive fixed power lens group disposed at a fixed position on the object side of the intermediate image and closer to the intermediate image than any other lens on the object side, and a negative fixed power lens group disposed at a fixed position on a final image side of the intermediate image and closer to the intermediate image than any other lens on the final image side; and
a plurality of moving lens groups disposed on the final image side of the intermediate image and further from the intermediate image than any fixed lens group on the final image side of the intermediate image.

US Pat. No. 10,558,008

LENS UNIT

Nittoh Inc., (JP)

1. A lens unit comprising:a display member that is in a cylindrical shape or a partial cylindrical shape, that rotates around an optical axis of the lens unit, and that has a scale indicating a photographing distance on an outer circumference surface of the display member, the display member having first and second holes therein, the first and second holes being spaced apart from each other along the optical axis;
a fixing base having a fixing part, the display member being fixed to the fixing base, the display member and the fixing base rotating around the optical axis at the same time when the display member is fixed to the fixing base;
a fixing projection selectively located in one of the first hole or the second hole to fix between the display member and the fixing base; and
a window member that is provided over the display member, that exposes part of the outer circumference surface including the scale of the display member, and that hides the other part of the outer circumference surface of the display member,
wherein the photographing distance has a first length unit and a second unit length that is different from the first length unit,
the display member is movable along the optical axis between a first position and a second position,
when the display member is in the first position and when the fixing projection is located at the first hole and the fixing part, the window member exposes the first length unit, and
when the display member is in the second position and when the fixing projection is located at the second hole and the fixing part, the window member exposes the second length unit.

US Pat. No. 10,761,415

PROJECTION OPTICAL SYSTEM AND PROJECTOR APPARATUS

NITTOH INC., Suwa-Shi, N...

1. A projection optical system that projects from a first image plane on a reducing side onto a second image plane on an enlargement side, comprising:a first refractive optical system that forms a first intermediate image on the enlargement side using light incident from the reducing side;
a second refractive optical system that forms the first intermediate image on the reducing side into a second intermediate image on the enlargement side, wherein the first intermediate image and the second intermediate image are formed on opposite sides of an optical axis; and
a first reflective optical system including a first reflective surface with positive refractive power that is positioned on the enlargement side of the second intermediate image,
wherein the second refractive optical system includes a first focus lens group that moves when focusing is carried out and a plurality of lenses that are fixed when focusing is carried out, and the first focus lens group includes a first distance correcting lens group that moves when focusing is carried out in response to changes in an optical distance between the first reflective surface and the second image plane, the first distance correction lens group being located closer to the first intermediate image than any lenses in the second refractive optical system that are fixed when focusing is carried out, and
the first refractive optical system includes a fixed lens that is positioned closer to the first intermediate image than any other lenses in the first refractive optical system.

US Pat. No. 10,645,353

PROJECTION OPTICAL SYSTEM AND PROJECTOR

NITTOH INC., Suwa-Shi, N...

1. A projection optical system that projects from a first image plane on a reducing side to a second image plane on an enlargement side, comprising:a first optical system that includes a plurality of lenses and forms, by light incident from the reducing side, an intermediate image on the enlargement side of the first optical system;
a second optical system that includes a first reflective surface with positive power which is positioned further to the enlargement side than the intermediate image; and
a glass block that is disposed between the first optical system and the first reflective surface and passes rays from the first optical system to the intermediate image.

US Pat. No. 10,222,576

PROJECTION LENS BARREL AND PROJECTION DISPLAY DEVICE

Nittoh Inc., (JP)

1. A projection lens barrel including a lens optical system that causes light from an image display element to form a projected image on a screen, the projection lens barrel comprising:a fixed barrel having a cylindrical shape and an inner side;
a first correction lens group that is configured to be corrected to suppress a reduction in image quality of the projected image that is caused by changes in optical characteristics that result from a change in temperature in the projection lens barrel, the first correction lens group being disposed on the inner side of the fixed barrel;
a second correction lens group that is configured to be corrected to suppress a reduction in image quality of the projected image that is caused by changes in optical characteristics that result from the change in temperature in the projection lens barrel, the second correction lens group being disposed on the inner side of the fixed barrel and having optical characteristics that are different from that of the first correction lens group;
a first correction mechanism which is provided at the first correction lens group and transfers the first correction lens group along an optical axis with respect to the fixed barrel;
a second correction mechanism which is provided at the second correction lens group and transfers the second correction lens group along the optical axis with respect to the fixed barrel independently from the first correction mechanism.

US Pat. No. 10,754,239

PROJECTION OPTICAL ASSEMBLY AND PROJECTOR DEVICE

NITTOH INC., Suwa-Shi, N...

1. A projection optical system that projects from a first image plane on a reducing side to a second image plane on an enlargement side, comprising:a first optical system that includes a plurality of lenses and forms light incident from the reducing side via a first intermediate image formed inside the first optical system into a second intermediate image on the enlargement side; and
a second optical system that includes a first reflective surface with positive reflective power that is positioned closer to the enlargement side than the second intermediate image,
wherein the first intermediate image is formed to be inclined toward the reducing side, and the first optical system includes a lens that is disposed closest to the enlargement side of the first intermediate image and has a surface of the reducing side that is convex on the reducing side;
wherein the first optical system includes a first refractive optical system disposed on the reducing side of the first intermediate image; and a second refractive optical system disposed on the enlargement side of the first intermediate image, and
wherein an effective diameter of a lens that is closest to the enlargement side of the second refractive optical system is smaller than a maximum effective diameter of the first refractive optical system.

US Pat. No. 10,754,120

PROJECTION LENS BARREL AND PROJECTION DISPLAY DEVICE

Nittoh Inc., (JP)

1. A projection lens barrel including a lens optical system that causes light from an image display element to form a projected image on a screen, the projection lens barrel comprising:at least two correction lens groups that each have different optical characteristics to be corrected in order to suppress reduction in image quality of the projected image, the reduction in image quality being caused by changes in optical characteristics that result from a change in temperature in the projection lens barrel;
a correction mechanism that is provided to each correction lens group, and that moves each correction lens group along an optical axis;
wherein the correction mechanism includes;
a thermal deforming frame that expands along an optical axis according to change in temperature;
a one end side holding part that abuts and holds one optical-axis end side of the thermal deforming frame in a state of abutting without being fixed thereto; and
an other end side holding part that abuts and holds an other optical-axis end side of the thermal deforming frame without being fixed thereto;
wherein each correction lens group is moved by expansion of the thermal deforming frame so as to correct the optical characteristics; and
the one end side holding part is energized to the rear side by a coil spring, and/or the other end side holding part is energized to the forward side by the coil spring.