Abstract: With a projection device, a projection system including the projection device and a display device receives an image from the display device, projects the received image onto a projection target, captures a range including the projection target, and transmits the captured image to the display device. With the display device, the projection system receives the captured image from the projection device, displays the received captured image on the display, generates a drawing image based on a drawing operation, and transmits the generated drawing image to the projection device.

Abstract: A lens includes a first surface, a second surface opposed to the first surface, a first outer circumferential part disposed at an outer circumferential side of the first surface, a second outer circumferential part disposed at an outer circumferential side of the second surface, three or more first reference parts provided to the first outer circumferential part, three or more second reference parts provided to the second outer circumferential part, and a first reference surface disposed at an outer circumferential side of the first outer circumferential part and the second outer circumferential part. The first surface and the second surface have a common design axis. A first imaginary plane including the first reference parts and a second imaginary plane including the second reference parts are perpendicular to the design axis respectively. The first reference surface extends in parallel to the design axis.

Abstract: A projection system includes a first optical system and a second optical system including an optical element and disposed on the enlargement side of the first optical system. The optical element has a first transmissive surface, a first reflection surface disposed on the enlargement side of the first transmissive surface, a second reflection surface disposed on the enlargement side of the first reflection surface, and a second transmissive surface disposed on the enlargement side of the second reflection surface. The second reflection surface has a concave shape. A first optical axis of the first optical system and a second optical axis of the second reflection surface intersect each other.

Abstract: An optical device includes a first optical system having an optical element, a second optical system having a lens and disposed at a reduction side of the first optical system, a first holding member holding the optical device, a second holding member holding the lens, and a movement mechanism configured to move the first holding member in optical axis directions. The optical element has a reflection surface. The first holding member has a first holding portion holding the optical element and a first coupling portion extending from the first holding portion to a second optical system side. The movement mechanism has a transport mechanism configured to move the first coupling portion along the optical axis directions, and a guide mechanism configured to guide the first holding member in the optical axis directions. The guide mechanism restricts rotation of the first holding member around the optical axis.

Abstract: A display method includes displaying a first image containing a first portion and a second portion different from the first portion on a screen by a projector, storing information representing a first shape which is a shape of the first portion when the screen is seen from a first direction, and, when the shape of the first portion as seen from the first direction changes to a shape different from the first shape, displaying, by the projector, a second image obtained by performing correction on the first image to make the shape of the first portion as seen from the first direction closer to the first shape, and not performing the correction on the second portion on the screen.

Abstract: A projection system having a first projection device and a second projection device is provided. The first projection device communicates with the second projection device to receive a first reception image, projects the first reception image onto a first projection target, captures a range including the first projection target, generates a first transmission image by removing, from a captured image of the first projection target, an image overlapping the first reception image, and transmits the first transmission image to the second projection device. The second projection device communicates with the first projection device to receive a second reception image, projects the second reception image onto a second projection target, captures a range including the second projection target, generates a second transmission image by removing, from a captured image, an image overlapping the second reception image, and transmits the second transmission image to the first projection device.

Abstract: A projection device includes: a projection unit configured to project image light to a projection target; an image-capturing unit configured to capture an image of a range including the projection target to generate a captured image; a communication unit; and a control unit configured to transmit the captured image to an information processing device by the communication unit and cause a reception image received by the communication unit from the information processing device to be projected by the projection unit. The projection unit includes an image light forming unit configured to form image light and a projection optical system configured to project the image light formed by the image light forming unit toward the projection target. The image-capturing unit includes an imaging element configured to receive light through the projection optical system.

Abstract: With a projection device, a projection system including the projection device and a display device receives an image from the display device, projects the received image onto a projection target, captures a range including the projection target, and transmits the captured image to the display device. With the display device, the projection system receives the captured image from the projection device, displays the received captured image on the display, generates a drawing image based on a drawing operation, and transmits the generated drawing image to the projection device.

Abstract: An optical system includes a first optical system having a first optical element, and a second optical system arranged at a reduction side of the first optical system. An intermediate image is formed between the first optical system and the second optical system. The first optical element has a first reflecting surface having a concave shape. The second optical system has a first relay element, a second relay element arranged at an enlargement side of the first relay element, and a correction optical element arranged at the enlargement side of the second relay element. The first relay element has a first relay reflecting surface having a concave shape. The second relay element has a second relay reflecting surface having a convex shape. The correction optical element curves the intermediate image generated by the first and second relay elements to reduce a field curvature generated by the first optical element.

Abstract: An optical system includes a first optical element, and a second optical element arranged at a reduction side of the first optical element. The first optical element has a first reflecting surface having a concave shape. The second optical element has a first transmission surface, a second reflecting surface arranged at the reduction side of the first transmission surface, and a second transmission surface arranged at the reduction side of the second reflecting surface. A first optical axis of the first reflecting surface is parallel to a second optical axis of the first transmission surface. At least one of the first transmission surface, the second reflecting surface, and the second transmission surface has power.

Abstract: An optical system includes a first optical element. The first optical element has a first transmission surface, a first reflecting surface arranged at a reduction side of the first transmission surface, and a second transmission surface arranged at the reduction side of the first reflecting surface. The first transmission surface has power. Light passing between the first transmission surface and the first reflecting surface includes peripheral light tilted in a direction of getting away from an enlargement-side conjugated plane as coming closer to the first transmission surface. The peripheral light is tilted in a direction of coming closer to the enlargement-side conjugated plane as getting away from the first transmission surface between the first transmission surface and the enlargement-side conjugated plane.

Abstract: In a projection system including a projector and a display device, the projector receives an image from the display device, projects the received image to a projection target, captures the range including the projection target, and transmits the captured image to the display device, and the display device generates a drawing image based on a drawing operation, displays the drawing image on a display, transmits the drawing image to the projector, receives the captured image from the projector, and performs processing of removing an image overlapping the captured image received from the projector from the drawing image displayed on the display so as to update the display of the display based on the captured image and the processed image.

Abstract: A projection system includes a first optical system including a plurality of lenses and a deflector, and a second optical system including an optical element having a concave reflection surface and disposed at the enlargement side of the first optical system. The deflector is disposed in one air gap of a plurality of air gaps provided between the lenses adjacent to each other in the first optical system, the air gap having the largest axial inter-surface distance in the first optical system. The first optical system includes a first section located at the reduction side of the deflector and a second section located at the enlargement side of the deflector. A first optical axis section of the first section and a second optical axis section of the second section intersect each other. The second section includes three or more lenses. The second section is shorter than the first section.

Abstract: A projection system includes a first and second optical system including an optical element. The optical element has a first transmissive surface, a reflection surface, and a second transmissive surface. The second transmissive surface has a convex shape an aspheric shape. An effective light ray range of the second transmissive surface has a first end close to an optical axis of the reflection surface in a first axis direction along a first axis perpendicular to the optical axis and a second end far from the optical axis. A first radius of curvature at the first end is greater than a second radius of curvature at the second end, and a first center of curvature of the first radius of curvature is farther than a second center of curvature of the second radius of curvature from the first end.

Abstract: A lens has a first transmissive surface, a reflective surface, and a second transmissive surface sequentially arranged from a demagnifying side toward a magnifying side. The first transmissive surface and the reflective surface are located at the lower side of an imaginary axis extending in an axis-Z direction, and the second transmissive surface is located at the upper side of the imaginary axis. The reflective surface has a concave shape, and the second transmissive surface has a convex shape protruding toward the magnifying side. An imaginary line that connects an upper intersection to a lower intersection inclines with respect to an imaginary vertical line perpendicular to the imaginary axis in a plane YZ.

Abstract: An optical element has a first member having a first refractive index and a second member having a second refractive index different from the first refractive index. The optical element has a first transmissive surface, a reflective surface, and a second transmissive surface arranged from a demagnifying side toward a magnifying side in order. The first transmissive surface and the reflective surface are located in one side with respect to an optical axis of the optical element. The second transmissive surface is located in the other side with respect to the optical axis of the optical element. the reflective surface has a concave shape.

Abstract: An optical device includes a first optical system having an optical element, a second optical system having a lens and disposed at a reduction side of the first optical system, a first holding member holding the optical device, a second holding member holding the lens, and a movement mechanism configured to move the first holding member in optical axis directions. The optical element has a reflection surface. The first holding member has a first holding portion holding the optical element and a first coupling portion extending from the first holding portion to a second optical system side. The movement mechanism has a transport mechanism configured to move the first coupling portion along the optical axis directions, and a guide mechanism configured to guide the first holding member in the optical axis directions. The guide mechanism restricts rotation of the first holding member around the optical axis.

Abstract: An optical device includes a first optical system having an optical element, a second optical system having a lens and disposed at a reduction side of the first optical system, a first holding member holding the optical element, and a first movement mechanism configured to move the first holding member in optical axis directions along an optical axis of the optical element. The optical element has a reflection surface. The first movement mechanism has a fixing member supporting the first holding member rotatably around a rotation axis and a transport portion configured to move the first holding member along the optical axis directions according to rotation of the first holding member. The reflection surface has a shape rotationally symmetrical with respect to the rotation axis. The rotation axis and the optical axis are the same axis.

Abstract: An optical device includes a plurality of optical elements, a holding member configured to hold the plurality of optical elements, and a partition wall. The first optical element is a lens and disposed in a position closest to an enlargement side out of the plurality of optical elements. The first optical element has an incident surface, a reflecting surface configured to reflect light which enters through the incident surface, and an exit surface configured to emit the light reflected by the reflecting surface. The incident surface and the exit surface are provided to a first surface facing to a reduction side in the first optical element. The partition wall partitions the incident surface and the exit surface.

Abstract: A lens includes a first surface, a second surface opposed to the first surface, a first outer circumferential part disposed at an outer circumferential side of the first surface, a second outer circumferential part disposed at an outer circumferential side of the second surface, three or more first reference parts provided to the first outer circumferential part, three or more second reference parts provided to the second outer circumferential part, and a first reference surface disposed at an outer circumferential side of the first outer circumferential part and the second outer circumferential part. The first surface and the second surface have a common design axis. A first imaginary plane including the first reference parts and a second imaginary plane including the second reference parts are perpendicular to the design axis respectively. The first reference surface extends in parallel to the design axis.