Abstract: According to one embodiment, a display device includes a display panel, a first light guide, and a second light guide. In the first light guide, a first main surface includes a first plane and first grooves between the first plane and a first side surface, a second main surface includes second grooves orthogonal to the first grooves, and a second plane between the second grooves and the first side surface. In the second light guide, a third main surface includes a third plane and third grooves located between the third plane and a fourth side surface, a fourth main surface includes fourth grooves orthogonal to the third grooves, and a fourth plane located between the fourth grooves and the fourth side surface.

Abstract: According to one embodiment, an illumination device includes a first light guide having a first side surface, a second side surface located on a side opposite to the first side surface in a first direction, a first main surface, and a first opposed surface located on a side opposite to the first main surface in a second direction intersecting the first direction and a first light source opposed to the first side surface to emit first P-polarized light to the first side surface, the first side surface is inclined to the first main surface and the first opposed surface, the first light source is inclined to a first straight line perpendicular to the first side surface.

Abstract: According to one embodiment, an illumination device, in which a plurality of light guides include a plurality of light guide pairs, each of the plurality of light guide pairs includes a first light guide and a second light guide, the plurality of light guide pairs are connected with their long sides opposed to each other, a plurality of laser light source elements include a plurality of first light source elements arranged to be opposed to a first side surface on a short side of the first light guide of the light guide pair, and a plurality of second light source elements arranged to be opposed to a second side surface of the second light guide of the light guide pair.

Abstract: According to one embodiment, an illumination device includes a light guide having a first plane, a second plane, a side plane, a first tilted plane, and a second tilted plane, an angle formed between the side plane and the first tilted plane and an angle formed between the side plane and the second tilted plane being acute angles, a first semiconductor laser element including a first light emitting part, and a second semiconductor laser element including a second light emitting part. The first light emitting part is opposed to a first intersection part of the side plane and the first tilted plane, and the second light emitting part is opposed to a second intersection part of the side plane and the second tilted plane.

Abstract: According to one embodiment, an illumination device includes red light emitting elements, green light emitting elements and blue light emitting elements opposing a first side surface of a first light guide, and the red light emitting elements, the green light emitting elements and the blue light emitting elements are disposed along the first side surface in a third direction that intersects the first direction and the second direction, and, arranged to be symmetrical with respect to a central axis of the third direction of the first side surface.

Abstract: According to one embodiment, an illumination device, in which a plurality of light guides include a plurality of light guide pairs, each of the plurality of light guide pairs includes a first light guide and a second light guide, the plurality of light guide pairs are connected with their long sides opposed to each other, a plurality of laser light source elements include a plurality of first light source elements arranged to be opposed to a first side surface on a short side of the first light guide of the light guide pair, and a plurality of second light source elements arranged to be opposed to a second side surface of the second light guide of the light guide pair.

Abstract: According to one embodiment, an illumination device includes a first light guide, a second light guide and a plurality of light sources. The first light guide includes a first main surface, a second main surface facing the first main surface, and a first side surface connected to the second light guide. The first side surface further includes a first connection surface and a second connection surface. The first connection surface extends from an end portion of the first main surface to the second main surface and obliquely extends so as to move away from the second side surface. The second connection surface perpendicularly extends from an end portion of the first connection surface to an end portion of the second main surface.

Abstract: According to one embodiment, an illumination device includes first and second light guides, first and second light sources, and first and second layers. The first light guide includes first and second main surfaces and first and second side surfaces. The second light guide includes third and fourth main surfaces and third and fourth side surfaces. The first light sources face a second side surface. The second light sources face the third side surface. The first layer includes first prisms in the second main surface. The second layer includes second prisms in the fourth main surface. The second and fourth side surfaces are displaced from each other in a first direction.

Abstract: According to one embodiment, an illumination device includes a light guide including a first main surface, a second main surface, a first side surface, and a second side surface, a plurality of convex portions provided on the second main surface, and a first light source element and a second light source element opposing the first side surface and the second side surface, respectively, and when an incident angle of a main ray of the light propagating in the light guide is expressed by ?, a diffusion angle of the light is ?, an angle of the convex portion of the light guide is ?, a critical angle of the light guide is ?c, and an angle which satisfies (90°??c) is ?0, a relationship: ((?0+?)/3)<?<((?0??)/2) is satisfied.

Abstract: According to one embodiment, an illumination device includes a first light guide including a first main surface, a second main surface, a first side surface and a second side surface, a first light source and a first layer including a first prism provided on the second side surface. The first prism protrudes from the second main surface toward the opposite side to the first main surface and has a cross-sectional shape of a triangle with a first slope and a second slope. The incident angle of light emitted from the first light source and entering the first light guide from the second side surface, the angle between the first slope and the first direction, and the angle between the first slope and the second slope are set to values that satisfy the predetermined conditions, respectively.

Abstract: According to an embodiment, an illumination device includes a light guide having a first plane, a second plane opposed to the first plane and substantially parallel to the first plane, and a tilted plane opposed to the first plane and tilted to the first plane, the tilted plane and the second plane being arranged in a first direction, and a light emitting device including a first light emitting part, a second light emitting part, and a third light emitting part which are located directly below the tilted plane, arranged in the first direction, and configured to emit light having wavelengths different from each other.

Abstract: According to one embodiment, a display device includes a display panel, a first light guide, and a second light guide. In the first light guide, a first main surface includes a first plane and first grooves between the first plane and a first side surface, a second main surface includes second grooves orthogonal to the first grooves, and a second plane between the second grooves and the first side surface. In the second light guide, a third main surface includes a third plane and third grooves located between the third plane and a fourth side surface, a fourth main surface includes fourth grooves orthogonal to the third grooves, and a fourth plane located between the fourth grooves and the fourth side surface.

Abstract: According to an embodiment, an illumination device includes a light guide having a first plane, a second plane opposed to the first plane and substantially parallel to the first plane, and a tilted plane opposed to the first plane and tilted to the first plane, the tilted plane and the second plane being arranged in a first direction, and a light emitting device including a first light emitting part, a second light emitting part, and a third light emitting part which are located directly below the tilted plane, arranged in the first direction, and configured to emit light having wavelengths different from each other.

Abstract: According to one embodiment, a display device includes a display panel, a first light guide, and a second light guide. In the first light guide, a first main surface includes a first plane and first grooves between the first plane and a first side surface, a second main surface includes second grooves orthogonal to the first grooves, and a second plane between the second grooves and the first side surface. In the second light guide, a third main surface includes a third plane and third grooves located between the third plane and a fourth side surface, a fourth main surface includes fourth grooves orthogonal to the third grooves, and a fourth plane located between the fourth grooves and the fourth side surface.

Abstract: According to one embodiment, a lens portion includes a first lens element converging while converting first circularly polarized light into second circularly polarized light and a second lens element converging while converting the second circularly polarized light into the first circularly polarized light. Each of the first lens element and the second lens element includes first liquid crystal molecules, and the alignment direction of the first liquid crystal molecules of the first lens element is line symmetry with the alignment direction of the first liquid crystal molecules of the second lens element.

Abstract: According to one embodiment, an illumination device includes a first light guide having a first side surface, a second side surface located on a side opposite to the first side surface in a first direction, a first main surface, and a first opposed surface located on a side opposite to the first main surface in a second direction intersecting the first direction and a first light source opposed to the first side surface to emit first P-polarized light to the first side surface, the first side surface is inclined to the first main surface and the first opposed surface, the first light source is inclined to a first straight line perpendicular to the first side surface.

Abstract: According to one embodiment, an illumination device includes a light guide including a first main surface, a second main surface, a first side surface, and a second side surface, a plurality of convex portions provided on the second main surface, and a first light source element and a second light source element opposing the first side surface and the second side surface, respectively, and when an incident angle of a main ray of the light propagating in the light guide is expressed by ?, a diffusion angle of the light is ?, an angle of the convex portion of the light guide is ?, a critical angle of the light guide is ?c, and an angle which satisfies (90°??c) is ?0, a relationship: ((?0+?)/3)<?<((?0??)/2) is satisfied.

Abstract: According to one embodiment, a display device includes a display panel, a first light guide, and a second light guide. In the first light guide, a first main surface includes a first plane and first grooves between the first plane and a first side surface, a second main surface includes second grooves orthogonal to the first grooves, and a second plane between the second grooves and the first side surface. In the second light guide, a third main surface includes a third plane and third grooves located between the third plane and a fourth side surface, a fourth main surface includes fourth grooves orthogonal to the third grooves, and a fourth plane located between the fourth grooves and the fourth side surface.

Abstract: According to one embodiment, a display device includes a display panel, a holographic element which reflects light having a specific incident angle and transmits light having an incident angle different from the specific incident angle, a retardation film provided between the display panel and the holographic element, a transflective element which reflects, of the light which passed through the holographic element, first circularly polarized light, and transmits second circularly polarized light rotating in an opposite direction of the first circularly polarized light, and a lens element which has a lens effect of condensing the second circularly polarized light which passed through the transflective element.

Abstract: According to one embodiment, an illumination device includes a light guide, a plurality of light source elements, and a reflector including a first portion parallel to a second edge of the light guide and a second portion parallel to a third edge of the light guide, and the third edge includes first short edges extending in the first direction and second short edges extending in the second direction, which are alternately arranged, and the second portion includes first pieces extending in the first direction and second pieces extending in the second direction, which are alternately arranged.