Abstract: A lens member includes a light-incident side; a light-exit side that is opposite to the light-incident side, a Fresnel lens arranged on a center axis that passes through a center of the light-incident side, and a diffraction grating structure arranged around a periphery of the Fresnel lens and having a center through which the center axis passes. Also, it is disclosed that the Fresnel lens may include a first Fresnel lens and a second Fresnel lens, the first Fresnel lens includes annular prisms that are divided from a convex lens and having a center through which the center axis of the light-incident side passes, and the second Fresnel lens includes annular prisms that are divided from a TIR lens and arranged around the periphery of the first Fresnel lens, centering around the center axis of the light-incident side.

Abstract: A lens member includes a central axis, a light-incident side including a Fresnel-lens surface provided with a plurality of annular prisms concentrically arranged with respect to the central axis, and a light-exit surface opposite to the light-incident side. The Fresnel-lens surface further includes an annular lens portion that is concentrically arranged with respect to the central axis and that is extended to be longer and wider than the plurality of annular prisms. Provided is an optical unit in which a light source and a lens member are combined, and parts are disposed in a space provided in an outer periphery of the annular lens portion.

Abstract: A lens member includes a light-incident side; a light-exit side that is opposite to the light-incident side, a Fresnel lens arranged on a center axis that passes through a center of the light-incident side, and a diffraction grating structure arranged around a periphery of the Fresnel lens and having a center through which the center axis passes. Also, it is disclosed that the Fresnel lens may include a first Fresnel lens and a second Fresnel lens, the first Fresnel lens includes annular prisms that are divided from a convex lens and having a center through which the center axis of the light-incident side passes, and the second Fresnel lens includes annular prisms that are divided from a TIR lens and arranged around the periphery of the first Fresnel lens, centering around the center axis of the light-incident side.

Abstract: A lens member of obtaining light-collecting properties even if using a light source with a large light-emitting surface area has a first lens portion refracting light to exit outward in radial directions perpendicular to a central axis of the lens member and a second lens portion totally internally reflecting the light that exited through the first lens portion. The first lens portion has a light incident surface disposed to face a light source and a conical light exit surface centered at the central axis of the lens member and slanted so that the distance between the conical surface and the light incident surface increases as the distance from the central axis increases outward in the radial directions perpendicular to the central axis. The second lens portion has an inner circumferential surface receiving light from the first lens portion and an outer circumferential surface positioned outward of the inner circumferential surface in the radial directions perpendicular to the central axis.

Abstract: A lens member includes at least one of the annular prisms including a facet at an edge between an inner annular surface and an outer surface of the at least one of the annular prisms. The prisms with facets may be provided at a central portion of the lens member and the facets are configured to refract light toward a light-exit side of the lens member.

Abstract: A plate-shaped lens member has concentric annular prisms each including an inner annular surface divided from a light-entrance surface of a conventional TIR lens and an outer annular surface divided from a light-reflection surface of the TIR lens in which the light-entrance surface has a concave shape provided in a lower portion of the TIR lens and the light-reflection surface has a convex shape positioned at a peripheral side of the TIR lens to surround the light-entrance surface. The light-entrance surface and light-reflection surface of the bulky TIR lens are Fresnel-ized or divided into a set of concentric annular prisms on a surface of the plate-shaped lens member and positions of divided portions from the TIR lens are efficiently arranged on the surface of the plate-shaped lens member.

Abstract: A film-shaped lightguide plate having high light entrance efficiency, and which is easy to make, has a lightguide plate body having an upper surface as a light-exiting surface, a lower surface opposite to the upper surface, and a peripheral side surface extending between the respective peripheral edges of the upper and lower surfaces. A circumferential part of the peripheral side surface forms a light-entrance surface that faces a light source. The lightguide plate further has an additional lightguide portion formed on at least one of the upper and lower surfaces of the lightguide plate body at the light-entrance surface side. The additional lightguide portion has a light-entrance surface facing the light source, together with the light-entrance surface of the lightguide plate body. The additional lightguide portion receives light from the light source through its light-entrance surface and guides the light into the lightguide plate body.

Abstract: A lens member includes a central axis, a light-incident side including a Fresnel-lens surface provided with a plurality of annular prisms concentrically arranged with respect to the central axis, and a light-exit surface opposite to the light-incident side. The Fresnel-lens surface further includes an annular lens portion that is concentrically arranged with respect to the central axis and that is extended to be longer and wider than the plurality of annular prisms. Provided is an optical unit in which a light source and a lens member are combined, and parts are disposed in a space provided in an outer periphery of the annular lens portion.

Abstract: A lens member includes at least one of the annular prisms including a facet at an edge between an inner annular surface and an outer surface of the at least one of the annular prisms. The prisms with facets may be provided at a central portion of the lens member and the facets are configured to refract light toward a light-exit side of the lens member.

Abstract: A lens member of obtaining light-collecting properties even if using a light source with a large light-emitting surface area has a first lens portion refracting light to exit outward in radial directions perpendicular to a central axis of the lens member and a second lens portion totally internally reflecting the light that exited through the first lens portion. The first lens portion has a light incident surface disposed to face a light source and a conical light exit surface centered at the central axis of the lens member and slanted so that the distance between the conical surface and the light incident surface increases as the distance from the central axis increases outward in the radial directions perpendicular to the central axis. The second lens portion has an inner circumferential surface receiving light from the first lens portion and an outer circumferential surface positioned outward of the inner circumferential surface in the radial directions perpendicular to the central axis.

Abstract: An electronic device includes a casing having a display part (2) provided with an image display panel (1), a operation part (4) provided with operation keys (3), and a joint part (5) that connects together the display part and the operation part, and a lightguide plate (6) disposed in the casing. The lightguide plate is an edge-light type lightguide plate having a display illuminating part (6a) illuminating the image display panel, a key illuminating part (6b) illuminating the operation keys, and a connecting part (6c) that connects together the display illuminating part and the key illuminating part and that guides light therebetween. The lightguide plate is deformable in accordance with the deformation of the casing.

Abstract: A plate-shaped lens member has concentric annular prisms each including an inner annular surface divided from a light-entrance surface of a conventional TIR lens and an outer annular surface divided from a light-reflection surface of the TIR lens in which the light-entrance surface has a concave shape provided in a lower portion of the TIR lens and the light-reflection surface has a convex shape positioned at a peripheral side of the TIR lens to surround the light-entrance surface. The light-entrance surface and light-reflection surface of the bulky TIR lens are Fresnel-ized or divided into a set of concentric annular prisms on a surface of the plate-shaped lens member and positions of divided portions from the TIR lens are efficiently arranged on the surface of the plate-shaped lens member.

Abstract: A film-shaped lightguide plate having high light entrance efficiency and easy to make has a lightguide plate body having an upper surface as a light-exiting surface, a lower surface opposite to the upper surface, and a peripheral side surface extending between the respective peripheral edges of the upper and lower surfaces. A circumferential part of the peripheral side surface forms a light-entrance surface that faces a light source. The lightguide plate further has an additional lightguide portion formed on at least one of the upper and lower surfaces of the lightguide plate body at the light-entrance surface side. The additional lightguide portion has a light-entrance surface facing the light source, together with the light-entrance surface of the lightguide plate body. The additional lightguide portion receives light from the light source through its light-entrance surface and guides the light into the lightguide plate body.

Abstract: An electronic device includes a casing having a display part (2) provided with an image display panel (1), a operation part (4) provided with operation keys (3), and a joint part (5) that connects together the display part and the operation part, and a lightguide plate (6) disposed in the casing. The lightguide plate is an edge-light type lightguide plate having a display illuminating part (6a) illuminating the image display panel, a key illuminating part (6b) illuminating the operation keys, and a connecting part (6c) that connects together the display illuminating part and the key illuminating part and that guides light therebetween. The lightguide plate is deformable in accordance with the deformation of the casing.

Abstract: A zoom lens system capable of changing the zoom magnification correctly with a single actuator has a magnification changing lens and a focusing lens aligned on an optical axis, a liquid crystal lens, an actuator for moving the magnification changing lens and the focusing lens along the optical axis, a cam mechanism set between the actuator and the magnification changing and focusing lenses, and a driver that applies a voltage to the liquid crystal lens to change the refractive index thereof. The cam mechanism is driven by the actuator to move the magnification changing lens and the focusing lens individually along the optical axis of the zoom lens system, thereby changing the zoom magnification. The driver adjusts the voltage applied to the liquid crystal lens to effect fine adjustment of the focus position.