Abstract: An illumination lens condenses a light from a light source and emits the light toward a display to illuminate the display. The illumination lens includes multiple first lens surface parts having a shape obtained by extracting multiple portions of a first virtual lens surface along a first optical axis, the first virtual lens surface defining the first optical axis on which the light source is disposed and being at least twice differentiable between optical axes arranged in a reference direction, and multiple second lens surface parts having a shape obtained by extracting multiple portions of a second virtual lens surface along a second optical axis, the second virtual lens surface defining the second optical axis and being at least once differentiable between the optical axes arranged in the reference direction. The first lens surface parts and the second lens surface parts are alternately arranged in the reference direction.

Abstract: A head-up display device is mounted in a vehicle and virtually displays an image to be viewable by an occupant by projecting the image on a light-transmissive projection member. The head-up display device includes a projector that projects the image as light polarized in a direction of a polarization axis, a polarizer that is disposed on an optical path of the light of the image and has a property of transmitting light polarized along a transmission axis, and a phase shifter that is disposed between the polarizer and the projection member on the optical path and has a property of changing a polarization direction of transmitted light by producing a phase difference. A fast axis direction of the phase shifter intersects with a direction corresponding to the polarization axis, a direction corresponding to the transmission axis, and a direction corresponding to S polarization of the projection member.

Abstract: A head-up display device virtually displays an image to be viewable by an occupant by projecting the image on a projection member located above an instrument panel of a vehicle in a vehicle upward direction. Assuming that a direction along an up-down direction of the vehicle when the image is virtually displayed is defined as a vertical direction of the image, the head-up display device includes a projector that projects an image as light polarized in a polarization direction intersecting the vertical direction of the image and a reflecting mirror that reflects and redirects the light of the image from the projector toward the projection member, on an optical path between the projector and the projection member, and has a difference between S polarization reflectance and P polarization reflectance for the light from the projector.

Abstract: A HUD apparatus is provided. The HUD apparatus is provided with: an optical source part having a light emission element; a condenser lens, which faces the optical source part, and collects light source light; a field lens, which further collects the light source light transmitted from the condenser lens side, and which projects light at a predetermined angle; and an image formation element, which forms an image when the light source light transmitted from the field lens side is inputted thereto, and which projects light of an image toward the windshield side. The field lens has a composite surface on at least one of the condenser lens side and the image formation element side, the composite surface having multiple continuous optical surfaces. The condenser lens has a diffusion part that diffuses the light source light.

Abstract: A head up display device mounted in a moving body uses a source light to project an image onto a projection member to display a virtual image so that the image is visible to a passenger, the projection member including a first transparent plate that maintains polarization state and has a first surface facing the passenger, a second transparent plate that maintains polarization state and has a second surface opposite to the first surface, and a waveplate interposed between the first and seconds transparent plates and including a fast axis and a slow axis that delays phase with respect to the fast axis, wherein the source light is emitted toward the first surface obliquely along a plane of incidence, the source light including an s-polarization component and a p-polarization component, and the slow axis of the waveplate is inclined with respect to the plane of incidence.

Abstract: An image displayed on an image display unit is illuminated by an image illumination unit, and the image is displayed for a driver using a display optical system having at least one concave mirror element. The image illumination unit has a light emitting surface that emits an illumination light, and a lens array that divides and focuses an entrance pupil of an eye box onto the light emitting surface. With the above configuration, since the light emitting surface and the eye box have a conjugate relationship through the lens array and the display optical system, the light emitted from the light emitting surface can efficiently reach the eye box. As a result, since the light can be efficiently used for illumination, the image having high luminance can be displayed without any increase in the luminance of a light source and any reduction in the number of displayable colors.

Abstract: An HUD device which is installed on a vehicle and displays an image as a virtual image in a visible region in a manner that is visually recognizable to an occupant by projecting the image onto a windshield includes an oscillator which oscillates a laser light flux, a screen member which has unevenness in a projection region in which the image is formed by projection of the laser light flux, a projection optical system which projects the laser light flux onto the screen member, a magnifying optical system which magnifies the image, projects the image onto the windshield, and guides light of the image to the visible region, and a controller which causes a focal length of the projection optical system to temporally oscillate. Accordingly, an appropriate visible region is secured, luminance inconsistencies in an image which is visually recognized are suppressed, and it becomes easy to secure space.

Abstract: An illumination unit includes a plurality of sets of illumination modules each having a light source placed at a conjugate position and a plurality of stages of condenser lenses that collect light from the light source toward a display device, a magnifying optical system being between the conjugate position and a viewing area. Each illumination module set includes an initial stage lens closest to the light source and a final stage lens farthest from the light source. In a surrounding illumination module of the illumination module sets, principal points of all stages of condenser lenses are positioned on a surrounding principal ray that passes through a periphery of an angle of view center of the display device to reach the viewing area, and the light source is positioned on the surrounding principal ray by being offset from a light axis of the initial stage lens in the reference direction.

Abstract: A head-up display device includes a projector, an expansion optical system, an estimating part, a determination part, and a light amount control part. The projector has a light source and a liquid crystal panel. The expansion optical system expands an imagery output from the projector. The estimating part estimates a relative position of the sun with respect to a mobile unit. The determination part determines whether the liquid crystal panel is protected based on a relation between the relative position estimated by the estimating part and a solid angle representing a range in which a light from the sun is incident to the liquid crystal panel through the expansion optical system. The light amount control part decreases an amount of light incident to the liquid crystal panel when the determination part determines that the liquid crystal panel should be protected.

Abstract: An HUD device which is installed on a vehicle and displays an image as a virtual image in a visible region in a manner that is visually recognizable to an occupant by projecting the image onto a windshield includes an oscillator which oscillates a laser light flux, a screen member which has unevenness in a projection region in which the image is formed by projection of the laser light flux, a projection optical system which projects the laser light flux onto the screen member, a magnifying optical system which magnifies the image, projects the image onto the windshield, and guides light of the image to the visible region, and a controller which causes a focal length of the projection optical system to temporally oscillate. Accordingly, an appropriate visible region is secured, luminance inconsistencies in an image which is visually recognized are suppressed, and it becomes easy to secure space.

Abstract: An illumination unit includes a plurality of sets of illumination modules each having a light source placed at a conjugate position and a plurality of stages of condenser lenses that collect light from the light source toward a display device, a magnifying optical system being between the conjugate position and a viewing area. Each illumination module set includes an initial stage lens as a condenser lens closest to the light source and a final stage lens as a condenser lens farthest from the light source. In each illumination module set, assuming a composite focal point of a composite lens combined from all stages of condenser lenses, a gap between a principal plane of the initial stage lens and the light source is set to be equal to or less than a gap between the principal plane and the composite focal point.

Abstract: An illumination lens condenses a light from a light source and emits the light toward a display to illuminate the display. The illumination lens includes multiple first lens surface parts having a shape obtained by extracting multiple portions of a first virtual lens surface along a first optical axis, the first virtual lens surface defining the first optical axis on which the light source is disposed and being at least twice differentiable between optical axes arranged in a reference direction, and multiple second lens surface parts having a shape obtained by extracting multiple portions of a second virtual lens surface along a second optical axis, the second virtual lens surface defining the second optical axis and being at least once differentiable between the optical axes arranged in the reference direction. The first lens surface parts and the second lens surface parts are alternately arranged in the reference direction.

Abstract: A head-up display device includes a projector, an expansion optical system, an estimating part, a determination part, and a light amount control part. The projector has a light source and a liquid crystal panel. The expansion optical system expands an imagery output from the projector. The estimating part estimates a relative position of the sun with respect to a mobile unit. The determination part determines whether the liquid crystal panel is protected based on a relation between the relative position estimated by the estimating part and a solid angle representing a range in which a light from the sun is incident to the liquid crystal panel through the expansion optical system. The light amount control part decreases an amount of light incident to the liquid crystal panel when the determination part determines that the liquid crystal panel should be protected.

Abstract: An optical display image is projected from a projector to a combiner. The combiner includes a front reflection surface, which is in a form of a curved concave surface and forms a front surface virtual image by reflecting the optical display image at a side of the combiner where an inside of a cabin is located, and a back reflection surface, which is in a form of a curved convex surface and forms a back surface virtual image by reflecting the optical display image at another side of the combiner where an outside of the cabin is located. Optical axes, which extend from the front reflection surface and the back reflection surface, respectively, to a predicted eye point of the occupant, are overlapped with each other, and a radius of curvature of the front reflection surface is smaller than a radius of curvature of the back reflection surface.

Abstract: An image displayed on an image display unit is illuminated by an image illumination unit, and the image is displayed for a driver using a display optical system having at least one concave mirror element. The image illumination unit has a light emitting surface that emits an illumination light, and a lens array that divides and focuses an entrance pupil of an eye box onto the light emitting surface. With the above configuration, since the light emitting surface and the eye box have a conjugate relationship through the lens array and the display optical system, the light emitted from the light emitting surface can efficiently reach the eye box. As a result, since the light can be efficiently used for illumination, the image having high luminance can be displayed without any increase in the luminance of a light source and any reduction in the number of displayable colors.

Abstract: An optical display image is projected from a projector to a combiner. The combiner includes a front reflection surface, which is in a form of a curved concave surface and forms a front surface virtual image by reflecting the optical display image at a side of the combiner where an inside of a cabin is located, and a back reflection surface, which is in a form of a curved convex surface and forms a back surface virtual image by reflecting the optical display image at another side of the combiner where an outside of the cabin is located. Optical axes, which extend from the front reflection surface and the back reflection surface, respectively, to a predicted eye point of the occupant, are overlapped with each other, and a radius of curvature of the front reflection surface is smaller than a radius of curvature of the back reflection surface.