Abstract: A head-up display of the present disclosure projects a display image on a transparent reflecting member. The head-up display includes: a display device that displays the display image; and a projection optical system that projects the display image displayed on the display device. On an assumption that light reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image is reference light, the projection optical system includes a prism element that has an incident surface, a reflection surface, and an emitting surface different from the incident surface sequentially in an optical path from the display device. The emitting surface is inclined to the reference light. An inclination amount ?2 of the reference light emitted from the emitting surface with respect to the emitting surface lies in a range of 15°<|?2|<45° in the optical path from the display device.

Abstract: A head-up display for displaying an image as a virtual image to an observer includes a projection optical system that includes a lens element and a reflecting mirror. A light beam reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image is defined as a reference light beam. The lens element is inclined with respect to the reference light beam. The lens element includes an entrance surface on which light of the image is incident, an exit surface from which light of the image emerges, a first edge portion, and a second edge portion. The second edge portion is inclined so that, when light emitted from the image travels through the entrance surface, the second edge portion, and the exit surface in this order, light emerging from the exit surface reaches below a central portion of the reflecting mirror.

Abstract: A head-up display is configured to project an image on a transparent reflection member to cause an observer to visually recognize a virtual image, and includes a display device configured to display the image, and a projection optical system configured to project the image displayed by the display device as the virtual image for the observer. The projection optical system is configured to form the image as an intermediate image, and includes a first optical element configured to condense light, a first lens configured to condense light, and a second optical element configured to diffuse light. The first optical element, the first lens, and the second optical element are disposed in this order along an optical path from the display device.

Abstract: An optical system according to the present disclosure includes a first sub-optical system including an aperture stop and a second sub-optical system including a prism. The prism has a first transmission surface located on the reduction side, a second transmission surface located on the magnification side, and at least one reflection surface located on the optical path between the first transmission surface and the second transmission surface. A first reflection surface closest to the intermediate imaging position has a shape with a concave surface facing a direction into which a light ray incident on first the reflection surface is reflected. A curvature shape of the first reflection surface is set such that some of multiple principal rays passing through the reduction conjugate point intersect on the optical path between the first reflection surface and the second transmission surface.

Abstract: A head-up display displays an image as a virtual image to an observer and includes: a display device to display the image; and a projection optical system to enlarge and project the image. The projection optical system includes first and second optical elements arranged in this order in an optical path from the image. The first optical element has a diverging action stronger in a horizontal direction than in a vertical direction. The second optical element has a converging action stronger in the horizontal direction than in the vertical direction. A combined power of the first and second optical elements is larger in the vertical direction than in the horizontal direction. The virtual image is inclined by 45 degrees or more with respect a line of sight of the observer to have a lower end close to the observer and an upper end far from the observer.

Abstract: The present disclosure provides an optical system that includes a prism having an incident surface, an exit surface, and one or more reflecting surfaces. A first intermediate imaging position of a light flux in a first direction is located inside the prism. The first intermediate imaging position is different from a second intermediate imaging position of the light flux in a second direction orthogonal to the first direction.

Abstract: The present disclosure provides an optical system that includes a prism having an incident surface, an exit surface, and one or more reflecting surfaces. The optical system includes a first scanning element configured to scan in a first direction a light that enters and reflect the light in a direction of the incident surface of the prism, and a second scanning element configured to scan in a second direction the light that exits from the exit surface of the prism, the second direction being orthogonal to the first direction. The incident surface of the prism has a convex shape with respect to the first scanning element.

Abstract: The present disclosure provides an optical system that includes a prism having an incident surface, an exit surface, and one or more reflecting surfaces. The optical system includes a first scanning element configured to scan a light that enters and has a plurality of wavelengths in a first direction, and reflect the light in a direction of the incident surface of the prism. The optical system includes a second scanning element configured to scan in a second direction the light that exits from the exit surface of the prism, the second direction being orthogonal to the first direction. The incident surface of the prism has a concave shape with respect to the first scanning element.

Abstract: In a display device, an irradiation unit includes an imaging optical system. The imaging optical system scans and irradiates a front surface of a screen with light to form an image. The light passing through the screen and output from the screen in a movement direction is incident on a projection unit as incident light. The projection unit irradiates a reflective member with the incident light to allow the reflective member to reflect the incident light to form a virtual image corresponding to the image in a target space. A locus of a focal position of the imaging optical system when the irradiation unit wholly scans the front surface of the screen is within a range between the front surface of the screen at a first position and the front surface of the screen at a second position.

Abstract: A display system includes an image producing unit, a projection unit and an adjustment unit. The image producing unit has a display surface, and is configured to produce an image on the display surface. The projection unit is configured to project a virtual image to a target space with an output light of the image producing unit. The virtual image corresponds to the image produced by the image producing unit. The display system is configured to change a visual distance between an eye-box and the virtual image. The adjustment unit is configured to adjust brightness of the virtual image according to the visual distance.

Abstract: A head-up display for displaying an image as a virtual image to an observer includes a projection optical system that includes a lens element and a reflecting mirror. A light beam reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image is defined as a reference light beam. The lens element is inclined with respect to the reference light beam. The lens element includes an entrance surface on which light of the image is incident, an exit surface from which light of the image emerges, a first edge portion, and a second edge portion. The second edge portion is inclined so that, when light emitted from the image travels through the entrance surface, the second edge portion, and the exit surface in this order, light emerging from the exit surface reaches below a central portion of the reflecting mirror.

Abstract: The head-up display includes an imaging position changer configured to change a position of a virtual image between a far visual position far from an observer and a near visual position close to the observer. The imaging position changer inclines the virtual image at the far visual position by a second inclination angle with respect to a perpendicular plane to a reference light beam reaching a center of a viewpoint region in which a viewpoint of the observer is located, to move an upper end thereof in a forward direction of the moving object, and inclines the virtual image at the near visual position by a first inclination angle smaller than the second inclination angle with respect to the perpendicular plane to the reference light beam, to move the upper end in the forward direction of the moving object.

Abstract: A head-up display displays an image as a virtual image to an observer and includes: a display device to display the image; and a projection optical system to enlarge and project the image. The projection optical system includes first and second optical elements arranged in this order in an optical path from the image. The first optical element has a diverging action stronger in a horizontal direction than in a vertical direction. The second optical element has a converging action stronger in the horizontal direction than in the vertical direction. A combined power of the first and second optical elements is larger in the vertical direction than in the horizontal direction. The virtual image is inclined by 45 degrees or more with respect a line of sight of the observer to have a lower end close to the observer and an upper end far from the observer.

Abstract: A head-up display includes a display device and a projection optical system; the projection optical system includes first and second optical elements arranged in order of an optical path from the image; and when optical paths corresponding to an upper end and a lower end of the virtual image are defined as an upper ray and a lower ray, respectively, and a diverging effect and a converging effect are defined as being negative and positive, respectively, the first and the second optical elements satisfy conditional expressions P_u1?P_l1<0 and P_u2?P_l2>0 (where P_u1 denotes a local power of the first optical element acting on the upper ray, P_l1 denotes a local power of the first optical element acting on the lower ray, P_u2 denotes a local power of the second optical element acting on the upper ray, P_l2 denotes a local power of the second optical element acting on the lower ray).

Abstract: A head-up display of the present disclosure projects a display image on a transparent reflecting member. The head-up display includes: a display device that displays the display image; and a projection optical system that projects the display image displayed on the display device. On an assumption that light reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image is reference light, the projection optical system includes a prism element that has an incident surface, a reflection surface, and an emitting surface different from the incident surface sequentially in an optical path from the display device. The emitting surface is inclined to the reference light. An inclination amount ?2 of the reference light emitted from the emitting surface with respect to the emitting surface lies in a range of 15°<|?2|<45° in the optical path from the display device.

Abstract: A head-up display is configured to project an image on a transparent reflection member to cause an observer to visually recognize a virtual image, and includes a display device configured to display the image, and a projection optical system configured to project the image displayed by the display device as the virtual image for the observer. The projection optical system is configured to form the image as an intermediate image, and includes a first optical element configured to condense light, a first lens configured to condense light, and a second optical element configured to diffuse light. The first optical element, the first lens, and the second optical element are disposed in this order along an optical path from the display device.

Abstract: A head-up display is configured to project an image on a transparent reflection member to cause an observer to visually recognize a virtual image, and includes a display device configured to display the image, and a projection optical system configured to project the image displayed by the display device as the virtual image for the observer. The projection optical system is configured to form an image as an intermediate image, and includes a first lens configured to condense light, and a first optical element configured to diffuse light. The first lens and the first optical element are disposed in this order along an optical path from the display device. The first lens is inclined with respect to a reference beam which is defined as a beam reaching a center of a viewpoint region of the observer and corresponding to a center of the virtual image.

Abstract: To provide a display device that can suppress generation of a double image. Display device includes plate-shape windshield having translucency and a projection unit that projects light expressing an image onto windshield such that the light is reflected toward a user by windshield. The projection unit changes a display distance between an eye of the user and a position of an image visually recognized as a virtual image by the user through windshield by the light projection. Windshield is formed such that a wedge angle that is of an angle formed between a front side and a back side at a region located at any level of windshield is continuously decreased with increasing level.

Abstract: The present invention provides a Fresnel lens that can reduce generation of concentric stray light. The Fresnel lens includes a sawtooth corrugated face that is formed by alternately disposing a first face inclined relative to optical axis A and a second face substantially parallel to optical axis A, and a light shielding mask is formed at a position corresponding to the second face.

Abstract: Head-up display includes display device, projection optical system, a polarization member, and a first polarizer. Display device displays an image. Projection optical system includes refraction lens. Projection optical system projects the image displayed on display device to an observer. The polarization member is disposed between projection optical system and a reflection member that reflects light from projection optical system. Transmittance of the polarization member depends on a polarization direction of transmitted light. The first polarizer is disposed behind refraction lens on an optical path starting from display device. The first polarizer rotates a predetermined polarized component by a quarter of wavelength.