Abstract: A display apparatus includes a housing and at least one mirror. The housing can be detachably mounted on a display and includes an entrance that allows light emitted from the display to enter the interior of the housing with the housing mounted on the display and an exit that allows the light having entered the interior of the housing through the entrance to exit to the exterior of the housing. The at least one mirror reflects the light having entered the interior of the housing through the entrance to the exit.

Abstract: A display system includes a display device, an optical device, and an operation receiver. The display device is switchable between an emitting state where first image light is allowed to be emitted from the display device and a non-emitting state where the first image light is not allowed to be emitted from the display device. The optical device is switchable between a reflecting state where light coming from a back of the mobile body is reflected from the optical device and a transmitting state where the light passes through the optical device. The operation receiver switches between a first mode where the display device is in the emitting state while the optical member is in the transmitting state and a second mode where the display device is in the non-emitting state while the optical member is in the reflecting state.

Abstract: A display system includes: a display device switchable between an emitting state where first image light is allowed to be emitted from the display device and a non-emitting state where the first image light is not allowed to be emitted from the display device; an optical device switchable between a reflecting state where light coming from a back of the mobile body is reflected from the optical device and a transmitting state where the light passes through the optical device; and an operation receiver that receives an operation for switching the display system between a first mode where the display device is in the emitting state while the optical member is in the transmitting state and a second mode where the display device is in the non-emitting state while the optical member is in the reflecting state.

Abstract: A tangent line, described next, is, in top view, parallel to a straight line extending in a width direction of the display surface in a range in which the attitude can be changed. The tangent line is present on a plane orthogonal to the up-down direction of the automobile, and contacts a center of the final reflective surface. In top view, of an angle formed by a straight line connecting a center of the final reflective surface with a center of the display surface and the tangent line of the final reflective surface, a supplementary angle which is supplementary to an angle that is on a rear side of the automobile and that is on a side where the observer is present is an acute angle of less than 90 degrees.

Abstract: A display device includes: a display element including a display surface on which image is displayed; a first mirror and a second mirror that reflects emission light emitted from the display surface of the display element; and a polarization element. The polarization element is configured to reflect and transmit the emission light from display surface. The emission light from display surface is reflected off polarization element twice and transmitted through polarization element once by a time the emission light is reflected off first mirror and second mirror and exits from display device.

Abstract: A display system includes: a display that emits light corresponding to image information; a half mirror that receives the light emitted, reflects, as reflected light, a first component of the light received, and transmits a second component different from the first component; and a first reflecting mirror having a concave surface that receives and reflects the reflected light toward the half mirror. The half mirror includes a first retardation film, a first support substrate, and a reflective polarizing film stacked in this order from a side on which the light emitted is received. The first retardation film changes a phase of the light received. The first support substrate is light-transmissive. The reflective polarizing film reflects a first polarized component and transmits a second polarized component different from the first polarized component.

Abstract: A camera system includes an image sensor, a wavelength filter, and an imaging optical system. The image sensor has an image capturing plane. The imaging optical system is configured to have light coming from a subject passed through the wavelength filter and imaged on the image capturing plane. The wavelength filter has a perpendicularly incident region and an obliquely incident region. On the perpendicularly incident region, a principal ray, which has passed through the imaging optical system, is incident perpendicularly. On the obliquely incident region, a principal ray, which has passed through the imaging optical system, is incident obliquely. The image sensor has sensitivity to a light ray having a predetermined wavelength. The light ray having the predetermined wavelength is transmitted at a higher transmittance through at least a part of the obliquely incident region than through the perpendicularly incident region.

Abstract: A display device includes: a display element including a display surface on which image is displayed; a first mirror and a second mirror that reflects emission light emitted from the display surface of the display element; and a polarization element. The polarization element is configured to reflect and transmit the emission light from display surface. The emission light from display surface is reflected off polarization element twice and transmitted through polarization element once by a time the emission light is reflected off first mirror and second mirror and exits from display device.

Abstract: A tangent line, described next, is, in top view, parallel to a straight line extending in a width direction of the display surface in a range in which the attitude can be changed. The tangent line is present on a plane orthogonal to the up-down direction of the automobile, and contacts a center of the final reflective surface. In top view, of an angle formed by a straight line connecting a center of the final reflective surface with a center of the display surface and the tangent line of the final reflective surface, a supplementary angle which is supplementary to an angle that is on a rear side of the automobile and that is on a side where the observer is present is an acute angle of less than 90 degrees.

Abstract: A display system includes: a display that emits light corresponding to image information; a half mirror that receives the light emitted, reflects, as reflected light, a first component of the light received, and transmits a second component different from the first component; and a first reflecting mirror having a concave surface that receives and reflects the reflected light toward the half mirror. The half mirror includes a first retardation film, a first support substrate, and a reflective polarizing film stacked in this order from a side on which the light emitted is received. The first retardation film changes a phase of the light received. The first support substrate is light-transmissive. The reflective polarizing film reflects a first polarized component and transmits a second polarized component different from the first polarized component.

Abstract: A fluid pressure control device includes a first switching valve provided on a downstream of a first travel control valve in the first main passage and having an open position and a priority position, a second switching valve provided on a downstream of a second travel control valve in the second main passage and having an open position and a priority position, and a merging passage connecting a downstream of the first switching valve and a downstream of the second switching valve. In a state where first work control valves and second work control valves are not operated and the first travel control valve is operated, the first switching valve is at a priority position, and in a state where the first work control valves and the second work control valves are not operated and the second travel control valves is operated, the second switching valve is at a priority position.

Abstract: Disclosed herein is a display system including an image producing unit and an optical system part. The image producing unit produces an image on a display screen by letting a light beam, which eventually forms a virtual image based on the image produced, emerge from the display screen. The optical system part forms a left-eye image and a right-eye image on a user's left and right eyes, respectively, and thereby projects the virtual image toward a user's left and right eyes by reflecting and/or refracting the light beam emerging from the display screen. The optical system part has an image distortion generation factor to make an image distortion of the left-eye image different from an image distortion of the right-eye image.

Abstract: A display system of one aspect according to the present disclosure includes: a display unit; a first optical member; and a second optical member. The display unit includes a display surface for displaying an image. The first optical member includes a first reflective surface for reflecting rays of light constituting the image. The second optical member includes a second reflective surface for reflecting rays of light reflected from the first reflective surface to form a virtual image in a target space. An angle of view in a length direction of an available area for display of the virtual image with regard to a point of view position for the virtual image is denoted by ? [deg]. A length of the display surface is denoted by W [mm]. W is equal to or greater than a prescribed value given by 12.0×??26.6. ? is equal to or greater than 8.0.

Abstract: An imaging optical system includes a lens system including a first lens, a second lens, a third lens, and a fourth lens, which are arranged in this order such that the first lens is located closest to an object, out of these four lenses and that the fourth lens is located closest to an image formed, out of these four lenses. One surface, facing the object, of the first lens has negative power. The other surface, facing the image, of the first lens has negative power as well.

Abstract: A camera system includes an image sensor, a wavelength filter, and an imaging optical system. The image sensor has an image capturing plane. The imaging optical system is configured to have light coming from a subject passed through the wavelength filter and imaged on the image capturing plane. The wavelength filter has a perpendicularly incident region and an obliquely incident region. On the perpendicularly incident region, a principal ray, which has passed through the imaging optical system, is incident perpendicularly. On the obliquely incident region, a principal ray, which has passed through the imaging optical system, is incident obliquely. The image sensor has sensitivity to a light ray having a predetermined wavelength. The light ray having the predetermined wavelength is transmitted at a higher transmittance through at least a part of the obliquely incident region than through the perpendicularly incident region.

Abstract: A fluid pressure control device includes a first switching valve provided on a downstream of a first travel control valve in the first main passage and having an open position and a priority position, a second switching valve provided on a downstream of a second travel control valve in the second main passage and having an open position and a priority position, and a merging passage connecting a downstream of the first switching valve and a downstream of the second switching valve. In a state where first work control valves and second work control valves are not operated and the first travel control valve is operated, the first switching valve is at a priority position, and in a state where the first work control valves and the second work control valves are not operated and the second travel control valves is operated, the second switching valve is at a priority position.

Abstract: A head-up display device projects a virtual image. The head-up display device includes a display, a first optical member, a second optical member, and an adjuster. The display outputs light that becomes a display image corresponding to the virtual image. The first optical member reflects the light incident from the display. The second optical member reflects or transmits the light reflected by the first optical member such that the virtual image is projected. The adjuster moves the first optical member to adjust a projection distance of the virtual image. The adjuster changes a distance between the first optical member and the second optical member and an inclination angle of the first optical member with respect to the display according to the projection distance of the virtual image.

Abstract: A fluid pressure control device includes a switching valve that has a pilot chamber to which the working oil is supplied from the supply passage through the second control valve, and a first relief valve that is provided on the downstream side of the switching valve. The second control valve allows supply of the working oil to the pilot chamber in a case where a flow of the working oil to a tilt cylinder is allowed, and blocks the supply of the working oil to the pilot chamber in a case where the flow of the working oil to the tilt cylinder is blocked. The switching valve allows a flow of the working oil to the first relief valve in a case where the working oil is supplied to the pilot chamber, and blocks the flow of the working oil to the first relief valve in a case where the supply of the working oil to the pilot chamber is blocked.

Abstract: Disclosed herein is a display system including an image producing unit and an optical system part. The image producing unit produces an image on a display screen by letting a light beam, which eventually forms a virtual image based on the image produced, emerge from the display screen. The optical system part forms a left-eye image and a right-eye image on a user's left and right eyes, respectively, and thereby projects the virtual image toward a user's left and right eyes by reflecting and/or refracting the light beam emerging from the display screen. The optical system part has an image distortion generation factor to make an image distortion of the left-eye image different from an image distortion of the right-eye image.

Abstract: A head-up display device includes a display element, a movable mirror, one or more first and second mirrors, and an movable unit. The display element emits light to form a display image. The movable mirror first reflects light emitted from the display element. The one or more first and second mirrors reflect light reflected off the movable mirror to project a virtual image. The movable unit adjusts a position of the movable mirror to adjust a projection distance of the virtual image. The movable mirror is disposed at a position such that light incident to the movable mirror is non-parallel to a normal of the movable mirror.