An image display device includes a light source, a screen, an optical system, a converging lens, an optical distance correction member, and a scanning unit. The converging lens is configured to converge the light emitted from the light source onto the screen. The optical distance correction member is disposed between the converging lens and the screen. The scanning unit scans the screen with the light from the light source. The screen is disposed so as to be inclined with respect to a plane perpendicular to an optical axis of the converging lens so that a viewing distance of the virtual image gradually varies. The optical distance correction member adjusts an optical distance of light transmitting through the optical distance correction member so that a distance between the screen and a focusing position of the light is made substantially identical over an entire image display region in the screen.

An illumination assembly for a vehicle is provided herein. The illumination assembly may employ a projection assembly that may be disposed within a housing extending from a portion of a vehicle. A window is disposed on the vehicle and may be optically coupled with the projection assembly. A luminescent structure may be disposed within the window and is excited by the projection assembly. A controller may be configured to activate the projection assembly to selectively illuminate indicia on the window.

A microlens array includes N lenses ranging from a 1.sup.st lens to an N.sup.th lens and a lens arrangement area. N is a positive integer. The lens arrangement area has the N lenses arranged in array. The lens arrangement area receives light emitted from a light source. An i.sup.th (i being 1.sup.st to N.sup.th) lens satisfies a conditional expression below:
2020 where denotes an angle formed by a main-axis orientation of double refraction and a reference orientation.

A head up display arrangement for a motor vehicle includes a head up display module having a picture generation unit emitting a light field. A plurality of linear polarizers are arranged in a stack. A first of the linear polarizers receives the light field from the picture generation unit. A last of the linear polarizers emits the light field. A windshield reflects the light field from the last linear polarizer such that the reflected light field is visible to a human driver of the motor vehicle as a virtual image.

The disclosure provides a light source device and an image display device. The light source device includes a laser light source configured to emit laser light having a wavelength in a range from 635 nm to 645 nm inclusive, a temperature sensor configured to detect temperature around the light source device, and a laser control circuit configured to control the laser light source. The laser control circuit approximates, with use of a quartic expression, change in threshold current of the laser light source relative to temperature, and approximates, with use of a quadratic expression, change in slope efficiency of the laser light source relative to temperature, to obtain threshold current and slope efficiency of the laser light source corresponding to detection temperature of the temperature sensor, and controls the laser light source in accordance with the threshold current and the slope efficiency thus obtained.

In order to provide a transmission type screen having a flat scattered intensity within a predetermined scattering angle, a transmission type screen (50) according to the present invention comprising a first surface (51), and a second surface (52) opposed to the first surface (51), wherein: the first surface (51) is equipped with a microlens array (57) including a plurality of microlenses; the second surface (52) is equipped with a light diffusion surface (60); and a diffusion angle ratio of a diffusion angle of the light diffusion surface (60) relative to a diffusion angle of the microlens array (57) is not less than 0.2 and not more than 0.4.

A video display system includes: a screen on which an mage for displaying a virtual image is projected; a light source that emits laser light; a scanner that projects the image onto the screen by biaxially scanning the laser light onto the screen; and a controller that generates the image and controls the light source using an image signal for causing the generated image to be projected onto the screen by the laser light, and receives an input of sensing information measured using a temperature sensor and controls the scanner in accordance with the input sensing information. When the sensing information indicates a temperature outside a given temperature range, the controller causes the scanner to reduce an amplitude of the biaxial scanning in at least one axial direction to a smaller value than when the sensing information indicates a second brightness or a temperature within the given temperature range.

It is aimed to provide a system for alerting a driver of a driver cabin of a motor vehicle, said system comprising: a plurality of light sources arranged in array to project a signal light against the windshield and/or side window, provided in the driver cabin along a horizontal contour of windshield and side windows, outside a line of sight of the driver, and arranged to show a mirror image of the light source in the windshield or side window, visible to the driver; a tracking controller, arranged to identify one or more objects to be tracked in the perimeter of the motor vehicle; a control system, coupled to the tracking controller for activating a number of light sources of the plurality of light sources, arranged to project a signal light indicative of said tracked object substantially centered along a virtual line of sight from the driver towards the identified object.

An optical filter having spectral properties that reflects light of a first wavelength band and transmits light of a second wavelength band that does not include the first wavelength band is provided between a greater distance optical system that displays a virtual image at a greater distance from an image reflection surface and a closer distance optical system that displays a virtual image at a closer distance from the image reflection surface. The optical filter aligns the optical paths of display light of the greater distance optical system and the closer distance optical system and guides the display light to the image reflection surface. Further, the powers of the greater distance optical system and the closer distance optical system are set to be different.

There is provided ahead-up display in a vehicle arranged to display a picture, the head-up display comprises a first optical sub-system disposed in an upper region of the windscreen and a second optical sub-system disposed underneath the dashboard of the vehicle proximate a lower region of the windscreen. The first optical sub-system is arranged to output a light field. The first optical sub-system comprises a light source and a spatial light modulator. The light source is arranged to emit light. The spatial light modulator is arranged to receive the light from the light source and spatially-modulated the light in accordance with a computer-generated hologram displayed on the spatial light modulator. The second optical sub-system is arranged to receive the light field from the first optical sub-system and project the light field onto a windscreen of the vehicle to form a virtual image on the windscreen.