A backlight unit includes a light source; a condensing unit that condenses light emitted from the light source; and a diverging unit that diverges the light entering from the condensing unit and that emits the light toward an image display unit of a light transmission type in a head-up display device. For example, the diverging unit is a lens in which both surfaces of an incident surface into which the light from the condensing unit enters as well as an emission surface from which the light is emitted toward the image display unit, are concave surfaces.
BACKLIGHT UNIT AND HEAD-UP DISPLAY DEVICE
2017-09-28
Patent
Electronic Resource
English