| 主权项 |
1. A display device for a vehicle comprising:
a substrate housing portion that includes a circuit substrate that outputs an image signal; an image display element that converts incident light into image display light based on the image signal input from the circuit substrate; a transmission-type intermediate image screen that images, as an actual image, the image display light converted by the image display element and that is provided with a diffusion layer in which bead diffusion materials that diffuse light related to the actual image are used; and a combiner that displays, as a virtual image, the light related to the actual image transmitted and diffused by the transmission-type intermediate image screen; wherein a luminous intensity half-value angle of a transmission light distribution angle of the light transmitted by the transmission-type intermediate image screen is ±7.5 to 10 degrees, and wherein given, when a virtual image of a size of about 10 inches is presented 1.7 to 2 meters ahead of a user of the display device for a vehicle, that a target value of the resolution of the actual image formed by the transmission-type intermediate image screen is set to be R and that the luminous intensity half-width at half-maximum angle of the transmission light distribution angle of the light transmitted through the diffusion layer is set to be A, a thickness T of the diffusion layer inside the transmission-type intermediate image screen satisfies 0<T≦R/(2*tan(A)). |
