{
  "$type": "site.standard.document",
  "description": "A light guide unit has a cold mirror unit to guide display light toward a projection window. In an XYZ color system, a wavelength region between a wavelength at which a value of a color matching function Z is maximum and a wavelength at which a value of the color matching function Y is maximum is a…",
  "path": "/patents/1239765",
  "publishedAt": "2019-07-25T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G02B27/0101",
    "DENSO CORPORATION"
  ],
  "textContent": "A light guide unit has a cold mirror unit to guide display light toward a projection window. In an XYZ color system, a wavelength region between a wavelength at which a value of a color matching function Z is maximum and a wavelength at which a value of the color matching function Y is maximum is a first wavelength region, and a wavelength region between a wavelength at which a value of a color matching function Y is maximum and a wavelength at which a value of a color matching function X is maximum is a second wavelength region. A minimum reflectance of the cold mirror unit to the display light takes a minimum value among reflectances of the respective wavelengths in a corresponding wavelength region. The minimum reflectance in the second wavelength region is larger than the minimum reflectance in the first wavelength region.",
  "title": "HEAD-UP DISPLAY DEVICE AND COLD MIRROR"
}