Patent ID: 11867902
Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  B  F | IPC B  F  G

Claim 14:
15. A head-up display having a display device, the display device comprising:
a light source that emits light;
a display panel that displays an image; and
a light guide panel that guides light emitted from the light source to the display panel, wherein
the light guide panel includes an incident surface facing the light source, an emission surface facing the display panel, a first reflective surface facing the incident surface, and a second reflective surface facing the emission surface,
the first reflective surface has a concave shape that reflects light so that reflected light becomes closer to parallel light when viewed in a facing direction of the display panel and the light guide panel in the light guide panel, is tilted at an angle larger than 0 degrees with respect to the incident surface, and intersects the second reflective surface at an angle smaller than 90 degrees, and
the head-up display satisfies following Equation, where size in an up-down direction of an eyebox is S(d2), a length in a longer direction of the display panel of the light guide panel is L, and a distance between light sources located at outermost positions is W, S
          ⁡
          
            (
            
              d
              ⁢
              
                
              
              ⁢
              2
            
            )
          
        
        <
        
          
            tan
            
              -
              1
            
          
          ⁢
          
            
              W
              
                1.5
                ×
                L
              
            
            .
          
        
      
    
    
      
        [
        
          Equation
          ⁢
          
            
          
          ⁢
          7
        
        ]