Display device emitting a light flux and mobile apparatus including the display device

A display device comprising:

• a projection unit configured to emit a light flux including image information;
• a divergence angle controlling unit configured to control a divergence angle of the light flux emitted from the projection unit to not more than a prescribed angle;
• and
• a transparent projection plate configured to reflect the light flux enabling an occupant to visually identify a virtual image locating in the reflection direction,
• wherein
• the divergence angle controlling unit includes a transmission unit transmitting the light flux emitted from the projection unit and a light shielding unit shielding part of the light flux,
• the part of the light flux is shielded by the light shielding unit so that the divergence angle of the light flux is controlled to not more than a prescribed angle, and
• an angle θd between a direction of the virtual image and a direction in which a double image can be viewed being not more than generally 1 mrad, the angle θd represented by equation:
• θ
• d
• =
• 2
• ⁢
• d
• ·
• cos
• ⁢
• ⁢
• θ
• ·
• sin
• ⁢
• ⁢
• θ
• L
• ⁢
• n
• 2
• -
• sin
• 2
• ⁢
• θ
• ,
• where a refractive index of the projection plate is n, a thickness is d, a distance from an eye point position of the occupant to a position of the virtual image is L, and an incident angle of the light flux to the projection plate is θ.

A mobile apparatus comprising:

• a display device including:
• a projection unit configured to emit a light flux including image information;
• a divergence angle controlling unit configured to control a divergence angle of the light flux emitted from the projection unit to not more than a prescribed angle;
• and
• a transparent projection plate onto which image information is projected, the transparent projection plate configured to reflect the light flux enabling an occupant to visually identify a virtual image located in the reflection direction,
• wherein
• the divergence angle controlling unit includes a transmission unit transmitting the light flux emitted from the projection unit and a light shielding unit shielding part of the light flux,
• the part of the light flux is shielded by the light shielding unit so that the divergence angle of the light flux is controlled to not more than a prescribed angle, and
• an angle θd between a direction of the virtual image and a direction in which a double image is viewable, is not more than substantially 1 mrad, the angle θd represented by θd=d·sin 2θ/nL, where a refractive index of the projection plate is n, a thickness is d, a distance from an eye point position of the occupant to a position of the virtual image is L, and an incident angle of the light flux to the projection plate is θ.