Title:
HEAD-UP TYPE DISPLAY DEVICE FOR VEHICLE
Document Type and Number:
Japanese Patent JP2959318
Kind Code:
B2
Abstract:
PURPOSE: To reduce the cost of a light source and to extend the life time by providing a holographic combiner and a light source means which throws light having the p-polarization direction as display light.
CONSTITUTION: A hologram element 102 is arranged between glass plates 101 facing each other, and a polarizing element 103 which rotates the polarization direction of incident light at 90° is so arranged that it is put on the face on the driver side of the hologram element 102, and the hologram element 102 and the polarizing element 103 are coupled by a PVB intermediate film 104, thus forming a holographic combiner 105. A device consists of this holographic combiner 105 and a light source 106 which throws display light having the p-polarization direction to the holographic combiner 105. In this case, the incident light from the light source 106 has a low reflectivity on the boundary face between air and glass plates 101 because being p-polarized light, and an incident light loss 107a is reduced. Thereafter, the light is converted to s- polarized light by the polarizing element 103 and is diffracted with a high diffraction efficiency by the hologram element 102 and is converted to p-polarized light again by the polarizing element 103, and thereby,. a diffracted light loss 108a is reduced too.
Inventors:
KAWANO TSUTOMU
Application Number:
JP6449493A
Publication Date:
October 06, 1999
Filing Date:
March 24, 1993
Export Citation:
Assignee:
NITSUSAN JIDOSHA KK
International Classes:
G02B27/01; G02B27/02; G02B27/28; B60K35/00; (IPC1-7): G02B27/02; B60K35/00; G02B27/28
Domestic Patent References:
| JP2141720A |