Head up display for vehicle

Abstract

Abstract PURPOSE:To assure a forward visual field by using a hologram for a semipermeable film and limiting the thickness of a photosensitive material to a specific range. CONSTITUTION:The hologram is sealed as the semipermeable film 3 between two sheets of the plate glasses 1, 1' and intermediate films 2, 2' consisting of polyvinyl butyral, etc., and the display information projected from a display device 4 such as CRT or fluorescent display tube is reflected by the semipermea ble film 3 so as to be visually recognized by a driver's eyes 5. The thickness of the photosensitive material for the semipermeable film 3 is specified to 7mu-40mu if both of two sheets of the plate glasses 1, 1' are colorless and transpar ent plates. Said thickness is specified to 7mu-30mu if either of two sheets of the glass plates is the colored transparent plate. The display image is thereby suffi ciently visually recognized with high diffraction efficiency and the transmittance of visible light as windshield glass is increased to >=70%.

Inventors

• 👤 Tomohisa Ishikawa

Bibliographic Details