Display apparatus for vehicles

• US 5,502,456 A
• Filed: 06/07/1995
• Issued: 03/26/1996
• Est. Priority Date: 04/21/1993
• Status: Expired due to Term

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Iino, Tadashi, Takashima, Makoto, Korenaga, Hidenobu
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): GOON, GIN F
• Application Number:
  US08/486,263
• Time in Patent Office: 293 Days
• Field of Search: 345/7, 345/8, 345/9, 359/40, 359/630, 359/632, 359/640, 340/980
• US Class Current: 345/9
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0165 associated with a head-down display
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/04 Prisms
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/13355 Polarising beam splitters [PBS]
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

The display apparatus for vehicles being reduced in reflection at the external light suppression prisms disposed on the surface of the display device and providing a bright display image, in which included are the display device and the external light suppression prisms consisting of first and second prisms being stacked together by directing the prism apex angles in opposite directions to each other and disposed close to the display surface of the display device, a reflecting member to reflect the display light emitted from the display device, which light has passed through the prisms, toward the viewing point of the driver, and a polarized direction rotating means being disposed between the prisms and the reflecting member for rotating the polarization direction of the display light by 90 degrees, whereby the display light is emitted as a P-polarization light with respect to the reflecting surface of the reflecting member.

Claims

1. A display apparatus for vehicles comprising:

a display device;

first and second prisms stacked together with the prism apex angles being directed in opposite directions to each other, the first and second prisms being disposed in close relation to the display surface of the display device;

a reflecting member to reflect the display light that has passed through the prisms toward the viewing point of a driver of the vehicle;

means for emitting the display light from the display device as a P-polarization light through said stacked prisms and toward the reflecting surface of the reflecting member; and

polarized direction rotating means disposed between the prisms and the reflecting member to rotate by 90 degrees to change the direction of light polarization from P-polarization light to S-polarization light the polarized direction of the display light which has passed the prisms wherein the light caused to impinge on the reflecting member is S-polarization light.

2. A display apparatus as defined in claim 1, wherein

said display device is a transmission type liquid crystal display element having a backlight.

3. A display apparatus as defined in claim 1, wherein

said polarized direction rotating means is comprised of a TN-type liquid crystal panel.

4. A display apparatus as defined in claim 1, wherein

said polarized direction rotating means is comprised of 1/2 wavelength plate.

5. A display apparatus as defined in claim 1, wherein said reflecting member comprises windshield means.

6. A display apparatus as defined in claim 1, wherein said first and second prisms are made of glass or resin.