Information display apparatus

Patent metadata

Field	Value
Publication number	US-11221480-B2
Application number	US-201616094173-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Apr 26, 2016
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A small information display apparatus capable of displaying video information on a windshield as a virtual image is provided. An information display apparatus configured to display video information of a virtual image on a windshield of a conveyance includes: a liquid crystal panel arranged as a video display apparatus configured to form the video information; and a virtual image optical system provided with a windshield for displaying the virtual image at a front of the conveyance by reflecting video of the liquid crystal panel by means of the windshield. The virtual image optical system is configured by arranging a concave mirror and an optical element between the concave mirror and the video display apparatus.

First claim

The invention claimed is:

1. An information display apparatus configured to display video information of a virtual image on a windshield of conveyance, the information display apparatus comprising:
a flat panel display configured to display the video information; and
a virtual image optical system configured to display a virtual image at a front of the conveyance by reflecting light emitted from the flat panel display by means of the windshield,
wherein the virtual image optical system includes a concave mirror and an optical element,
wherein the concave mirror is arranged between the flat panel display and the windshield,
wherein the optical element is arranged between the flat panel display and the concave mirror,
wherein a horizontal cross-sectional shape of the concave mirror is a shape in which an average radius of curvature of an upper portion of the optical element is smaller than that of a lower portion of the optical element on a basis of a vertical direction in a state where the concave mirror is arranged on an optical path,
wherein the flat panel display is arranged so as to be inclined with respect to an optical axis of the concave mirror,
wherein the flat panel display is arranged within a focal point distance of the concave mirror so that a center of a surface of the flat panel display, where an image is displayed, in a vertical direction of the surface is positioned at a lower side than a center of the concave mirror, and
wherein a distance between the concave mirror and the flat panel display is within a range that prevents light reflected from the concave mirror from being blocked out by the optical element and the flat panel display.

2. The information display apparatus according to claim 1 ,
wherein the virtual image optical system includes an optical element with weak negative refractive power, and the optical element with weak negative refractive power is configured to emit, after video light from the flat panel display is focused on and made incident on the optical element to become substantially parallel light, the substantially parallel light toward the concave mirror.

3. The information display apparatus according to claim 1 ,
wherein the virtual image optical system includes an optical element with weak positive refractive power, and the optical element with weak positive refractive power is configured to emit, after video light from the flat panel display is diverged and made incident on the optical element to become substantially parallel light, the substantially parallel light toward the concave mirror.

4. The information display apparatus according to claim 1 ,
wherein a liquid-crystal display panel is used as the flat panel display.

5. The information display apparatus according to claim 4 ,
wherein the liquid-crystal display panel that is the flat panel display includes:
a solid light source;
an optical element configured to cause a divergent angle of divergent light from the solid light source to be smaller;
an optical member configured to subject the divergent light whose divergent angle is caused to be smaller by the optical element to polarization conversion; and
an illuminating light source unit configured to cause light with a desired polarization direction to be incident on the liquid-crystal display panel.

6. The information display apparatus according to claim 5 ,
wherein after emission light from the illuminating light source unit passes through the liquid-crystal display panel, an emission state of light when viewed from a longitudinal direction of the liquid-crystal display panel is different from an emission state of light when viewed from a short direction thereof.

7. The information display apparatus according to claim 4 , further comprising:
a λ/4 plate provided at a side of the virtual image optical system of the liquid-crystal display panel that is the flat panel display.

8. The information display apparatus according to claim 4 , further comprising:
an optical member configured to reflect any one of an ultraviolet ray, an infrared ray, or both the ultraviolet ray and the infrared ray, the optical member being provided at a side of the virtual image optical system of the liquid-crystal display panel that is the flat panel display.

9. An information display apparatus configured to display video information of a virtual image on a windshield of conveyance, the information display apparatus comprising:
a flat panel display configured to display the video information; and
a virtual image optical system configured to display a virtual image at a front of the conveyance by reflecting light emitted from the flat panel display by means of the windshield,
wherein the virtual image optical system includes a concave mirror and an optical element,
wherein the concave mirror is arranged between the flat panel display and the windshield,
wherein the optical element is arranged between the flat panel display and the concave mirror,
wherein a shape of the optical element is a shape in which an average radius of curvature of a cross-sectional shape in a vertical direction is different from an average radius of curvature of a cross-sectional shape in a horizontal direction,
wherein the flat panel display is arranged so as to be inclined with respect to an optical axis of the concave mirror,
wherein the flat panel display is arranged within a focal point distance of the concave mirror so that a center of a surface of the flat panel display, where an image is displayed, in a vertical direction of the surface is positioned at a lower side than a center of the concave mirror, and
wherein a distance between the concave mirror and the flat panel display is within a range that prevents light reflected from the concave mirror from being blocked out by the optical element and the flat panel display.

10. The information display apparatus according to claim 9 ,
wherein the virtual image optical system includes an optical element with weak negative refractive power, and the optical element with weak negative refractive power is configured to emit, after video light from the flat panel display is focused on and made incident on the optical element to become substantially parallel light, the substantially parallel light toward the concave mirror.

11. The information display apparatus according to claim 9 ,
wherein the virtual image optical system includes an optical element with weak positive refractive power, and the optical element with weak positive refractive power is configured to emit, after video light from the flat panel display is diverged and made incident on the optical element to become substantially parallel light, the substantially parallel light toward the concave mirror.

12. The information display apparatus according to claim 9 ,
wherein a liquid-crystal display panel is used as the flat panel display.

13. The information display apparatus according to claim 12 ,
wherein the liquid-crystal display panel that is the flat panel display includes:
a solid light source;
an optical element configured to cause a divergent angle of divergent light from the solid light source to be smaller;
an optical member configured to subject the divergent light whose divergent angle is caused to be smaller by the optical element to polarization conversion; and
an illuminating light source unit configured to cause light with a desired polarization direction to be incident on the liquid-crystal display panel.

14. The information display apparatus according to claim 13 ,
wherein after emission light from the illuminating light source unit passes through the liquid-crysta

Assignees

• Maxell Ltd
• Hitachi Ind & Control Solutions Ltd

Inventors

• Hirata Koji
• Yatsu Masahiko
• Sugiyama Toshinori
• Kaneko Kazuomi
• Hoshino Shigeki

Classifications

• B60K35/50 Primary

  Instruments characterised by their means of attachment to or integration in the vehicle (B60K35/231 takes precedence) · CPC title

• B60K35/28

  characterised by the type of the output information, e.g. video entertainment or vehicle dynamics information; characterised by the purpose of the output information, e.g. for attracting the attention of the driver · CPC title

• B60K35/23

  Head-up displays [HUD] (optical aspects of head-up displays G02B27/01) · CPC title

• G02B27/0101 Primary

  characterised by optical features (G02B27/0172 takes precedence) · CPC title

• G02B2027/0116

  comprising devices for correcting chromatic aberration · CPC title