INFORMATION DISPLAY DEVICE

• US 20180341110A1
• Filed: 10/27/2015
• Published: 11/29/2018
• Est. Priority Date: 10/27/2015
• Status: Active Grant

• Current Assignee: Hitachi Industry & Control Solutions, Ltd. (Hitachi, Ltd.), Maxell, Ltd.
• Original Assignee: Hitachi Industry & Control Solutions, Ltd. (Hitachi, Ltd.), Maxell, Ltd.
• Inventors: HIRATA, Koji, YATSU, Masahiko, SUGIYAMA, Toshinori, KAJIKAWA, Hiroyuki, KANEKO, Kazuomi
• Granted Patent: US 10,670,864 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 2360/23 using reflectors
• CPC Class Codes: B60K 2360/25 using filters
• CPC Class Codes: B60K 2360/334 Projection means
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: B60K 35/23 Head-up displays [HUD] optical aspects of head-up displays G02B27/01
• CPC Class Codes: G02B 17/08 Catadioptric systems used in non-imaging applications G02B19/00
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0145 creating an intermediate image
• CPC Class Codes: G02B 2027/0185 Displaying image at variable distance
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence

Abstract

Provided is a small-sized information display device displaying video image information as a virtual image by use of an eyepiece optical system including a concave mirror having desired reflection characteristics in a specific polarization direction, where a liquid crystal display panel is used as a video image light source. The information display device has a liquid crystal display panel as a flat display forming video image information disposed therein, and includes a virtual image optical system including a member to be projected for displaying virtual images in front of a vehicle by making a video image displayed on the liquid crystal display panel reflect on the member to be projected. The virtual image optical system includes a concave mirror, and a reflective film of the concave mirror has desired reflection characteristics in a specific polarization direction, so that virtual images having uniform brightness and chromaticity can be obtained.

Claims

1. An information display device displaying video image information of a virtual image on a windshield of a vehicle, comprising:

a liquid crystal display panel displaying the video image information; and

a virtual image optical system displaying the virtual image in front of the vehicle by reflecting light emitted from the liquid crystal display panel on the windshield,

wherein the virtual image optical system includes a concave mirror and a plurality of optical elements,

wherein the concave mirror includes a reflection surface made of a metal film having a high and uniform spectral reflectance with respect to a visible light, on a front surface of a base material, and

wherein the plurality of optical elements are disposed between the liquid crystal display panel and the concave mirror so as to separate a video image light flux to establish each virtual image of a plurality of virtual images such that the plurality of virtual images are respectively established at a plurality of positions corresponding to viewpoint positions of a driver from an upper portion to a lower portion of the windshield.

2. The information display device according to claim 1,

wherein the virtual image optical system includes a first optical element having a positive refractive power and a second optical element having a negative refractive power, and

wherein the first optical element and the second optical element are independently disposed to be directed from a side of the liquid crystal display panel to the concave mirror in order of the first optical element and the second optical element.

3. The information display device according to claim 1,

wherein the virtual image optical system displays a plurality of video images in a divisional manner on the liquid crystal display panel to form the plurality of virtual images to be respectively established at the plurality of positions corresponding to the viewpoint positions of the driver.

4. The information display device according to claim 1, further comprising:

means detecting a position of an eye of the driver of the vehicle.

5. The information display device according to claim 1,

wherein the concave mirror includes a reflective film made of silver or a silver alloy formed on a plastic substrate.

6. The information display device according to claim 1,

wherein the concave mirror includes an aluminum reflective film formed on a plastic substrate, and a reflection enhancing film formed on an interfacial surface of the reflective film on a side contacting air.

7. The information display device according to claim 1,

wherein the concave mirror includes a reflective film made of silver or a silver alloy formed on a glass substrate.

8. The information display device according to claim 1,

wherein the concave mirror includes an aluminum reflective film formed on a glass substrate, and a reflection enhancing film formed on an interfacial surface of the reflective film on a side contacting air.

9. The information display device according to claim 1,

wherein the virtual image optical system further includes a cylinder mirror, and

wherein the cylinder mirror includes a reflective film made of silver or a silver alloy formed on a plastic substrate.

10. The information display device according to claim 1,

wherein the virtual image optical system further includes a cylinder mirror, and

wherein the cylinder mirror includes a reflective film made of silver or a silver alloy formed on a glass substrate.

11. The information display device according to claim 1,

wherein the virtual image optical system further includes a cylinder mirror, and

wherein the cylinder mirror includes an aluminum reflective film formed on a plastic substrate, and a reflection enhancing film formed on an interfacial surface of the reflective film on a side contacting air.

12. The information display device according to claim 1,

wherein the virtual image optical system further includes a cylinder mirror, and

wherein the cylinder mirror includes an aluminum reflective film formed on a glass substrate, and a reflection enhancing film formed on an interfacial surface of the reflective film on a side contacting air.

14. The information display device according to claim 1,

wherein the liquid crystal display panel includes a light source including a solid light source, an optical element reducing a divergence angle of diverging light from the solid light source, an optical member polarizing and converting the diverging light the divergence angle of which is reduced by the optical element, and an illumination light source section making light in a desired polarization direction incident on the liquid crystal display panel.

15. The information display device according to claim 1,

wherein a λ

/4 plate is provided on a side of the virtual image optical system of the liquid crystal display panel.

16. The information display device according to claim 1,

wherein an optical member reflecting an ultraviolet ray, an infrared ray, or the ultraviolet ray and the infrared ray is provided on a side of the virtual image optical system of the liquid crystal display panel.

13. (canceled)