Head-up display

• US 6,504,518 B1
• Filed: 06/30/1997
• Issued: 01/07/2003
• Est. Priority Date: 10/09/1996
• Status: Expired due to Fees

• Current Assignee: Shimadzu Corporation
• Original Assignee: Shimadzu Corporation
• Inventors: Nasu, Ryutaro, Sugibuchi, Toshihiko, Kuwayama, Yukiko
• Primary Examiner(s): Lieu, Julie
• Application Number:
  US08/885,831
• Time in Patent Office: 2,017 Days
• Field of Search: 345/7, 345/8, 359/630, 359/629, 359/631, 359/632, 359/633, 359/637, 359/639, 340/980, 340/425
• US Class Current: 345/7
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0149 characterised by mechanical features G02B27/0176 takes precedence

Abstract

An optical path of image displaying light projected from an image displaying face of a display element is changed by a combiner, which is to be arranged in front of an observer. A virtual image, that is a subject of observation, is formed in front of the combiner. An optical component facing the image displaying face is provided so that the image displaying light is introduced to the combiner. The optical component is capable of diverging incident light.

Claims

1. A head-up display, comprising:

a combiner to be arranged in front of an observer, external light passing through the combiner; and

a display element which projects image displaying light from its image displaying face;

wherein a virtual image, that is a subject of observation, is formed in front of the combiner by changing the optical path of the image displaying light by the combiner;

wherein an optical component facing the image displaying face is provided so that the image displaying light is introduced to the combiner by changing the optical path of the image displaying light; and

wherein the optical component diverges incident light which includes the external light.

2. The head-up display according to claim 1, wherein:

the optical path changing face of the optical component is arranged so as to be inclined with respect to the vertical direction to allow the image displaying light to ascend as the light goes forward by changing the optical path; and

wherein the image displaying face is arranged so as to be inclined with respect to the vertical direction to allow itself to depart from the optical component as it descends.

3. The head-up display according to claim 2, wherein:

the optical path changing face of the optical component change the optical path of the external light, which passes through the combiner, so that the external light does not again go to the combiner.

4. The head-up display according to claim 1, wherein:

the optical path of the image displaying light, which is projected from any one point of the display element, from the optical component to the combiner is located above the optical path of the image displaying light from the projection point to the optical component and also below the optical path of the image displaying light from the combiner to the observer'"'"'s pupil.

5. The head-up display according to claim 1, wherein:

the combiner comprises a body, and a reflecting layer which covers one face of the body;

wherein at least one side of the body is configured with a platy material made of synthetic resin;

wherein;

the platy material is covered with a coating which is harder and smaller in thermal expansion coefficient than the platy material;

wherein the reflecting layer is formed on the coating;

wherein the reflecting layer is configured with a plurality of laminated films, which are smaller in thermal expansion coefficient than the platy material and have mutually different refractive indexes; and

wherein each of the films has residual compressive stress at normal temperature.

6. The head-up display according to claim 1, wherein:

the image displaying light is projected from a liquid crystal display element having a backlight device;

wherein the light source for backlight of the liquid crystal display device has a fluorescent tube, a driving circuit for the fluorescent tube, a lead which connects the fluorescent tube to the driving circuit, and a support portion;

wherein the light source for backlight is made as a unit attachable to, and detachable from a housing which houses the liquid crystal display element;

wherein the fluorescent tube is supported by the support portion so that it is arranged in a space outside the support portion;

wherein the driving circuit and the lead are arranged in a space inside the support portion; and

wherein the outer surface of the support portion serves as a backlight reflecting surface which reflects the light beam for backlight generated by the fluorescent tube.

7. The head-up display according to claim 6, wherein:

at least the outer surface of the support portion is configured with a shielding material capable of shielding electromagnetic waves, and the shielding material constitutes the backlight reflecting surface.

8. The head-up display according to claim 1, wherein:

the image displaying light is projected from a liquid crystal display element; and

wherein the display element has a transmission type monochromatic simple matrix liquid crystal display device whose liquid crystal action mode is the BTN mode, a backlight device capable of changing the light emission wavelength peak of the light which irradiates the liquid crystal display device, and a controller which synchronizes the image displaying timing on the liquid crystal display device and the light emission timing at the desired light emission wavelength peak in the backlight device.

9. The head-up display according to claim 1, wherein:

one of the housing and the combiner is provided with an insertion portion;

wherein the other of the housing and the combiner is provided with a pit into which the insertion portion is extractably inserted; and

wherein the combiner is supported by the housing via the insertion portion and the pit.

10. The head-up display according to claim 9, wherein:

the contact portions of the insertion portion and the pit are curved so that the normal direction of the optical path changing face of the combiner changes as the depth of insertion of the pit into the insertion portion changes.

11. The head-up display according to claim 9, wherein:

the outer face of the insertion portion and the inner face of the pit are formed along a cylindrical face so that the normal direction of the optical path changing face of the combiner changes as the insertion portion rotates relative to the pit.

12. The head-up display according to claim 9, wherein:

the insertion portion is capable of exerting an elastic force on the pit, and the position of the insertion portion relative to the pit can be retained by the frictional force generated by the elastic force.

13. The head-up display according to claim 10, wherein:

one of the insertion portion and the pit is provided with a plurality of grooves along the direction of insertion of the insertion portion into the pit;

wherein a retention element having a projection, which can be fitted into each groove, is attachable to, and detachable from the other of the housing and the combiner; and

wherein the projection is fitted into any one of the grooves to retain the position of the insertion portion relative to the pit.