Patent Application
20170307882
The disclosure relates to a head up display in a motor vehicle.
Automotive head up displays have traditionally had a field of view of about 5°×3°, to present simple information such as speed, below the driver's view of the road ahead. Increasingly, automakers would like to implement additional features, such as augmented reality, that require a larger field of view.
The currently used automotive head up displays primarily use a large concave mirror (aspherical) and a small flat mirror. There is no internal focus.
The present invention may provide an optical arrangement for a head up display with a larger field of view than is currently possible with a conventional automotive head up display.
In one embodiment, the invention comprises a head up display arrangement for a motor vehicle, including an image source providing an illuminated image. A first concave mirror is positioned to provide a first reflection of the illuminated image. A second concave mirror is positioned to receive the first reflection and provide a second reflection of the illuminated image. A windshield is positioned to receive the second reflection and provide a third reflection of the illuminated image such that the third reflection is visible to a driver of the vehicle.
In another embodiment, the invention comprises a head up display method for a motor vehicle, including providing an illuminated image. The illuminated image is reflected off of a first concave mirror to provide a first reflection of the illuminated image. The first reflection is reflected off of a second concave mirror to provide a second reflection of the illuminated image. The second reflection is reflected off of a windshield to provide a third reflection of the illuminated image such that the third reflection is visible to a driver of the vehicle.
In yet another embodiment, the invention comprises a head up display arrangement for a motor vehicle, including a display screen configured to display an image. A first aspherical, concave mirror is positioned to provide a first reflection of the image. A second aspherical, concave mirror is positioned to receive the first reflection and provide a second reflection of the illuminated image. A windshield is positioned to receive the second reflection and provide a third reflection of the illuminated image such that the third reflection is visible to a driver of the vehicle.
An advantage of the present invention is that it may provide a wide field of view from a compact package with a small, relatively low-cost image source.
A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings.
Both reflective freeform mirrors 14, 16 are concave, and are arranged to provide an intermediate focus 20 between the two mirrors. Light from image source 12 reflects from the first, smaller freeform mirror 14, passes through intermediate focus 20, reflects from the second, larger freeform mirror 16, and reflects from windshield 18 to be seen by a human driver 22. The driver sees the virtual image 24 as being disposed beyond windshield 18. Virtual image 24 is inverted from the image produced on image source 12, which may be a display screen. In one embodiment, image source 12 is a 40 mm×20 mm liquid crystal display.
In one embodiment, virtual image 24 measures 10°×4° as seen by the driver, with a seven-meter distance between driver 22 and virtual image 24. In one embodiment, image source 12 and mirrors 14, 16 are included in a head up display package with a volume of 7.2 liters.
In a next step 204, the illuminated image is reflected off of a first concave mirror to provide a first reflection of the illuminated image. For example, the light field from image source 12 may be reflected off of a first concave mirror 14 to provide a first reflection.
Next, in step 206, the first reflection is reflected off of a second concave mirror to provide a second reflection of the illuminated image. For example, the reflection off of mirror 14 may be further reflected off of second concave mirror 16 to provide a second reflection of the illuminated image.
In a final step 208, the second reflection is reflected off of a windshield to provide a third reflection of the illuminated image such that the third reflection is visible to a driver of the vehicle. For example, the reflection off of mirror 16 may be further reflected off of windshield 18 to provide a third reflection of the illuminated image that is visible to driver 22 as a virtual image 24.
The foregoing description may refer to “motor vehicle”, “automobile”, “automotive”, or similar expressions. It is to be understood that these terms are not intended to limit the invention to any particular type of transportation vehicle. Rather, the invention may be applied to any type of transportation vehicle whether traveling by air, water, or ground, such as airplanes, boats, etc.
The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications can be made by those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention.
This application claims benefit of U.S. Provisional Application No. 62/327,737 filed on Apr. 26, 2016, which the disclosure of which is hereby incorporated by reference in its entirety for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 62327737 | Apr 2016 | US |
