GB2244569A

GB2244569A - Image source for head-up display

Info

Publication number: GB2244569A
Application number: GB9109211A
Authority: GB
Inventors: Morgan Daniel Murphy; Alan Richard Greenland
Original assignee: Delco Electronics LLC
Current assignee: Delco Electronics LLC
Priority date: 1990-06-01
Filing date: 1991-04-29
Publication date: 1991-12-04
Also published as: GB9109211D0; DE4116903A1

Abstract

An image source for a head-up display comprises a first display source 30, 18, 19, 20 disposed in a first plane and adapted to display first information along a first optical path, a second display source 10 mounted on a side wall 28 of the first display source substantially perpendicularly to the first plane and adapted to display second information along a second optical path. A mirror 14 is provided for reflecting an image of the second information from the second display source into the first optical path, thereby increasing the amount of information in the first optical path and hence in the head-up display without substantial increase in the size of the image source. <IMAGE>

Description

-I- IMAGE SOURCE FOR HEAD-UP DISPLAY :21:21 -Q A, S 6:1 t3 The present

invention relates to an image source for a head-up display.

Head-up displays have long been used in airplanes to aid the pilots. The head-up display reflects information the pilot needs off of a half mirror or the windshield and projects that information at a distance in front of the plane so that the pilot does not have to look into the cockpit to see the information.

More recently, head-up displays have been used in automotive applications. In many of these automotive applications, the image is projected up and reflected off of the vehicle front windshield to appear at a distance in front of the driver. with a head-up display in a vehicle, the driver does not have to adjust his eyes from the road to read information, such as vehicle speed, which is normally displayed in the vehicle instrument panel.

One limitation of head-up displays is the space required for the display source and optics. In the past, the display source and optics of the head-up display have been placed in or on the instrument panel. The difficulty in this placement of the display source and optics of the head-up display is that the instrument panel usually has very little space available for such systems.

One method of working with the limited space available for the head-up display system is to limit the amount of information displayed in the head-up display. Another method is to use digital displays instead of analogue gauges because digital displays are flat and take up less space than bulky analogue gauges.

The difficulty of using digital displays is that some vehicle operators prefer certain information in analogue form on analogue gauges. If analogue gauges are used, the amount of information that can be displayed is limited, given the spatial restrictions for any head-up display system. consequently it is desired to have an image source that Provides an analogue display without the sacrifice of information or the requirement of more room for the display.

The present invention seeks to provide an improved image source for a head-up display.

Accordingly, an aspect of the present invention provides an image source for a head-up display comprising a first display source disposed in a first plane adapted to display first information along a first optical path and comprising a side wall extending at an angle to the first plane, a second display source disposed at an angle to the first plane and adapted to display second information along a second optical path, and a mirror for reflecting an image of the second information from the second display source into the first optical path.

The present invention can provide an image source for a head-up display system that includes an analogue display without sacrificing the amount of information shown and without significantly increasing the space required.

Preferably, a first display source displaying information along an optical path is mounted in a first plane orthogonal to the optical path and requires limited area in the first plane and planes parallel to the first plane. A second display source is preferably mounted perpendicular to the first plane and, in combination with the first display source, does not require significantly increased area in the first plane and planes parallel to the first plane over the amount of area required by the first display source alone.

A mirror can reflect an image of the second display source so that the reflected image appears in combination with the information from the first display source to a viewer of the head-up display.

In a preferred embodiment, the first display source is an analogue display and the second display source is a digital display. The mirror reflects the information in the digital display to appear within the analogue display. Thus, information in addition to that provided by the analogue display can be displayed without the image source requiring significantly more space.

The invention is also directed to the combination of two display sources mounted in different planes to save space and combining the images of those display sources into a composite image to be used as an image source for a head-up display. The use of the above image source to provide head-up display images can easily be implemented by those skilled in the art and such an implementation will not be set forth in detail here.

An embodiment of the present invention is described below, by way of illustration only, with reference to the accompanying drawing, in which:Figure 1 is a cut-away side view of the improved image source showing an analogue gauge display source, a vacuum fluorescent display source and a mirror; and Figure 2 is a front elevational view of the image source of Figure 1 showing an embodiment of combined analogue-digital display.

Figure 1 shows an embodiment of combined digital display source and analogue display source which can increase the amount of information that the head-up display can display. The vacuum fluorescent display 10, mirror 14, and bracket 16 are mounted on the front of housing 28. These components add digital information to the analogue display and as they are mounted do not require significantly more room than the analogue display alone.

The analogue gauge 30 has a shaft 20 to which a pointer 18 is attached. As the gauge 30 is energized, shaft 20 rotates and the pointer 18 moves along the graphics plate 19 containing the graphics pattern 33 (Figure 2) to indicate engine speed (in revolutions per minute).

The gauge 30 is mounted on the housing 28 to which the vacuum fluorescent display 10 is mounted and the mirror 14 is mounted via bracket 16. Zenon bulbs 24 and 26 together with the parabolic-type reflector 22 provide backlighting for the analogue display graphics 33 (Figure 2). The terminals 12 are used to control the vacuum fluorescent display 10 and the gauge leads 32 are used to energize the gauge 30.

In use, as can be seen in Figure 2, the vacuum fluorescent display 10, although mounted in a different plane than the analogue gauge 30, provides a digital image 34 displaying vehicle speed which appears in combination with the graphics 33 of the analogue gauge 30 (Figure 1) via mirror 14. As can be seen, the amount of additional space required by adding the graphics display 10 in combination with the analogue gauge 30 is minimal. Additionally, the mirror 14 does not block the viewing of any relevant information from the analogue gauge. The important part of the pointer 18 and the graphics 33 can still 9.

11 be seen.

The spatial advantages of this embodiment can be described with reference to the perimeter of the housing 28. By extending along the optical path of the analogue display an imaginary cylinder whose outer boundary is defined by the perimeter of housing 28, it can be seen that the majority of the vacuum fluorescent display 10 falls within the imaginary cylinder. Only the insignificant portion of the vacuum fluorescent display 10 falling outside the imaginary cylinder represents an increase in the spatial requirements of this embodiment.

other types of display may be used as the digital display source in place of the vacuum fluorescent display. Of course, other types and combinations of information can be displayed on the two displays 10,19.

Claims

Claims:

1. An image source for a head-up display comprising a first display source disposed in a first plane adapted to display first information along a first optical path and comprising a side wall extending at an angle to the first plane, a second display source disposed at an angle to the first plane and adapted to display second information along a second optical path, and a mirror for reflecting an image of the second information from the second display source into the first optical path.

2. An image source according to claim 1, wherein the second display source is disposed substantially perpendicular to the first plane.

3. An image source according to claim 1 or 2,, wherein the second display source is mounted on the side wall of the first display source.

4. An image source according to claim 3, wherein the side wall has a substantially cylindrical perimeter, the second display source being disposed within the substantially cylindrical perimeter.

5. An image source according to any preceding claim, wherein the second display source includes a digital display.

6. An image source according to any preceding claim, wherein the first display source includes an analogue gauge.

7. An image source according to claim 6, wherein the analogue gauge includes a graphics pattern and a pointer comprising a pointer hub, a pointer body and a tip positionable along the graphics pattern, the pointer hub and body being obscured in use by the image reflected off the mirror.

8. An image source according to claim 6 or 1 1 k_ 7,. wherein the analogue gauge is adapted to be back-lit.

9. An image source according to any preceding claim, wherein the mirror is disposed within the first optical path of the first display source.

10. An image source substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

is Published 1991 at 7be Patent Office. Concept House, Cardiff Road, Newport. Gwent NP9 I RH. Further copies may be obtained from Sales Branch, Unit 6. Nine Mile Point Cwmfelinfach, Cross Keys, Newport. NP1 7HZ. Printed by Multiplex techniques lid, St Mary Cray, Kent.